JPH07121187B2 - Heat sterilizer for liquid fertilizer for hydroponics - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to the sterilization of liquid fertilizer for hydroponics.
The present invention relates to a heating / cooling device and a method of using the device.

[0002]

2. Description of the Related Art The applicant of the present invention has filed a patent application for a heating and sterilizing apparatus for liquid fertilizer for hydroponics (Japanese Patent Laid-Open No. 3-1
No. 27918), the invention relates to a liquid storage tank for storing liquid fertilizer (nutrient liquid) returning from a cultivation bed, a pump for feeding the liquid fertilizer in the liquid storage tank to a heat exchange pipe arranged in the heat exchange tank, and a liquid fertilizer. A heat exchange tank for storing and internally storing a water-to-water heat exchanger in which a heat exchange pipe is arranged in the liquid fertilizer, a lower part and an upper part are connected by piping, and heat is transferred by the outlet and piping of the heat exchange pipe. It is equipped with a heating tank connected to the upper part of the exchange tank and housing the heating means inside, a liquid supply tank connected to the lower part of the heat exchange tank by a pipe, and supplying liquid fertilizer to the cultivation bed through the pipe. In the water heat exchanger, the liquid fertilizer in the liquid storage tank and the liquid fertilizer heated and sterilized in the heating tank exchange heat.

[0003]

The above-mentioned device is actually in use, and there is no particular problem.
To make more effective use of the device as it is currently installed,
More specifically, it was considered that the apparatus had the functions of heating and cooling the liquid fertilizer supplied to the cultivation bed and sterilizing the cultivation bed itself.

[0004]

The apparatus of the present invention includes a heating part (11), a heat exchange part (12) and a cooling part (13), and is used as a liquid fertilizer from the second tank (22) to the cultivation bed (24). The liquid fertilizer which has been supplied from the cultivation bed (24) is guided to the first tank (21), and is heated from the heating section (11) to the heat exchange section (1).
2), piping (20) to the outlet (17) through the cooling unit (13)
C), (20D), first path connected by (20G) (heating unit 11 → pipe 20C → heat exchange unit 12 → pipe 20D
→ Cooling part 13 → Piping 20G → Four-way valve 15 → Piping 20K →
A heating and sterilizing device for liquid fertilizer for hydroponic culture having an outlet 17), which passes through a part of a heat exchange part (12) from a heating part (11) and is connected to an outlet (17) by pipes (20C, 20E). 2nd route (heating section 11 → piping 20C → part of heat exchange section 12 → piping 20E → four-way valve 15 → piping 20K → outlet 1
7) and a third path (heating unit 11 → pipe 20) connected from the heating unit (11) to the outlet (17) by the pipe (20F).
F → four-way valve 15 → pipe 20K → outlet 17), and these paths can be selectively switched in the four-way valve (15) where they join.

In the method for sterilizing and heating liquid fertilizer of the present invention, the liquid fertilizer for hydroponics is introduced from the first tank (21) to the heat exchange section (12) through the inlet (16) and heated there, and the heating is performed. The heated liquid fertilizer is further heated and sterilized by the heating unit (11), the heated liquid fertilizer is passed through only a part of the heat exchange unit to lower the temperature to a predetermined temperature, and the cooled liquid fertilizer is cooled ( 13)
The second tank (2
It is characterized in that it is stored in 2) and then supplied to the cultivation bed (24).

Further, in the method for sterilizing a cultivation bed for hydroponic culture of the present invention, liquid fertilizer for hydroponic culture is introduced from an inlet (16) to a heating section (11) through a heat exchange section (12) and a predetermined heating section is used. Of the liquid fertilizer heated to the predetermined temperature and stored in the second tank (22) through the outlet (17), and the heated liquid fertilizer is heated from the second tank (22) to the cultivation bed (2).
4) and is used for sterilization of the cultivation bed.

