Nitrate nitrogen-containing water production apparatus, liquid fertilizer production apparatus, and nitrate nitrogen concentration control apparatus

Abstract

To provide a nitrate nitrogen-containing water production apparatus which produces water containing nitrate nitrogen from water and atmospheric nitrogen and adds fine bubbles of air by shock waves thereto so as to increase the amount of inorganic ions containing nitrate nitrogen absorbed, and also has a nitrate concentration meter, a pressure gauge, and a flow meter to control pressure, plasma intensity, and flow rate, and to make the nitrate nitrogen concentration of the produced hydroponic water suitable for growing plants.SOLUTION: A nitrate nitrogen-containing water production apparatus includes a water transport section for conveying water, a bubble generating section for generating bubbles in the water, a plasma generating section located downstream of the bubble generating section for irradiating the bubbles generated by the bubble generating section with plasma, a gas introducing section located upstream of the plasma generating section for introducing gas into the water, and a shock wave generating section located downstream of the plasma generating section for adding shock waves to the water.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a nitric acid nitrogen-containing water production apparatus, a liquid fertilizer production apparatus, and a nitric acid nitrogen concentration control apparatus.

Background Art

[0002] The elements necessary for plant growth are light energy, water, carbon dioxide, oxygen, temperature, and nutrients. In open-field cultivation where vegetables are grown in fields, etc., plants grow while utilizing the nutrients in the soil by supplementing water and nutrients to some extent. However, in hydroponics, water is of course necessary, and nutrients must be artificially supplied with all the elements necessary for plant growth in order for plants to grow. Those nutrients are nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur, which are required in large amounts, and iron, manganese, boron, copper, zinc, molybdenum, chlorine, etc., which are required in trace amounts.

[0003] Nitrogen is necessary for plants as a component of proteins that make up protoplasm, enzyme proteins, and various other physiologically important nitrogen-containing compounds. When plants are deficient in nitrogen, the proteins in old leaves are decomposed, and the nitrogen is transferred to new leaves and reused, so the withering of lower leaves occurs earlier, and crop growth becomes poor. Plants grow by absorbing all the nutrients in the form of ions whether organic fertilizers or inorganic fertilizers are applied. Regarding nitrogen, plants absorb inorganic nitrogen as nitrate, but in a reducing environment, they absorb it as ammonium ions.

[0004] In Patent Document 1, there is provided a nitrogen source supply device that supplies water containing a nitrogen source, and a discharge unit that discharges (for example, streamer discharge) in the supplied water when the water containing the nitrogen source is supplied from the nitrogen source supply device. A water quality control device, a plant cultivation system using the same, and a plant cultivation method are disclosed.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in conventional water quality control devices, plant cultivation systems using the same, and plant cultivation methods, even if the decomposition of nitrogen, organic nitrogen, and NH4 ions present in water is promoted and inorganic nitrate ions and nitrite ions are generated, there has been a problem as to whether the negative ions, nitrate ions and nitrite ions, can be effectively delivered to the cell wall of roots that also have a negative charge. + Even if the decomposition of nitrogen, organic nitrogen, and NH4 ions present in water is promoted and inorganic nitrate ions and nitrite ions are generated, there has been a problem as to whether the negative ions, nitrate ions and nitrite ions, can be effectively delivered to the cell wall of roots that also have a negative charge.

[0007] The present invention has been made to solve the above problems, and an object thereof is to produce water containing nitrate nitrogen from water and nitrogen in the atmosphere, and increase the absorption amount of inorganic ions containing nitrate nitrogen by adding fine bubbles of air by shock waves. Another object is to provide a hydroponic water production device equipped with a nitrate concentration meter, a pressure gauge, and a flow meter, which controls the pressure, plasma intensity, and flow rate to make the nitrate nitrogen concentration of the produced hydroponic water suitable for plant growth. Furthermore, in addition to radical generation by plasma, an improvement in the sterilization effect by shock waves can also be expected.

Means for Solving the Problems

[0008] In order to solve the above problems, the present invention employs the following means. That is, a nitrate nitrogen-containing water production device according to an embodiment of the present invention includes a water transport unit that transports water, a bubble generation unit that generates bubbles in the water, a plasma generation unit that is disposed downstream of the bubble generation unit and irradiates the bubbles generated by the bubble generation unit with plasma, a gas introduction unit that is disposed upstream of the plasma generation unit and introduces gas into the water, and a shock wave generation unit that is disposed downstream of the plasma generation unit and applies a shock wave to the water, and is characterized by comprising these components.

