JPH044850B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a plant cultivation nutrient solution preparation device used for hydroponic cultivation, etc., and in particular, it relates to a plant cultivation nutrient solution preparation device for use in hydroponic cultivation, etc., and in particular, a highly concentrated undiluted solution of a nutrient solution necessary for cultivation such as fertilizer. and the dilution of highly concentrated nutrient solutions with agricultural water, etc.

[Conventional technology]

In contrast to conventional soil cultivation, which uses soil to cultivate plants, plants are planted in an artificial culture medium such as fibrous materials, and nutrients such as fertilizers necessary for growth are dissolved in water. There is culture cultivation in which cultivation is performed by supplying a nutrient solution.

Compared to soil cultivation, culture medium cultivation has excellent characteristics such as being more hygienic, allowing optimal growth conditions to be set for each plant to be cultivated, and easy cultivation management. It is extremely important to control the concentration of the nutrient solution.

FIG. 3 shows an outline of a general hydroponic cultivation apparatus for plants. This hydroponic cultivation device uses a nutrient solution mixing and diluting device 2 along with dilution water Wr such as agricultural water.
A highly concentrated nutrient solution (hereinafter referred to as undiluted solution M) containing dissolved fertilizer, etc. as the basis of Wm is supplied from the undiluted solution tank 4, and this undiluted solution M is mixed with dilution water Wr.
By diluting the nutrient solution Wm, a nutrient solution Wm with a fertilizer concentration suitable for growing plants is obtained.

Then, this nutrient solution Wm is sent to the cultivation area 10 via a nutrient solution supply device 6 consisting of a pressure pump, a filter, etc., and a supply pipe line 8. In the cultivation area 10, a plurality of branch pipes 12 attached to the supply pipe line 8 are arranged near the bed 16 in which the plants 14 are planted, and a drip nozzle 18 as a supply nozzle is provided to each branch pipe 12 for each plant. will be established. Therefore,
The nutrient solution Wm pressure-fed through the supply pipe line 8 is dripped and supplied to the vicinity of the plants 14 from the drip nozzle 18 via the branch pipe 12.

[Problem that the invention seeks to solve]

In such a hydroponic cultivation device, the formulation of the nutrient solution Wm needs to be set to the optimal fertilizer distribution and concentration for the plants 14, and the fertilizer distribution and concentration differ for each plant 14. Since it varies greatly depending on the growth state and weather conditions, it is necessary to set the fertilizer distribution and concentration of the nutrient solution Wm while referring to growth data and weather data each time.

Conventionally, in mixing and diluting the nutrient solution Wm for diluting the stock solution M by mixing it with the dilution water Wr, the dilution water
In a diluter that sucks in Wr, the dilution ratio of the stock solution M varies depending on the flow rate wr and pressure of the dilution water Wr, making it impossible to obtain a constant concentration of the nutrient solution Wm.
It was not possible to freely change the concentration. Therefore, when the dilution ratio changes, it is necessary to change the fertilizer concentration of the stock solution M, which requires very troublesome work.

In addition, as a way to automate the conventional preparation of nutrient solution Wm, a certain amount of dilution water is added to the nutrient solution mixing and diluting device 2.
After incorporating Wr, stock solution M with a specific concentration is added to it.
There is a method in which the necessary concentration is set by gradually adding Wm and monitoring the concentration of the nutrient solution Wm using a concentration sensor. This is because the nutrient solution Wm is prepared by taking in the dilution water Wr in fixed amounts, so there is no need to continuously correct the concentration. Continuous supply control of the nutrient solution Wm cannot be performed, and the nutrient solution
In order to set a constant concentration for Wm, an expensive concentration sensor was required.

For this reason, the flow rate of dilution water Wr for the concentration setting is
A plant cultivation nutrient solution preparation device has been proposed that obtains a nutrient solution Wm by continuously controlling the supply amount of the stock solution M according to wr.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plant cultivation nutrient solution mixing device that can appropriately control the concentration by taking into account the concentration data of the nutrient solution prepared according to the concentration setting and the flow rate of dilution water.

