JP2013138649A - Purification apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable to integrally regulate temperature control and water purification to a nutrient solution for hydroponics.SOLUTION: There is provided a purification apparatus including a heat pump (21) for regulating the temperature of the nutrient solution, a purification unit (60) for purifying the nutrient solution, and a control unit (103). The purification unit (60) has a discharging unit (62) for generating electric discharge in the nutrient solution and an ultrasonic wave generating unit (94) for irradiating the nutrient solution with ultrasonic waves, and the discharging unit (62) has an electrode pair (64, 65, 464, 465, 564, 565, 664, 665) generating the discharge of forming hydroxy radicals in the nutrient solution and a power source unit (70). The ultrasonic wave generating unit (94) is constituted so as to convert hydrogen peroxide converted from hydroxy radicals in the nutrient solution to hydroxy radicals. The control unit (103) regulates the temperature of the heat pump (21) and controls the operations of the discharging unit (62) and the ultrasonic wave generating unit (94).

Description

  The present invention relates to a purification device, and particularly relates to a purification device for hydroponics.

  In contrast to the conventionally known cultivation methods for growing plants in soil, hydroponics are now known. In general, hydroponics pumps up an aqueous solution containing nutrients using a pump, etc., flows it through a pipe or other cultivation tube, and then circulates the plant planted in the meantime. , Enabling an efficient supply of nutrients.

  Since various organic nutrients flow into the nutrient solution pipe or dust in the air is mixed, scales and impurities adhere to the nutrient solution pipe. Such scales and impurities cause proliferation of various germs and clogging of pipes. However, since the plant touches the nutrient solution flowing through the nutrient solution pipe, it is difficult to wash it by pouring a cleaning agent into the pipe. In response to this, for example, an ozone generator is used to sterilize pipes (Patent Document 1).

  On the other hand, in such hydroponics, a heat pump chiller is used in order to keep the temperature of the nutrient solution constant for the purpose of increasing the yield and periodic cultivation.

JP 2001-299116 A

  However, in conventional hydroponics, the heat pump chiller and the ozone generator for sterilizing the nutrient solution in the nutrient solution pipe are configured separately to maintain the temperature of the nutrient solution at a constant level. The liquid temperature control and the sterilization operation were controlled separately. For this reason, in order to install both a heat pump chiller and an ozone generator, there existed a problem that an installation area (installation volume) expanded. On the other hand, since an ozone generator requires additional members, such as an air supply pump and an exhaust gas recovery device, there is a problem that the installation location is further expanded.

  The present invention has been made in view of such a point, and an object of the present invention is to perform temperature adjustment and purification of a nutrient solution with an integrated apparatus in hydroponics.

  The 1st aspect of the purification apparatus which concerns on this invention is aimed at the purification apparatus which purifies the nutrient solution of a hydroponic cultivation system (10), The heat pump (21) which adjusts the temperature of a nutrient solution, and purification of a nutrient solution A purification unit (60) for performing the control, and a control unit (103). The purification unit (60) includes a discharge unit (62) for performing discharge in the nutrient solution and an ultrasonic wave generating unit (for irradiating the nutrient solution with ultrasound) ( 94), and the discharge part (62) includes an electrode pair (64, 65, 464, 465, 564, 565, 664, 665) that causes discharge in the nutrient solution, and an electrode pair (64, 65, 464, 465, 564, 565, 664, 665). A power supply unit (70) for applying a voltage, and is configured to generate hydroxyl radicals in the nutrient solution by discharge. The ultrasonic generator (94) changes the generated hydroxyl radicals. The hydrogen peroxide in the nutrient solution produced in this way is converted to hydroxyl radicals, and the controller (103) is configured to convert the temperature of the heat pump (21). Regulation, operation and ultrasonic generator of the discharge portion (62) (94) for controlling the operation.

  As a second aspect, the control unit (103) operates and stops the discharge unit (62) and the ultrasonic wave generation unit (94) so that the concentration of hydrogen peroxide in the nutrient solution is within a predetermined range. You may control.

  In this case, the control unit (103) keeps the discharge unit (62) in an operating state until the concentration of hydrogen peroxide in the nutrient solution reaches a preset lower limit value, and turns the ultrasonic generation unit (94) on. After reaching the lower limit value until the lower limit value is reached, the discharge unit (62) and the ultrasonic wave generation unit (94) are in the operating state until reaching the upper limit value, and after reaching the upper limit value, the lower limit value is reached. Until then, it is preferable that the discharge part (62) is in a stopped state and the ultrasonic wave generating part (94) is in an operating state.

  In this case, it is preferable to further include a sensor for measuring the concentration of hydrogen peroxide in the nutrient solution.

  As a third aspect, the electrode pair (564,565) is configured by plate-like electrodes arranged to face each other, and the power supply unit (70) is a pulse power supply that applies a pulse voltage to the electrode pair (564,565). The discharge unit (62) may include a bubble generation unit (520) that generates bubbles in the nutrient solution between the electrode pair (564,565).

  As a 4th aspect, a hydroponics system (10) has the cultivation floor (12) which plants a plant (14), the nutrient solution passage (11,81) through which nutrient solution circulates, and a purification unit ( 60) may be disposed in the nutrient solution passageway (11, 81).

  As a fifth aspect, the heat pump (21) includes a compressor (23), an expander (25), a heat source side heat exchanger (26), and a use side heat exchanger (27), and reversibly refrigerates the refrigerant. It has a refrigerant circuit (22) which circulates and performs a refrigerating cycle, and use side heat exchanger (27) may be arranged in nutrient solution channel (11).

  As a 6th aspect, the purification | cleaning unit (60) may be arrange | positioned in the water storage tank (82) which stores the nutrient solution which circulates through the nutrient solution channel | path (81).

  According to the purification apparatus according to the present invention, the temperature adjustment and purification of the nutrient solution can be performed by an integrated apparatus in hydroponics.