[0009] According to this embodiment, by irradiating bubbles containing nitrogen in the atmosphere with plasma in water, water containing nitrate nitrogen is produced, and by adding fine bubbles of air by a shock wave thereto, the absorption amount of inorganic ions containing nitrate nitrogen can be increased, and an apparatus for producing water containing nitrate nitrogen can be provided.

[0010] Furthermore, as an embodiment of the present invention, it is characterized by comprising a first pressure gauge for measuring the pressure on the upstream side of the shock wave generating section, a second pressure gauge for measuring the pressure on the downstream side of the shock wave generating section, and a flow meter for measuring the flow rate. Thereby, by comprising a nitric acid concentration meter, a pressure gauge, and a flow meter, controlling the pressure, plasma intensity, and flow rate, the nitrate nitrogen concentration of the water for hydroponics to be produced can be made suitable for plant growth.

[0011] A liquid fertilizer manufacturing apparatus according to an embodiment of the present invention includes a water transport section for transporting water, a gas introduction section for introducing gas into the water, and a bubble generation section for generating bubbles in the water. It is characterized by comprising a plasma generation section for irradiating the bubbles generated by the bubble generation section with plasma, and a shock wave generation section for applying a shock wave to the water. Thereby, it is possible to provide a liquid fertilizer manufacturing apparatus that can produce water containing nitrate nitrogen from water and nitrogen in the atmosphere, and increase the absorption amount of inorganic ions containing nitrate nitrogen by adding fine bubbles of air by a shock wave thereto.

[0012] A nitrate nitrogen concentration control apparatus according to an embodiment of the present invention controls the nitrate nitrogen concentration based on one or more measured values among the flow rate or pressure of water, the amount of gas introduced by the gas introduction section, the diameter or amount of bubbles generated by the bubble generation section, and the plasma intensity generated by the plasma generation section, in a liquid fertilizer manufacturing system including a water transport section for transporting water, a gas introduction section for introducing gas into the water, a bubble generation section for generating bubbles in the water, a plasma generation section for irradiating the bubbles generated by the bubble generation section with plasma, and a shock wave generation section for applying a shock wave to the water. Accordingly, it is possible to control the operation while feeding back each measured value of the water flow rate or pressure, the amount of gas, the diameter or amount of bubbles, and the plasma intensity.

Advantages of the Invention

[0013] According to the present invention, it is possible to provide a nitric acid nitrogen-containing water production apparatus that produces water containing nitric acid nitrogen from water and nitrogen in the atmosphere and increases the absorption amount of inorganic ions containing nitric acid nitrogen by adding fine bubbles of air by a shock wave. Further, it is possible to provide a nitric acid nitrogen concentration control device including a nitric acid concentration meter, a pressure gauge, and a flow meter, controlling the pressure, plasma intensity, and flow rate, and making the nitric acid nitrogen concentration of the water for hydroponics to be suitable for plant growth.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0015] Hereinafter, embodiments of a nitric acid nitrogen-containing water production apparatus and a nitric acid nitrogen-containing water production method according to the present invention will be described in detail with reference to the drawings. Note that the nitric acid nitrogen-containing water production apparatus and the nitric acid nitrogen-containing water production method described in the embodiments are merely examples for explaining the nitric acid nitrogen-containing water production apparatus and the nitric acid nitrogen-containing water production method according to the present invention. The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the object of the present invention.

[0016] In an embodiment of the present invention, the nitric acid nitrogen-containing water may be an aqueous solution suitable for hydroponics. For example, it can be prepared using tap water, purified water, ion-exchanged water, distilled water, or the like. In terms of increasing the electrical conductivity of the nitric acid nitrogen-containing water according to the embodiment of the present invention, it is preferably an aqueous solution containing an electrolyte described later.

[0017] The nitric acid nitrogen-containing water in the embodiment of the present invention may be a liquid (including a liquid in which a gas is dissolved) or a gas-liquid mixed-phase fluid in which bubbles are mixed into the liquid.