[Means for solving problems]

The plant cultivation nutrient solution preparation device of this invention has a dilution water
Dilution water supply line where Wr is supplied (supply line 30)
and the nutrient solution supply path (supply path 34) which is to supply the nutrient solution Wm to the culture medium (cultivation area 10), receives dilution water from the dilution water supply path, and uses this dilution water to Mixing and diluting means (mixing diluter 22, mixing and diluting means) which dilutes the stock solution Ma, Mb or both stock solutions to form the nutrient solution, and flows out the nutrient solution to the medium side according to the water pressure of the dilution water. tank 23), a first stock solution tank 28A for storing the first stock solution to be supplied to the mixing and diluting means, and a second stock solution tank for storing the second stock solution to be supplied to the mixing and diluting means. 28B, a first quantitative discharger 26A installed in the stock solution supply path between the first stock solution tank and the mixing and diluting means to supply the first stock solution to the mixing and diluting means; a second quantitative discharger 26B installed in the stock solution supply path between the second stock solution tank and the mixing and diluting means and supplying the second stock solution to the mixing and diluting means;
Alternatively, a driving means (a fixed-rate dispenser drive circuit 32) for driving the second fixed-rate dispenser, a flow rate sensor 20 installed in the dilution water supply path to detect the flow rate of the dilution water, and a flow sensor 20 for detecting the flow rate of the dilution water in the nutrient solution supply route. First and second concentration sensors 27A and 27B installed in the provided concentration detection unit 29 to detect the concentration of the nutrient solution, and the flow rate data from the flow rate sensor and concentration data set in advance according to the cultivation conditions. A stock solution amount calculating unit 241 is installed to calculate the supply amount of the first or second stock solution to be supplied to the mixing and diluting means from the first or second stock solution.
a detection signal comparison unit 242 that compares the detection signal obtained by the second concentration sensor with the detection signal of the second concentration sensor to determine a deviation in the detected concentration, and generates a determination signal indicating whether or not the deviation is within a standard; A stock solution amount correction unit that is installed and corrects the stock solution amount calculated by the stock solution amount calculation unit using the judgment signal obtained by the detection signal comparison unit and the detection signal of one or both of the first and second concentration sensors. A section 243 is installed, which generates a control output based on the corrected stock solution amount obtained by the stock solution amount correction section, and operates the first or second metering dispenser through the drive means in accordance with this control output, The present invention is characterized by comprising a stock solution amount control device 24 for supplying the first stock solution, the second stock solution, or both stock solutions to the mixing and diluting means.

[Effect]

According to this cultivation nutrient solution mixing device, the necessary stock solution amount mn can be obtained for the concentration setting of the nutrient solution Wm and the flow rate wr of the dilution water Wr. Concentration sensor 27A, 27B
The detection outputs of the first and second concentration sensors 27 are compared, and when the detection error of both is within a certain range, the detection outputs of the first and second concentration sensors 27 are compared.
The stock solution volume mn is corrected based on the detection outputs of A and 27B or the detection outputs of the first and second concentration sensors 27A and 27B to set an appropriate stock solution volume mo, and the stock solution M set to this stock solution volume mn is and dilution water Wr, the stock solution volume mn is controlled in immediate response to flow fluctuations of dilution water Wr, and the final output nutrient solution
The reliability of Wm concentration is increased.

In this case, the preparation of the nutrient solution Wm consists of multiple stock solutions Ma,
When using Mb, this refers to mixing and diluting each stock solution Ma, Mb and dilution water Wr, and when using a single stock solution M, mixing and diluting the stock solution M with dilution water Wr.

