JP2556231Y2 - Chemical liquid flow expansion device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for proportionally mixing a chemical solution such as a liquid fertilizer at an arbitrary flow rate at a fixed magnification in an automatic irrigation system or a hydroponic system, and more particularly to a variable mixing ratio of a chemical solution. The present invention relates to a device whose range can be greatly expanded.

[0002]

2. Description of the Related Art When cultivating plants such as vegetables using an automatic irrigation system or a hydroponic cultivation system, various systems have been proposed for mixing liquid fertilizer into raw water in a predetermined desired amount. However, for example, Japanese Utility Model Laid-Open No. 64-429 can be mentioned. According to the publication, as shown in FIG. 2, the flow rate of raw water flowing through the main pipe 1 is detected by a pulse-type main pipe flow sensor 2, while the liquid fertilizer is sent out from a liquid fertilizer tank 6 by a pump 7, and At the same time, the flow rate of the liquid fertilizer is also detected by the pulse-type liquid fertilizer flow rate sensor 3. And both of these sensors 2,
The detection results of 3 are sequentially sent to the controller 4 for comparison and calculation, and the control valve 5 is adjusted so as to have a dilution ratio (liquid fertilizer flow rate) determined by the external magnification setting pulse oscillator 8.

In other words, a predetermined instruction magnification is determined by the ratio of the detection values of the respective flow sensors 2 and 3.
The range of the indicated magnification is greatly influenced by the characteristics of the individual flow sensors 2 and 3, and the magnification is generally several hundred to 1,000 times. For example, in the conventional apparatus described here, the detectable range of the liquid fertilizer flow rate sensor 3 is 35 cc / as shown in the graph of FIG.
Every minute to 1000 cc / minute, the indicated magnification at this time, that is, the variable range of the ratio of liquid fertilizer: raw water is 1
/ 570 to 1/200.

[0004]

[Problem to be solved by the invention] If only one kind of plant is cultivated, the amount of the chemical supplied is constant.
Using the system as described above does not cause any inconvenience, but when multiple types of plants must be cultivated, the required supply amount of the chemical solution for each plant, that is, the instruction magnification for proportional mixing of the chemical solution, Often different. As the flow rate sensor used in the above, an inexpensive rotary type or pulse type is usually used. Such an inexpensive flow rate sensor does not have a very wide flow rate detection range, and a wide-range flow rate sensor capable of detecting a flow rate over a wide range is very expensive. It was difficult to adopt easily. For this reason, when changing the indicated magnification, it is often necessary to change the specifications of the system, that is, to replace a flow sensor having a detection range that matches the desired indicated magnification, or in the worst case, to newly add a system. This had to be purchased, putting additional financial burden on farmers.

[0005] The present invention has been developed in view of such a situation, and by combining appropriately used members as appropriate, a low-cost and simple structure can be achieved in a wide range. It is an object of the present invention to provide a device which can obtain an instruction magnification of proportional mixing.

[0006]

In order to achieve the above object, a chemical liquid introduced from a chemical liquid supply means in an apparatus for mixing a chemical liquid at a predetermined magnification with respect to raw water at an appropriate position in a main pipe through which raw water flows. The pipe is formed into a plurality of branch flow paths that are branched into at least two flow paths and merged again to be connected to the main pipe. A chemical liquid flow rate detecting means and a chemical liquid flow rate controlling means having different detection ranges are provided for each, while a raw water flow rate detecting means is provided in the main pipe, and the flow path switching means is operated according to the detection result of the above-mentioned chemical liquid flow rate detecting section to appropriately branch. In addition to selecting a flow path, a chemical solution is mixed in proportion to each detection result of the chemical solution flow rate detecting means and the raw water flow rate detecting means.
In this case, a chemical liquid pipe led from a means for supplying a chemical liquid is branched into at least two flow paths to provide a plurality of branch flow paths, and each of the branch flow paths is an inflow side of a chemical liquid flow rate control means provided for each of the flow paths. And the outflow side of the chemical liquid flow rate control means is connected to the inflow side of each of the chemical liquid flow rate detection means provided for each branch flow path and having a different flow rate detection range. Is connected to each inflow port of the flow path switching means having at least two or more inflow ports, and the outflow port of the flow path switching means is connected to be mixable with raw water flowing through the main pipe. Means is provided, the flow path switching means is operated in accordance with the detection result of the above-mentioned chemical liquid flow rate detecting means, and the branch flow path is appropriately selected, and the chemical liquid is proportionally mixed based on each detection result of the chemical liquid flow rate detecting means and the raw water flow rate detecting means. It is preferable to.