[0018] 〔First Embodiment〕 Hereinafter, the nitric acid nitrogen-containing water production apparatus 10a according to the first embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic explanatory view of the nitric acid nitrogen-containing water production apparatus according to the first embodiment of the present invention. In hydroponics, a solution in which phosphorus, potassium, and nitrogen fertilizers that are nutrients for plants are dissolved in cultivation water is used. The nitrogen fertilizer is ionized in the solution, and nitrate nitrogen and ammonia nitrogen mainly exist in the solution. The nitric acid nitrogen-containing water production apparatuses 10a, 10b, and 10c in the embodiment of the present invention produce treated water 31 containing nitrate nitrogen by particularly utilizing nitrogen in the air. As a method for supplying the treated water 31, there are a method of flowing the surplus of the supplied treated water 31 directly onto the ground without recovery (overflow method) and a method of recovering the surplus water, adjusting the components, and supplying it again (circulation method). The nitric acid nitrogen-containing water apparatus in the embodiment of the present invention is applicable to either method.

[0019] As shown in Fig. 1, a nitric acid nitrogen-containing water production apparatus 10a according to the first embodiment includes a pump 14 as a water transport section, a bubble generation section 11, a plasma generation section 12, a shock wave generation section 13, and a gas introduction section 15. The pump 14 is placed in a water storage tank 41 that holds the water to be treated 31. Using the water to be treated 31 as raw water 21, it is caused to flow into the bubble generation section 11 through piping or the like. The water to be treated 31 that has flowed out of the bubble generation section 11 further flows into the shock wave generation section 13. The water to be treated 31 that has flowed out of the shock wave generation section 13 may return to the water storage tank 41 as the raw water 21, or may be supplied as nitric acid nitrogen-containing water to a hydroponic cultivation facility (not shown).

[0020] (Water transport section) As the water transport section, there is a pump 14. The pump 14 is an element that has the effect of causing the raw water 21 to flow through the nitric acid nitrogen-containing water production apparatus 10a by performing mechanical work on the water to be treated 31 held in the water storage tank 41 and giving the water to be treated 31 energy of position, velocity, and pressure. Pumps widely used in apparatuses such as this embodiment include centrifugal pumps, reciprocating pumps, and rotary pumps. As a method of controlling the flow rate of the pump, there is a method of controlling the rotational speed of the pump using an inverter. The pump 14 as the water transport section of this embodiment also has the effect of changing the capabilities of the gas generation section 11, the shock wave generation section 13, and the gas introduction section 15 by varying the flow velocity of the raw water 21 within the nitric acid nitrogen-containing water production apparatus 10a.

[0021] (Bubble generation section) As the bubble generation mechanism of the bubble generation section 11, there are a swirling flow method, a static mixer method, an ejector type, a venturi type, a pressure dissolution method, a cavitation method, and the like. The swirling flow method is a method of crushing bubbles by a high-speed swirling flow and generating fine bubbles in the liquid. The static mixer method is a method of pumping gas and liquid together into a flow path and generating fine bubbles by shearing the bubbles with obstacles or protrusions. It is possible to continuously generate fine bubbles, and by further circulating them, the fine bubble concentration and bubble diameter can be made uniform. The ejector method is a method of rapidly changing the pressure in the flow path to crush bubbles finely. It creates a pressure difference by injection from a nozzle inside. The Venturi method is also a method of rapidly changing the pressure in the flow path to crush bubbles finely, but by constricting the flow of the fluid, it increases the flow velocity and generates a lower pressure compared to the low-velocity part. The pressure dissolution method pressurizes the gas-liquid in the tank using a pump and dissolves the gas in the liquid in a supersaturated state. Then, it decompresses to generate fine bubbles in the liquid. The cavitation method is a method that utilizes the phenomenon called cavitation, which is also known as the cavity phenomenon. The cavity phenomenon is the phenomenon where a cavity is formed near a place where the cross-section or direction of flowing water changes, causing a vortex. By utilizing this principle, the dissolved gas contained in the liquid is precipitated to generate fine bubbles. Regardless of the method, the adjustment of the capacity of the bubble generation unit 11 is made by adjusting the flow rate of the raw water 21 by the pump 14.

[0022] The bubbles generated in the bubble generation unit 11 are for more effectively generating plasma by dispersing the gas phase in the raw water 21 or the water to be treated 31. During the passage of the raw water 21 or the water to be treated 31, the gas phase by the bubbles is continuously formed, enabling plasma generation at a low breakdown voltage. As a result, the reaction of radicals near the plasma is promoted, and the generation of nitrate nitrogen proceeds.