It is a figure which shows the structure of the hydroponic cultivation system which concerns on Embodiment 1. FIG. It is a figure which shows schematic structure of the power supply device which concerns on this embodiment. It is a block diagram of the purification | cleaning unit which concerns on Embodiment 1, and shows the state before starting water purification operation | movement. 2 is a perspective view of an insulating casing according to Embodiment 1. FIG. It is a figure which shows the modification of an ultrasonic wave generation part. It is a figure which shows the modification of an ultrasonic wave generation part. It is a block diagram of the discharge part of the purification | cleaning unit which concerns on Embodiment 1, and starts the water purification operation | movement and shows the state in which the bubble was formed. It is a figure which shows the basic cycle of the process in a purification | cleaning unit. It is a timing chart which shows an example of a drive of a purification unit. It is a timing chart which shows an example of a drive of a purification unit. It is a block diagram which shows an example of the control part of a purification | cleaning unit. It is a figure which shows the 1st modification of a discharge unit. It is a perspective view of the insulation casing in the 1st modification of a discharge unit. It is a figure which shows the 2nd modification of a discharge unit, and shows the state before starting water purification operation | movement. It is a figure which shows the 2nd modification of a discharge unit, and starts the water purification operation | movement, and shows the state in which the bubble was formed. It is a top view of the cover part of the insulation casing of the 3rd modification of a discharge unit. It is a figure which shows the purification | cleaning unit which concerns on Embodiment 2. FIG. It is a figure which shows the purification | cleaning unit which concerns on Embodiment 3. FIG. It is a figure which shows the purification | cleaning unit which concerns on Embodiment 4. FIG. It is a figure which shows the structure of the hydroponic cultivation system which concerns on Embodiment 5. FIG. It is a figure which shows the modification of a control part.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
<overall structure>
FIG. 1 is a diagram showing a configuration of a hydroponic cultivation system (10) according to Embodiment 1 of the present invention. This hydroponics system (10) is used in so-called facility horticulture (for example, a greenhouse) or a plant factory that grows plants using artificial light in a closed environment. As shown in FIG. 1, the hydroponics system (10) includes a circulation tank (11), a pump (13), and a nutrient solution treatment device (20). In this hydroponics system (10), the nutrient solution (L) containing the nutrients necessary for plant cultivation circulates in the circulation tank (11). In FIG. 1, the circulation direction of the nutrient solution (L) is indicated by arrows.

  The circulation tank (11) is a tank that circulates a predetermined amount of nutrient solution (L), and constitutes the nutrient solution passage according to the present invention. A cultivation bed (12) is formed in a part of the circulation passage of the circulation tank (11). A plant (14) is planted on the cultivation floor (12). The plant (14) planted absorbs the nutrient solution (L) stored in the cultivation floor (12) and uses the nutrients in the absorbed nutrient solution (L). The pump (13) is a pump for circulating the nutrient solution (L) in the circulation tank (11).

  The nutrient solution treatment device (20) includes a purification unit (60), a heat pump (21), a power supply device (31), and a control unit (103), and constitutes a purification device according to the present invention.

  The purification unit (60) generates hydrogen peroxide through hydroxyl radicals in water by discharge in water (specifically, nutrient solution (L)), and converts the generated hydrogen peroxide into hydroxyl radicals by ultrasonic waves. The nutrient solution is purified by conversion. The purification of the nutrient solution is a concept including sterilization of various germs in the solution, decomposition of organic substances that cause generation of dirt existing in the solution, and the like. The configuration of the purification unit (60) will be described in detail later. The purification unit (60) is arranged on the downstream side of the cultivation bed (12) in the nutrient solution (L) of the circulation tank (11).

  The heat pump (21) is provided with a reversible refrigerant circuit (22) in which the refrigerant circulates and constitutes a vapor compression refrigeration cycle.

  The refrigerant circuit (22) includes a compressor (23), a four-way switching valve (24), an outdoor heat exchanger (26) that is a heat source side heat exchanger according to the present invention, and an expander according to the present invention. A certain expansion valve (25) and an indoor heat exchanger (27), which is a use side heat exchanger according to the present invention, are connected in series by a refrigerant pipe in order. And the indoor heat exchanger (27) is arrange | positioned in the nutrient solution (L) which circulates through the circulation tank (11).

  As shown in FIG. 2, the power supply device (31) supplies an AC voltage (for example, 100 V) of a so-called outlet (30) installed in a home or the like to the heat pump (21) and the purification unit (60). It is. Specifically, the power supply device (31) rectifies the AC voltage of the outlet (30) by the converter (32), converts the AC voltage by the inverter (33), and converts the AC voltage to the motor (23a) of the compressor (23). To supply. The power supply device (31) rectifies the AC voltage of the outlet (30) by the converter (34), and then supplies a predetermined high voltage (for example, 1 kV) to the electrode pair (64, 65) by the step-up transformer (35). The power supply unit (70) is configured. The power supply unit (70) will be described later.

  The control unit (103) individually controls the operation of both the heat pump (21) and the purification unit (60). Specifically, the control unit (103) (controller) includes a purification control unit (42) and a temperature control unit (43).

  The temperature control section (43) controls the refrigerant circulation direction in the refrigerant circuit (22) by controlling the capacity of the compressor (23) and switching the four-way switching valve (24) of the refrigerant circuit (22). Or the adjustment of the nutrient solution temperature by the heat pump (21) is controlled by adjusting the opening degree of the expansion valve (25). In addition, a temperature control part (43) may connect a temperature sensor to a circulation tank (11), and may control a heat pump (21) based on the nutrient solution temperature in this circulation tank (11).

  The purification control unit (42) controls the operation operation (ON / OFF of the discharge unit and the ultrasonic wave generation unit) which is the purification operation of the purification unit (60). The control unit (103) controls the heat pump (21) according to the operation of the purification unit (60), or operates the purification unit (60) according to the operation operation of the heat pump (21), the nutrient solution temperature, or the like. The operation may be controlled.

<Detailed structure of purification unit (60)>
The nutrient solution treatment apparatus (20) includes a purification unit (60). The purification unit (60) generates hydrogen peroxide through hydroxyl radicals in water by electric discharge in water, and converts the generated hydrogen peroxide into hydroxyl radicals by ultrasonic waves. The nutrient solution is purified by the generated hydrogen peroxide and hydroxyl radical. The purification unit (60) has a discharge part (62) and an ultrasonic wave generation part (94) arranged in the circulation tank (11) (see FIG. 3).

  In addition, you may make it comprise a part of circulation tank (11) with a copper member. By producing copper ions from the inner wall of the copper member, the copper ions can be supplied to the circulation tank (11).

  The discharge unit (62) includes an electrode pair (64, 65) including a first electrode (64) and a second electrode (65), and a power supply unit (70) for applying a voltage to the electrode pair (64, 65). And an insulating casing (71) for accommodating the first electrode (64) therein.

  The electrode pair (64, 65) is for causing discharge in water. The first electrode (64) is disposed inside the insulating casing (71). The 1st electrode (64) is formed in the shape of a flat plate up and down. The first electrode (64) is connected to the positive electrode side of the power supply section (70). The first electrode (64) is made of a conductive metal material such as stainless steel or copper.

  The second electrode (65) is disposed outside the insulating casing (71). The second electrode (65) is provided above the first electrode (64). The second electrode (65) has a flat plate shape in the vertical direction, and is configured in a mesh shape or a punching metal shape having a plurality of through holes (66) in the vertical direction. The second electrode (65) is disposed substantially parallel to the first electrode (64). The second electrode (65) is connected to the negative electrode side of the power supply unit (70). The second electrode (65) is made of a conductive metal material such as stainless steel or brass.

