Urea water transfer system, urea water transfer method, and urea water production method

Abstract

Provided are a urea water transfer system, a urea water transfer method, and a urea water manufacturing method, which transfer stored urea water and homogenize the concentration and / or adjust the concentration of urea water in a system through which the urea water flows. [Solution] A urea water transfer system for transferring urea water, comprising: a plurality of storage means capable of storing urea water; a urea water supply means connected to the plurality of storage means and supplying urea water to the storage means; a delivery means connected to the plurality of storage means and delivering the urea water stored in the storage means; a transfer means connected to the delivery means and the urea water supply means and delivering the urea water delivered from the delivery means to the urea water supply means; and a control means for setting a source storage means from which the stored urea water is delivered and a destination storage means to which the delivered urea water is transferred.

Description

[Technical field]

[0001] The present invention relates to a urea water transfer system, a urea water transfer method, and a urea water production method that transfer stored urea water and homogenize and / or adjust the concentration of the urea water. [Background technology]

[0002] Urea solution is used in technology to purify nitrogen oxides (NOx) and is utilized to purify exhaust gas from internal combustion engines such as diesel engines. When urea water is used to purify exhaust gas, the urea water is sprayed and introduced into the exhaust gas. When urea water is introduced into the exhaust gas, ammonia is generated from the urea contained in the urea water, and the ammonia acts as a reducing agent to react with NOx in the exhaust gas. NOx is reduced to nitrogen and water, reducing the amount of NOx in the exhaust gas and purifying the exhaust gas. The exhaust gas purification method using urea solution has attracted attention as an effective clean technology.

[0003] Urea water is used as an important reducing agent in purifying exhaust gas, and various efforts are being made on the technology for producing urea water. For example, Patent Document 1 discloses an apparatus for producing an aqueous urea solution, which automatically measures and supplies urea and pure water (raw water) to a stirring vessel and stirs them to easily produce an aqueous urea solution (urea water) of a desired concentration and volume on a small scale.

[0004] Furthermore, Patent Document 2 discloses a method for producing urea water on a large scale by dissolving urea in hot water obtained from a water jacket of a dry distillation / gasification incineration treatment device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4514431 [Patent Document 2] Patent Publication No. 2021-177112 Summary of the Invention [Problem to be solved by the invention]

[0006] When urea water is produced on a large scale, it is necessary to store (preserve) the produced urea water until it is shipped. In order to store urea water produced on a large scale (in large quantities), multiple urea water tanks (storage means) may be provided. Taking into consideration the construction costs and operating rate of the facility, one delivery means (or a number of delivery means less than the number of storage means) is usually provided for multiple storage means. The stored urea water is delivered to a transport vehicle such as a tank truck and shipped. After the urea water has been shipped, the urea water delivered from the storage means remains in the delivery means. In particular, in the case of a large-scale facility, a considerable amount of urea water will remain in the delivery means.

[0007] On the other hand, when a plurality of storage means are provided, by storing urea water of different concentrations in the storage means, it becomes possible to quickly ship urea water of different concentrations. However, when the concentration of the urea water newly shipped differs from that of the urea water previously shipped, the concentration of the newly shipped urea water may be affected because the urea water previously shipped with a different concentration remains in the delivery means. In particular, in large-scale facilities, the relative ratio of the amount of the urea water previously shipped remaining in the delivery means to the amount of the newly shipped urea water becomes large, and the impact on the concentration of the newly collected urea water cannot be ignored.

[0008] In addition, when urea water of different concentrations is stored in a plurality of storage means, a new urea water of a different concentration from the stored urea water may be required, but if the required amount is small, it may not reach the production lot and new production may not be possible. Particularly in large-scale facilities, cases where small-lot production is not possible are likely to occur.

[0009] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a urea water transfer system, a urea water transfer method, and a urea water manufacturing method that transfer stored urea water and homogenize the concentration and / or adjust the concentration of urea water in a system through which the urea water flows. [Means for solving the problem]

[0010] As a result of intensive research aimed at solving the above problems, the present inventors discovered that the following invention meets the above object, and thus completed the present invention.

[0011] That is, the present invention relates to the following inventions. <1> A urea water transfer system for transferring urea water, comprising: a plurality of storage means capable of storing urea water; a urea water supply means connected to the plurality of storage means and supplying the urea water to the storage means from a urea water supply source; a delivery means connected to the plurality of storage means and delivering the urea water stored in the storage means; a transfer means connected to the delivery means and the urea water supply means and transferring the urea water delivered from the delivery means to the urea water supply means; and a control means for setting a source storage means from which the supplied urea water is sent out by the sending means and a destination storage means to which the sent-out urea water is transferred by the transferring means, wherein the control means controls the urea water supply means, the storage means, the sending means and the transferring means so as to send out the urea water from the source storage means and transfer the urea water to the destination storage means based on the settings of the source storage means and the destination storage means. <2> The source storage means and the destination storage means set in the control means are the same. <1> The urea water transfer system according to claim 1. <3> The source storage means set by the control means and the destination storage means set by the control means are partially or entirely different from each other, and the urea water stored in the source storage means and the destination storage means set have two or more concentrations. <1> The urea water transfer system according to claim 1. <4> The transfer destination storage means includes the storage means in which urea water is not stored. <3> The urea water transfer system according to claim 1.

[0012] <1a> The urea water supply source is a urea water production system that produces the urea water by mixing raw water and urea. <1> from <4> 2. The urea water transfer system according to claim 1 , <2a> The urea water transfer system described in <1a>, wherein the urea water production system comprises a mixing means for mixing raw water and urea and dissolving the urea in the raw water to produce the urea water, a raw water supply means having a heating device for heating the raw water and supplying the raw water heated by the heating device to the mixing means, a urea supply means for supplying the urea to the mixing means, and a control means for controlling one or more of the raw water supply means and the urea supply means. <3a> The urea water transfer system described in <2a>, wherein the control means sets two or more production condition set values ​​selected from the group consisting of the following set values ​​(a) to (d), and the control means calculates a control value based on the production condition set values, and controls one or more of the raw water supply means and the urea supply means based on the production condition set values ​​and / or the control value so as to prevent the urea water produced in the mixing means from becoming cloudy. Set value (a): the supply amount of the raw water supplied to the mixing means Set value (b): Amount of urea supplied to the mixing means Set value (c): concentration of the urea water produced by the mixing means Set value (d): the amount of the urea water produced by the mixing means <4a> The urea water transfer system according to <3a>, wherein the production condition set values ​​set in the control means are set value (b) and set value (c). <5a> A urea water transfer system as described in <4a>, wherein the set value (c) is limited to a predetermined range, and the control means calculates a target heating control temperature of the raw water supplied to the mixing means as a control value (e) based on the set value (c) limited to the predetermined range and the heat of dissolution of urea in water so that the urea water produced in the mixing means has a temperature at which it does not become cloudy, and controls the raw water supply means so that the temperature of the raw water supplied to the mixing means becomes the calculated control value (e). <6a> The urea water supplied from the urea water supply source is urea water produced by a urea water production method for producing urea water prevented from becoming cloudy, the urea water production method comprising: a step (1) of setting two or more production condition set values ​​selected from the group consisting of the following set values ​​(a) to (d) and calculating a control value based on the production condition set values; a step (2) of heating the raw water based on the production condition set values ​​and / or the control value and supplying the urea to a mixing means; a step (3) of supplying the urea to the mixing means based on the production condition set values ​​and / or the control value; and a step (4) of mixing the raw water supplied in the step (2) and the urea supplied in the step (3) in the mixing means and dissolving the urea in the raw water to produce the urea water. <1> from <4> 2. The urea water transfer system according to claim 1 , Set value (a): the supply amount of the raw water supplied to the mixing means Set value (b): Amount of urea supplied to the mixing means Set value (c): concentration of the urea water produced by the mixing means Set value (d): the amount of the urea water produced by the mixing means

[0013] <1b> <1> from <4> A method for transferring urea water stored in the storage means, using the urea water transfer system described in any one of <1a> to <6a>. <2b> <1> from <4> <1a> to <6a>, or any one of the urea water transfer systems described in <1a> to <6a>, to transfer the urea water stored in the storage means to produce urea water of a predetermined concentration. Effect of the Invention

[0014] According to the present invention, it is possible to provide a urea water transfer system, a urea water transfer method, and a urea water manufacturing method, which transfer stored urea water and homogenize the concentration and / or adjust the concentration of urea water in a system through which the urea water flows. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing a urea water transfer system according to an embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is a schematic diagram showing a control means (first aspect) according to an embodiment of the present invention. [Diagram 3] FIG. 4 is a urea water transfer control flow diagram according to the embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of urea water transfer (first embodiment) according to an embodiment of the present invention. [Diagram 5] FIG. 2 is a schematic diagram of urea water transfer (second embodiment) according to an embodiment of the present invention. [Figure 6] 5A and 5B are schematic diagrams of urea water transfer (third embodiment) according to an embodiment of the present invention ((A) is a schematic diagram at the start of control, and (B) is a schematic diagram at the stop (completion of control)). [Figure 7] 5A and 5B are schematic diagrams of urea water transfer (fourth embodiment) according to an embodiment of the present invention ((A) is a schematic diagram at the start of control, and (B) is a schematic diagram at the stop (completion of control)). [Figure 8] 1A and 1B are schematic diagrams of urea water transfer (fifth embodiment) according to an embodiment of the present invention ((A) is a schematic diagram at the start of control, and (B) is a schematic diagram at the stop (completion of control)). [Figure 9] 1A and 1B are schematic diagrams of urea water transfer (sixth embodiment) according to an embodiment of the present invention ((A) is a schematic diagram at the start of control, and (B) is a schematic diagram at the stop (completion of control)). [Figure 10] 1 is a schematic diagram showing a urea water production system according to an embodiment of the present invention. FIG. [Figure 11] FIG. 4 is a schematic diagram of a control means (second aspect) according to an embodiment of the present invention. [Figure 12]FIG. 4 is a schematic diagram of a control means (third aspect) according to an embodiment of the present invention. [Figure 13] FIG. 2 is a main flow diagram of the urea water production method according to the embodiment of the present invention. [Figure 14] FIG. 2 is a flow chart showing a production condition setting process of the urea water production method according to the embodiment of the present invention. [Figure 15] FIG. 2 is a flow diagram of a raw water supply process of the urea water production method according to the embodiment of the present invention. [Figure 16] FIG. 2 is a flow diagram of a urea supply process of the urea water production method according to the embodiment of the present invention. [Figure 17] FIG. 2 is a flow diagram of a mixing process of the urea water production method according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <1. Urea solution transport system> The urea water transfer system of the present invention is a urea water transfer system for transferring urea water, and includes a plurality of storage means capable of storing urea water, a urea water supply means connected to the plurality of storage means and supplying the urea water to the storage means from a urea water supply source, a delivery means connected to the plurality of storage means and delivering the urea water stored in the storage means, a transfer means connected to the delivery means and the urea water supply means and transferring the urea water delivered from the delivery means to the urea water supply means, and a plurality of other components. and a control means for setting, from among a number of the storage means, a source storage means from which the stored urea water is sent out by the sending means and a destination storage means to which the sent-out urea water is transferred by the transferring means, and the control means controls the urea water supply means, the storage means, the sending means and the transferring means so as to send out urea water from the source storage means and transfer the urea water to the destination storage means based on the settings of the source storage means and the destination storage means.