[0023] (Plasma generation unit) The plasma generation unit 12 in the present embodiment has a function of generating plasma in water and using the molecules in the gas phase of the raw water 21 that has become a gas-liquid mixed phase as active species. When a voltage is applied to an electrode placed in water with a short pulse width and a high repetition frequency, plasma can be stably generated in the water by applying a breakdown voltage that is relatively low for the gas phase. The plasma generation technology in water is a technology for generating plasma by imparting high-density energy to the water. It has the characteristics of a faster reaction than vacuum plasma or reduced-pressure plasma and the ability to utilize solution reactions. The simplest plasma generation device is a method in which electrodes are opposed and power is supplied thereto. The plasma generation unit 12 in the present embodiment is provided such that one anode and one cathode face each other with a gap therebetween, and is placed in the flow path of the raw water 21 (not shown). By applying a voltage between the anode and the cathode, plasma is generated in the gap between the anode and the cathode. This gap becomes the plasma generation region.

[0024] The underwater plasma generated in the plasma generation unit 12 can form active species such as radicals, electrons, and ions having a positive or negative potential by partially or completely ionizing the molecules constituting the gas (gas phase) that is generated as bubbles in the water by applying a voltage to the anode and cathode immersed in the raw water 21. The air introduced from the gas introduction unit 15 into the raw water 21 contains nitrogen as a gas. When water containing a nitrogen source is continuously brought into contact with the plasma, the decomposition of nitrogen, organic nitrogen, and NH4 + ions is promoted, and inorganic nitrate ions and nitrite ions are generated.

[0025] The plasma generation unit 12 in the present embodiment may utilize atmospheric pressure plasma. When using atmospheric pressure plasma, plasma may be generated in advance under atmospheric pressure and sent into the flow path from the regression introduction unit 15. In this case, if a process gas containing nitrogen is used, nitrogen oxide radicals are generated in the same manner as underwater plasma and are effective for plant growth.

[0026] When nitrogen components are contained in the bubbles generated in the bubble generation unit 11, nitrogen oxide radicals are generated by the effect of underwater plasma. Nitrate nitrogen (nitrate radical) is useful for plant growth. OH radicals generated from water molecules by plasma are highly reactive and also have the effect of decomposing water-soluble organic substances. Due to this effect, underwater plasma also has a sterilizing effect. Also, the type of plasma is not limited to the plasma generated in water, and the plasma generated in the air can also be sucked into the flow path.

[0027] (Shock wave generation unit) A shock wave is generated when an object moves at high speed and pushes aside the gas or liquid in front of it, forming a region with high density and high pressure, which is transmitted as a wave. When the raw water 21 is, for example, a gas-liquid two-phase flow, a shock wave is generated when the flow velocity exceeds the wave propagation velocity in the fluid of the gas-liquid two-phase mixture. Specifically, by rapidly narrowing the pipe diameter of the raw water 21 system, the flow velocity at the narrowed portion increases, thereby generating a shock wave. Also, by placing an object having, for example, the cross-sectional shape of a wing in the pipe of the raw water 21 system while reducing the cross-sectional area of the pipe of the raw water 21 system without obstructing the flow of the raw water 21, a shock wave can also be generated. The adjustment of the ability of the shock wave generation unit 13 is made by adjusting the flow velocity of the raw water 21 by the pump 14.

[0028] The shock wave generation unit 13 has a function of generating a shock wave in the raw water 21 and generating, for example, ultra-fine bubbles in the raw water 21. Fine bubbles are divided into two types: ultra-fine bubbles and microbubbles. Since fine bubbles rise very slowly in water, the gas that once becomes a fine bubble is held in the water for a certain period of time or more. In particular, ultrafine bubbles remain for more than several weeks, and their behavior becomes Brownian motion. As a result, oxygen and nitrogen contained in the atmosphere can be retained in water over a long period of time, which also has the effect of ensuring the time for oxygen and nitrogen to dissolve in water.

[0029] The bubbles generated in the shock wave generation unit 13 are preferably microbubbles or ultrafine bubbles that are retained in the raw water 21 and the water to be treated 31 for a long time. In particular, when the bubbles are ultrafine bubbles, since almost no buoyancy acts on the bubbles, the bubble state is retained for a long time. According to this configuration, since the bubbles are retained for a long time, the active species contained in the raw water 21 and the water to be treated 31 can be maintained for a long time. By introducing fine bubbles into the nitrate nitrogen-containing water, it is expected to promote plant growth, increase yield, and improve quality. In water, the surface of the fine bubble is negatively charged. The negatively charged fine bubble attracts positively charged ions. In addition, the fine bubbles gather at the roots of plants and promote drainage. This is because the roots of plants secrete root acid and are positively charged. In addition, since oxygen is also dissolved in the bubbles in addition to nitrogen, it also has the effect of supplying oxygen to the roots of plants.