In this cultivation nutrient solution mixing device, the first
The second concentration sensors 27A and 27B are connected to the nutrient solution Wm of the concentration detection unit 29 installed on the output side of the mixing diluter 22 or the nutrient solution in the mixing dilution tank 23.
If installed within Wm, the concentration of the nutrient solution Wm can be detected reliably.

[First Embodiment] FIG. 1 shows a first embodiment of the plant cultivation nutrient solution preparation device of the present invention.

For example, agricultural water such as groundwater or rainwater is used as the dilution water wr for obtaining the nutrient solution Wm with a specific concentration. This dilution water Wr is continuously supplied from a tank or the like (not shown) through a supply pipe line 30 serving as a dilution water supply line. A flow rate sensor 20 is installed as a detection means, and the flow rate wr of the dilution water Wr is electrically detected by this flow rate sensor 20.

Vwr indicates a flow rate signal representing the flow rate wr of dilution water Wr.

Then, the dilution water Wr is mixed with the stock solution M by a mixing diluter 2 installed as a mixing and diluting means.
2. Dilution water of this mixing diluter 22
First and second stock solution tanks 28A and 28B are installed as stock solution storage means for storing first and second fertilizer stock solutions to be supplied to Wr. The two stock solutions Ma and Mb are supplied to the mixing diluter 22 via first and second metering dispensers 26A and 26B as electrically controlled stock solution supply means. The supply of the stock solutions Ma and Mb to the mixing diluter 22 is set, for example, so that the necessary amount of the stock solution Ma or Mb is dripped by gravity or a specific pressure through the metering dispensers 26A and 26B.

In addition, a supply pipe line 30 on the output side of the mixing diluter 22
The nutrient solution prepared by the mixer diluter 22 is
A concentration detection unit 29 for detecting the concentration of Wm is provided, and this concentration detection unit 29 includes first and second
The first and second concentration sensors 27A, 2 electrically detect the concentration of the nutrient solution Wm as concentration detection means.
7B is installed.

Then, the flow rate signal obtained by the flow rate sensor 20
Vwr is applied to the stock solution amount calculation section 241 of the stock solution amount control device 24 installed as a stock solution amount control means. The stock solution amount calculation unit 241 calculates the stock solution amount necessary to obtain the concentration Xn from the flow rate data obtained by the constantly changing flow rate signal Vwr and the concentration data representing the concentration Xn set as necessary. mn
Calculate. For example, this stock solution amount calculation section 241
For flow rate data and concentration data, a storage means is installed that stores stock solution volume data according to the flow rate data, and the required stock solution volume mn data is read out by inputting the flow rate data and concentration data. Make it. Vwn represents the stock volume signal.

Further, the concentration of the nutrient solution Wm is detected from the nutrient solution Wm of the concentration detection unit 29 by concentration sensors 27A and 27B, respectively, Vna is a concentration signal representing the concentration Na obtained by the concentration sensor 27A, and Vnb is a concentration signal representing the concentration Na obtained by the concentration sensor 27A. This is a concentration signal representing the concentration Nb obtained by the concentration sensor 27B. Each concentration signal Vna, Vnb is applied to a detection signal comparison unit 242 that compares the detection output and detects an abnormality in the detection output from the deviation, and calculates the deviation between the two, and the deviation value ΔN is within a certain error range. Judgment signal that determines whether or not and indicates pass/fail.
Output Vgn.

Then, the undiluted solution amount signal of the undiluted solution amount calculation section 241
Vmn, the judgment signal Vgn of the detection signal comparison section 242, and the first and second concentration sensors 27A, 2
The concentration signals Vna and Vnb from 7B are sent to the stock solution amount correction unit 24.
Added to 3. When the determination signal Vgn does not indicate an abnormality detected by the concentration sensors 27A, 27B, the raw solution amount correction unit 243 adjusts the output side concentration Na,
The amount of stock solution mo is corrected according to Nb, but when the judgment signal Vgn indicates a detection abnormality of the concentration sensors 27A and 27B, the judgment signal Vgn indicating the abnormality
Detection abnormality signal Vx is generated based on the detected abnormality signal Vx.