[0017] By adopting such a configuration, the urea water transfer system of the present invention can transfer (circulate) urea water through the urea water supply means, storage means, delivery means and transfer means, and can homogenize the concentration of urea water in the system through which the urea water circulates within the facility. Furthermore, by appropriately setting the source storage means and the destination storage means, it is possible to produce urea water of a desired concentration in addition to making the concentration of the urea water uniform.

[0018] Preferred embodiments of the present invention will now be described with reference to the drawings. The present invention is not limited to the following embodiments, and can be modified as desired without departing from the scope of the present invention. The dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In addition, in all drawings, similar components are given similar reference symbols, and descriptions are omitted as appropriate.

[0019] FIG. 1 is a schematic diagram showing a urea water transfer system according to an embodiment of the present invention. The urea water transfer system 2 includes a urea water supply means 50, a storage means 60, a sending means 70, a transfer means 80, and a control means 90. The urea water transfer system 2 has six (plural) storage means 60, and the six storage means 60 are indicated in the figure with the reference numerals 60a to 60f, respectively.

[0020] [1-1. Urea water supply means] The urea water supply means 50 is connected to a plurality of storage means 60, and supplies urea water from a urea water supply source UWin to each of the storage means 60. The urea water supply means 50 supplies urea water to the storage means 60, so that the urea water can be stored in the storage means 60. The urea water supplied by the urea water supply means 50 may be produced using any urea water production system or any urea water production method. For example, the urea water may be produced using a urea water production system described below.

[0021] The urea water supply means 50 includes a first liquid delivery device 51, a first on-off valve 52, a first flow path 53, and a first branch portion . The first liquid delivery device 51 is installed in the first flow path 53, and delivers the urea water from the urea water supply source UWin to the storage means 60. The first liquid delivery device 51 may be any device as long as it can deliver the urea water, and is typically a pump. The first on-off valve 52 is disposed downstream of the first liquid delivery device 51 in the first flow path 53, and opens or closes the first flow path 53. The first on-off valve 52 may be any valve as long as it can open or close the first flow path 53, and is typically a motor-operated valve. The first branch section 54 is disposed downstream of the first flow path 53, and is connected to six storage means 60 to supply urea water to the storage means 60. The first branch section 54 branches into seven flow paths, and each of the branched flow paths is connected to the six storage means 60 and a transfer means 80 (a fifth path 82) described later.

[0022] In this embodiment, the first on-off valve 52 is disposed downstream of the first liquid delivery device 51 in the first flow path 53, but may be disposed upstream of the first liquid delivery device 51 in the first flow path 53. In addition, in this embodiment, the first branch portion 54 branches into seven flow paths, but the number of branched flow paths may be any number as long as it does not impair the object of the present invention.

[0023] [1-2. Storage means] The storage means 60 (storage means 60a to 60f) stores the urea water supplied from the urea water supply means 50 and the urea water transferred via the delivery means 70, the transfer means 80, and the urea water supply means 50. The storage means 60 delivers the stored urea water and stores (and / or circulates) the delivered urea water again via the transfer means 80 and the urea water supply means 50, thereby making the concentration of the urea water in the system uniform and / or adjusting the concentration. A method for making the concentration of the urea water in the system uniform and / or adjusting the concentration will be described later.

[0024] The storage means 60 are provided so as to be connected to each of the six flow paths branched off from the first flow path 54. Each of the six storage means 60 has a storage device 61, a second on-off valve 62, a third on-off valve 63, a second flow path 64, and a third flow path 64. In addition, the six storage means 60a to 60f are shown in the figure with the storage device 61 being indicated with the symbols 61a to 61f, the second on-off valve 62 being indicated with the symbols 62a to 62f, the third on-off valve 63 being indicated with the symbols 63a to 63f, the second flow path 64 being indicated with the symbols 64a to 64f, and the third flow path 64 being indicated with the symbols 64a to 64f.

[0025] A plurality of (six) storage means 60 are provided, and each of the storage means 60a to 60f has the same configuration and function. The configurations and functions of the multiple storage means according to the present invention may all be the same, or may be partially or entirely different, as long as the object of the present invention is not impaired.

[0026] The storage device 61 stores the urea water supplied from the urea water supply means 50 and the urea water transferred from the transfer means 80. The urea water stored in the storage device 61 is supplied and transferred via a second flow path 64. The urea water stored in the storage device 61 is delivered via a third flow path 65. The storage device 61 is a cylindrical tank with a height of 6.2 m and a diameter of 3.3 m, and has a capacity of 50,000 L. The second flow path 64 connects the urea water supply means 50 (first branch portion 54) and the storage device 61. A second on-off valve 62 is provided in the second flow path 64. The second on-off valve 62 opens or closes the second flow path 64. The second on-off valve 62 may be any valve as long as it can open or close the second flow path 64, and is typically a motor-operated valve. The third flow path 65 connects the storage device 61 and the delivery means 70 (second branch portion 74). A third on-off valve 63 is provided in the third flow path 65. The third on-off valve 63 opens or closes the third flow path 65. The third on-off valve 63 may be any valve as long as it can open or close the third flow path 65, and is typically an electrically operated valve. The delivery of the urea water from the storage means 60 (storage device 61) and the delivery of the urea water to the storage means 60 (storage device 61) are controlled by opening and closing the second on-off valve 62 and the third on-off valve 63. Details will be described later.

[0027] [1-3. Transmission means] The sending means 70 is connected to the storage means 60, and sends out the urea water stored in each of the storage means 60 to the transfer means 80 or the urea water shipping port UWout. The delivery means 70 includes a second liquid delivery device 71, a flow rate measurement device 72, a fourth on-off valve 73, a fourth flow path 75, a second branch portion 74, and a third branch portion 76. The second branching section 74 is disposed downstream of the storage means 60 (third flow paths 65), and is connected to the six storage means 60 (third flow paths 65) to deliver the urea water. In the second branching section 74, the six branched flow paths are integrated, and the second branching section 74 is connected to the fourth flow path 75. The fourth flow path 75 connects the second branch portion 74 and the third branch portion 76 . A second liquid delivery device 71 is provided in the fourth flow path 75, and delivers the urea water from the storage means 60 to the urea water shipping port UWout or the transfer means 80. The second liquid delivery device 71 may be any device as long as it can deliver the urea water, and is typically a pump. The flow rate measuring device 72 is disposed downstream of the second liquid sending device 71 in the fourth flow path 75 , and measures the flow rate of the urea water flowing through the fourth flow path 75 . The third branch section 76 is disposed downstream of the fourth flow path 75 and branches into two flow paths. The two flow paths branched into by the third branch section 76 are connected to the transfer means 80 and the fifth flow path 77, respectively. The fifth flow path 77 connects the third branch portion 76 and the urea water delivery port UWout. The urea water is sent to the urea water delivery port UWout via the fifth flow path 77 and is delivered. A fourth on-off valve 73 is provided in the fifth flow path 77 and opens or closes the fifth flow path 77. The fourth on-off valve 73 may be any valve as long as it can open or close the fifth flow path 77, and is typically an air-operated valve. The fourth on-off valve 73 switches the flow path of the third branch section 76 by working in conjunction with a fifth on-off valve 81 of the transfer means 80 described later.

[0028] [1-4.Transportation means] The transfer means 80 is connected to the delivery means 70 and the urea water supply means 50, and transfers the urea water delivered from the delivery means 70 to the urea water supply means 50. The transfer means 80 transfers the urea water delivered from the delivery means 70 to the urea water supply means 50, thereby transferring (circulating) the urea water to the storage means 60 again. The transfer means 80 has a fifth on-off valve 81 and a sixth flow path 82 . The sixth flow path 82 connects the delivery means 70 (the third branch portion 76) and the urea water supply means 50 (the first branch portion 54). The urea water flows through the sixth flow path 82 and is transported. A fifth on-off valve 81 is provided in the sixth flow path 82 and opens or closes the sixth flow path 82. The fifth on-off valve 81 may be any valve as long as it can open or close the sixth flow path 82, and is typically an electrically operated valve. The fifth on-off valve 81 switches the flow path of the third branch section 76 by working in conjunction with the fourth on-off valve 73 of the delivery means 70.

[0029] [1-5. Control Means] The control means 90 controls the urea water supply means 50, the storage means 60, the delivery means 70 and the transfer means 80 so as to transfer the urea water stored in the storage means 60, thereby homogenizing the concentration within the system through which the urea water flows and / or adjusting the concentration of the urea water. FIG. 2 shows a schematic diagram of the control means according to the embodiment.

[0030] As shown in FIG. 2, a control means 90 according to the embodiment of the present invention includes a setting unit 91, a receiving unit 93, and a control unit 94.