[0007]

The present invention configured as described above has the following functions. The chemical liquid flowing through the chemical liquid pipe guided from the chemical liquid supply means such as a chemical liquid tank flows through at least one of the branch flow paths branched into at least two flow paths by the flow path switching means and joins the raw water of the main pipe. Here, the flow rate of the chemical solution flowing through the branch flow path is detected by the chemical solution flow rate detecting means, and the flow rate of the raw water flowing through the main pipe is detected by the raw water flow rate detecting means, respectively.
By comparing and calculating this detection result, the liquid fertilizer flow rate control means is controlled to obtain a constant chemical liquid flow rate, so that the designated magnification of the chemical liquid: raw water is maintained. When the designated magnification is changed, the set value of the chemical solution flow detecting means is changed. However, this set value is out of the detectable range of the chemical solution flow detecting means, and the chemical solution flow set value is extremely large. If the desired designated magnification cannot be obtained due to the capacity or small capacity, the branch flow path having the chemical liquid flow rate detecting means capable of obtaining the desired designated magnification by operating the above-mentioned flow switching means. Is appropriately selected.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the configuration is as shown in FIG. That is, the pump 32 is
Is divided into two flow paths, a first branch flow path 22a and a second branch flow path 22b. The first branch flow path 22a has a first flow rate of an electric actuator mounted type. A control valve 25 and a first flow rate sensor 24 are provided, and a second flow rate control valve 28 and a second flow rate sensor 27 having an electric actuator are similarly provided in the other second branch flow path 22b. These sensors 24, 2
As described above, for example, the first flow rate sensor 24 is provided with 3 so as to obtain an instruction magnification for proportional mixing of a wide range of chemicals as described above.
The detection range is different from the one that can detect the flow rate of the chemical solution from 5 cc / min to 1000 cc / min, and the one that can detect the flow rate of the chemical solution from 330 cc / min to 3300 cc / min. Something is used together.

[0009] The two branch flow paths 22a thus configured,
The outflow side of 22b is connected to the inflow port of a three-way valve 29 equipped with an electric actuator used as a flow path switching means. The outflow port of the three-way valve 29 is connected by a connection pipe 30 so as to merge with the main pipe 20. On the other hand, in the main pipe 20, a raw water flow rate sensor 21 for detecting a raw water flow rate flowing therethrough is provided in a bypass flow path. The outputs of the flow sensors 21, 24 and 27 are connected to the input of a controller 33, and the control output of the controller 33 is
5, 28 and the three-way valve 29 are connected to actuator control terminals.

Here, the operation of the present embodiment will be described. The chemical liquid flowing through the chemical liquid pipe 22 led from the chemical liquid tank 31 flows through one of the first branch flow path 22 a and the second branch flow path 22 b branched into two flow paths, and passes through the three-way valve 29 through the main pipe. 20 and is mixed with raw water flowing through the main pipe 20. Here, when a chemical is flowing through the first branch channel 22a, the flow rate of the chemical flowing through the first branch flow path 22a is detected by the first flow sensor, and the flow rate of the raw water flowing through the main pipe 20 is detected by the raw water flow sensor 20, respectively. Based on the detection result, the controller 33 performs an appropriate calculation and controls the first flow control valve 25 to obtain a constant flow rate of the chemical solution, whereby the designated magnification of the chemical solution: raw water is maintained.

This is shown in a specific example of this embodiment. As described above, the first flow sensor 24 is 35 cc / min.
Since the flow rate of the chemical solution can be detected at 0 cc / min, and the second flow sensor 27 capable of detecting the flow rate of the chemical solution at 330 cc / min to 3300 cc / min is appropriately switched and used. Equivalently, as shown in the graph of FIG. 3, it has a wide continuous detectable range of 35 cc / min to 3300 cc / min. Accordingly, if the flow rate of raw water flowing through the main pipe 20 is 20,000 cc / min to 200,000 cc / min, about 1/60 to 1 /
Proportional mixing of the drug solution can be performed at an instruction magnification of 570. That is,
The detectable range is expanded by appropriately switching and using two sensors having different detectable ranges.

When the designated magnification is changed,
In accordance with an instruction from the controller 33, any of the flow sensors 2
This is performed by changing the set value of 4 or 27. But,
If the set value is out of the detectable range of any of the flow sensors and the desired indicated magnification cannot be obtained, the three-way valve 29 is operated to detect the chemical liquid flow rate at which the desired indicated magnification is obtained. This is performed by appropriately selecting the branch flow path having the means, that is, the first branch flow path 22a or the second branch flow path 22b.

For example, when the flow rate of the chemical is 35 cc / min.
In the case of 000 cc / minute, the first flow rate sensor 24 is used. As a result, the chemical flows from the chemical pipe 22 through the first branch flow path 22 a having the first flow control valve 25 and the first flow sensor 24, passes through the three-way valve 29, and is mixed with the raw water in the main pipe 20. On the other hand, when the flow rate of the chemical solution exceeds 1000 cc / min, the second flow sensor 27 is used.
The three-way valve 29 is switched by an instruction from the controller 33. As a result, the chemical liquid flows from the chemical liquid pipe 22 to the second flow control valve 2.
8, flows through the second branch flow path 22b having the second flow rate sensor 27, passes through the three-way valve 29, and is mixed with the raw water in the main pipe 20.