  The power supply unit (70) applies a predetermined voltage to the electrode pair (64, 65). The power supply unit (70) may be a pulse power supply that repeatedly applies a high voltage instantaneously to the electrode pair (64, 65), but is always several kilovolts for the electrode pair (64, 65). A direct current power source that applies the voltage of may be used. In the case of a DC power supply, the negative electrode side to which the second electrode (65) is connected in the power supply section (70) may be connected to the ground. The power supply unit (70) is provided with a constant power control unit (not shown) that controls the discharge power of the electrode pair (64, 65) to be constant. The power supply unit (70) may be a pulse power supply that repeatedly applies a high voltage to the electrode pair (64, 65) instantaneously. When the power supply unit (70) is a DC power supply, it is possible to reduce the sound at the time of discharge compared to when the power supply unit (70) is a pulse power supply.

  The insulating casing (71) is installed at the bottom of the circulation tank (11). The insulating casing (71) is made of an insulating material such as ceramics. The insulating casing (71) has a container-like case body (72) whose one surface (upper surface) is open, and a plate-like lid (73) that closes the open portion above the case body (72). doing.

  The case body (72) has a square cylindrical side wall (72a) and a bottom (72b) that closes the bottom of the side wall (72a). The first electrode (64) is laid on the upper side of the bottom (72b). In the insulating casing (71), the vertical distance between the lid (73) and the bottom (72b) is longer than the thickness of the first electrode (64). That is, a predetermined interval is ensured between the first electrode (64) and the lid (73). Thereby, inside the insulating casing (71), a space (S) is formed among the first electrode (64), the case body (72), and the lid portion (73).

  As shown in FIGS. 3 and 4, the opening (74) penetrating the lid (73) in the thickness direction is formed in the lid (73) of the insulating casing (71). The opening (74) allows the formation of an electric field between the first electrode (64) and the second electrode (65). The inner diameter of the opening (74) of the lid (73) is preferably 0.02 mm or more and 0.5 mm or less. The opening (74) as described above constitutes a current density concentration portion that increases the current density of the current path between the electrode pair (64, 65).

  As described above, the insulating casing (71) accommodates only one electrode (first electrode (64)) of the electrode pair (64, 65) inside, and the opening (74) as the current density concentration portion. ).

  In addition, in the opening (74) of the insulating casing (71), the current density in the current path increases, so that water is vaporized by Joule heat to form bubbles (B). That is, the opening (74) of the insulating casing (71) functions as a gas phase forming part that forms bubbles (B) as a gas phase part in the opening (74).

  The ultrasonic wave generator (94) includes a plate-shaped piezoelectric ceramic plate (95) and a pair of metal plates (96a, 96b) provided so as to sandwich the piezoelectric ceramic plate (95). The case (97) enclosing the ultrasonic wave generation unit (94) is sealed and disposed at the bottom of the circulation tank (11).

  The metal plate (96a, 96b) is supplied with an output signal (AC voltage) of the ultrasonic waveform generator (308) amplified by the amplifier (309). Thereby, the ultrasonic wave generation unit (94) can irradiate the nutrient solution in the circulation tank (11) with ultrasonic waves having an arbitrary frequency. However, in order to decompose hydrogen peroxide and efficiently generate hydroxyl radicals, it is preferable that the ultrasonic frequency be about 100 kHz or more.

  In addition, the ultrasonic wave generation part (94) may be installed in arbitrary positions in the range which can irradiate a liquid in a circulation tank (11) with an ultrasonic wave. For example, as shown in FIG. 5, the ultrasonic wave generator (94) may be installed outside the bottom of the circulation tank (11). When the ultrasonic generator (94) is installed outside the bottom of the circulation tank (11), the ultrasonic waves are transmitted to the nutrient solution via the wall surface of the circulation tank (11).

  Further, as shown in FIG. 6, the ultrasonic wave generation unit (94) sandwiches a plate-like piezoelectric ceramic plate (95) between the upper portion of the metal case (97a) and the metal plate (96), and an alternating current therebetween. It may be configured to supply voltage.

  When the nutrient solution is continuously circulated, the concentration of hydrogen peroxide in the circulation tank (11) is higher than that of the discharge portion (62) even when the discharge portion (62) is operated. Then it may not be high. For this reason, it is preferable to provide the ultrasonic wave generation part (94) on the outflow side with respect to the discharge part (62). However, when the nutrient solution in the circulation tank (11) is sterilized when the pump (102) is stopped, the ultrasonic generator (94) is provided on the inflow side with respect to the discharge part (62). There is no problem.

-Operation of hydroponic system (10)-
In the hydroponic cultivation system (10) of the first embodiment, when the pump (13) is turned on, the nutrient solution (L) is circulated through the circulation tank (11) and supplied to the cultivation bed (12). In the cultivation floor (12), each plant (14) absorbs a necessary amount of nutrient solution (L). The nutrient solution (L) not absorbed by the plant (14) circulates from the cultivation bed (12) through the circulation tank (11) and passes through the purification unit (60).

  The nutrient solution (L) discharged from the purification unit (60) is supplemented with insufficient components and water, and flows into the cultivation bed (12) again. An apparatus for adjusting the components and amount of the nutrient solution (L) is not shown in FIG. Note that the nutrient solution (L) may be circulated continuously or at an appropriate time interval.

-Operation of the purification unit (60)-
In the hydroponics system (10) of Embodiment 1, the purification | cleaning unit (60) is drive | operated and the water (specifically nutrient solution (L)) which flows through a circulation tank (11) is purified. The water purification operation by the purification unit (60) will be described in detail. The operation of the purification unit (60) is controlled by the purification control unit (42) of the control unit (103).

  At the start of the operation of the purification unit (60), as shown in FIG. 3, the space (S) in the insulating casing (71) is in a flooded state. When a predetermined voltage (for example, 1 kV) is applied from the power supply unit (70) to the electrode pair (64, 65), an electric field is formed between the electrode pair (64, 65). The periphery of the first electrode (64) is covered with an insulating casing (71). For this reason, the leakage current between the electrode pair (64, 65) is suppressed, and the current density of the current path in the opening (74) is increased.

  As the current density in the opening (74) increases, the Joule heat in the opening (74) increases. As a result, in the insulating casing (71), the vaporization of water is promoted in the vicinity of the opening (74) to form bubbles (B). As shown in FIG. 7, the bubbles (B) cover almost the entire area of the opening (74), and water on the negative electrode side conducting to the second electrode (65) and the first electrode (64) on the positive electrode side. Bubbles (B) are interposed between them. Therefore, in this state, the bubble (B) functions as a resistance that prevents conduction through water between the first electrode (64) and the second electrode (65). Thereby, the leakage current between the first electrode (64) and the second electrode (65) is suppressed, and a desired potential difference is maintained between the electrode pair (64, 65). Then, in the bubble (B), discharge is generated with dielectric breakdown.