In this case, the determination signal Vgn is the density sensor 27A,
When no abnormality is detected in 27B, the nutrient solution Wm
The method of correcting the stock solution volume mo using the output side concentrations Na and Nb is to use either the detected concentrations Na or Nb as the correction data, or to use the average (for example, arithmetic mean) value of the detected concentrations Na or Nb as the correction data. The former method includes a method of taking a small value or a large value of the detected concentrations Na and Nb, and a method of using the detected concentrations Na and Nb alternately as correction data.

Regardless of which method is adopted, the stock solution amount correction section 2
43 compares the concentration signal Vn and the set concentration signal Xn to find the deviation, and uses the deviation to correct the stock solution volume signal Vmn representing the stock solution volume mn from the stock solution volume calculation unit 241 to obtain an appropriate value. A stock solution amount signal Vmo representing the stock solution amount mo is output.

If there is an abnormality in concentration detection,
The stock solution volume mn is output as the corrected stock solution volume mo, and the generated detection abnormality signal Vx is added to the detection abnormality alarm 31.
Notify Wm detection abnormality. Detection abnormality alarm 3
1 can be composed of optical means such as a lamp, sound generating means such as a buzzer, etc.

Then, the amount of stock solution obtained by the stock solution amount correction unit 243
The original yield signal Vmo representing mo is applied to the stock solution amount supply control section 242 to generate the stock solution control signal Vcm for supplying the required stock solution amount mo. In this case, for example, the blending ratio of the stock solutions Ma and Mb is calculated simultaneously based on the stock solution volume signal Vmo, and for example, each stock solution Ma, Mb is automatically calculated according to the concentration data.
By setting the blending ratio of Mb, the blending ratio can be obtained for determining the concentration. Therefore, the stock control signal
Vcm is the stock solution Ma for setting the required concentration,
This is a data signal representing the amount of Mb and its blending ratio.

The stock solution control signal Vcm is applied to a metering dispenser drive circuit 32 installed as a stock solution supply drive means, and the metering dispenser drive circuit 32 receives the stock solution control signal.
Drive signals Va and Vb corresponding to Vcm are output and applied to each metering dispenser 26A and 26B. Fixed amount dispenser 26
A, 26B indicate the fixed quantity dispenser 2 for the supply ratio of the stock solutions Ma, Mb set in the stock solution control signal Vcm.
The operation time of 6A and 26B is controlled, and the dilution water
The stock solution Ma or the stock solution Mb, or both, is supplied to the mixing diluter 22 in an amount necessary to obtain the set concentration Xn for the flow rate wr of Wr.

The supplied stock solutions Ma and Mb are transferred to the mixing diluter 22
A nutrient solution Wm of a required concentration is obtained by stirring inside the dilution water Wr according to the flow of the dilution water Wr, and is supplied to the cultivation area through a supply path 34 serving as a nutrient solution supply path. In that case, the nutrient solution Wm is sent by the nutrient solution supply device 6 with a pressure necessary for the cultivation value, as shown in FIG.

Therefore, according to such a cultivation nutrient solution mixing device, the necessary stock solution amount mn can be obtained for the concentration setting of the nutrient solution Wm and the flow rate wr of the dilution water Wr, but the concentration of the nutrient solution Wm cannot be detected. Concentration sensor 27A, 27
When the detection output of B is compared and the detection error of both is within a certain range, the detection output of either concentration sensor 27A, 27B or concentration sensor 27A, 27B is detected.
The stock solution volume mn is corrected based on the detection outputs of both to set an appropriate stock solution volume mo, and the stock solution M set to this stock solution volume mo is mixed with the dilution water Wr, so that the flow rate fluctuation of the dilution water Wr is reduced. In addition to controlling the stock solution amount mo in immediate response to this, it is possible to improve the reliability of the concentration of the final output nutrient solution Wm.

