JPS5840455B2 - Automatic nutrient solution supply control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic preparation and supply control device for a nutrient solution for plant cultivation.

In recent years, with the spread of greenhouse horticulture such as soybeans and flowering plants, grasshoppers have become larger and more immobile, and due to continuous cropping, salt accumulation in grassland soil and soil diseases have become major problems.

Hydroponic cultivation has attracted attention as an effective means to improve the labor productivity of vegetable and flower cultivation and to solve the above problems.
Research is being carried out in various places, and it is at the stage where it will be incorporated into actual management and become widespread.

There are various types of hydroponic cultivation, such as hydroponics, gravel cultivation, sand cultivation, dump cultivation, spray cultivation, and hydroponics, but the basic method of supplying the culture solution is to install a culture solution tank and use a pump for cultivation. A method is adopted in which the culture medium is supplied to the bed, and the excess liquid is collected and reused.

In hydroponic cultivation, the water and nutrients required by plants all depend on the culture solution, so the concentration of the culture solution, the composition of fertilizer components, and the interval and time of supply of the culture solution are extremely important.

Currently, the culture solution is prepared by sequentially dissolving several types of inorganic salts, or by dissolving a mixture of inorganic salts that has been mixed in advance at a certain ratio.

However, it is usually impossible to dissolve and mix solid fertilizer salts in a culture solution tank of several m3, so a stock solution with a concentration of 5 to 10% of the nutrient solution used is prepared and used. The method used is to dilute it in culture medium.

However, in actual situations, it takes time and effort to dissolve fertilizer salts, so they are not dissolved properly, causing precipitation at the bottom of the tank or forming insoluble salts, resulting in poor growth and nutrient deficiencies due to an imbalance in the composition of the culture solution. However, many problems remained.

In addition, two culture solution tanks, a stock solution tank and a circulation nutrient solution tank, are required, and if the area becomes large, a large capacity tank is required, which increases the equipment cost.

In addition, in order to maintain a constant concentration of the culture solution, either analyze the fertilizer components in the culture solution tank and make up for the shortage with fertilizer salt based on calculations, or measure the electrical conductivity (EC meter) of the culture solution and use concentrated undiluted solution. A method is used to replenish the EC and adjust it to a constant EC, but the analysis operation requires skill and cannot be done overnight and requires a specialist.

Adjusting the nutrient solution using an EC meter is simple and can save a certain amount of labor, but the conventional method of diluting the stock solution using 5 to 10 cultures requires the preparation of the stock solution frequently, so it is not possible to achieve significant labor savings.

Furthermore, in hydroponic cultivation, intermittent warm drainage is generally carried out using a timer, but there is a high risk of damage from drying out or over-humidification depending on the weather and the growth stage of the crop. Many problems remained.

The present inventors have conducted various studies in order to develop an ideal automatic culture solution supply control device for hydroponic cultivation that overcomes these drawbacks, and as a result has achieved the present invention.

The present invention includes a nutrient solution tank 1 which is provided with a liquid level gauge 5 inside, the content nutrient solution is supplied to the cultivation bed 3 through a line 12, and the surplus nutrient solution is returned and collected through a line 13, and a liquid level gauge 6 inside. The nutrient solution adjustment tank 2 is equipped with a nutrient solution adjustment tank 2 in which the nutrient solution is adjusted and stored, and the nutrient solution in the nutrient solution tank 1 is consumed and the liquid level in the tank is detected by the liquid level gauge 5 at a preset lower surface level. When it descends to the top, the communication line 8 between the nutrient solution tank 1 and the nutrient solution adjustment tank 2 is connected via the relay in the controller 11.
is opened, the nutrient solution adjusted and stored in the nutrient solution adjustment tank 2 is supplied to the nutrient solution tank 1, and the liquid level in the nutrient solution adjustment tank 2 reaches the lower surface detection level set in advance by the liquid level gauge 6. When descending, the electromagnetic valve 7 closes the communication line 8 via the relay in the controller 11, and the liquid level in the nutrient solution adjustment tank 2 is supplied to the nutrient solution tank 1, and the lower surface of the liquid level gauge 6 is detected. After the liquid level has descended to the level, the water supply line 14 communicating with the nutrient solution adjustment tank 2 is opened via the relay in the controller 11 until the liquid level reaches the upper surface detection level preset by the liquid level gauge 6. , a solenoid valve 9 that closes after supplying water or water-liquid fertilizer, and a mixing dilution device that quantitatively mixes liquid fertilizer into water through one or more liquid fertilizer suction devices in the middle of the water supply line 14; A liquid fertilizer mixing device 1 that directly supplies a certain amount of liquid fertilizer into the nutrient solution adjustment tank 2 in accordance with the amount of water supplied to the same tank.
This is an automatic nutrient solution supply control device configured by installing 0 and 0.

The present invention will be explained below with reference to the drawings.

FIG. 1 is a principle diagram of the automatic nutrient solution supply control device according to the present invention;
Figure 2 shows a principle diagram of a liquid fertilizer quantitative supply device that sucks and mixes the same liquid fertilizer into a water supply line, and Figure 3 shows a principle diagram of a similar liquid fertilizer supply device to a nutrient solution adjustment tank. .

That is, the nutrient solution tank is filled with a nutrient solution for plant cultivation adjusted to a preset optimal fertilizer concentration in an amount that maintains a constant liquid level.

Each of the nutrient solution tanks 1 is equipped with a liquid level gauge 5 for constantly measuring and instructing the level of the nutrient solution.

This liquid level gauge is preferably of a floatless type.

The nutrient solution filled in the nutrient solution tank 1 is supplied to the cultivation zone 3 through a line 12 and a nutrient solution supply pump 4.

The cultivation bed is made up of gravel, sludge, foamed synthetic materials, etc. as a plant cultivation medium.

The remaining surplus of the nutrient solution absorbed or adsorbed by the cultivation bed 3 is collected at the bottom of the cultivation bed 3 and returned to the nutrient solution tank 1 through the line 13.

At this time, the nutrient solution supply pump 4 is linked to a timer and is configured to operate at regular intervals or according to a preset cycle, thereby fertilizing the cultivation bed 3 with the nutrient solution.

As the nutrient solution in the nutrient solution tank 1 is consumed, the level of the nutrient solution in the tank gradually decreases, and when it becomes below a certain level, it is controlled in accordance with the instructions from the level gauge 5. The electromagnetic valve 7 opens, and the nutrient solution that has been adjusted in advance is supplied from the nutrient solution adjustment tank 2 through the line 8.

A certain amount of nutrient solution is measured by a liquid level gauge 6 installed in the nutrient solution adjustment tank 2.
Supplied metered by.

When the liquid level in the nutrient solution adjustment tank 2 reaches a set position, the electromagnetic valve 7 is activated and closed in response to an instruction from the liquid level gauge 6.

At the same time, the solenoid valve 9 opens to open the water supply line 14 and water is supplied to the nutrient solution adjustment tank 2.

At this time, the liquid fertilizer quantitative supply device 10 is activated and a fixed amount of liquid fertilizer is supplied.

When a predetermined amount of water is supplied and the liquid level in the nutrient solution adjustment tank 2 returns to its original position, the electromagnetic valve 9 linked thereto is closed in response to an instruction from the liquid level gauge 6, stopping the supply of water.

It is preferable to supply water to the nutrient solution adjustment tank 2 by introducing the tip of the line to the lower end of the tank 2 and narrowing the tip to increase the flow rate and provide a mixing and stirring effect.

In this way, a certain amount of culture solution is automatically created.

When water is supplied from the line 14 to the nutrient solution adjustment tank 2, a liquid fertilizer quantitative supply device as shown in FIG. 2 is installed in the line 14, and the liquid fertilizer is quantitatively mixed into the water line 14.

That is, when the electromagnetic valve 7 opens, the electromagnetic valve 17 opens at the same time and the liquid fertilizer concentrate is introduced from the tank 16 through the line 19 into the measuring cup 18, and the upper end of the liquid level of the concentrate rising to the air vent pipe 21 reaches the tank. Stop at the same height as the liquid level in 16.

When the solenoid valve 7 is closed, the solenoid valve 17 is also closed, and water flows into the water line 14, so that the liquid fertilizer stock solution in the measuring cup 18 passes through the siphon 20 to the bow suction device 150.
Due to its action, it is sucked into the water.

The amount of liquid fertilizer that is suction-mixed into the water is determined by the length l inserted into the measuring cup 18 of the siphon 20.

Since the siphon 20 is movable, the amount of liquid fertilizer can be changed arbitrarily.

By using a plurality of liquid fertilizer quantitative supply devices, it is possible to simultaneously mix into the water line a plurality of types of liquid fertilizer that cause a chemical reaction when mixed with each other in the liquid fertilizer stock solution.

At this time, it is desirable that the suction section of the water line 14 branch into as many branches as the number of liquid fertilizers to be used.

Reference numeral 15 indicates an ejector, sucker, or the like that generates negative pressure when water flows through the line 14 and sucks liquid fertilizer from the measuring cup 18 using the siphon 20 to mix it into the water.