  As described above, when discharge is performed with the bubbles (B), hydroxyl radicals are generated in the water (specifically, in the nutrient solution) in the circulation tank (11). The generated hydroxyl radicals react rapidly to become hydrogen peroxide. For this reason, the hydrogen peroxide concentration in the circulation tank (11) gradually increases. When the nutrient solution is irradiated with ultrasonic waves after the hydrogen peroxide concentration has sufficiently increased, the hydrogen peroxide in the nutrient solution is decomposed and hydroxyl radicals are generated again. Hydroxyl radicals generated by ultrasonic irradiation are combined again to return to hydrogen peroxide. For this reason, as shown in FIG. 8, the conversion from hydrogen peroxide to hydroxyl radicals and the conversion from hydroxyl radicals to hydrogen peroxide are circulated. However, since the hydroxyl radical used to purify the nutrient solution such as sterilization is changed to water, the concentration of hydrogen peroxide gradually decreases when the discharge is stopped and only ultrasonic irradiation is performed.

  In order to sufficiently purify the nutrient solution with hydrogen peroxide, the concentration of hydrogen peroxide in the nutrient solution must be increased. Hydrogen peroxide is relatively safe at low concentrations, but it can adversely affect plants at higher concentrations. On the other hand, hydroxyl radicals have a much higher purification capacity than hydrogen peroxide. Therefore, the nutrient solution can be sufficiently purified even at a low concentration. However, the hydroxyl radical is unstable and immediately reacts to become hydrogen peroxide. For this reason, in order to purify the nutrient solution with hydroxyl radicals, the hydroxyl radicals must be continuously generated.

  In the case of electric discharge, water is decomposed and hydroxyl radicals are generated. Therefore, when the operation is continuously performed, the concentration of hydrogen peroxide in the nutrient solution increases more and more. On the other hand, in the case of ultrasonic irradiation, conversion from hydrogen peroxide to hydroxyl radicals occurs, but water does not decompose. For this reason, even if it produces | generates a hydroxyl radical continuously, the density | concentration of hydrogen peroxide does not rise. Therefore, by generating hydrogen peroxide by discharge and generating hydroxyl radicals by ultrasonic waves, purification can be performed much more efficiently than when purification is performed using only discharge. Moreover, since the concentration of hydrogen peroxide can be kept low, a safer purification device can be realized.

  Since the hydroxyl radical is highly reactive, if the hydroxyl radical is in direct contact with the plant (200) cultivated on the cultivation floor (101), the plant (200) may be adversely affected. However, since the lifetime of the hydroxyl radical is very short, if the position of the purification unit (60) is provided at a distance from the plant (200) in the circulation tank (11), the plant (200) is almost affected. There is nothing. Also, low concentrations of hydrogen peroxide have little effect on the plant (200).

  The hydrogen peroxide in the nutrient solution convects in the circulation tank (11) by the heat accompanying the discharge. This promotes diffusion of active species and hydrogen peroxide in water. Further, when the discharge is performed with the bubbles (B), an ion wind is easily generated with the bubbles (B) along with the discharge. Therefore, in the circulation tank (11), the effect of diffusing active species and hydrogen peroxide can be further improved by utilizing this ion wind.

  Further, as described above, the copper ions eluted from the copper member are supplied to the circulation tank (11). In the presence of hydrogen peroxide and copper ions, copper ions act catalytically by the Fenton reaction to promote the generation of hydroxyl radicals. Thereby, the purification efficiency of the water by a hydroxyl radical improves. In addition, since copper ions have the effect of suppressing the growth of bacteria, the bactericidal action in water also increases.

  As described above, active species such as hydroxyl radicals diffused in water are used to purify water by oxidizing and decomposing components to be treated (for example, ammonia) contained in water. In addition, hydrogen peroxide diffused in water is used for water sterilization.

  The discharge part (62) and the ultrasonic wave generation part (94) may be always in an operating state. However, if the hydrogen peroxide concentration in the nutrient solution is low, sufficient hydroxyl radicals can be obtained even if the ultrasonic wave is irradiated. I can not expect the occurrence of. Moreover, if the discharge part (62) is continuously operated, the hydrogen peroxide concentration in the nutrient solution may become too high. For this reason, it is preferable to perform an operation as shown in FIG. First, only the discharge part (62) is operated to raise the hydrogen peroxide in the circulation tank (11), and then the operation of the ultrasonic wave generation part (94) is started to start the generation of hydroxyl radicals. Thereafter, when the concentration of hydrogen peroxide in the circulation tank (11) is sufficiently increased, the operation of the discharge part (62) is stopped and only the ultrasonic wave generation part (94) is operated. When the concentration of hydrogen peroxide in the circulation tank (11) decreases, the operation of the discharge part (62) is started again to increase the concentration of hydrogen peroxide in the circulation tank (11).

  Although the control as described above may be performed based on a preset timing, the control as shown in FIG. 10 may be performed based on the measured value of the hydrogen peroxide concentration in the circulation tank (11). In this case, as shown in FIG. 11, a sensor (307) for measuring the hydrogen peroxide concentration is provided in the circulation tank (11), and based on the sensor output, the control unit (103) causes the discharge unit (62). And the ultrasonic wave generator (94) may be controlled. The control unit (103) may be an arithmetic circuit provided with a central processing unit (CPU).

  In addition, although the example which starts the driving | operation of an ultrasonic generation part (94) during the driving | operation of a discharge part (62) was shown, operation | movement of an ultrasonic generation part (94) is stopped after driving | operation of a discharge part (62) is stopped. May start. Further, when the discharge unit (62) is re-operated, the ultrasonic wave generation unit (94) may be in a paused state.

-Heat pump operation-
In the hydroponic cultivation system (10) of the first embodiment, the temperature of water (specifically, nutrient solution (L)) flowing through the circulation tank (11) is adjusted by operating the heat pump (21). . The temperature control of the nutrient solution using such a heat pump (21) will be described in detail. The operation of the heat pump (21) is controlled by the temperature control unit (43) of the control unit (103).

  First, during the cooling operation, when the four-way switching valve (24) is switched to the solid line side and the compressor (23) is driven, the refrigerant discharged from the compressor (23) is transferred to the outdoor heat exchanger (26). Then, the pressure is reduced by the expansion valve (25) and then evaporated by the indoor heat exchanger (27) to return to the compressor (23). This operation is repeated to cool the nutrient solution by the indoor heat exchanger (27).

  Further, during the heating operation, when the four-way switching valve (24) is switched to the broken line side and the compressor (23) is driven, the refrigerant discharged from the compressor (23) is supplied to each indoor heat exchanger (27 ), The pressure is reduced by the expansion valve (25), and then evaporated by the outdoor heat exchanger (26) to return to the compressor (23). This operation is repeated to heat the nutrient solution by the indoor heat exchanger (27).