By the way, the plant cultivation nutrient solution mixing device of the present invention uses a diluter that calculates the dilution level based on the flow rate of dilution water and the set concentration, and dilutes the stock solution based on the calculation result. In order to compensate for errors that occur due to control, the concentration of the diluted nutrient solution is measured, and corrections corresponding to the errors are made to ensure proper dilution. In such concentration control, first and second concentration sensors 27A and 2 which are concentration measuring means for measuring the concentration of the nutrient solution are used.
The reliability of 7B greatly affects the reliability of the entire control system. Therefore, in order to improve the reliability of the entire control system, two concentration sensors 27A and 27B are installed, and by comparing and determining the detection signals of both, 1
This compensates for the reliability loss caused by two detectors. Here, in the comparative judgment by both concentration sensors 27A, 27B, it is determined that the detection signal level of both concentration sensors 27A, 27B is normal if it is within a specific range, and the concentration signals obtained by the concentration sensors 27A, 27B are determined to be normal. Since the set concentration is corrected using either or both of Vna and Vnb and the stock solution is diluted, highly accurate nutrient solution preparation or dilution becomes possible. When both the concentration sensors 27A and 27B have an extreme level difference or are not within a specific range, it is determined that there is an abnormality.In that case, an alarm is generated and notified without performing concentration correction, and the concentration of the nutrient solution is determined. This prevents abnormalities from occurring and avoids danger.

Moreover, detection abnormalities of the concentration sensors 27A and 27B can be known from their detection outputs, and the occurrence of abnormalities in concentration control can be prevented.

The stock solution amount control device 24 is constituted by an arithmetic processing device such as a microcomputer, and can control the stock solution amount.

[Second Embodiment] FIG. 2 shows a second embodiment of the plant cultivation nutrient solution preparation device of the present invention.

In the embodiment shown in FIG. 1, a concentration detection section 29 is installed on the output side of the mixing diluter 22,
7A and 27B were installed, but as shown in FIG. 2, concentration sensors 27A and 27B as first and second concentration detection means were installed inside the mixing dilution tank 23 installed as the mixing and dilution means. , concentration signal Vna from each concentration sensor 27A, 27B,
Vnb may be used for density correction.

In this case, the mixed dilution tank 23 is mixed with the nutrient solution Wm inside and mixed with the undiluted solutions Ma and Mb and diluted water.
A stirring pipe 36 is provided with a stirring pump 35 as a stirring means for quickly mixing with Wr. If such a stirring pipe 36 is installed, the circulation of the nutrient solution Wm will allow the mixing and dilution tank 2
The nutrient solution Wm of 3 is generated and the nutrient solution Wm is stirred,
The nutrient solution Wm can be quickly mixed and diluted.

The rest of the configuration is the same as that of the first embodiment, so a description thereof will be omitted.

[Modified example]

In each embodiment, first and second stock solution tanks 28A and 28B are installed to store two kinds of stock solutions Ma,
We have explained the case of using Mb, but it is possible to mix fertilizers with the necessary ingredients in advance and set up the necessary stock solution tank, or to install a stock solution tank for each fertilizer to avoid inconveniences caused by combinations of fertilizers. , fertilizer may be mixed according to the concentration setting.

Further, in this invention, the fertilizer stock solution is stored in the first stock solution tank 28A, and the PH is stored in the second stock solution tank 28B.
If the concentration correction stock solution is stored, it can be used to correct the PH concentration.