[0031] The setting unit 91 has a display and can set transfer condition set values ​​required for transferring urea water. The transfer condition set values ​​that can be set by the setting unit 91 are the following set values ​​(p) to (r). Note that options or units for setting the transfer condition set values ​​are added. Setting value (p): Source storage means (options: storage means 60a to 60f) Setting value (q): Destination storage means (options: storage means 60a to 60f) Set value (r): Transfer time (unit: minutes)

[0032] A setting unit 91 (control means 90) sets a source storage means (set value (p)) from which the stored urea water is sent out by the sending means 70 from the multiple storage means 60, and a destination storage means (set value (q)) to which the sent urea water is transferred by the transfer means 80. The setting unit 91 also sets a transfer time for transferring the urea water stored in the storage means 60 set as the source storage means (set value (p)) to the storage means 60 set as the destination storage means (set value (q)).

[0033] In the setting unit 91, the source storage means (set value (p)) set from among the multiple storage means 60 (storage means 60a to 60f) is 1 or 2 or more. Also, in the setting unit 91, the destination storage means (set value (q)) set from among the multiple storage means 60 is 1 or 2 or more.

[0034] In addition, the sending source storage means (set value (p)) and the transfer destination storage means (set value (q)) set in the setting unit 91 may all be the same. Furthermore, the set value (p) set by the setting unit 91 and the set value (q) set by the setting unit 91 may be partially different (or partially the same). Furthermore, the set value (p) set by the setting unit 91 and the set value (q) set by the setting unit 91 may all be different.

[0035] In the setting unit 91 (control means 90), when the source storage means (setting value (p)) and the destination storage means (setting value (q)) set are different in part or in whole, the concentrations of urea water stored in the source storage means and the destination storage means set may be one type (all the same concentration) or two or more types (some or all may be different).

[0036] The transfer destination storage means (set value (q)) to be set may include storage means 60 in which urea water is not stored. When the transfer destination storage means (set value (q)) includes storage means 60 in which urea water is not stored, it becomes easy to prepare urea water of a predetermined concentration.

[0037] Regarding the set value (p) and the set value (q) set among the plurality of storage means 60, the manner in which the urea water is transferred under various conditions will be described later.

[0038] The setting values ​​(p) to (r) set in the setting unit 91 are transmitted to the control unit 94.

[0039] The receiving unit 93 receives signals transmitted from devices included in each of the urea water supplying means 50, the storing means 60, the sending means 70, and the transferring means 80. The urea water supply means 50 transmits signals related to the operation output of the first liquid delivery device 51 and the open / close state of the first on-off valve 52 . The storage means 60 transmits signals relating to the open / close states of the second on-off valves 62 (second on-off valves 62a to 62f) and the third on-off valves 63 (third on-off valves 63a to 63f). The sending means 70 sends signals relating to the operation output of the second liquid sending device 71, the urea water flow rate of the flow rate measuring device 72, and the open / close state of the fourth on-off valve 73. The transfer means 80 transmits a signal regarding the open / closed state of the fifth on-off valve 73 . The receiving unit 93 receives these signals and transmits them to the control unit 94 .

[0040] The receiving unit according to the present invention may receive signals other than the above-mentioned signals as long as it is capable of transferring the stored urea water and homogenizing and / or adjusting the concentration of the urea water. For example, the receiving unit may receive a signal related to the level or amount of the stored urea water from the storing means (when the urea water supplying means has a means for measuring the level or amount).

[0041] The control unit 94 receives the setting value from the setting unit 91 and various signals from the receiving unit 93 . The control unit 94 controls the urea water supply means 50 , the storage means 60 , the delivery means 70 and the delivery means 80 based on the setting values ​​received from the setting unit 91 . The control contents by the control unit 94 (control means 90) will be described with reference to the drawings. Fig. 3 shows a urea water transfer control flow according to the embodiment.

[0042] As shown in FIG. 3, when the urea water transferring step (S500) is started, the setting values ​​(setting values ​​(p) to (r)) are input and set in the setting unit 91 (S510).

[0043] When the set value is set and control is started, the on-off valve and the liquid delivery device are operated under the control of the control unit 94 (S520). Specifically, all the on-off valves of the urea water transfer system 2 are controlled from a closed state. The first on-off valve 52 of the urea water supply means 50 and the fourth on-off valve 73 of the delivery means 70 are kept closed, and the fifth on-off valve 81 of the transfer means 80 is opened. In addition, the third on-off valve 63 (the third on-off valves 63a to 63f) of the storage means 60 (the storage means 60a to 60f) set as the set value (p) is opened in response to the set value (p) (the delivery source storage means) (the other third on-off valves 63 are kept closed). In addition, the second on-off valve 62 (the second on-off valves 62a to 62f) of the storage means 60 (the storage means 60a to 60f) set as the set value (q) is opened in response to the set value (q) (the delivery destination storage means) (the other second on-off valves 62 are kept closed). By setting the on-off valve in this manner, a route for transporting the urea water stored in the storage means 60 from the set source storage device 60 to the set destination storage means can be secured without the urea water being discharged from an unintended route (e.g., the urea water supply source UWin and the urea water shipping port UWout). After the on-off valve is controlled to a predetermined open / close state, the second liquid delivery device 71 starts operating.

[0044] When the second liquid delivery device 71 starts operating, a timer (not shown) of the control unit 94 starts accumulating the operating time. The control unit 94 controls the second liquid delivery device 71 to continue operating until the operating time reaches the set value (r) (transfer time) (S530). When the operation time reaches the set value (r) (transfer time), the control unit 94 stops the operation of the second liquid delivery device 71 and controls all the on-off valves of the urea water transfer system 2 to close (S540). Then, the process proceeds to a stop step (S900).

[0045] As described above, the urea water transfer system 2 according to the embodiment of the present invention has a configuration in which the setting unit 91 sets the set value (p) (source storage means) and the set value (q) (destination storage means), respectively. However, the urea water transfer system of the present invention may have a set value (s) (circulation storage means) that serves as both the set value (p) (source storage means) and the set value (q) (destination storage means) in the setting unit. By adopting such a configuration, the urea water transfer system of the present invention can simplify the setting work, easily circulate the urea water stored in the set storage means, and achieve uniform concentration of the urea water in the system. Even when the set value (s) (circulation storage means) is used instead of the set value (p) (source storage means) and the set value (q) (destination storage means), the control including the on-off valve is as described above (the same control is performed except that the second on-off valve 62 and the third on-off valve corresponding to the set value (s) are opened).

[0046] In addition, the urea water transfer system 2 according to the embodiment of the present invention sets a set value (r) (transfer time) in the setting unit 91 to control the operation of the urea water transfer control by time (S530), but the urea water transfer system of the present invention may set a set value (t) (transfer amount) in the setting unit 91 and control the operation of the urea water transfer control by the transfer amount of urea water (accumulated flow rate) using an accumulated value of the measurement value of the flow measuring device.

[0047] <2. Method for transporting urea solution and method for producing urea solution> The urea water transfer method of the present invention transfers the urea water stored in the storage means by using the above-mentioned urea water transfer system. By adopting such a configuration, the urea water transfer method of the present invention can transfer the stored urea water and make the concentration of the urea water uniform and / or adjust the concentration of the urea water in a system through which the urea water flows. Furthermore, the urea water production method of the present invention uses the above-mentioned urea water transfer system to transfer the urea water stored in the storage means to produce urea water of a predetermined concentration. By adopting such a configuration, the urea water transfer method of the present invention can produce urea water of a predetermined concentration by transferring the stored urea water and adjusting the concentration of the urea water.

[0048] The urea water transfer system, the urea water transfer method, and the urea water production method of the present invention have been described above. Below, an embodiment of the urea water transfer according to the present invention will be described with reference to the drawings. Figure 4 shows a schematic diagram of urea water transfer (first aspect) according to an embodiment of the present invention, Figure 5 shows a schematic diagram of urea water transfer (second aspect) according to an embodiment of the present invention, Figure 6 shows a schematic diagram of urea water transfer (third aspect) according to an embodiment of the present invention, Figure 7 shows a schematic diagram of urea water transfer (fourth aspect) according to an embodiment of the present invention, Figure 8 shows a schematic diagram of urea water transfer (fifth aspect) according to an embodiment of the present invention, and Figure 9 shows a schematic diagram of urea water transfer (sixth aspect) according to an embodiment of the present invention. In addition, explanations that overlap with the above content may be omitted as appropriate.

[0049] <3. Aspects of urea water transfer according to the present invention> [3-1. Urea water transfer - first aspect] As shown in FIG. 4, the urea water transfer system 2 used in the first embodiment of urea water transfer is a urea water transfer system for transferring urea water, and includes a plurality of storage means 60 capable of storing urea water, a urea water supply means 50 connected to the plurality of storage means 60 and supplying urea water to each of the storage means 60, a delivery means 70 connected to the plurality of storage means 60 and delivering the urea water stored in each of the storage means 60, and a urea water supply means 50 connected to the delivery means 70 and the urea water supply means 50 and delivering the urea water delivered from the delivery means 70. The urea water supply system further comprises a transfer means 80 for transferring the urea water to a supply means 50, a control means 90 for setting a source storage means to which the stored urea water is transferred by a transfer means 70 from a plurality of storage means 60, and a destination storage means to which the transferred urea water is transferred by the transfer means 80, and the control means 90 controls the urea water supply means 50, the storage means 60, the transfer means 70 and the transfer means 80 so as to transfer the urea water from the source storage means and transfer the urea water to the destination storage means based on the settings of the source storage means and the destination storage means.

[0050] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60a Set value (q) (transfer destination storage means): storage means 60a Set value (r) (transfer time): 60 minutes That is, the set value (p) and the set value (q) are set to one each for the same storage means 60a (S510). The set value (p) and the set value (q) are the same.

[0051] In the control operation in the first mode of urea water transfer, after a set value is input, the first on-off valve 52 of the urea water supply means 50 and the fourth on-off valve 73 of the delivery means 70 remain closed, and the fifth on-off valve 81 of the transfer means 80 opens (in the drawings, open on-off valves are shown in white, and closed on-off valves are shown in black). The third on-off valve 63a of the storage means 60a opens in response to the set value (p), and the second on-off valve 62a of the storage means 60a opens in response to the set value (q). After the on-off valves are controlled to a predetermined open / close state, the second liquid delivery device 71 starts operating (S520). The urea water is transferred according to the arrows shown in the drawing. When the operation time reaches 60 minutes, which is the set value (r), the control means 90 (control unit 94) stops the operation of the second liquid delivery device 71 (S530) and controls all the on-off valves of the urea water transfer system 2 to close (S540). Then, the process proceeds to a stop step (S900).