-Effect of Embodiment 1-
According to the first embodiment, since the control unit (103) that controls both the heat pump (21) and the purification unit (60) is provided, both devices (21, 60) are controlled by one control unit (103). can do. Thereby, since the member of both apparatuses (21, 60) can be made common and simplified, expansion of the installation area (installation volume) of the nutrient solution treatment apparatus (20) can be suppressed. However, the heat pump (21) and the purification unit (60) may be controlled independently. Furthermore, it is good also as a structure which controls a discharge part (62) and an ultrasonic wave generation part (94) independently.

  Moreover, in this embodiment, the purification | cleaning unit (60) is made to perform discharge and ultrasonic irradiation. The purification unit (60) by discharge and ultrasonic irradiation has fewer members necessary for the apparatus configuration than a conventional ozone generator or the like. For this reason, since an apparatus structure can be simplified, the expansion of the installation area (installation volume) of a purification apparatus can be suppressed.

  Further, in the present embodiment, discharge is performed to generate hydrogen peroxide. Hydrogen peroxide is not easily decomposed even when the water temperature rises, compared to hypochlorous acid. For this reason, water (nutrient solution (L)) can fully be sterilized and purified with hydrogen peroxide. In addition, since a large amount of active species are generated in water by discharge and ultrasonic irradiation, harmful substances in water (nourishing liquid (L)) can be effectively removed by the active species.

  Moreover, since the purification | cleaning unit (60) has been arrange | positioned in the circulation tank (11), the water (nutrient solution (L)) supplied to a cultivation bed (12) can be purified reliably.

  On the other hand, since the refrigerant circuit (22) is provided and the indoor heat exchanger (27) is disposed in the circulation tank (11), the water (the nutrient solution (L)) in the circulation tank (11) is heated or cooled. be able to. Moreover, since the indoor heat exchanger (27) is disposed in the circulation tank (11), the circulation tank (11) and the heat pump (21) are connected by a water pipe, and water (nutrient solution (L)) is supplied to the heat pump (21). It is not necessary to send it up to heating or cooling. Thereby, water (nutrient solution (L)) can be heated or cooled, without providing the water piping for connecting a heat pump (21) and a circulation tank (11). Thereby, the increase in the cost accompanying water piping installation, the contamination of the water (nurturing solution) sent with a water piping, and the increase in the amount of circulating nutrient solution can be prevented.

<Variation 1 of discharge part>
In Embodiment 1, one opening (74) is formed in the lid part (73) of the insulating casing (71). However, for example, as shown in FIGS. 12 and 13, a plurality of openings (74) may be formed in the lid portion (73) of the insulating casing (71). In this modified example, the lid portion (73) of the insulating casing (71) is formed in a substantially square plate shape, and a plurality of openings (74) are arranged in a grid pattern in the lid portion (73) at equal intervals. Has been. On the other hand, the first electrode (64) and the second electrode (65) are formed in a square plate shape over all the openings (74).

  Also in this modification, each opening (74) functions as a current density concentration part and a gas phase formation part. Thereby, when a voltage is applied to the electrode pair (64, 65) from the power supply unit (70), the current density of each opening (74) increases, and bubbles (B) are formed in each opening (74). . As a result, discharge is generated in each bubble (B), and active species such as hydroxyl radicals and hydrogen peroxide are generated.

<Modification 2 of the discharge part>
The discharge part (62) may be configured as follows. As shown in FIG. 14, the discharge part (62) of the modification 2 is comprised by what is called a flange unit type inserted and fixed toward the inside from the outer side of a circulation tank (11). Moreover, the discharge part (62) of the modification 2 has the 1st electrode (64), the 2nd electrode (65), and the insulation casing (71) assembled integrally.

  The insulation casing (71) of Modification 2 has a substantially outer shape that is cylindrical. The insulating casing (71) has a case main body (72) and a lid part (73).

  The case body (72) of Embodiment 2 is made of an insulating material made of glass or resin. The case main body (72) includes a cylindrical base portion (76), a cylindrical wall portion (77) protruding from the base portion (76) toward the circulation tank (11), and the cylindrical wall portion (77). And an annular convex part (78) projecting further toward the circulation tank (11) side. The case body (72) is integrally formed with a distal end cylindrical portion (79) on the distal end side of the annular convex portion (78). A cylindrical insertion opening (76a) extends in the axial direction in the axial center of the base (76). A cylindrical space (S) that is coaxial with the insertion port (76a) and has a larger diameter than the insertion port (76a) is formed inside the cylindrical wall portion (77).

  The cover part (73) of Embodiment 2 is formed in a substantially disc shape, and is fitted inside the annular convex part (78). The lid (73) is made of a ceramic material. As in the first embodiment, one circular opening (74) penetrating the lid (73) vertically is formed at the axis of the lid (73).

  The first electrode (64) is a vertically long bar-shaped electrode having a circular cross section perpendicular to the axis. The first electrode (64) is fitted in the insertion opening (76a) of the base (76). Thereby, the 1st electrode (64) is accommodated in the inside of an insulation casing (71). In the second embodiment, the end of the first electrode (64) opposite to the circulation tank (11) is exposed to the outside of the circulation tank (11). For this reason, the power supply part (70) arrange | positioned outside the circulation tank (11) and the 1st electrode (64) can be easily connected by electrical wiring.

  The end (64a) on the circulation tank (11) side of the first electrode (64) faces the space (S) inside the insulating casing (71). In the example shown in FIG. 14, the end portion (64a) of the first electrode (64) protrudes above the opening surface of the insertion port (76a) (on the circulation tank (11) side). The tip surface of the portion (64a) may be substantially flush with the opening surface of the insertion port (76a), or the end portion (64a) may be recessed below the opening surface of the insertion port (76a). Moreover, the 1st electrode (64) has ensured the predetermined space | interval between the cover parts (73) which have an opening (74) similarly to Embodiment 1. FIG.

  The second electrode (65) has a cylindrical electrode body (65a) and a flange (65b) projecting radially outward from the electrode body (65a). The electrode body (65a) is externally fitted to the case body (72) of the insulating casing (71). The flange portion (65b) constitutes a fixed portion that is fixed to the wall portion of the circulation tank (11) and holds the discharge portion (62). In a state where the discharge part (62) is fixed to the circulation tank (11), a part of the electrode body (65a) of the second electrode (65) is immersed.