〔Effect of the invention〕

As explained above, according to the present invention, the amount of stock solution required for the flow rate of dilution water is calculated according to the concentration setting of the nutrient solution, and the amount of stock solution is controlled based on the calculation result. In addition to being able to control the amount of stock solution in immediate response to fluctuations in the flow rate of the nutrient solution, the concentration of the nutrient solution is detected by the first and second concentration sensors, and the detection outputs of both are compared to detect the presence or absence of an abnormality.
Since the set concentration and the detected nutrient solution concentration are compared and the amount of stock solution is corrected based on the error, it is possible to mix, dilute, and continuously prepare the nutrient solution at the set stock solution concentration and supply it to the culture medium. This can contribute to highly reliable hydroponic cultivation.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a first embodiment of the plant cultivation nutrient solution blending device of the present invention, FIG. 2 is a block diagram showing a second embodiment of the plant cultivation nutrient solution blending device of the present invention, and FIG. The figure is a block diagram showing an outline of a general hydroponic system for plants. Wm... Nutrient solution, Wr... Dilution water, Ma... First stock solution, Mb... Second stock solution, 20... Flow rate sensor, 22... Mixing diluter (mixing dilution means), 2
3... Mixing dilution tank (mixing dilution means), 2
4... Raw solution amount control device, 26A... First fixed amount dispenser, 26B... Second fixed amount dispenser, 27A...
First concentration sensor, 27B...Second concentration sensor, 28A...First stock solution tank, 28B...Second stock solution tank, 29...Concentration detection unit, 30...
Supply pipe line (dilution water supply line), 31... Concentration abnormality alarm, 32... Fixed amount dispenser drive circuit (drive means),
34... Supply path (nutrient solution supply path), 241... Raw solution amount calculation section, 242... Detection signal comparison section, 243...
...Standard solution volume correction section.

Claims (1)

[Scope of Claims] 1. A dilution water supply channel that is inserted between a dilution water supply channel to which dilution water is supplied and a nutrient solution supply channel that is to supply nutrient solution to the culture medium to receive dilution water from the dilution water supply channel; a mixing and diluting means for diluting the first or second stock solution or both stock solutions with dilution water to form the nutrient solution, and flowing out the nutrient solution to the medium side according to the water pressure of the dilution water; a first stock solution tank for storing the first stock solution to be supplied to the diluting means; a second stock solution tank for storing the second stock solution to be supplied to the mixing and diluting means; and the first stock solution tank. and a first quantitative discharger installed in a stock solution supply path between the stock solution tank and the mixing and diluting means to supply the first stock solution to the mixing and diluting means; and the second stock solution tank and the mixing and diluting means. a second metering dispenser installed in the stock solution supply path between the device and supplying the second stock solution to the mixing and diluting device; and a driving device for driving the first or second metering dispenser. , a flow rate sensor installed in the dilution water supply path to detect the flow rate of the dilution water, and first and second flow rate sensors installed in the concentration detection section provided in the nutrient solution supply path to detect the concentration of the nutrient solution. a concentration sensor, and a stock solution that calculates the supply amount of the first or second stock solution to be supplied to the mixing dilution means from the flow rate data from the flow rate sensor and concentration data set in advance according to cultivation conditions. A quantity calculation unit is installed, and a detection signal obtained by the first concentration sensor and a detection signal from the second concentration sensor are compared to determine a deviation in the detected concentration, and a determination is made to indicate whether or not the deviation is within a standard. A detection signal comparison unit that generates a signal is installed, and the raw solution amount calculation unit calculates the determination signal obtained by the detection signal comparison unit and the detection signal of one or both of the first and second concentration sensors. A stock solution amount correction section is installed to correct the stock solution amount obtained by the stock solution amount correction section, and generates a control output based on the corrected stock solution amount obtained by the stock solution amount correction section. Operate the metered dispensing device,
A plant cultivation nutrient solution mixing device comprising: a stock solution amount control device for supplying the first stock solution, the second stock solution, or both stock solutions to the mixing and diluting means. 2. The stock solution amount control device is configured to generate an abnormal concentration signal when the error in the concentration of the nutrient solution becomes large with respect to the set concentration, and the alarm is activated by the abnormal concentration signal. A plant cultivation nutrient solution preparation device according to claim 1, characterized in that: