Steam humidity adjustment system

Abstract

To provide a vapor wetness adjustment system which can properly adjust wetness, and can effectively utilize drain to be discharged.SOLUTION: Flash vapor produced by a flash tank 2 is imparted to an air / liquid separator 4, and vapor and drain are separated from each other. The separated drain is imparted to the flash tank 2 as reflux drain, and is made to recirculate for effective utilization. Also, the separate vapor is imparted to a moisner 6 as mixing vapor, and the moisner 6 mixes the vapor and mixing drain, and injects derived vapor. The wetness of the derived vapor is detected by a humidity sensor 15, and a controller 8 controls a steam valve 11 and a drain valve 12 on the basis of the detected wetness, and adjusts the wetness of the derived vapor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The steam humidity adjustment system according to the present application relates to a technique for obtaining steam with a desired humidity.

Background Art

[0002] The steam humidity adjustment system is used, for example, for equipment for humidifying a target product. As the steam humidity adjustment system, there are techniques disclosed in Patent Document 1 and Patent Document 2 described below.

[0003] First, in the cardboard sheet paper dust adhesion prevention device disclosed in Patent Document 1, a plurality of hot plates 2a, 2b, 2c using superheated steam as a heat source are linearly arranged, and a canvas belt 3 circulates so as to face the upper surfaces of these hot plates 2a, 2b, 2c. Then, a liner paper 6b is overlapped and inserted on the glued corrugated paper 6a between the hot plates 2a, 2b, 2c, and the corrugated paper 6a and the liner paper 6b are adhered while heating.

[0004] The superheated steam used as the heat source of the hot plates 2a, 2b, 2c is taken into the flash tank 12 and subjected to gas-liquid separation. Then, the steam extracted from this flash tank 12 is sprayed onto the canvas belt 3 through the nozzle 14. Further, the steam extracted from the flash tank 12 is directly sprayed onto the liner paper 8 from the gaps between the plurality of hot plates 2a, 2b, 2c through the nozzles 13a, 13b. Thereby, the generation of static electricity in the manufacturing process of the cardboard sheet is suppressed, and it is possible to prevent paper dust from adhering to the cardboard sheet due to static electricity and reduce printing defects.

[0005] Next, in the steam quality control device disclosed in Patent Document 2, the steam transferred through the steam pipeline 1 is decompressed to a predetermined pressure by the pressure control valve 2 and supplied to the gas-liquid separator 3. Then, the condensed water mixed in the steam is separated in the gas-liquid separator 3 and discharged to the outside of the system from the steam trap 10 and the discharge pipe 11.

[0006] The steam from which the condensed water has been removed is supplied to the heating and cooling means 6 via the steam flow meter 5, and in the heating and cooling means 6, a mixture of high-pressure and high-temperature steam and cooling water is injected into the steam. As a result, the steam is heated or cooled as required, and steam with a desired humidity or the like can be obtained.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0008] In the technique disclosed in the aforementioned Patent Document 1, the steam extracted from the flash tank 12 is sprayed onto the object through the nozzles 14, 13a, and 13b. For this reason, the dryness of the sprayed steam cannot be appropriately adjusted.

[0009] On the other hand, in the technique disclosed in Patent Document 2, the gas-liquid separator 3 separates the condensed water from the steam and discharges it out of the system through the discharge pipe 11, and supplies the steam from which the condensed water has been separated to the heating and cooling means 6. Then, by injecting a mixture of high-pressure and high-temperature steam and cooling water in the heating and cooling means 6, steam with a desired humidity or the like can be obtained. However, since the condensed water separated by the gas-liquid separator 3 is discharged out of the system, effective utilization of the condensed water cannot be achieved.

[0010] Therefore, an object of the steam humidity adjustment system according to the present application is to provide a steam humidity adjustment system that can appropriately adjust the humidity and further effectively utilize the drained water to be discharged.

Means for Solving the Problems

[0011] The steam humidity adjustment system according to the present application Re-evaporation means for taking in condensed water generated by condensation of steam and re-evaporating the condensed water to generate re-evaporated steam, Separation means for taking in the re-evaporated steam and separating the re-evaporated steam into separated steam and separated water, Return flow means for supplying the separated water to the re-evaporation means for return flow, Mixing means for taking in the separated steam and mixing it with a humidity adjustment fluid to generate final steam, Detection means for detecting the humidity of the final steam and outputting a detection signal, Control means for controlling the degree of mixing of the separated steam and the humidity adjustment fluid in the mixing means based on the detection signal to generate final steam having a desired humidity, It is characterized by comprising the above.

Advantages of the Invention

[0012] In the steam humidity adjustment system according to the present application, the detection means detects the humidity of the final steam and outputs a detection signal, and the control means controls the degree of mixing of the separated steam and the humidity adjustment fluid in the mixing means based on this detection signal to generate final steam having a desired humidity. Therefore, the humidity of the final steam can be appropriately adjusted.

[0013] Also, the return flow means supplies the separated water to the re-evaporation means for return flow. Therefore, the separated water separated by the separation means can be effectively utilized.

Brief Description of the Drawings

[0014]

Figure 1

Modes for Carrying Out the Invention

[0015] [Term Explanation in the Embodiment] The main terms shown in the embodiment respectively correspond to the following elements of the steam humidity adjustment system according to the present application.

[0016] Flash tank 2... Re-evaporation means Gas-liquid separator 4... Separation means Moistener 6... Mixing means Controller 8... Control means Humidity sensor 15... Detection means Return line 61... Return means Drain... Condensate Flash steam... Re-evaporated steam Steam for mixing... Separated steam Drain for mixing... Humidity adjustment fluid Return drain... Separated water Derived steam... Final steam

[0017] [First Embodiment] The first embodiment of the steam humidity adjustment system according to the present application will be described with reference to FIG. 1. FIG. 1 is a block diagram of the steam humidity adjustment system in this embodiment.

[0018] In industrial plants and the like, a piping system for transferring steam generated by a boiler may be installed, and the steam is sent to each device through this piping system and used as a heat source or the like. The steam condenses due to heat dissipation during transfer or heat exchange in each device, and drain (condensate) is generated in the piping system.

[0019] Such drain flows into the transfer pipe 51 shown in FIG. 1, and a steam trap 20 is provided in this transfer pipe 51. The steam trap 20 is an automatic valve that operates to appropriately discharge the drain outside the pipe and prevent steam from leaking as much as possible.

[0020] There are various structures for steam traps. The float type trap has a hollow float built into the valve chamber. And normally, this float closes the drain outlet formed near the bottom of the valve chamber (closed valve state) and blocks the passage of drain through the valve chamber. On the other hand, when drain flows into the valve chamber, during operation, this float floats up (open valve state) as the drain accumulates, and automatically opens the drain outlet to open the valve.

[0021] When the drain outlet is opened, the passage of the drain through the valve chamber is allowed, and the drain staying in the valve chamber is automatically discharged from the drain outlet under the influence of the high pressure in the pipe. After the drain is discharged, the float descends and resets, closing the drain outlet again. Note that although the float repeats ascending and descending to discharge the drain in this way, since the drain outlet is always submerged in the drain, no steam leakage occurs from the steam trap.

[0022] The drain discharged by the steam trap 20 is introduced into the flash tank 2 and stored therein. The flash tank 2 re-evaporates the drain introduced by the pressure difference to generate flash steam (also referred to as re-evaporated steam). Note that in the flash tank 2, the surplus drain exceeding a predetermined level is discharged to the outside through the overflow pipe 53.

[0023] The flash steam generated in the flash tank 2 is supplied to the gas-liquid separator 4 through the flash steam pipe 55. The gas-liquid separator 4 is provided with, for example, swirling blades inside (not shown), swirls the introduced flash steam, and while discharging the moisture (drain) with a large mass to the outer periphery by centrifugal force, allows the steam with a small mass to flow out from the central part. Thereby, the steam as a gas and the drain as a liquid can be separated.

[0024] In this embodiment, the drain separated from the flash steam in the gas-liquid separator 4 is supplied to the flash tank 2 as the reflux drain through the reflux path 61 and refluxes. Thereby, the drain separated by the gas-liquid separator 4 can be effectively utilized.

[0025] The steam separated from the flash steam in the gas-liquid separator 4 is taken into the Moisner 6 as mixing steam through a steam pipe 59. A steam valve 11 is provided in the steam pipe 59 immediately before the Moisner 6, and opens and closes in response to a valve open signal or valve close signal from the controller 8, thereby finely adjusting the opening of the steam valve 11.

[0026] In addition, a drain pipe 57 is connected to the above-mentioned flash tank 2, and the drain stored in the flash tank 2 is taken into the Moisner 6 through this drain pipe 57 as a drain to be mixed. A pump 25 is provided in the drain pipe 57, and the drain to be mixed is pressure-fed from the flash tank 2 to the Moisner 6. In addition, a drain valve 12 is provided in the drain pipe 57 immediately before the Moisner 6, and opens and closes in accordance with a valve open signal or valve close signal from the controller 8, finely adjusting the opening of the drain valve 12.

[0027] In this way, the mixing steam and the mixing drain are taken into the moisture collector 6. The moisture collector 6 mixes the mixing steam and the mixing drain and injects this as outlet steam to the outside through the outlet passage 63. The injected outlet steam is used, for example, to humidify the target product.

[0028] In this embodiment, a humidity sensor 15 is provided in the outlet path 63, which detects the wetness of the outlet steam and outputs a detection signal. This detection signal is provided to the controller 8, which grasps the current wetness of the outlet steam as a "detected wetness". The controller 8 also stores a desired wetness for the outlet steam as a "set wetness" in advance in an internal memory (not shown). For this reason, the controller 8 compares the "set wetness" with the "detected wetness" and controls the openings of the steam valve 11 and the drain valve 12 so that the "detected wetness" matches the "set wetness".

[0029] That is, when the "detected humidity" is higher than the "set humidity", the controller 8 outputs either or both of an opening valve signal toward the steam valve 11 or a closing valve signal toward the drain valve 12, and adjusts so that the mixing amount of steam in the moisturizer 6 becomes relatively larger than the mixing amount of the drain. As a result, the "detected humidity" is adjusted to be lower, and the "detected humidity" can be made to match the "set humidity".

[0030] Conversely, when the "detected humidity" is lower than the "set humidity", the controller 8 outputs either or both of a closing valve signal toward the steam valve 11 or an opening valve signal toward the drain valve 12, and adjusts so that the mixing amount of the drain in the moisturizer 6 becomes relatively larger than the mixing amount of the steam. As a result, the "detected humidity" is adjusted to be higher, and the "detected humidity" can be made to match the "set humidity".

[0031] As described above, the controller 8 compares the "set humidity" with the "detected humidity" and controls the steam valve 11 and the drain valve 12 so that the "detected humidity" matches the "set humidity", so that the humidity of the derived steam can be adjusted to the "set humidity", and derived steam with an appropriate humidity can be obtained.

[0032] [Other Embodiments] In the above-described embodiment, the flash tank 2 is exemplified as the re-evaporation means, but other configurations can be used as long as they re-evaporate the drain to generate re-evaporated steam. Also, in the above-described embodiment, the gas-liquid separator 4 is exemplified as the separation means, but other configurations can be used as long as they take in the re-evaporated steam and separate it into steam (separated steam) and drain (separated water).

[0033] Furthermore, in the above-described embodiment, the return passage 61 is exemplified as the return means, but other shapes and structures may be adopted as long as they supply the drain (separated water) to the re-evaporation means (such as the flash tank 2) and return it.

[0034] In the above-described embodiment, the moisner 6 is exemplified as the mixing means. However, other configurations may be adopted as long as they take in steam (separated steam) and drain (humidity adjustment fluid) and generate steam (final steam) by mixing the two.

Explanation of Signs

[0035] 2: Flash tank 4: Gas-liquid separator 6: Moisner 8: Controller 15: Humidity sensor 61: Return path

Claims

1. A re-evaporation means for taking in condensed water generated by condensation of steam and re-evaporating the condensed water to generate re-evaporated steam; A separation means for taking in the re-evaporated steam and separating the re-evaporated steam into separated steam and separated water; A reflux means for supplying the separated water to the re-evaporation means for reflux; A mixing means for taking in the separated steam and mixing it with a humidity adjustment fluid to generate final steam; A detection means for detecting the humidity of the final steam and outputting a detection signal; A control means for controlling the degree of mixing of the separated steam and the humidity adjustment fluid in the mixing means based on the detection signal to generate final steam having a desired humidity; A steam humidity adjustment system, characterized by comprising the above.

2. In the steam humidity adjustment system according to Claim 1, the humidity adjustment fluid is the condensed water taken in by the re-evaporation means and the separated water supplied by the reflux means to the re-evaporation means; A steam humidity adjustment system, characterized by this.

Images