  The second electrode (65) includes an inner cylindrical portion (65c) having a smaller diameter than the electrode main body (65a) and a connecting portion (between the inner cylindrical portion (65c) and the electrode main body (65a)). 65d). The inner cylinder part (65c) and the connecting part (65d) are immersed in the water in the circulation tank (11). The inner cylinder part (65c) forms the cylindrical space (67) in the inside. One end of the inner cylinder portion (65c) in the axial direction constitutes a holding portion that contacts the lid portion (73) and holds the lid portion (73). In addition, a distal end cylindrical portion (79) of the case main body (72) is fitted between the electrode main body (65a), the inner cylindrical portion (65c), and the connecting portion (65d). On the other end side in the axial direction of the inner cylindrical portion (65c), a mesh-shaped leakage preventing material (68) is provided so as to cover the cylindrical space (67). The leakage preventing material (68) is substantially grounded by being in contact with the second electrode (65). Thereby, the leakage preventive material (68) prevents leakage from the inside to the outside of the cylindrical space (67) in the space (underwater) inside the circulation tank (11).

  The second electrode (65) is in a state where a part of the electrode body (65a) is exposed to the outside of the circulation tank (11). For this reason, a power supply part (70) and a 2nd electrode (65) can be easily connected by electrical wiring.

-Operation of the purification unit-
Also in the modified example 2, the purification unit (60) is operated to purify the water flowing through the circulation tank (11).

  At the start of the operation of the purification unit (60), as shown in FIG. 14, the space (S) in the insulating casing (71) is in a flooded state. When a predetermined voltage (for example, 1 kV) is applied from the power supply unit (70) to the electrode pair (64, 65), the current density inside the opening (74) increases.

  When the voltage is continuously applied to the electrode pair (64, 65) from the state shown in FIG. 14, the water in the opening (74) is vaporized to form bubbles (B) (see FIG. 15). ). In this state, the bubble (B) covers almost the entire area of the opening (74), and the resistance of the bubble (B) is between the negative electrode side water in the cylindrical space (67) and the first electrode (64). Is granted. Thereby, the electric potential difference between the 1st electrode (64) and the 2nd electrode (65) is maintained, and discharge occurs with air bubbles (B). As a result, in water, hydrogen peroxide is generated via hydroxyl radicals.

<Modification 3 of discharge part>
In Modification 2, one opening (74) is formed in the axis of the disc-shaped lid (73), but a plurality of openings (74) may be formed in this lid (73). In the example shown in FIG. 16, five openings (74) are arranged at equal intervals on a virtual pitch circle centered on the axis of the lid (73). Thus, by forming a plurality of openings (74) in the lid (73), it is possible to cause discharges in the vicinity of each opening (74).

  In addition, the power supply part (70) of Embodiment 1 and each modification uses the constant power control part which controls the discharge power of discharge uniformly. However, instead of the constant power control unit, a constant current control unit that controls the discharge current during discharge to be constant may be provided. When this constant current control is performed, the discharge is stabilized regardless of the conductivity of the washing water, so that the occurrence of sparks can be avoided in advance.

  In the first embodiment and each modification, when the power supply unit (70) is a DC power supply, the first electrode (64) is connected to the positive electrode, and the second electrode (65) is connected to the negative electrode of the power supply unit (70). Just connect. However, the first electrode (64) is connected to the negative electrode of the power supply unit (70), the second electrode (65) is connected to the positive electrode of the power supply unit (70), and between the electrode pair (64, 65), So-called negative discharge may be performed. The power supply unit (70) may be an AC power supply or a pulse power supply.

(Embodiment 2)
FIG. 17 is a configuration diagram illustrating a purification unit (60B) according to the second embodiment. In FIG. 17, about the structure similar to the purification | cleaning unit (60) of Embodiment 1, the same code | symbol as FIG. 3 is attached | subjected. In FIG. 17, the description of the control unit (103) and the like is omitted. In the following, differences from the purification unit (60) according to the first embodiment will be mainly described.

  The purification unit (60B) of the present embodiment includes a discharge part (62) disposed in the circulation tank (11) and an ultrasonic wave generation part (94). The discharge part (62) has an electrode pair (464, 465) and a power supply part (70) connected to the electrode pair (464, 465). The ultrasonic generator (94) is installed at the bottom of the circulation tank (11).

  The electrode (464) is housed inside the insulating casing (471a), and the electrode (465) is housed inside the insulating casing (471b). The electrode (464) and the electrode (465) are each formed in a flat plate shape. The electrode (464) and the electrode (465) are made of a conductive metal material such as stainless steel or copper. The power supply unit (70) supplies an alternating voltage of about several kilovolts to the electrode pair (464, 465).

  The insulating casings (471a, 471b) are made of an insulating material such as ceramics, and have the same configuration as the insulating casing (71) shown in FIG.

  That is, the insulating casing (471a) includes a container-like case main body (480a) whose one surface (the right side surface in FIG. 17) is opened, and a plate-like lid portion (blocking the open portion of the case main body (480a)). 473a). The insulating casing (471b) includes a container-like case main body (480b) whose one surface (left surface in FIG. 17) is opened, and a plate-like lid portion (blocking the open portion of the case main body (480b)). 473b).

  One opening (474a) that penetrates the lid (473a) in the thickness direction is formed in the lid (473a) of the insulating casing (471a). One opening (474b) penetrating the lid portion (473b) in the thickness direction is also formed in the lid portion (473b) of the insulating casing (471b). These openings (474a and 474b) allow formation of an electric field between the electrode (464) and the electrode (465). The inner diameter of the openings (474a, 474b) is preferably 0.02 mm or more and 0.5 mm or less. The openings (474a, 474b) as described above constitute a current density concentration portion that increases the current density of the current path between the electrode pairs (464, 465).

  The insulating casings (471a, 471b) are installed at positions facing each other in the circulation tank (11) so that the lid portions (473a, 473b) face each other. In other words, the electrode (464) and the electrode (465) are arranged to face each other.

  In the openings (474a, 474b) of the insulating casings (471a, 471b), the current density in the current path increases, so that the liquid is vaporized by Joule heat and bubbles are formed. That is, the opening (474a, 474b) of the insulating casing (471a, 471b) functions as a gas phase forming part that forms bubbles as a gas phase part in the opening (474a, 474b). With this configuration, when an AC voltage is supplied to the electrode pair (464, 465), discharge can be generated in the bubbles between the electrode pair (464, 465).

  In addition, what is necessary is just to make the specific structure of an ultrasonic generation part (94) the same as that of Embodiment 1, and although it is preferable to install in the bottom part of a circulation tank (11), the liquid in a circulation tank (11) is sufficient. As long as it can be irradiated with ultrasonic waves, it can be installed at any position.

  By adopting the above configuration, even when an AC voltage is supplied to the electrode pair (464, 465), a discharge can be generated between the electrode pair (464, 465), and the concentration of hydrogen peroxide is suppressed while being high. The purification ability can be demonstrated.

  An AC voltage may be applied from the power supply unit (70) to the electrode pair (464, 465), but a discharge can be generated between the electrode pair (464, 465) even if a rectangular wave is applied. .