[0030] (Gas introduction part) The gas introduction unit 15 is a device having a function of introducing air into the system of the raw water 21, but it may also be a device that directly introduces a gas intended to be introduced into the raw water 21, such as nitrogen gas. The blowing of air by the gas introduction unit 15 may be by a blower, but if it is by an aspirator, the power source is not required and it is more energy-saving. An aspirator is, for example, a mechanism that narrows the pipe diameter of the system of the raw water 21 where the gas introduction unit 15 is located and then expands it, creating a decompressed state by the Venturi effect to introduce air into the system of the raw water 21. The adjustment of the capacity of the gas introduction unit 15 is made by adjusting the flow rate of the raw water 21 by the pump 14.

[0031] The air introduced from the gas introduction part 15 into the raw water 21 system becomes bubbles and mixes into the raw water 21. The nitrogen contained in the mixed air dissolves in the raw water 21 with a predetermined solubility, but it takes a certain amount of time. The raw water 21 in the gas-liquid mixed phase state with air mixed in is formed into ultra-fine bubbles by the shock wave generated by the action of the shock wave generation part 13.

[0032] By introducing nitrogen in the atmosphere into the raw water 21, water containing nitrate nitrogen can be produced. By adding fine bubbles of air by the shock wave to this, the absorption amount of inorganic ions containing nitrate nitrogen by plants can be increased. In addition, in addition to radicals by plasma, an amplification of the bactericidal effect by the shock wave is also expected. Further, by supplying the treated water 31 rich in dissolved oxygen to plants, oxygen can be efficiently supplied to the roots of the plants, so that the roots of the plants can be activated, and nutrients can be attracted to the vicinity of the roots and absorption can be promoted by utilizing the characteristics of the fine bubbles. As a configuration in which the gas introduction part 15 is arranged upstream of the plasma generation part 12, it is also possible to arrange the gas introduction part 15 downstream of the bubble generation part 11 and upstream of the plasma generation part 12. However, from the viewpoint of promoting the dissolution of nitrogen in the raw water 21, it is more efficient to generate bubbles after introducing the gas serving as the nitrogen source.

[0033] 〔Second Embodiment〕 Hereinafter, the cold nitric acid nitrogen-containing water production apparatus 10b according to the second embodiment will be described with reference to FIG. 2. FIG. 2 is a schematic explanatory view of the nitric acid nitrogen-containing water production apparatus according to the second embodiment of the present invention. The nitric acid nitrogen-containing water production apparatus 10b of the second embodiment includes a pump 14 which is a water transport part, a bubble generation part 11, a plasma generation part 12, a shock wave generation part 13, and a gas introduction part 15, similarly to the nitric acid nitrogen-containing water production apparatus 10a. Since other configurations are the same as those of the nitric acid nitrogen-containing water production apparatus 10a of the first embodiment, the same reference numerals are given in the drawings and the description is omitted. The same applies to the description from the third embodiment onwards.

[0034] The nitric acid nitrogen-containing water production apparatus 10b of the second embodiment includes a gas introduction unit 15 on the downstream side of the plasma generation unit 12 and a shock wave generation unit 13 on the downstream side of the gas introduction unit 15 when viewed from the flow direction of the raw water 21. In the first embodiment, the gas introduction unit 15 was provided upstream of the plasma generation unit 12. However, the gas introduction unit 15 may be arranged downstream of the plasma generation unit 12. In this case, the nitrogen present in the bubble generation unit 11 can be plasma-treated by the plasma generation unit. Furthermore, by providing the gas introduction unit 15 downstream of the plasma generation unit 12, there is an advantage that the control range of the bubble particle size and the concentration distribution of the nitric acid concentration can be widened. Furthermore, the gas introduction unit 15 may be arranged upstream and downstream of the plasma generation unit 12 respectively. In this case, not only the generation of nitrate nitrogen becomes effective, but also the control range of the particle shape of the valve and the winning concentration can be widened.

[0035] 〔Third Embodiment〕 Hereinafter, the cold nitric acid nitrogen-containing water production apparatus 10c according to the third embodiment will be described with reference to FIG. 3. FIG. 3 is a schematic explanatory view of the nitric acid nitrogen-containing water production apparatus according to the third embodiment of the present invention.

[0036] The nitric acid nitrogen-containing water production apparatus 10c includes a nitric acid concentration meter 55 for measuring the nitric acid concentration of the water to be treated 31, a first pressure meter 53a for measuring the pressure on the upstream side of the shock wave generation unit 13, a flow meter 52 for measuring the flow rate of the raw water 21 on the downstream side, and a second pressure meter 53b for measuring the pressure, and maintains the nitric acid concentration at a predetermined value or more by controlling the plasma intensity of the plasma generation unit 12, the flow rate, and the pressure of the raw water 21. By measuring the pressures on the upstream side and the downstream side of the shock wave generation unit 13, it is possible to monitor whether the necessary shock wave can be applied to the raw water 21. If the indicated value of the first pressure meter 53a < the indicated value of the second pressure meter 53b holds, it is considered that a shock wave is generated. In addition, a sensor (not shown) capable of measuring the EC (electrical conductivity) of the water to be treated 31 is provided, and by measuring this, it becomes possible to more accurately measure the content of nitric acid nitrogen and control the generation time of the necessary plasma. Since the other configurations are the same as those of the nitric acid nitrogen-containing water production apparatus 10a of the first embodiment, the same reference numerals are given in the drawings and the description thereof is omitted.

[0037] By providing the gas introduction part 15 on the upstream side of the plasma generation part 12, raw water 21 immediately after taking in the atmosphere containing nitrogen can be continuously brought into contact with the plasma, and there is an effect that high reaction efficiency can be obtained.

[0038] 〔Other Embodiments〕 Hereinafter, the control range of the nitric acid nitrogen-containing water production apparatus according to other embodiments will be described with reference to FIG. 4. FIG. 4 is a schematic explanatory view showing the control range of the nitric acid nitrogen-containing water production apparatus of the third embodiment of the present invention. Since the configuration is the same as that of the nitric acid nitrogen-containing water production apparatus 10c of the third embodiment, the same reference numerals are given in the drawings and the description thereof is omitted.

[0039] FIG. 5 is a functional block diagram of the control unit of the nitric acid nitrogen-containing water production apparatus according to the embodiment of the present invention. The control unit 51 includes a measurement value reception unit 511, a measurement value storage unit 512, an arithmetic unit 513, a control unit 514, and a control signal transmission unit 515. The measurement value reception unit 511 receives, in the control unit 51, the measurement value of the nitric acid concentration meter 55, the measurement value of the flow meter 52, and the measurement values of the first pressure meter 53a and the second pressure meter 53b. The measurement value storage unit 512 stores, as data, the respective measurement values of the nitric acid concentration meter 55, the flow meter 52, the first pressure meter 53a, and the second pressure meter 53b received by the measurement value reception unit 511. Also, the numerical values of the initial output W0 [W] of the pump 14, which is a fluid transport unit, the initial voltage P0 [V] and the initial frequency F0 [Hz] of the plasma generation unit 12, and the initial value Xm of the pH, which are shown in the flowchart of the control operation described later, are also stored as data. The arithmetic unit 513 retrieves and calculates the data stored in the measurement value storage unit 512 at any time, and outputs the data of the calculation result to the control unit 514. Based on the calculation result data output from the calculation unit 513 and the comparison value for control operation, the control unit 514 outputs control data for the pump 14, which is a fluid transport unit, and the plasma generation unit 12 to the control signal transmission unit 515. Based on the control data output from the control unit 514, the control signal transmission unit 515 transmits control signals to the pump 14, which is a fluid transport unit, and the plasma generation unit 12.

[0040] (Control Flow) Hereinafter, using FIG. 6 as an example of the configuration of the nitric acid nitrogen-containing water production apparatus 10c of the third embodiment, the control operation will be described. FIG. 6 is a flowchart of the control operation of the nitric acid nitrogen-containing water production apparatus according to the embodiment of the present invention.

[0041] By starting the pump 14, which is a fluid transport unit, with the initial output W0 [W], the control operation of the nitric acid nitrogen-containing water production apparatus 10c is started (A11). When the water transport unit 14 starts, raw water 21 flows into the nitric acid nitrogen-containing water production apparatus 10c, and the introduction of outside air from the gas introduction unit 15 also operates due to the attracting action by the flow rate of the raw water 21 (A12). At the same time, the plasma generation unit 12 also starts with the initial voltage P0 [V] and the initial frequency F0 [Hz] (A13), and its operating state is continued for t hours (A14).

[0042] After continuing the above operating state for t hours, the measured value of the nitric acid concentration of the water to be treated 31 is obtained from the nitric acid concentration meter 55 (A15). If the measured value of the nitric acid concentration exceeds 100 [mg / L], the operation of A17 is entered, and if the measured value of the nitric acid concentration is less than 100 [mg / L], the operations of B11 and C11 are entered (A16).

[0043] In the operation of A17, the measured value of the pH of the water to be treated 31 is obtained from the pH meter 57 (A17), and the determination operation of A18 is entered. In the determination operation of A18, it is determined whether the measured value of the pH is in the range exceeding Xm - 0.5 and less than Xm + 0.5. If the measured value of the pH is in the range exceeding Xm - 0.5 and less than Xm + 0.5, the operation of A19 is entered, and if not, the operation of A22 is entered (A18). When the measured pH value is not in the range above Xm - 0.5 and below Xm + 0.5, the pH is adjusted (A22), and the measured pH value of the water to be treated 31 is obtained again from the pH meter 57 (A17). The pH adjustment is performed by adding a commercially available pH adjuster to the water to be treated 31 or the like.

[0044] When the measured pH value is in the range above Xm - 0.5 and below Xm + 0.5, the plasma generation unit 12 stops, and the voltage and frequency are initialized (A19). Then, the gas introduction unit 15 is stopped (A20), the pump 14 which is the fluid transport unit stops, the output is initialized (A20), and the operation ends. The stop of the gas introduction unit 15 is performed by stopping the power supply to the motor in the case of a blower, and by closing the outside air intake in the case of an aspirator.

[0045] In the determination operation of A16, when the measured nitric acid concentration is less than 100 [mg / L], the operations of B11 and C11 are entered (A16). In B11, after measuring the current voltage P [V] of the plasma generation unit 12 (B11), the voltage of the plasma generation unit 12 is changed to P + 0.1P0 [V] (B12). P + 0.1P0 [V] means changing the voltage to a voltage increased by an amount corresponding to 0.1 times of P0 [V], that is, 10% of the initial voltage P0 [V], with respect to the current voltage P [V]. After the operation of changing the voltage of the plasma generation unit 12 in B12, the operation of A14 is entered, and the current operating state is continued for t hours (A14).

[0046] In the determination operation of A16, when the measured nitric acid concentration is less than 100 [mg / L], in addition to the above operation of B11, the operation of C11 is also entered (A16). In the operation of C11, the current output W [W] of the pump 14 which is the fluid transport unit is measured (C11). Next, the current pressure Pm [Pa] of the bubble generation unit 11 is measured by a pressure gauge (not shown) provided in the bubble generation unit 11 (C12). In the next operation of C13, based on the measured value of the current output W [W] of the pump 14 and the measured value of the current pressure Pm [Pa] of the bubble generation unit 11, the target flow rate vbm [L / min] of the bubble generation unit 11 is calculated from the performance according to the specifications of the bubble generation unit 11 (C13). Then, the current flow rate vb [L / min] of the bubble generation unit 11 is measured (C14).

[0047] In the operation of C15, it is determined whether the current flow rate vb [L / min] of the bubble generation unit 11 exceeds 0.9vbm [L / min] and is less than 1.1vbm [L / min] with respect to the target flow rate vbm [L / min] (C15). 0.9vbm [L / min] is a numerical value that is 0.9 times the target flow rate vbm [L / min], that is, 90% of the target flow rate vbm [L / min]. 1.1vbm [L / min] is a numerical value that is 1.1 times the target flow rate vbm [L / min], that is, 110% of the target flow rate vbm [L / min]. If the current flow rate vb [L / min] of the bubble generation unit 11 exceeds 0.9vbm [L / min] and is less than 1.1vbm [L / min] with respect to the target flow rate vbm [L / min], the operation proceeds to C16. If the current flow rate vb [L / min] of the bubble generation unit 11 is less than 0.9vbm [L / min] with respect to the target flow rate vbm [L / min], the operation proceeds to C20. If the current flow rate vb [L / min] of the bubble generation unit 11 exceeds 1.1vbm [L / min] with respect to the target flow rate vbm [L / min], the operation proceeds to C21.

[0048] In the operation of C20, the output of pump 14, which is a fluid transport unit, is increased to W + 0.1W0 [W], and the operation proceeds to C11. In the operation of C21, the output of pump 14, which is a fluid transport unit, is decreased to W - 0.1W0 [W], and the operation also proceeds to C11. W + 0.1W0 [W] means changing the output of pump 14 to an output increased by an output corresponding to 0.1 times the initial output W0 [W], that is, 10% of the initial output W0 [W], with respect to the current output W [W]. W - 0.1W0 [W] means changing the output of pump 14 to an output decreased by an output corresponding to 0.1 times the initial output W0 [W], that is, 10% of the initial output W0 [W], with respect to the current output W [W].