[0052] According to this embodiment, the urea water stored in the storage means 60a is transferred (circulated) via the delivery means 70, the transfer means 80, and the urea water supply means 50, and the concentration in the system through which the urea water flows can be made uniform. In particular, when the concentration of the urea water remaining in the delivery means 70 is different from the concentration of the urea water stored in the storage means 60a, the concentration of the urea water remaining in the delivery means 70 becomes equivalent to the concentration of the urea water stored in the storage means 60a, and the urea water from the storage means 60a can be shipped at the specified concentration even in a small amount.

[0053] [3-2. Urea water transfer - second mode] As shown in FIG. 5, the urea water transfer system 2 used in the second embodiment of the urea water transfer has the same configuration as the urea water transfer system 2 used in the first embodiment of the urea water transfer.

[0054] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60a, 60b Set value (q) (transfer destination storage means): storage means 60a, 60b Set value (r) (transfer time): 60 minutes That is, two set values ​​(p) and two set values ​​(q) are set for the storage means 60a and the storage means 60b (S510). The set values ​​(p) and the set values ​​(q) are the same. The concentrations of the urea water stored in the storage means 60a and the storage means 60b are the same.

[0055] The control operation is the same as that in the first mode of urea water transfer, except that the third on-off valve 63a and the third on-off valve 63b open in response to the set value (p) and the second on-off valve 62a and the second on-off valve 62b open in response to the set value (q).

[0056] According to this embodiment, the urea water stored in the storage means 60a and the storage means 60b is transferred (circulated) via the delivery means 70, the transfer means 80, and the urea water supply means 50, and the concentration in the system through which the urea water flows can be made uniform. In particular, when the concentration of the urea water remaining in the delivery means 70 is different from the concentration of the urea water stored in the storage means 60a and the storage means 60b, by setting two (plural) storage means 60, it is possible to transfer (circulate) more urea water, and the influence of the concentration of the urea water remaining in the delivery means 70 can be mitigated. In addition, the concentration of the urea water remaining in the delivery means 70 becomes equivalent to the concentration of the urea water stored in the storage means 60a and the storage means 60b, and the urea water from the storage means 60a and the storage means 60b can be shipped at a predetermined concentration even in a small amount.

[0057] [3-3. Urea water transfer - third embodiment] As shown in FIG. 6, the urea water transfer system 2 used in the third embodiment of the urea water transfer has the same configuration as the urea water transfer system 2 used in the first embodiment of the urea water transfer.

[0058] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60b Set value (q) (transfer destination storage means): storage means 60a Set value (r) (transfer time): 60 minutes That is, the storage means 60a and the storage means 60b are set with one set value (p) and one set value (q) (S510). The set value (p) and the set value (q) are different. The concentrations of the urea water stored in the storage means 60a and the storage means 60b are the same.

[0059] The control operation is the same as that in the first mode of urea water transfer, except that the third on-off valve 63b opens in response to the set value (p) and the second on-off valve 62a opens in response to the set value (q).

[0060] According to this embodiment, the urea water stored in the storage means 60b can be transferred via the delivery means 70, the transfer means 80, and the urea water supply means 50, thereby making the concentration uniform within the system through which the urea water flows (see FIG. 6(B)). In particular, when the concentration of the urea water remaining in the delivery means 70 is different from the concentration of the urea water stored in the storage means 60a and 60b, the concentration of the urea water remaining in the delivery means 70 becomes equivalent to the concentration of the urea water stored in the storage means 60a and 60b, and the urea water from the storage means 60a and 60b can be shipped at a predetermined concentration even in small amounts. Also, the number of storage means 60 in which the urea water is stored can be consolidated from two to one (see FIG. 6(B)).

[0061] [3-4. Urea water transfer - fourth aspect] As shown in FIG. 7, the urea water transfer system 2 used in the fourth embodiment of the urea water transfer has the same configuration as the urea water transfer system 2 used in the first embodiment of the urea water transfer.

[0062] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60a, 60b Set value (q) (transfer destination storage means): storage means 60a, 60b Set value (r) (transfer time): 60 minutes That is, two set values ​​(p) and two set values ​​(q) are set for the storage means 60a and the storage means 60b (S510). The set values ​​(p) and (q) are the same. The concentrations of the urea water stored in the storage means 60a and the storage means 60b are different (the concentration Cb of the urea water in the storage means 60b is higher than the concentration Ca of the urea water in the storage means 60a).

[0063] The control operation is the same as that in the first mode of urea water transfer, except that the third on-off valve 63a and the third on-off valve 63b open in response to the set value (p) and the second on-off valve 62a and the second on-off valve 62b open in response to the set value (q).

[0064] According to this embodiment, the urea water stored in the storage means 60a and the storage means 60b is transferred (circulated) via the delivery means 70, the transfer means 80, and the urea water supply means 50, and the concentration in the system through which the urea water flows can be made uniform. Also, from the concentration Ca and the stored amount Va of the urea water stored in the storage means 60a, and the concentration Cb and the stored amount Vb of the urea water stored in the storage means 60b, the urea water of a prescribed concentration C1 (see formula (1)) can be produced (see FIG. 7(B)).

[0065]

number

[0066] In particular, when the concentration of urea water remaining in the delivery means 70 is different from the concentration of urea water stored in the storage means 60a and 60b, by providing two (plural) storage means 60, it is possible to transfer (circulate) a larger amount of urea water and mitigate the influence of the concentration of urea water remaining in the delivery means 70. In addition, the concentration of urea water remaining in the delivery means 70 becomes equivalent to the concentration of urea water stored in the storage means 60a and 60b, and the urea water from the storage means 60a and 60b can be shipped at a predetermined concentration even in small amounts.

[0067] [3-5. Urea water transfer - fifth aspect] As shown in FIG. 8, the urea water transfer system 2 used in the fifth embodiment of the urea water transfer has the same configuration as the urea water transfer system 2 used in the first embodiment of the urea water transfer.

[0068] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60b Set value (q) (transfer destination storage means): storage means 60a Set value (r) (transfer time): 30 minutes That is, one set value (p) and one set value (q) are set for the storage means 60a and the storage means 60b, respectively (S510). The set value (p) and the set value (q) are different. The concentrations of the urea water stored in the storage means 60a and the storage means 60b are different (the concentration Cb of the urea water in the storage means 60b is higher than the concentration Ca of the urea water in the storage means 60a). The set value (r) (transfer time) is set by calculating the transfer amount Vadd of urea water transferred from the storage means 60b required to produce urea water of a predetermined concentration C2 in the storage means 60a from the concentration Ca and storage amount Va of urea water stored in the storage means 60a and the concentration Cb of urea water stored in the storage means 60b, and calculating the transfer time (set value (r)) corresponding to the transfer amount Vadd in consideration of the urea water transfer flow rate v due to the operation of the second liquid delivery device 71. Specifically, the following formulas (2) and (3) are used.

[0069]

number

[0070]

number

[0071] The control operation is the same as that in the first mode of urea water transfer, except that the third on-off valve 63b opens in response to the set value (p), the second on-off valve 62a opens in response to the set value (q), and the set value (r) (transfer time) is 30 minutes.

[0072] According to this embodiment, the urea water stored in the storage means 60b can be transferred via the delivery means 70, the transfer means 80, and the urea water supply means 50, to produce urea water of a predetermined concentration (see FIG. 8(B)).

[0073] Furthermore, by performing the first mode of urea water transfer after this mode (the fifth mode of urea water transfer), the concentration Cb of urea water remaining in the delivery means 70 becomes equivalent to the concentration C2 of urea water stored in the storage means 60a, and the urea water from the storage means 60a can be shipped at the predetermined concentration C2, even in a small amount.

[0074] [3-6. Urea water transfer - 6th mode] As shown in FIG. 9, the urea water transfer system 2 used in the sixth embodiment of the urea water transfer has the same configuration as the urea water transfer system 2 used in the first embodiment of the urea water transfer.

[0075] In the urea water transfer control in this embodiment, the setting values ​​set in the control means 90 (setting unit 91) are as follows. Setting value (p) (source storage means): storage means 60a, 60b Set value (q) (transfer destination storage means): storage means 60c Set value (r) (transfer time): 30 minutes That is, the set value (p) sets the storage means 60a and the storage means 60b, and the set value (q) sets the storage means 60c (S510). The set value (p) and the set value (q) are different. The concentrations of the urea water stored in the storage means 60a and the storage means 60b are different (the concentration Cb of the urea water in the storage means 60b is higher than the concentration Ca of the urea water in the storage means 60a). The set value (r) (transfer time) can be calculated by dividing the amount V of urea water stored (produced) in the storage means 60c by the urea water transfer flow rate v by the operation of the second liquid delivery device 71.

[0076] The control operation is the same as that in the first mode of urea water transfer, except that the third on-off valve 63a and the third on-off valve 63b open in response to the set value (p), the second on-off valve 62c opens in response to the set value (q), and the set value (r) (transfer time) is 30 minutes.

[0077] According to this embodiment, the urea water stored in the storage means 60b is transported via the delivery means 70, the transfer means 80, and the urea water supply means 50, and when the delivery amounts from the storage means 60a and 60b are the same, the urea water having the predetermined concentration C1 as described above can be produced in the storage means 60c (see FIG. 9(B)).

[0078] The urea water supplied from the urea water supply source UWin used in the present invention can be any urea water, as long as it does not impair the object of the present invention. Moreover, the urea water supplied from the urea water supply source UWin used in the present invention can be produced using any urea water production system and / or any urea water production method, as long as it does not impair the object of the present invention. Moreover, the urea water supply source UWin used in the present invention can be any urea water production system, as long as it does not impair the object of the present invention. A preferred urea water production system and method for producing the urea water supplied from the urea water supply source UWin used in the present invention will now be described.

[0079] <4. Urea solution production system> As the urea water supply source UWin used in the present invention, a urea water production system that produces urea water by mixing raw water and urea can be used. In addition, the urea water producing system according to the present invention has a mixing means for mixing raw water and urea and dissolving the urea in the raw water to produce the urea water, a raw water supplying means having a heating device for heating the raw water and supplying the raw water heated by the heating device to the mixing means, a urea supplying means for supplying the urea to the mixing means, and a control means for controlling one or more of the raw water supplying means and the urea supplying means.

[0080] With this configuration, the urea water production system according to the present invention can mix urea with raw water and produce urea water that is prevented from becoming cloudy.

[0081] Furthermore, in the urea water producing system of the present invention, two or more production condition set values ​​selected from the group consisting of the following set values ​​(a) to (d) are set in the control means, and the control means calculates a control value based on the production condition set values, and can control one or more of the raw water supply means and the urea supply means based on the production condition set values ​​and / or the control value so as to prevent the urea water produced in the mixing means from becoming cloudy. Set value (a): the supply amount of the raw water supplied to the mixing means Set value (b): Amount of urea supplied to the mixing means Set value (c): concentration of the urea water produced by the mixing means Set value (d): the amount of the urea water produced by the mixing means

[0082] By adopting such a configuration, the urea water production system according to the present invention can set production conditions and calculate control values ​​that can prevent the urea water from becoming cloudy, and can automatically produce urea water that is prevented from becoming cloudy.

[0083] In the present invention, the production condition set value is a set value that specifies the conditions necessary for producing urea water. The production condition set value is composed of two or more selected from the group consisting of set values ​​(a) to (d) and is set as a numerical value. The supply amounts related to the set values ​​(a) and (b) may be in weight units (e.g., kg) or volume units (e.g., L). The concentration related to the set value (c) may be in weight units (e.g., wt%) or molar units (e.g., mol%). The production amount related to the set value (d) may be in weight units (e.g., kg) or volume units (e.g., L). In the present invention, the control value is a control variable used for controlling the production of urea water, and is a control variable that specifies the conditions required for producing urea water. The manufacturing condition setting values ​​and control values ​​according to the present invention will be described in detail later.

[0084] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the urea water production system according to the present invention will be described with reference to the drawings. The urea water production system according to the present invention is not limited to the following embodiments, and can be modified as desired without departing from the scope of the present invention. The dimensions, materials, and other specific values ​​shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In addition, in all drawings, similar components are given the same reference numerals, and descriptions thereof will be omitted as appropriate.

[0085] FIG. 10 is a schematic diagram showing a urea water production system according to an embodiment of the present invention. The urea water production system 1 is a system that mixes urea with raw water to produce urea water that is prevented from becoming cloudy. The urea water production system includes a raw water supply means 10, a urea supply means 20, a mixing means 30, and a control means 90.

[0086] [4-1. Raw water supply means] The raw water supplying means 10 heats raw water (water that is a raw material for urea water) and supplies the heated raw water to the mixing means 30. By supplying the heated raw water to the mixing means 30 in this manner, it is possible to suppress a decrease in temperature of the urea water due to the dissolution of urea in water, which is an endothermic reaction, and to produce urea water that is prevented from becoming cloudy due to precipitation of urea due to a decrease in saturation solubility.

[0087] The raw water supply means 10 includes a raw water purification device 11 , a raw water storage device 13 , a liquid delivery device 16 , a heating device 12 , and a flow meter 17 .

[0088] As shown in FIG. 10, raw water supplied from a raw water supply source W is purified by a raw water purification device 11 that purifies the raw water. In raw water purification apparatus 11, the raw water is purified to remove foreign matter from the raw water, which makes it possible to avoid precipitation of urea caused by the foreign matter and to prevent the urea water from becoming cloudy.

[0089] In this embodiment, the raw water supplied from the raw water supply source W to the raw water purification apparatus 11 is tap water. In the present invention, the raw water supplied to the raw water purification apparatus can be any type as long as it can be purified in the raw water purification apparatus and the urea water using the purified raw water does not become cloudy.

[0090] Here, the raw water purification apparatus according to the present invention is an apparatus that purifies raw water by removing foreign matter contained in the raw water. The raw water purification apparatus can use any device or member as long as it can purify raw water so as to prevent the urea water from becoming cloudy. Examples of any device or member that can be used in the raw water purification apparatus include a reverse osmosis membrane (RO membrane), a decarbonation membrane, a continuous deionization treatment device (EDI device), an ion exchange resin, a filter medium, and the like. Among these, it is preferable that the raw water purification apparatus has a continuous electric deionization treatment device. By using a continuous electric deionization treatment device, the raw water purification apparatus can purify raw water without using chemicals, etc., thereby simplifying maintenance and enabling continuous purification of the raw water. The raw water purification apparatus can use any combination of the above devices and components depending on the purpose.

[0091] The raw water purified in raw water purification apparatus 11 is stored in raw water storage apparatus 13, which is installed downstream of the raw water purification apparatus. Raw water storage apparatus 13 stores the raw water purified in raw water purification apparatus 11. Raw water storage apparatus 13 is a cylindrical tank with a height of 6.2 m, a diameter of 3.3 m, and a capacity of 50,000 L. The raw water storage device 13 has a water level gauge (not shown) that measures the level of the stored raw water. The raw water stored in the raw water storage device 13 is managed to a predetermined amount according to the measurement value of the water level gauge.

[0092] The raw water stored in the raw water storage device 13 is sent to the heating device 12 by a liquid sending device (water sending pump) 16 arranged downstream of the raw water storage device 13.

[0093] The raw water sent to the heating device 12 by the liquid sending device 16 is heated by the heating device (boiler) 12. The heated raw water is supplied from the heating device 12 to the mixing means 30. In other words, the raw water supplying means 10 has the heating device 12 that heats the raw water, and can supply the raw water heated by the heating device 12 to the mixing means 30. In this manner, by supplying heated raw water to the mixing means 30, the urea water in the mixing means 30 can be maintained at a predetermined temperature or higher, thereby avoiding precipitation of urea in the produced urea water and preventing the urea water from becoming cloudy.

[0094] The heating device 12 has a thermometer (not shown) that measures the temperature of the heated raw water. While measuring the temperature of the heated raw water using the thermometer, the heating device 12 is controlled by a control means described later, and heats the raw water to a predetermined temperature (control value (e)). Details of the control will be described later.

[0095] A flow meter 17 for measuring the flow rate of the heated raw water is installed downstream of the heating device 12. By integrating the flow rate measured by the flow meter 17, the amount of urea water required to be produced by the mixing means 30 can be grasped.

[0096] [4-2. Urea supply means] The urea supplying means 20 supplies urea to the mixing means 30 . In the present invention, the urea supplying means is arbitrary as long as it can supply urea to the mixing means. For example, the urea supplying means may be configured to have a urea supply path and to be able to manually supply urea to the mixing means, or may be configured to be able to supply urea to the mixing means using a flexible container bag (FIBC), or may be configured to have a urea storage container and an on-off valve and to automatically supply urea to the mixing means. When urea is manually supplied to the mixing means, the supply amount of urea can be set to a set value (a), and the control means described later does not need to control the urea supplying means.

[0097] In this embodiment, the urea supplied from the urea source U to the urea supply means 20 (and the urea supplied from the urea supply means 20 to the mixing means 30) is in a powder form. Note that in the present invention, the form of urea supplied by the urea supply means can be any form of urea as long as the mixing means can mix raw water and urea and dissolve urea in the raw water to produce urea water, and may be in a form other than powder, for example, granular.

[0098] [4-3. Mixing means) The mixing means 30 mixes the raw water supplied from the raw water supply means 10 and the urea supplied from the urea supply means, and dissolves the urea in the raw water to produce urea water. The mixing means 30 is a cylindrical tank having a height of 2.0 m, a diameter of 2.7 m, and a capacity of 10,000 L.

[0099] The mixing means 30 includes an agitator (not shown). The raw water and urea supplied to the mixing means 30 are agitated and mixed by the agitator. By mixing the raw water and urea in the agitator, the urea is dissolved in the raw water to produce urea water. Note that, as long as the urea is dissolved in the raw water in the mixing means 30 to produce urea water, the mixing means 30 does not need to include an agitator.

[0100] The mixing means 30 is of a non-heated type. As described above, since heated raw water is supplied by the raw water supply means 10, even if the mixing means 30 is of a non-heating type, the temperature of the raw water (or urea water) (saturation solubility of urea) can be increased to prevent urea precipitation, and urea water that is prevented from becoming cloudy can be produced. Furthermore, by using a non-heating type mixing means 30, it is possible to avoid unnecessary capital investment and an increase in energy consumption due to the addition of heat. This is particularly advantageous when producing urea water on an industrial scale. The mixing means according to the present invention may be of a heating type as long as it does not impair the object of the present invention.

[0101] In the present invention, the mixing means may include a thermometer for measuring the temperature of the urea water (or raw water). By including the thermometer in the mixing means, the control means controls the raw water supply means to supply heated raw water based on the measurement value of the thermometer, and by increasing the temperature of the urea water in the mixing means and decreasing the urea concentration, it is possible to avoid precipitation of urea and prevent the urea water from becoming cloudy. In the present invention, the mixing means may include a water level meter that measures the level of the urea water (or raw water). By including the water level meter in the mixing means, the control means can control the raw water supply means to supply (add) raw water to the mixing means based on the measurement value of the water level meter. Furthermore, the control means may control the urea supply means to supply (add) urea to the mixing means as necessary.

[0102] The urea water produced in the mixing means 30 is sent to a storage means (not shown) disposed downstream of the mixing means 30 and stored therein.

[0103] [4-4. Control means] As described above, the urea water production system 1 mixes raw water supplied from the raw water supply means 10 with urea supplied from the urea supply means 20 in the mixing means 30, and dissolves the urea in the raw water to produce urea water. In order to produce urea water that is prevented from becoming cloudy by dissolving urea in raw water, the urea water production system 1 has a control means 90 that controls one or more of the raw water supply means and the urea supply means. The control means 90 has a second mode (control means 90B) and a third mode (control means 90C), which will be described with reference to the drawings. FIG. 11 shows a schematic diagram of a control means (second aspect) according to an embodiment of the present invention, and FIG. 12 shows a schematic diagram of a control means (third aspect) according to an embodiment of the present invention.