  Also in the purification unit (60B) of the present embodiment, it is preferable to perform control as shown in FIG. 9 or FIG.

(Embodiment 3)
FIG. 18 is a configuration diagram showing a purification unit (60C) according to Embodiment 3 of the present invention. In FIG. 18, the same reference numerals as those in FIG. 3 are assigned to the same configurations as those of the purification unit (60) of the first embodiment. In FIG. 18, the control unit (103) and the like are not shown. In the following, differences from the purification unit according to the first embodiment will be mainly described.

  The purification unit (60C) of the present embodiment includes a discharge unit (62) disposed in the circulation tank (11) and an ultrasonic wave generation unit (94). The discharge section (62) includes an electrode pair (564, 565) provided in the circulation tank (11), a power supply section (70) connected to the electrode pair (564, 565), and a bubble generation section (520). And have. The ultrasonic generator (94) is installed at the bottom of the circulation tank (11).

  In the purification unit (60C) of the present embodiment, the power supply unit (70) is supplied with a high voltage pulse voltage to the first electrode (64) and the second electrode (565).

  Further, an insulating casing surrounding the first electrode (564) may not be provided. The first electrode (564) and the second electrode (565) are both plate-shaped and are installed in the circulation tank (11) so as to face each other.

  The bubble generating unit 520 is a nozzle (discharging unit) provided at least between the electrode pair (564, 565) and lower than the electrode pair (564, 565), such as the bottom of the circulation tank (11). (519) and an air pump (sending means) (518) for sending a gas such as air to the nozzle (519). The gas sent out by the air pump (518) is sent into the circulation tank (11) through the nozzle (519) to generate bubbles in the circulation tank (11). In addition, it is good also as a structure which takes in gas from the exterior also as a structure which circulates the gas in a circulation tank (11).

  The configuration of the ultrasonic generator (94) may be the same as that of the first embodiment, and is preferably installed at the bottom of the circulation tank (11), but the liquid in the circulation tank (11) is irradiated with ultrasonic waves. It can be installed at any position as much as possible.

  At least during the discharge treatment, gas is sent from the nozzle (519) into the nutrient solution, and bubbles are generated. When a pulse voltage is supplied to the electrode pair (564, 565) in a state where bubbles are present in the nutrient solution, a discharge is generated inside the bubbles to generate hydroxyl radicals, and hydrogen peroxide is generated from the hydroxyl radicals. .

  Also in the purification unit (60B) of the present embodiment, it is preferable to perform control as shown in FIG. 9 or FIG.

  According to the above configuration and method, even when pulse discharge is generated between the electrode pair (564, 565), by combining with ultrasonic irradiation, high purification ability can be exhibited while suppressing the concentration of hydrogen peroxide. it can.

(Embodiment 4)
FIG. 19 is a configuration diagram showing a purification unit (60D) according to Embodiment 4 of the present invention. 19, the same code | symbol as FIG. 3 is attached | subjected about the structure similar to the purification | cleaning unit (60) of Embodiment 1. FIG. In FIG. 19, the description of the control unit (103) and the like is omitted. In the following, differences from the purification unit (60) according to the first embodiment will be mainly described.

  The purification unit (60D) of the present embodiment includes a discharge part (62) disposed in the circulation tank (11) and an ultrasonic wave generation part (94). The discharge part (62) has an electrode pair (664, 665) and a power supply part (70) connected to the electrode pair (664, 665). The ultrasonic generator (94) is installed at the bottom of the circulation tank (11). The power supply unit (70) is configured with, for example, an AC power supply, but may be configured with a DC power supply, or may be configured with a power supply that supplies a rectangular wave or a pulse voltage.

  The electrode (664) and the electrode (665) are installed in the circulation tank (11) so as to face each other.

  The electrode (664) has at least one conductive part (654) and an insulating part (655) surrounding the conductive part (654). The electrode (665) has at least one conductive part (656) and an insulating part (657) surrounding the conductive part (656).

  As described above, since the areas of the exposed surface of the conductive portion (654) in the electrode (664) and the exposed surface of the conductive portion (656) in the electrode (665) are small, voltage is supplied to the electrode pair (664, 665). In this case, a concentrated portion of current density is formed on the surface of the conductive portion (654, 656). Therefore, on the surface of the conductive portion (654, 656), the liquid is vaporized by Joule heat and bubbles are formed. By continuing the voltage supply from the power supply unit (70) in a state where the exposed surface of the conductive unit (654, 656) is covered by the bubbles, a discharge is generated inside the bubbles.

  In addition, what is necessary is just to make the specific structure of an ultrasonic generation part (94) the same as that of Embodiment 1, and although it is preferable to install in the bottom part of a circulation tank (11), the liquid in a circulation tank (11) is sufficient. As long as it can be irradiated with ultrasonic waves, it can be installed at any position.

  Even with the above configuration, by combining discharge between the electrode pair (664, 665) and ultrasonic irradiation, it is possible to exhibit a high purification ability while suppressing the concentration of hydrogen peroxide.

  Also in the purification unit (60D) of this embodiment, it is preferable to perform control as shown in FIG. 9 or FIG.

(Embodiment 5)
Next, a fifth embodiment of the present invention will be described. As shown in FIG. 20, the hydroponics system (10) which concerns on this embodiment differs from Embodiment 1, and the indoor heat exchanger (27) is arrange | positioned in the place away from the cultivation floor (12). .

  Specifically, the hydroponic cultivation system (10) of the third embodiment includes a nutrient solution tank (81), pipes (83, 84), and a water storage tank (82).

  The nutrient solution tank (81) forms a cultivation bed (12) by accumulating a predetermined amount of nutrient solution. The pipes (83, 84) are composed of an inflow pipe (83) through which the nutrient solution flows into the nutrient solution tank (81) and an outflow pipe (84) through which the nutrient solution flows out from the nutrient solution tank (81). ing.

  Each of the inflow pipe (83) and the outflow pipe (84) is a liquid pipe, and one end is connected to the nutrient solution tank (81) and the other end is connected to the water storage tank (82). In addition, the inflow pipe (83) is disposed in the vicinity of the indoor heat exchanger (27) of the heat pump (21) at an intermediate portion (heat transfer section (83a)). That is, in the heat transfer section (83a), the temperature of the nutrient solution (L) is adjusted by heat exchange between the nutrient solution (L) and the indoor heat exchanger (27). In addition, you may make it comprise inflow piping (83) or outflow piping (84) with a copper pipe. The inflow pipe (83) or the outflow pipe (84) can supply copper ions to the circulation tank (11) by generating copper ions from the inner wall.

  The water storage tank (82) is for temporarily storing the nutrient solution (L). That is, in the hydroponic cultivation system (10) of the third embodiment, the nutrient solution in the water storage tank (82) is pumped by the pump (13) through the inflow pipe (83) and the cultivation bed (12) in the nutrient solution tank (81). And is circulated so as to be collected again in the water storage tank (82) via the outflow pipe (84).