[0007]

The apparatus 10 of the present invention comprises a heating section 11 and a heat exchange section 1.
2, the cooling unit 13 is included, and the apparatus 10 can switch the pipes by using the four-way valve 15, and the heat exchange unit 12 applies the first heating to the liquid fertilizer entering from the first tank 21. None, the heating unit 11 performs the second heating,
The second warmed liquid fertilizer gives heat to the liquid fertilizer coming from the inlet 17 at a part of the heat exchange section 12 to lower the temperature, and the lowered liquid fertilizer is stored in the second tank 22 and then stored in the second tank 22. Liquid fertilizer is supplied to the cultivation bed, or the liquid fertilizer heated in the heating unit 11 is supplied to the cultivation bed in which no plant exists through the second tank 22 without passing through the heat exchange unit 12 and the cooling unit 13. The bed is sterilized by heating.

[0008]

EXAMPLES There are three modes of using the apparatus 10 described above. To use for sterilization and cooling, liquid fertilizer is used in the cooling unit 1.
It is cooled to about 20 ° C. in 3 and is supplied to the cultivation bed 24 to maintain the cultivation bed at an appropriate temperature of about 25 ° C.

In the first embodiment of the present invention, in sterilizing and heating liquid fertilizer, the liquid fertilizer heated in the heating unit 11 is cooled to a predetermined temperature (approximately 30 ° C.) in the heat exchange unit and cooled. Since the liquid fertilizer is supplied to the cultivation bed 24 without doing so, the liquid manure is not only sterilized but also used as a nutrient solution while heating the cultivation bed.

In the second embodiment of the present invention, the heating unit 1
The liquid fertilizer is heated up to about 60 ° C in 1 and is heated in the second tank 2
It is supplied to the cultivation bed 24 where there is no crop through 2 to sterilize the pathogenic bacteria present in the cultivation bed 24, and the temperature of 60 ° C. is sufficient for sterilization after about 60 minutes, and the cultivation is continued. Sterilization does not damage the cultivation bed 24 (it is realized) because the temperature is such that the plastic material forming the bed does not soften.

The present invention will be described below in detail with reference to the embodiments shown in the drawings. FIG. 1 is a schematic diagram showing the basic arrangement of the device of the present invention. In the figure, the part surrounded by a chain double-dashed line and shown by reference numeral 10 is the device according to the present invention, 11 is a heating part, 12 is a heat exchange part,
13 is a cooling unit, 14 is a pump for flowing liquid fertilizer into the apparatus 10, 15 is a four-way valve, 16 is an inlet, 17 is an outlet, 20
A, 20B ... 20K are pipes, 21 is a first tank for storing liquid fertilizer (also referred to as nutrient solution) before treatment, 22 is a second tank for storing liquid fertilizer after treatment, and 23 is a liquid fertilizer circulated to the cultivation bed. Pump 24, cultivation bed 24, and crop 25. The cultivation bed 24 may be provided with a discharge port 26 instead of the pipe 20J.

The heating section 11 is a section for further heating the liquid fertilizer sent from the inlet 16 to the heat exchange section 12 by the pump 14 and heated in the heat exchange section, and is known as an electric heater or an oil-fired burner for heating. The heating means is used.

The heat exchange section 12 is a section containing a water-to-water heat exchanger 12A manufactured and sold by the present applicant, and the liquid fertilizer sent from the inlet 16 is heated by the heating section 11 in the heat exchange section 12. The liquid fertilizer is heated by exchanging heat with the liquid fertilizer, and further heated by the heating unit 11 to be sterilized, while the liquid fertilizer further heated by the heating unit 11 exchanges heat with the liquid fertilizer supplied by the pump 14 in the heat exchange unit 12. To lower the temperature.

When it is required to cool the liquid fertilizer, the heat exchange section 1
The liquid fertilizer supplied from 2 through the pipe 20D is cooled by the cooling unit 13. The cooling unit 13 cools the liquid fertilizer by using a cooler or groundwater, or when the outside air temperature is low, heat is exchanged with outside air by a radiator.

The heated or cooled liquid fertilizer is stored in the second tank 22 from the outlet 17 through the pipe 20H, is then supplied to the cultivation bed 24 by the pump 23, is made to flow in the cultivation bed in the direction of the arrow 1, and is then supplied. It is returned to the first tank 21.

The four-way valve 15 is manually or automatically switched. There are three ways of switching the pipes. In the case of "normal" shown in FIG. 1, the liquid fertilizer is heat-sterilized and then heat-exchanged to lower the temperature, and is sent to the second tank 22 as it is or after further cooling. FIG. 1 shows an example of cooling by the cooling unit 13.

In the case of "warming" shown in FIG. 1, heat sterilization of the liquid fertilizer is followed by heat exchange up to the middle of the water-to-water heat exchanger 12A of the heat exchange section 12, and the liquid fertilizer is shown in a warm state by a broken line 20E. It is sent to the four-way valve 15 through the path and then supplied to the second tank 22 through the pipe 20K.

In the case of "bed sterilization" shown by the alternate long and short dash line in FIG. 1, the liquid fertilizer is supplied to the second tank 22 through the outlet 17 through the pipe 20F while being heated and then to the cultivation bed 24. It

As can be understood from the above description, the apparatus shown in FIG. 1 has the following three paths. First route heating section 11 → piping 20C → heat exchange section 12 → piping 20D →
Cooling unit 13 → Pipe 20G → Four-way valve 15 → Pipe 20K → Outlet 17 Second path Heating unit 11 → Pipe 20C → Part of heat exchange unit 12 → Pipe 2
0E → Four-way valve 15 → Pipe 20K → Outlet 17 Third route Heating part 11 → Pipe 20F → Four-way valve 15 → Pipe 20K → Outlet 17

The device of FIG. 1 can only be used for the purpose of sterilizing liquid manure. An example of this use is shown in FIG. 2, which utilizes the heat exchange section 12 and the heating section 11 to perform heat sterilization of liquid fertilizer. It should be noted that the water-to-water heat exchanger 12A is omitted in FIGS. 2 and below for the sake of simplicity. Entrance 1
The liquid fertilizer at 20 ° C. in 6 is sent to the heat exchange section 12 by the pump 14 through the pipe 20A and heated, and when it exits the heat exchange section 12, the liquid fertilizer is heated to 75 ° C. and passes through the pipe 20B to the heating section 11.
Is heated to 80 ° C. there, enters the heat exchange section 12 via the pipe 20C, and the liquid fertilizer that has exchanged heat with the 20 ° C. liquid fertilizer in the heat exchange unit is cooled to 25 ° C. and the pipes 20D, 20G,
It is led from the outlet 17 to the second tank 22 through the four-way valve 15 and the pipe 20K. This use example is the same as the use form of the invention of the above-mentioned patent application. In this case, the pipes 20D and 20
The operation of the cooling unit 13 arranged between G and G is turned off, and liquid fertilizer only passes through.

In this example of use, the temperature of the liquid fertilizer at the outlet 17 is slightly higher (5 to 10 ° C.) than the liquid fertilizer temperature at the inlet 16. The rate of increase depends on the capacity of the heat exchanger, but is 100%
Close heat exchange is practically impossible. Due to the temperature rise of 5 ° C. to 10 ° C., when there is a certain amount of heat radiation from the cultivation bed 24 such as in the winter, or when the amount of liquid fertilizer to be processed is small as in rock wool cultivation, the temperature of the liquid fertilizer may affect the cultivation bed. Use this method for smaller cases.

In the example of use shown in FIG. 3, the heat exchange section 12 and the heating section 11 are used for heat sterilization, and then the cooling section 13 is used.
To cool. In summer, the outside temperature is high and the temperature of the cultivation bed is likely to rise, so that the load on the cooling unit 13 increases.

The liquid fertilizer flowing out of the heat exchange section 12 at a temperature of 25 ° C. passes through the pipe 20D and is cooled at a temperature of 25 ° C. in the cooling section 13.
Then, it is cooled to 20 ° C., stored in the second tank 22 through the pipe 20G, the four-way valve 15, the pipe 20K, the outlet 17, and the pipe 20H, and then supplied to the cultivation bed 24 by the pump 23. In addition to feeding the crop 25, the liquid fertilizer keeps the temperature in the cultivation bed 24 at an appropriate temperature of about 25 ° C.

The first embodiment of the present invention is an example of sterilization heating shown in FIG. The heat exchange unit 12 and the heating unit 11 are used to heat and sterilize the liquid fertilizer, but a part of the water-to-water heat exchanger of the heat exchange unit 12 is not used, and the liquid fertilizer is cultivated in a state in which the temperature is high to some extent. Supply to. This method is used when the temperature of the cultivation bed tends to decrease, such as in the severe winter season.

The process until the liquid fertilizer at 80 ° C. is supplied to the heat exchange unit 12 is the same as in the case of FIGS. 2 and 3, but in the example of FIG. 4, liquid fertilizer is fed from the middle of the heat exchanger of the heat exchange unit. The liquid fertilizer outlet is set so that the temperature of the liquid fertilizer coming out of the heat exchanger is about 30 ° C.

Further, the liquid fertilizer at 30 ° C. is stored in the second tank 22 at a temperature of 30 ° C. through the pipe 20E and the outlet 17,
Then, it is supplied to the cultivation bed 24 through the pipe 20I to heat the cultivation bed and feed the crop 25.

The second embodiment of the present invention is the cultivation bed sterilization shown in FIG. The liquid fertilizer is sterilized by heating using only the heating unit 11, and the liquid fertilizer is supplied to the cultivation bed at a high temperature and sterilized. This method is carried out to kill pathogenic bacteria that have adhered to the cultivation bed when there is no crop in the cultivation bed.

In the hydroponic culture, even if only a small amount of pathogenic bacteria enters the liquid fertilizer, the liquid fertilizer is supplied to the cultivation bed at a temperature suitable for the pathogenic bacteria at 20 ° C to 25 ° C. Proliferate and spread inside. The liquid fertilizer is sterilized for the purpose of preventing it, but the sterilization of the cultivation bed is performed by selecting the time when no crop is cultivated in the cultivation bed in order to eliminate the pathogenic bacteria.

Conventionally, the sterilization of the cultivation bed has been performed by either a method using a drug or a method using steam. However, recently, the use of drugs is considered to be unfavorable from the viewpoint of the effects on crops and the environment. Although the use of steam does not have the above-mentioned effect, it requires a device such as a boiler to prepare the steam, and there is a risk that the user will be burned, which is a problem in practice.

Therefore, in the present invention, as shown in FIG. 5, the liquid fertilizer heated to 60 ° C. in the heating section 11 is directly connected to the pipe 20C, the pipe 20F indicated by the alternate long and short dash line, and the four-way valve 1.
5, through the pipe 20K, the outlet 17 directly to the second tank 22, the liquid fertilizer at 60 ℃ from the second tank 22 by the pump 23 through the pipe 20I, the cultivation bed 2 without crops.
Supply to 4.

There are two reasons for heating liquid fertilizer to 60 ° C.
One is that most of the bacteria that pose a problem in cultivation can be sterilized even if the liquid fertilizer at 60 ° C is used for 60 minutes, and the second is that most of the materials generally used in the field of hydroponics are plastic materials. Since many of these plastic materials soften above 60 ° C,
The upper limit of the temperature of the liquid fertilizer supplied to the cultivation bed is about 60 ° C.

In the embodiment described above, the cultivation bed 24 is used.
Although the description has been made only up to the point of supplying the liquid fertilizer to the first embodiment, the liquid fertilizer is returned from the cultivation bed 24 to the first tank 21 using the pipe 20J, and the above-described process is repeated. The operation and circuit of each part are switched and used according to the purpose of use, but it is possible to automate by incorporating an electric valve, a thermostat, or the like.

In the example of FIGS. 2 to 4 described above, the liquid fertilizer used in the cultivation bed 24 is returned to the first tank 21 through the pipe 20J, but instead is discharged from the discharge port 26 to the outside. Can be When and under what conditions discharge is determined by the usage of the cultivation bed, but the discharge port 26 is useful when replacing the liquid fertilizer that has been used with another liquid fertilizer. The discharge port 26 is the pipe 20
It is also possible to provide a valve at the connection part of the cultivation bed of J and to operate the valve to discharge the liquid fertilizer to the outside of the pipe 20J.

Table 1 shows the modes of use of the apparatus of the present invention described above. In addition, in the column of the heat exchange section in Table 1, the terms "primary side (low temperature side)" and "secondary side (high temperature side)" refer to the side entering the water-to-water heat exchanger 12A from the pipe 20A and the pipe 20C, respectively. Say.

[0035]

[Table 1]

[0036]

As described above, according to the present invention,
By using one device for hydroponic culture, only four sterilization modes, sterilization liquid fertilizer cooling and sterilization liquid fertilizer heating, and bed sterilization are possible, and liquid fertilizer is used by diversifying one device. The effect of expanding the use of hydroponics was obtained.

[Brief description of drawings]

FIG. 1 is an overall view showing the arrangement of the device of the present invention.

FIG. 2 is a diagram showing one usage state of the apparatus of FIG.

FIG. 3 is a diagram showing another usage state of the apparatus of FIG.

FIG. 4 is a diagram of a first embodiment of the present invention.

FIG. 5 is a diagram of a second embodiment of the present invention.

[Explanation of symbols]

 10 Device of the Present Invention 11 Heating Section 12 Heat Exchange Section 12A Water-to-Water Heat Exchanger 13 Cooling Section 14 Pump 15 Four-way Valve 16 Inlet 17 Outlet 20A, 20B ... 20K Piping 21 First Tank 22 Second Tank 23 Pump 24 Cultivation bed 25 Crop 26 Discharge port

Claims (3)

[Claims] 1. A liquid fertilizer is supplied from a second tank (22) to a cultivating bed (24) including a heating section (11), a heat exchange section (12) and a cooling section (13), and the cultivating bed (24).
The liquid fertilizer discharged from the tank is guided to the first tank (21), and the heating section (1
The first route (heating unit 11 → pipe 20C → heat ) that is connected to the outlet (17) through the pipes (20C), (20D) and (20G) from 1) through the heat exchange unit (12) and the cooling unit (13) Exchange
Section 12 → piping 20D → cooling section 13 → piping 20G → four-way valve
A heating and sterilizing device for liquid fertilizer for hydroponic cultivation, which comprises 15 → pipe 20K → exit 17) , which passes through a part of a heat exchange part (12) from a heating part (11) to a pipe (20C, 20E) Second path connected (heating section 11 → pipe 20C → part of heat exchange section 12 →
Piping 20E → four-way valve 15 → piping 20K → outlet 17) , and heating section (11) through piping (20F) to outlet (17)
Third route connected to (heating part 11 → piping 20F → square
Valve 15 → piping 20K → exit 17) and Ri name provided, this
These routes are selected at the four-way valve (15) where they meet.
Heat sterilization apparatus of hydroponics for liquid manure, characterized in possible der Rukoto switched択的. 2. A first tank (21) for supplying liquid fertilizer for hydroponics.
Through the inlet (16) to the heat exchange section (12) where it is heated, and the heated liquid fertilizer is further heated and sterilized in the heating section (11), and the heated liquid fertilizer is heated in the heat exchange section . Only a part of the liquid is allowed to pass through to cool to a predetermined temperature, and the cooled liquid fertilizer is cooled (1
A method for sterilizing and heating liquid fertilizer for hydroponic cultivation, characterized in that the liquid fertilizer is stored in the second tank (22) through the outlet (17) without being cooled in 3) and then supplied to the cultivation bed (24). 3. A liquid fertilizer for hydroponic culture is introduced from an inlet (16) through a heat exchange section (12) to a heating section (11), and is heated to a predetermined temperature by the heating section (11) to obtain the predetermined temperature. The liquid fertilizer heated up to 10 is stored in the second tank (22) through the outlet (17), and the heated liquid fertilizer is supplied from the second tank (22) to the cultivation bed (24) and used for sterilization of the cultivation bed. Method for sterilizing a cultivation bed for hydroponics.