[0104] (4-4-1. Control Means - Second Aspect) As shown in FIG. 11, a control means 90B according to the embodiment of the present invention includes a setting unit 91, a calculation unit 92, a receiving unit 93, and a control unit 94.

[0105] The setting unit 91 has a display and can set the manufacturing condition set values ​​required for manufacturing the urea water. The manufacturing condition set values ​​that can be set by the setting unit 91 are the following set values ​​(a) to (d). Note that the units for setting the manufacturing condition set values ​​are also indicated. Set value (a): Amount of raw water supplied to the mixing means 30 (unit: kg) Set value (b): Amount of urea supplied to the mixing means 30 (unit: kg) Set value (c): concentration of urea water produced in the mixing means 30 (unit: weight %) Set value (d): Amount of urea water produced in the mixing means 30 (unit: kg)

[0106] In the setting unit 91, two or more production condition set values ​​selected from the group consisting of the set values ​​(a) to (d) can be set. As described later, the calculation unit 92 calculates a control value required for the production of urea water from two or more production condition set values ​​selected from the group consisting of the set values ​​(a) to (d). The control unit 94 controls one or more of the raw water supply means 10 and the urea supply means 20 based on the production condition set values ​​and / or the control values. That is, in the control means 90, two or more production condition set values ​​selected from the group consisting of the set values ​​(a) to (d) are set, and the control means 90 calculates a control value based on the production condition set values, and controls one or more of the raw water supply means 10 and the urea supply means 20 based on the production condition set values ​​and / or the control value so as to prevent the urea water produced in the mixing means 30 from becoming cloudy.

[0107] In the setting unit 91, two or more production condition set values ​​selected from the group consisting of the above set values ​​(a) to (d) can be arbitrarily set, but the production condition set values ​​set in the control means may be set values ​​(b) and (c). By setting the production condition set values ​​to set values ​​(b) and (c), the control for producing urea water can be simplified. By setting the supply amount of urea supplied to the mixing means by manual work or the like as set value (b) and setting the concentration of urea water to be produced as set value (c), the control means 90 can produce urea water that is prevented from becoming cloudy by controlling only the raw water supply means 10.

[0108] The calculation unit 92 receives the production condition setting values ​​from the setting unit 91, and calculates control values ​​necessary for control to produce urea water prevented from becoming cloudy. The control values ​​can include the following control values ​​(a) to (e). Control value (a): Control target value of the supply amount of raw water supplied to the mixing means 30 Control value (b): Control target value of the amount of urea supplied to the mixing means 30 Control value (c): Control target value of the concentration of the urea water produced in the mixing means 30 Control value (d): Control target value of the amount of urea water produced in the mixing means 30 Control value (e): Control target value of the heating temperature of the raw water supplied to the mixing means 30 (target heating control temperature of the raw water)

[0109] The control values ​​to be calculated are control values ​​other than the manufacturing conditions set as the manufacturing condition set values. For example, when set values ​​(a) and (b) are set as the manufacturing condition set values, the control values ​​to be calculated are control values ​​(c) to (e). When set values ​​(b) and (c) are set as the manufacturing condition set values, the control values ​​to be calculated are control values ​​(a), (d), and (e). The details of the calculations in the calculation unit 92 will be described later.

[0110] The calculation unit according to the present invention does not need to calculate all of the control values ​​(a) to (e) as long as the control unit can control each means so as to produce urea water that is prevented from becoming cloudy. For example, when set values ​​(a) and (b) are set as the production condition set values, the calculated control value can be only the control value (e). The control unit can control the raw water supply means based on the set value (a) and the control value (e), and control the urea supply means based on the set value (b). In addition, when the set values ​​(b) and (c) are set as the production condition set values, the calculated control values ​​can be the control values ​​(a) and (e). The control unit can control the raw water supply means based on the control values ​​(a) and (e), and control the urea supply means based on the set value (b). When the set values ​​(c) and (d) are set as the production condition set values, the calculated control values ​​can be the control values ​​(a), (b) and (e). The control unit can control the raw water supply means based on the control values ​​(a) and (e) and control the urea supply means based on the set value (b).

[0111] The calculation unit 92 transmits the manufacturing condition setting values ​​and the control values ​​to the control unit 94 .

[0112] The calculation unit 92 can calculate the control value from the manufacturing condition setting value, but the control means according to the present invention may display the control value calculated in the calculation unit on a display unit (not shown), reset the displayed control value in the setting unit, and the calculation unit may transmit the manufacturing condition setting value to the control unit as the reset setting value. For example, the setting unit may set the setting values ​​(b) and (c) as the manufacturing condition setting values, the calculation unit may calculate the control values ​​(a) and (e), the control value (a) may be displayed on the display unit, the control value (a) displayed on the display unit may be set as the manufacturing condition setting value (setting value (a)) in the setting unit, and the setting value (a) may be transmitted from the calculation unit to the control unit. Also, the control value (a) displayed on the display unit may be set as the manufacturing condition setting value (setting value (a)) in the setting unit, and the setting value (a) may be transmitted from the setting unit to the control unit (without passing through the calculation unit).

[0113] The receiving unit 93 receives signals transmitted from the devices included in the raw water supplying means 10, the urea water supplying means 20, and the mixing means 30, respectively. Signals are transmitted from the raw water supply means 10 regarding the operating status of the raw water purification device 11, the water level of the water level gauge of the raw water storage device 13, the operating output of the liquid delivery device 16, the operating status of the heating device 12, the raw water temperature after heating, and the raw water flow rate of the flow rate measuring device 17. The urea supply means 20 sends a signal regarding the amount of urea to be supplied to the mixing means 30 . The mixing means 30 transmits a signal regarding the operating status of the agitator. The receiving unit 93 also receives signals transmitted from devices included in the urea water supply means 50, the storage means 60, the sending means 70, and the transfer means 80 that configure the urea water transfer system 2 according to the embodiment of the present invention. The signals transmitted from each of these means are as described above, and therefore description thereof will be omitted. The receiving unit 93 receives these signals and transmits them to the control unit 94 .

[0114] The receiving unit according to the present invention may receive signals other than those mentioned above, so long as it is capable of producing urea water that is prevented from becoming cloudy. For example, the receiving unit may receive signals related to the operating time of the raw water purification apparatus and the amount of raw water processed from the raw water supplying means. Furthermore, if the mixing means is equipped with a thermometer and / or a water level gauge, the receiving unit may receive signals related to the temperature and / or water level of the urea water (raw water) from the mixing means. In addition, the receiving unit according to the present invention may not receive some of the above-mentioned signals as long as it can produce urea water that is prevented from becoming cloudy. For example, when the setting value (b) (the amount of urea supplied to the mixing means) is set in the setting unit, the receiving unit may not receive a signal regarding the amount of urea supplied from the urea supply means.

[0115] The control unit 94 receives manufacturing condition setting values ​​and control values ​​from the calculation unit 92 , and receives various signals from the receiving unit 93 . The control unit 94 controls the raw water supplying means 10, the urea supplying means 20, and the mixing means 30 based on the production condition set values ​​and control values ​​received from the calculation unit 92. The control unit 94 controls (adjusts) each of the means based on various signals from the receiving unit 93 obtained by controlling each of the means so that the various signals become the production condition set values ​​and / or control values. Specifically, the control unit 94 controls the raw water supplying means 10 based on a set value (a) or a control value (a) and a set value (e) or a control value (e). The control unit 94 also controls the urea water supplying means 20 based on a set value (b) or a control value (b). In this manner, the control means 90 controls the raw water supply means 10, the urea supply means 20, and the mixing means 30, so that the urea water production system 1 can produce urea water that is prevented from becoming cloudy.

[0116] Although the control unit 94 according to the embodiment of the present invention controls the raw water supply means 10, the urea supply means 20, and the mixing means 30, the control unit according to the present invention controls one or more of the raw water supply means and the urea supply means. For example, when urea is supplied manually via the urea supply means, the control unit according to the present invention does not need to control the urea supply means. Furthermore, when the mixing means according to the present invention does not have a stirring device or a measuring instrument, the control unit according to the present invention does not need to control the mixing means.

[0117] The calculation unit 92 can calculate control values ​​for the concentration of urea water, the production amount of urea water, the supply amount of raw water, and the supply amount of urea by using two or more production condition setting values ​​selected from the group consisting of setting values ​​(a) to (d) set in the setting unit 91. Specifically, by using simultaneous equations including variables Xa to Xd corresponding to four set values ​​(a) to (d), the following control values, which are unset manufacturing conditions, can be appropriately calculated from two or more set manufacturing condition set values. Control value (a): Control target value of the supply amount of raw water supplied to the mixing means 30 Control value (b): Control target value of the amount of urea supplied to the mixing means 30 Control value (c): Control target value of the concentration of the urea water produced in the mixing means 30 Control value (d): Control target value of the amount of urea water produced in the mixing means 30

[0118] As will be described later, it is also possible to determine the target temperature at which the raw water should be heated in order to produce urea water that is free from cloudiness. Control value (e): Control target value of the heating temperature of the raw water supplied to the mixing means 30 (target heating control temperature of the raw water)

[0119]

number

[0120]

number

[0121] For example, when a set value (a) (amount of raw water supplied) and a set value (b) (amount of urea supplied) are set in the setting unit 91, the amount of urea water produced (control value (d)) can be calculated by adding the set value (a) and the set value (b) using equation (4), and the concentration of urea water (control value (c)) can be calculated by dividing the set value (b) by the calculated amount of urea water produced using equation (5). Similarly, the control value of an unset manufacturing condition can be calculated from two or more set manufacturing condition values ​​other than the above (set value (a) and set value (b)). Therefore, by using two or more production condition setting values ​​selected from the group consisting of setting values ​​(a) to (d) set in the setting unit 91, the calculation unit 92 can set the conditions for producing urea water prevented from becoming cloudy (the supply amount of raw water, the supply amount of urea, the concentration of urea water, and the production amount of urea water) as production condition setting values ​​and control values.

[0122] The calculation unit 92 calculates the temperature of the raw water heated by the raw water supply means 10 based on the set or calculated supply amount of raw water and the set or calculated supply amount of urea so as to prevent the urea water produced in the mixing means 30 from becoming cloudy. The dissolution of urea into water is an endothermic reaction, and by heating the raw water to a predetermined temperature or higher, precipitation of urea (urea being contained in an amount greater than the saturation solubility) can be prevented, thereby preventing clouding.