At this time, if the ejector, sucker, etc. do not work because the water pressure in the water line 14 is low, a liquid fertilizer supply device shown in FIG. 3 may be used instead of the liquid fertilizer quantitative supply device described above.

In other words, by opening and closing the solenoid valve 22 which operates simultaneously with the solenoid valve 9, liquid fertilizer is directly supplied into the nutrient solution adjustment tank 2 through the line 23.
The apparatus is the same as the apparatus shown in the second figure except that the siphon effect is omitted.

The feeding ratio between the fertilizers can be adjusted by changing the inner diameter of the measuring cup 18 and the insertion length l of the siphon.

As the liquid fertilizer used here, commercially available liquid fertilizers can be used as they are.
It can be diluted to about 0.00 times.

Therefore, it is unnecessary to manufacture a stock solution or re-dilute the conventional solution of solid fertilizer.

Furthermore, it is not necessary to install an intermediate stock solution tank, and a small tank is sufficient.

In this way, the nutrient solution controlled to a preset fertilizer concentration is mixed and stored in the nutrient solution adjustment tank 2 in an amount that maintains a constant liquid level.

The fertilizer composition and fertilizer concentration of the nutrient solution stored in the nutrient solution tank 1 tend to change slightly as it is used over a long period of time, so it is preferable to use the same nutrient solution for a long period of time. Rather, in the method of the present invention, the amount of nutrient solution in the nutrient solution tank 1 is normally stored in an amount that is consumed in one or two irrigations.

Therefore, a very small and small capacity nutrient solution tank is sufficient.

Further, according to the present invention, failures in crop cultivation due to errors in supplying the culture solution or adjusting the concentration can be eliminated, and there is an advantage that stable production can be achieved.

Furthermore, by adopting this device, even those with no experience in hydroponic cultivation can easily perform hydroponic cultivation, which can greatly contribute to labor saving and stable production of side dishes.

[Brief explanation of the drawing]

Fig. 1 is a principle diagram showing an embodiment of the automatic nutrient solution supply control device according to the present invention, Fig. 2 is a principle diagram of the same liquid fertilizer quantitative supply device, and Fig. 3 is a principle diagram of the same liquid fertilizer supply device. in,
1 is a nutrient solution tank, 2 is a nutrient solution adjustment tank, 3 is a cultivation bed, 4 is a nutrient solution supply pump, 5 and 6 are liquid level gauges, 7 and 9 are solenoid valves, 8 and 1213 are nutrient solution lines, and 10 is a Liquid fertilizer quantitative supply device or liquid fertilizer supply device, 11 is a controller, o-ler 14 is a water supply line, 15 is an ejector or part of a sucker, 16 is a liquid fertilizer stock solution tank, 1722 is a solenoid valve,
18 is a measuring cup, 19 and 23 are liquid fertilizer lines, 20
2 shows a siphon, and 21 shows an air venting capillary tube.

Claims (1)

[Claims] 1 A liquid level gauge 5 is provided inside, and the content nutrient solution is fed to the line 12.
The excess nutrient solution is supplied to the cultivation bed 3 through the line 1.
3, a nutrient solution adjustment tank 2 in which a nutrient solution is adjusted and stored, and a nutrient solution adjustment tank 2 in which a nutrient solution is adjusted and stored; When the liquid level in the tank falls to the lower surface detection level set in advance by the liquid level gauge 5, the communication line 8 between the nutrient solution tank 1 and the nutrient solution adjustment tank 2 is opened via the relay in the controller 11, and the nutrient solution is The nutrient solution adjusted and stored in the adjustment tank 2 is supplied to the nutrient solution tank 1, and when the liquid level in the nutrient solution adjustment tank 2 falls to the lower surface detection level set in advance by the liquid level gauge 6, a relay in the controller 11 is activated. After the nutrient solution is supplied to the nutrient solution tank 1 and the liquid level in the nutrient solution adjustment tank 2 drops to the level detected by the lower surface of the liquid level gauge 6, the controller A water supply line 1 that communicates with the nutrient solution adjustment tank 2 via a relay in 11
4 is opened and water or water-liquid fertilizer is supplied until the liquid level reaches the upper surface detection level set in advance by the liquid level gauge 6, and then the solenoid valve 9 and the water supply line 14 are closed.
During the process, a mixing dilution device quantitatively mixes liquid fertilizer into the water through one or more liquid fertilizer suction devices, or a certain amount of liquid fertilizer is added to the nutrient solution adjustment tank 2 corresponding to the amount of water supplied to the tank. An automatic nutrient solution supply control device characterized by being configured by installing a liquid fertilizer mixing device 10 that is directly supplied.