  The purification unit (60) is disposed in the water storage tank (82) and is configured to purify water (specifically, nutrient solution (L)) in the water storage tank (82). According to the third embodiment, since the purification unit (60) is disposed in the water storage tank (82), the water in the water storage tank (82) can be reliably purified. Other configurations, operations, and effects are the same as those in the first embodiment. The configuration of the purification unit (60) may be as in the second to fourth embodiments.

<Configuration of ion supply unit>
In each embodiment mentioned above, the copper member is made into the ion supply part of a copper ion by using a part of circulation tank (11) or piping (83,84) as a copper member. However, as the ion supply unit, for example, an iron member that generates iron ions can be used. Since iron ions, like copper ions, promote the Fenton reaction in the presence of hydrogen peroxide, the amount of hydroxyl radicals generated can be increased.

  The copper member and the iron member can be provided at other locations as long as they are water flow paths communicating with the circulation tank (11) and the nutrient solution tank (81). Specifically, in each embodiment, for example, the heat transfer tube of the indoor heat exchanger (27) can be formed of a copper tube. Moreover, these can also be made into an ion supply part by immersing a copper piece and an iron piece in a circulation tank (11), for example. Note that the ion supply unit may not be provided.

  Moreover, as shown in FIG. 21, about each embodiment, you may comprise so that a control part (103) may be integrated in the inside of a heat pump (21).

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or its use.

  As described above, the present invention is useful for the nutrient solution purification means of the hydroponic cultivation system.

DESCRIPTION OF SYMBOLS 10 Hydroponics system 11 Circulation tank 12 Cultivation floor 13 Pump 14 Plant 20 Nutrient processing device 21 Heat pump 22 Refrigerant circuit 23 Compressor 23a Motor 24 Four-way switching valve 25 Expansion valve 26 Outdoor heat exchanger 27 Indoor heat exchanger 30 Outlet 31 power supply device 32 converter 33 inverter 34 converter 35 step-up transformer 42 purification control unit 43 temperature control unit 60 purification unit 60B purification unit 60C purification unit 60D purification unit 62 discharge unit 64 first electrode 64a end 65 second electrode 65a electrode body 65b The flange portion 65c The inner cylinder portion 65d The connecting portion 66 The through hole 67 The cylindrical space 68 The leakage prevention material 70 The power supply portion 71 The insulating casing 72 The case body 72a The side wall portion 72b The bottom portion 73 The lid portion 74 The opening portion 76 The base portion 76a The insertion port 77 Convex part 79 Tip tube part 8 DESCRIPTION OF SYMBOLS 1 Nutrient solution tank 82 Water storage tank 83 Inflow piping 83a Heat transfer part 84 Outflow piping 94 Ultrasonic wave generation part 95 Piezoelectric ceramic board 96 Metal plate 97 Case 97a Metal case 101 Cultivation floor 102 Pump 103 Control part 200 Plant 307 Sensor 308 Ultrasonic waveform Generator 309 Amplifier 464 Electrode 465 Electrode 471a Insulating casing 471b Insulating casing 473a Lid 473b Lid 474a Open 474b Open 480a Case main body 480b Case main body 518 Air pump 519 Nozzle 520 Bubble generator 564 First electrode 565 Second electrode 654 Conductive portion 655 Insulating part 656 Conductive part 657 Insulating part 664 Electrode 665 Electrode

Claims (8)

A purification device for purifying the nutrient solution of the hydroponic cultivation system (10),
A heat pump (21) for adjusting the temperature of the nutrient solution;
A purification unit (60) for purifying the nutrient solution;
A control unit (103),
The purification unit (60) has a discharge part (62) for discharging in the nutrient solution and an ultrasonic generator (94) for irradiating the nutrient solution with ultrasonic waves,
The discharge part (62) applies a voltage to the electrode pair (64, 65, 464, 465, 564, 565, 664, 665) that causes the discharge in the nutrient solution and the electrode pair (64, 65, 464, 465, 564, 565, 664, 665). Having a power supply unit (70) to be applied, and configured to generate hydroxyl radicals in the nutrient solution by the discharge,
The ultrasonic generator (94) is configured to convert hydrogen peroxide in the nutrient solution generated by the generated hydroxyl radicals to change into hydroxyl radicals,
The said control part (103) controls the temperature adjustment of the said heat pump (21), operation | movement of the said discharge part (62), and operation | movement of the said ultrasonic generation part (94), The purification apparatus characterized by the above-mentioned.   The control unit (103) controls the operation and stop of the discharge unit (62) and the ultrasonic wave generation unit (94) so that the concentration of hydrogen peroxide in the nutrient solution is within a predetermined range. The purification apparatus according to claim 1. The control unit (103) has a concentration of hydrogen peroxide in the nutrient solution.
Until the preset lower limit value is reached, the discharge part (62) is in an operating state, the ultrasonic wave generation part (94) is in a stopped state,
After reaching the lower limit, until the preset upper limit is reached, the discharge part (62) and the ultrasonic wave generation part (94) are in an operating state,
The said discharge part (62) is made into a stop state and the said ultrasonic wave generation part (94) is made into an operation state after reaching the said upper limit, until it reaches the said lower limit. Purification equipment.   The purification device according to claim 2 or 3, further comprising a sensor for measuring a concentration of hydrogen peroxide in the nutrient solution. The electrode pair (564,565) is composed of plate-like electrodes arranged to face each other,
The power supply unit (70) is a pulse power supply that applies a pulse voltage to the electrode pair (564,565),
The said discharge part (62) has the bubble generation part (520) which generates a bubble in the said nutrient solution between the said electrode pair (564,565), The any one of Claims 1-4 characterized by the above-mentioned. The purification device according to item 1. The hydroponic system (10) has a cultivation floor (12) for planting a plant (14), and a nutrient solution passage (11,81) through which the nutrient solution circulates,
The said purification | cleaning unit (60) is arrange | positioned in the said nutrient solution channel | path (11,81), The purification apparatus of any one of Claims 1-5 characterized by the above-mentioned. The heat pump (21) has a compressor (23), an expander (25), a heat source side heat exchanger (26), and a use side heat exchanger (27), and refrigerates the refrigerant reversibly. A refrigerant circuit (22) for performing
The said utilization side heat exchanger (27) is arrange | positioned in the said nutrient solution channel | path (11), The purification apparatus of Claim 6 characterized by the above-mentioned.   The said purification | cleaning unit (60) is arrange | positioned in the water storage tank (82) which stores the nutrient solution which circulates through the said nutrient solution channel | path (81), The purification apparatus of Claim 6 or 7 characterized by the above-mentioned.

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