[0123] The calculation unit 92 can calculate the temperature change (decrease) when urea is dissolved in water from the set or calculated supply amount of raw water and the set or calculated supply amount of urea using the dissolution enthalpy of urea in water and the specific heat of water.

[0124]

number

[0125] The molecular weight of urea (M) is 60, and the enthalpy of dissolution of urea in water (H UW ) is 15.4 kJ / mol, and the specific heat of water (C W ) is 4.2 kJ / kg K, so equation 3 can be transformed as follows:

[0126]

number

[0127] As shown in equations (6) and (7), the supply amount of raw water is included as a variable in the denominator, and the supply amount of urea is included as a variable in the numerator. If the relative supply amounts (supply ratio) of raw water and urea can be grasped, the temperature change (decrease) when urea is dissolved in water can be calculated. The relative supply amounts (supply ratio) of raw water and urea can be calculated from the concentration of the urea water. Therefore, by setting a set value (c) or control value (c), which is the concentration of the urea water, the temperature change (decrease) when urea is dissolved in water can be calculated.

[0128] In order to prevent the urea water from becoming cloudy, it is necessary to maintain the temperature of the urea water produced in the mixing means 30 at a predetermined temperature or higher, and a control value (e) (target temperature to which the raw water is heated) is calculated taking into account the temperature drop caused when urea is dissolved in water. That is, the control value (e) can be calculated by adding the temperature change (ΔT) of urea when it is dissolved in water to the temperature of the urea water to be maintained.

[0129] By performing the above calculation in the calculation unit 92, it is possible to calculate the control values ​​(a) to (e) from two or more manufacturing condition set values ​​selected from the group consisting of the set values ​​(a) to (d).

[0130] From the viewpoint of producing high quality urea water, when the setting unit 91 selects the set value (c) which is the concentration of the urea water, it is preferable that the set value (c) is limited to a predetermined range. If the concentration of the urea water of the set value (c) is too low, the urea contained in the urea water will be reduced, and there is a possibility that sufficient effect will not be obtained when the urea water is used. If the concentration of the urea water of the set value (c) is too high, urea will precipitate, causing the urea water to become cloudy.

[0131] The range of the set value (c) (the concentration of the urea water produced in the mixing means) is, for example, 20% by weight to 50% by weight, 25% by weight to 45% by weight, or 30% by weight to 40% by weight.

[0132] The set value (c) may be set by selecting the concentration of the urea water from among options in the setting unit 91. As the options for the concentration of the urea water, for example, two or more options selected from the group consisting of 20 wt%, 22.5 wt%, 25 wt%, 27.5 wt%, 30 wt%, 32.5 wt%, 35 wt%, 37.5 wt%, and 40 wt% may be set. By allowing the concentration of the urea water to be set by selecting it from among the options in this way, the setting can be simplified.

[0133] When the set value (c) is limited to a predetermined range, the control unit 94 (control means 90B) calculates a control value (e), which is a target heating control temperature of the raw water supplied to the mixing means 30, based on the set value (c) limited to the predetermined range and the heat of dissolution of urea in water so that the urea water produced in the mixing means 30 does not become cloudy, and controls the raw water supplying means 10 so that the temperature of the raw water supplied to the mixing means 30 becomes the control value (e).

[0134] When the temperature of the raw water is low, urea is difficult to dissolve in the raw water, and even if urea dissolves, there is a possibility that it will precipitate. In addition, when the temperature of the raw water (or urea water) is high, ammonia is generated from the dissolved urea, and the quality of the urea water may deteriorate, such as by generation of an unpleasant odor. In order to prevent the produced urea water from becoming cloudy and to maintain the quality, it is preferable that the temperature of the raw water in the mixing means 30, i.e., the temperature of the urea water produced in the mixing means 30, is within a predetermined temperature range. The temperature of the urea water produced in the mixing means 30 is, for example, 20°C or higher and 80°C or lower, 30°C or higher and 75°C or lower, or 40°C or higher and 70°C or lower.

[0135] In order to keep the urea water at a predetermined temperature or higher, the raw water is heated while taking into consideration the temperature drop caused by dissolving urea in water. When the temperature of the urea water is kept at 20°C or higher and the temperature drop caused by dissolving urea in water is 30°C, the temperature of the raw water supplied to the mixing means 30 becomes 50°C or higher.

[0136] On the other hand, if the temperature of the raw water supplied to the mixing means 30 is too high, the energy required for heating will be wasted, and if the temperature of the urea water is too high, decomposition of urea into ammonia (and the unpleasant odor of ammonia) will occur. Therefore, it is preferable to control the temperature of the raw water supplied to the mixing means 30 within a predetermined temperature range. The temperature of the raw water supplied to the mixing means 30 is, for example, 50°C or higher and 80°C or lower, 55°C or higher and 75°C or lower, or 60°C or higher and 70°C or lower.

[0137] (4-4-2. Control Means - Third Aspect) As shown in FIG. 12, a control means according to an embodiment of the present invention (third aspect, hereinafter, control means 90C) includes a setting unit 91, a calculation unit 92, a receiving unit 93, a control unit 94, and a storage unit 95.

[0138] The details of the setting unit 91 and the receiving unit 93 are as described above, and therefore will not be described here. Also, the details of the calculation unit 92 and the control unit 94 may be omitted where appropriate if they overlap with the above contents. The storage unit 95 is a component newly added to the control means 90B (second aspect), and will be described in detail below.

[0139] The memory unit 95 stores control values ​​necessary for the control unit 94 to control each means. One of the control values ​​stored in the memory unit 95 is a control value (e) (a control target value for the heating temperature of the raw water supplied to the mixing means 30 (target heating control temperature of the raw water)). The memory unit 95 transmits the control value (e) to the control unit 94. The storage unit according to the present invention can store any control value and transmit it to the control unit so that the urea water producing system produces urea that is prevented from becoming cloudy.

[0140] As described above, the calculation unit 92 can calculate the control values ​​(a) to (d) by using two or more set values ​​selected from the group consisting of the set values ​​(a) to (d) set in the setting unit 91. Note that since the memory unit 95 stores the control value (e) (target heating control temperature of the raw water) and transmits it to the control unit 94, the calculation unit 92 does not need to calculate the heating temperature.

[0141] The control value (e) stored in the memory unit 95 is arbitrary as long as it can prevent the urea water produced in the mixing means 30 from becoming cloudy. The control value (e) stored in the memory unit 95 can be, for example, 50°C or higher and 80°C or lower, 55°C or higher and 75°C or lower, or 60°C or higher and 70°C or lower.

[0142] The control unit 94 receives manufacturing condition setting values ​​and control values ​​from the calculation unit 92 and the storage unit 95 , and receives various signals from the receiving unit 93 . The control unit 94 controls the raw water supplying means 10, the urea supplying means 20 and the mixing means 30 based on the production condition set values ​​and control values ​​received from the calculation unit 92 and the memory unit 95. The control unit 94 controls (adjusts) each of the means based on various signals from the receiving unit 93 obtained by controlling each of the means so that the various signals become the production condition set values ​​and control values. In this way, the control unit 90 controls the raw water supplying means 10, the urea supplying means 20 and the mixing means 30, so that the urea water production system 1 can produce urea water that is prevented from becoming cloudy.

[0143] The urea water production system according to the present invention has been described above. Hereinafter, the urea water production method according to the present invention will be described with reference to the drawings. Figure 13 shows a main flow diagram of the urea water production method according to an embodiment of the present invention, Figure 14 shows a flow diagram of the raw water supply process of the urea water production method according to an embodiment of the present invention, Figure 15 shows a flow diagram of the urea supply process of the urea water production method according to an embodiment of the present invention, Figure 16 shows a flow diagram of the urea supply process of the urea water production method according to an embodiment of the present invention, and Figure 17 shows a flow diagram of the mixing process of the urea water production method according to an embodiment of the present invention. In addition, explanations that overlap with the above content may be omitted as appropriate.

[0144] <5. Urea water production method> The urea water production method according to the present invention is a urea water production method for producing urea water prevented from becoming cloudy, and includes the steps of: a step (1) of setting two or more production condition set values ​​selected from the group consisting of the following set values ​​(a) to (d) and calculating a control value based on the production condition set values; a step (2) of heating the raw water and supplying it to a mixing means based on the production condition set values ​​and / or the control value; a step (3) of supplying the urea to the mixing means based on the production condition set values ​​and / or the control value; and a step (4) of mixing the raw water supplied in step (2) and the urea supplied in step (3) in the mixing means and dissolving the urea in the raw water to produce the urea water. Set value (a): the supply amount of the raw water supplied to the mixing means Set value (b): Amount of urea supplied to the mixing means Set value (c): concentration of the urea water produced by the mixing means Set value (d): the amount of the urea water produced by the mixing means

[0145] By adopting such a configuration, the urea water producing method according to the present invention can produce urea water that is prevented from becoming cloudy by mixing urea and raw water.

[0146] FIG. 13 shows a main flow diagram of the urea water production method according to the embodiment of the present invention. The urea water producing method according to the embodiment of the present invention includes a setting step (S100), a raw water supplying step (S200), a urea supplying step (S300), and a mixing step (S400).

[0147] The urea water production method according to the embodiment of the present invention is carried out in the order of production condition setting step (S100), raw water supply step (S200), urea supply step (S300) and mixing step (S400), but as long as the object of the present invention is not impaired, the urea water production method according to the present invention may carry out the urea supply step before the raw water supply step, or may carry out the raw water supply step and the urea supply step in parallel. Furthermore, the urea water production method according to the present invention may carry out the raw water supply step, urea supply step and mixing step in parallel. By carrying out each step in parallel, the production time can be shortened. In addition, in the urea water producing method according to the present invention, the above-mentioned urea water transfer step of the present invention may be carried out after the mixing step. By carrying out the urea water transfer step, it is possible to make the concentration of the urea water uniform and / or adjust the concentration of the urea water in the system through which the urea water flows.