[0049] In the operation of C16, the current pressure Pi [Pa] of the shock wave generation unit 13 is measured (C16). The current pressure Pi [Pa] of the shock wave generation unit 13 is measured by the second pressure gauge 53b. Next, the operation proceeds to C17. In the operation of C17, based on the measured value of the current pressure Pi [Pa] of the shock wave generation unit 13, the target flow rate vim [L / min] of the shock wave generation unit 13 is calculated from the performance according to the specifications of the shock wave generation unit 13 (C17). Then, the current flow rate vi [L / min] of the shock wave generation unit 13 is measured (C18). The current flow rate vi [L / min] is measured by the flow meter 52.

[0050] In the operation of C19, it is determined whether the current flow rate vi [L / min] of the shock wave generation unit 13 exceeds 0.9vim [L / min] and is less than 1.1vim [L / min] with respect to the target flow rate vim [L / min] (C19). 0.9vim [L / min] is a numerical value that is 0.9 times the target flow rate vim [L / min], that is, 90% of the target flow rate vim [L / min]. 1.1vim [L / min] is a numerical value that is 1.1 times the target flow rate vim [L / min], that is, 110% of the target flow rate vim [L / min]. If the current flow rate vi [L / min] of the shock wave generation unit 13 exceeds 0.9vim [L / min] and is less than 1.1vim [L / min] with respect to the target flow rate vim [L / min], the operation proceeds to A14. When the current flow rate vi [L / min] of the shock wave generation unit 13 is lower than 0.9vim [L / min] with respect to the target flow rate vim [L / min], the operation proceeds to C20. When the current flow rate vi [L / min] of the shock wave generation unit 13 exceeds 1.1vim [L / min] with respect to the target flow rate vim [L / min], the operation proceeds to C21.

[0051] By performing the control operation as described above, in the exemplified nitric acid nitrogen-containing water production apparatus 10c, it becomes possible to perform an operation to maintain the nitric acid concentration of the water to be treated 31 exceeding 100 [mg / L].

Explanation of Signs

[0052] 10a, 10b, 10c,... nitric acid nitrogen-containing water production apparatus, 11... bubble generation unit, 12... plasma generation unit, 13... shock wave generation unit, 14... pump, 15... gas introduction unit, 21... raw water, 31... water to be treated, 41... storage tank, 51... control unit, 52... flow meter, 53a... first pressure gauge, 53b... second pressure gauge, 55... nitric acid concentration meter, 56... thermometer, 57... pH meter, 511... measurement value receiving unit, 512... measurement value storage unit, 513... calculation unit, 514... control unit, 515... control signal transmitting unit

Claims

1. A water transport section for transporting water, A bubble generation section for generating bubbles in the water, A plasma generation section disposed downstream of the bubble generation section for irradiating the bubbles generated by the bubble generation section with plasma, A gas introduction section disposed upstream of the plasma generation section for introducing a gas into the water, A shock wave generation section disposed downstream of the plasma generation section for applying a shock wave to the water, wherein the nitric acid nitrogen-containing water production apparatus is characterized by comprising the shock wave generation section.

2. A first pressure gauge for measuring the pressure upstream of the shock wave generation section, A second pressure gauge for measuring the pressure downstream of the shock wave generation section and a flow meter for measuring the flow rate, wherein the nitric acid nitrogen-containing water production apparatus according to claim 1 is characterized by comprising the second pressure gauge and the flow meter.

3. A water transport section for transporting water, A gas introduction section for introducing a gas into the water, A bubble generation section for generating bubbles in the water, A plasma generation section for irradiating the bubbles generated by the bubble generation section with plasma, A shock wave generation section for applying a shock wave to the water, wherein the liquid fertilizer production apparatus is characterized by comprising the shock wave generation section.

4. In a liquid fertilizer production system comprising a water transport section for transporting water, a gas introduction section for introducing a gas into the water, a bubble generation section for generating bubbles in the water, a plasma generation section for irradiating the bubbles generated by the bubble generation section with plasma, and a shock wave generation section for applying a shock wave to the water, a nitric acid nitrogen concentration control device for controlling the nitric acid nitrogen concentration based on one or more measured values of the flow rate or pressure of the water, the amount of gas introduced by the gas introduction section, the diameter or amount of bubbles generated by the bubble generation section, and the plasma intensity generated by the plasma generation section.

Images