[0148] [5-1. Manufacturing condition setting process] The manufacturing condition setting step (S100) is a step (1) of setting two or more manufacturing condition setting values ​​selected from the group consisting of the following setting values ​​(a) to (d) and calculating a control value based on the manufacturing condition setting values. Set value (a): the supply amount of the raw water supplied to the mixing means Set value (b): Amount of urea supplied to the mixing means Set value (c): concentration of the urea water produced by the mixing means Set value (d): the amount of the urea water produced by the mixing means FIG. 14 shows a flow chart of a production condition setting process of the urea water production method according to the embodiment of the present invention.

[0149] In the manufacturing condition setting step (S100), two or more set values ​​selected from the group consisting of the following set values ​​(a) to (d) are input (set) as set values ​​used in the manufacturing method of urea water prevented from becoming cloudy (S110). From the two or more input set values, control values ​​(a) to (e) are calculated (S120). The calculation of the control values ​​is as described above, and a description thereof will be omitted. When the calculation of the control value is completed, the process proceeds to the raw water supplying step (S200).

[0150] As long as the object of the present invention is not impaired, the method for producing urea water according to the present invention may have the following configurations. For example, instead of calculating the control value, a control value stored in a storage unit can be used. The manufacturing condition set values ​​set in step (1) may be set values ​​(b) and (c). In addition, the set value (c) may be limited to a predetermined range, and the temperature of the raw water supplied to the mixing means may be calculated as a control value (e) based on the set value (c) limited to the predetermined range and the heat of dissolution of urea in water so that the urea water produced in the mixing means does not become cloudy, and the raw water supplying means may be controlled so that the temperature of the raw water supplied to the mixing means in step (2) becomes the calculated control value (e). The set value (c) may be 20% by weight or more and 50% by weight or less.

[0151] [5-2. Raw water supply process] The raw water supplying step (S200) is a step (2) of heating the raw water and supplying it to a mixing means based on the production condition set values ​​and / or the control values. FIG. 15 shows a flow diagram of a raw water supply process in the urea water production method according to the embodiment of the present invention.

[0152] When the process proceeds to the raw water supply step (S200), purification of the raw water is started (S210). The purification of the raw water is performed by removing foreign matter from the raw water (tap water) using a raw water purification device. By purifying the raw water, foreign matter in the raw water is removed, and clouding of the urea water caused by the foreign matter can be prevented. The purified raw water is stored in a raw water storage device. A water level gauge installed in the raw water storage device measures the water level of the stored raw water, and the raw water is purified until it reaches a predetermined water level (S210, S220). When the level of the raw water stored in the raw water storage device reaches a predetermined level, the raw water is heated by the heating device, and the heated raw water is supplied to the mixing means (S230). That is, the raw water supplying means supplies raw water to the mixing means after the amount of raw water stored in the raw water storage device exceeds a predetermined amount. By performing such processes (S220, 230), the raw water can be heated and supplied thereafter without interruption, and the waiting time for restart due to interruption can be avoided. By avoiding the waiting time for restart, it is possible to prevent a drop in the temperature of the heated raw water already supplied to the mixing means and the clouding of the urea water due to urea precipitation caused by the temperature drop. The heating of the raw water by the heating device is performed based on a set value or a control value calculated from the set value. The calculation and control regarding the heating of the raw water are as described above, and therefore a description thereof will be omitted. By supplying the heated raw water to the mixing means, the saturated solubility of urea in the urea water is increased, precipitation of urea is prevented, and urea water that is prevented from becoming cloudy can be produced. A flow meter provided in the raw water supplying means measures the integrated flow rate of raw water supplied to the mixing means. Raw water is heated and supplied to the mixing means until the integrated flow rate reaches a set value (a) (the supply amount of raw water) or a control value calculated from the set value (S230, S240). After the integrated flow rate reaches a set value (a) (the supply amount of raw water) or a control value calculated from the set value, the process proceeds to the urea supply step (S300).

[0153] As long as the object of the present invention is not impaired, the method for producing urea water according to the present invention may have the following configurations. For example, the temperature of the raw water supplied to the mixing means may be 50°C or higher and 80°C or lower. As described above, in step (2), before heating the raw water and supplying it to the mixing means (S230), a process for purifying the raw water (S210) and a process for storing the purified raw water (S220) are further included. However, the process for purifying the raw water (S210) and the process for storing the purified raw water (S220) do not necessarily have to be included. As described above, in step (2), the raw water is supplied to the mixing means after the stored raw water exceeds a predetermined amount (S220, S230), but the raw water may be supplied to the mixing means before the stored raw water exceeds a predetermined amount. In step (2), the raw water may be purified using a continuous electrodeionization treatment device (EDI device).

[0154] [5-3. Urea supply process] The urea supplying step (S300) is a step of supplying the urea to the mixing means based on a set value. FIG. 16 shows a flow diagram of the urea supply process in the urea water production method according to the embodiment of the present invention.

[0155] When the process proceeds to the urea supply step (S300), the supply of urea to the mixing means is started (S310). Urea is manually supplied to the mixing means until the supply amount of urea (set value (b) or control value) is reached (S310). After the urea is supplied to the mixing means, the process proceeds to a mixing step (S400).

[0156] The supply of urea may be automatically performed by providing a urea storage container and an on-off valve to the mixing means.

[0157] [5-4. Mixing process] The mixing step (S400) is a step of mixing the raw water supplied in the raw water supplying step and the urea supplied in the urea supplying step in a mixing means to dissolve the urea in the raw water and produce urea water. FIG. 17 shows a flow diagram of a mixing process in the method for producing urea water according to the embodiment of the present invention.

[0158] When the process proceeds to the mixing step (S400), the agitator provided in the mixing device is operated (S410). By operating the agitator, the raw water and urea supplied to the mixing means are agitated and mixed in the mixing means. By mixing the raw water and urea in the mixing means, the urea is dissolved in the raw water, and urea water is produced. In addition, the raw water supplied to the mixing means is purified to remove foreign matter, and the raw water is heated before being supplied, so that precipitation of urea caused by foreign matter and solubility saturation can be avoided, and urea water that is prevented from becoming cloudy can be produced. When the agitator has been running for a predetermined time and the production of urea water is completed, the agitator is stopped (S420, S430). When the agitator is stopped, the production of urea water is completed (S900).

[0159] As long as the object of the present invention is not impaired, the method for producing urea water according to the present invention may have the following configurations. For example, the temperature of the urea water produced in the mixing means may be 20°C or higher and 80°C or lower. The mixing means may be of a non-heating type.

[0160] Although the embodiments of the present invention have been described above with reference to the drawings, the embodiments disclosed herein are illustrative in all respects and are not restrictive. In particular, in the embodiments disclosed herein, matters not expressly disclosed, such as operating conditions, operating conditions, various parameters, dimensions, weights, volumes of components, etc., do not deviate from the scope of ordinary practice by a person skilled in the art, and values ​​that can be easily assumed by a person skilled in the art are adopted. [Industrial Applicability]

[0161] INDUSTRIAL APPLICABILITY The present invention has industrial applicability in the field of urea water production, particularly in the field of industrial urea water production, as a urea water transport system, a urea water transport method, and a urea water production method. [Explanation of symbols]

[0162] 1. Urea water production system 2. Urea water transfer system 10 Raw water supply means 11 Raw water purification equipment 12 Heating device 13 Raw water storage device 16 Liquid delivery device 17 Flow Measuring Device 20 Urea supply means 30 Mixing means 50 Urea water supply means 51 First liquid delivery device 52 First opening and closing valve 53 First Channel 54 First Branch 60,60a~f Storage means 61, 61a~f Storage device 62, 62a~f Second opening and closing valve 63, 63a~f Third opening and closing valve 64, 64a-f Second flow path 65, 65a~f Third flow path 70 Delivery means 71 Second liquid delivery device 72 Flow Measuring Device 73 4th opening and closing valve 74 Second Branch 75 4th Stream 76 Third Branch 77 5th Stream 80 Means of transport 81 5th opening and closing valve 82 5th Channel 90 Control Means 90, 90A, 90B, 90C Control means 91 Setting section 92 Arithmetic section 93 Receiving section 94 Control Unit 95 Memory section UWin urea water source UWout Urea water shipping port

Claims

1. A urea water transfer system for transferring urea water, A plurality of storage means for storing urea water; a urea water supply means connected to the plurality of storage means and supplying the urea water from a urea water supply source to the storage means; a delivery means connected to the plurality of storage means and configured to deliver the urea water stored in the storage means; a transfer means connected to the sending means and the urea water supply means, for transferring the urea water sent from the sending means to the urea water supply means; a control means for selecting, from among the plurality of storage means, a source storage means from which the stored urea water is sent out by the sending means, and a destination storage means to which the sent urea water is transferred by the transferring means, the storage means stores the urea water supplied from the urea water supply source and the urea water transferred via the sending means, the transfer means, and the urea water supply means; The urea water transfer system is characterized in that the control means controls the urea water supply means, the storage means, the sending means and the transfer means so as to send urea water from the source storage means and transfer urea water to the destination storage means based on settings of the source storage means and the destination storage means.

2. In the control means, 2. The urea water transfer system according to claim 1, wherein the source storage means and the destination storage means are the same.

3. In the control means, The sending source storage means to be set and the transfer destination storage means to be set are partially or entirely different from each other, 2. The urea water transfer system according to claim 1, wherein the urea water stored in the source storage means and the destination storage means have two or more concentrations.

4. 4. The urea water transfer system according to claim 3, wherein the destination storage means includes the storage means in which no urea water is stored.

5. 2. The urea water transfer system according to claim 1, wherein the urea water supply source is a urea water production system that produces urea water by mixing raw water and urea.

6. The urea water producing system comprises: a mixing means for mixing raw water and urea and dissolving the urea in the raw water to produce urea water; a raw water supply means having a heating device for heating the raw water and supplying the raw water heated by the heating device to the mixing means; a urea supplying means for supplying the urea to the mixing means; 6. The urea water transfer system according to claim 5, further comprising: a control means for controlling at least one of the raw water supply means and the urea supply means.

7. 7. A method for transferring urea water stored in the storage means, using the urea water transfer system according to claim 1.

8. 7. A method for producing urea water, comprising: transferring urea water stored in said storage means, using the urea water transfer system according to claim 1, to produce urea water of a predetermined concentration.

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