On the other hand, when the flow rate of the chemical solution decreases in the second branch channel 22b, the three-way valve
9 is not operated, the flow rate detection by the second flow rate sensor 27 is maintained, and when the lower limit of the detectable range of the second flow rate sensor 27 is reached, the three-way valve 29 is operated, and the first branch flow path 22 is operated.
a. By overlapping the upper and lower limits of the detectable range of each of the flow sensors 24 and 27 in this manner, for example, the flow rate of the chemical solution at around 1000 cc / min, which is the upper limit of the detectable range of the first flow sensor 22a. Smooth flow path selection can be performed even for fluctuations. Therefore, the three-way valve 2
9 can be avoided and troubles can be prevented from occurring.

The main pipe 20 is provided with a raw water flow rate sensor 21 for detecting a flow rate of raw water flowing therethrough.
In this case, the same member as the flow rate sensor 24 or 27 described above can be used by providing a bypass flow path 34 having an appropriate diameter in the main pipe 20 and dividing a large volume of raw water flow into a small volume.

As described above, the flow sensors 21, 24, and 27 used here are inexpensive rotary or pulse sensors conventionally used, and the flow control valves 25, 28 and the three-way valve are used. 29 uses a synthetic resin ball valve on which an electric actuator is mounted.
In order to input the data (detectable range, etc.) of the two flow sensors 21 and 24 described above, an inexpensive 8-bit CPU is used. However, such members are not limited to those used here, and various members can be used. For example, each flow sensor 21, 2
Other types are used for 4 and 27, a butterfly valve equipped with a fluid actuator is used for each flow control valve 25 and 28, and each control valve 25 and 28 and a three-way valve 29 are analogously used for the controller 33. May be used. Therefore, it can be configured in various modes by appropriate selection during implementation.

In this embodiment, as described above, two branches (two-stage switching) using a large-capacity and a small-capacity flow sensor are used. It is possible to further increase the variable range of the indicated magnification by opening the appropriate number of branch channels at the same time. In such a case, although not shown, it is preferable to form and implement a flow path switching means appropriately combining a three-way valve, a valve, and the like. Further, the flow path switching means can be provided on the upstream side of the flow rate detecting means, and its operation and effect are not changed at all, so that it can be appropriately selected at the time of implementation. Further, the configuration of this embodiment can be effectively used not only in the agricultural field but also in other industrial fields such as the food industry and the chemical industry.

[0018]

As apparent from the above description, the present invention has a number of excellent effects as described below. That is, without using an expensive wide-range flow rate sensor, a flow rate detecting means for a chemical solution using an inexpensive conventional flow rate sensor is disposed in parallel to the flow path, and each detecting means is used by appropriately switching. As a result, a device equivalent to a device using a wide-range flow sensor can be implemented at very low cost. In addition, the present invention, combined with a simple configuration and the adoption of a corrosion-resistant member, has no fear of failure and improves maintainability. Such inexpensive equipment costs and good maintainability can greatly reduce the economic burden on production facilities for farmers, which in turn leads to benefits for general consumers. have.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an embodiment of the present invention.

FIG. 2 is a system diagram showing a conventional example.

FIG. 3 is a graph showing a relationship between a detectable range of a chemical solution flow rate and a designated magnification in the present invention and a conventional example.

[Explanation of symbols]

 Reference Signs List 20 Main pipe 21 Raw water flow sensor 22a First branch flow path 22b Second branch flow path 24 First flow sensor 25 First flow control valve 27 Second flow sensor 28 Second flow control valve 29 Three-way valve 31 Chemical liquid tank 33 Controller

Claims (2)

(57) [Scope of request for utility model registration] 1. A device for mixing a chemical solution in proportion to raw water at a predetermined ratio at an appropriate position in a main pipe through which raw water flows, wherein a chemical solution pipe guided from a chemical solution supply means is provided with at least two chemical solutions.
It is formed into a plurality of branch flow paths that are branched into more than the flow paths and joined again to be connected to the main pipe. The branch flow paths include a means for appropriately switching the flow paths, and a detection range for each flow path. Different chemical liquid flow rate detecting means and chemical liquid flow rate controlling means are provided, while a main pipe is provided with raw water flow rate detecting means, and the branch flow path is appropriately selected by operating the flow path switching means based on the detection result of the above-mentioned chemical liquid flow detecting section. In addition, a chemical liquid flow enlarging apparatus characterized in that a chemical liquid is mixed in proportion to each detection result of the chemical liquid flow rate detecting means and the raw water flow rate detecting means. 2. A method according to claim 1, wherein a plurality of branch channels are provided by branching at least two channels from a solution pipe introduced from a means for supplying the solution. Connected to the inflow side, the outflow side of this chemical liquid flow rate control means is connected to the inflow side of each of the chemical liquid flow rate detection means provided for each branch flow path and having a different flow rate detection range. The outflow side is connected to each inflow port of the flow path switching means having at least two or more inflow ports,
The outflow port of the flow path switching means is connected so as to be mixable with raw water flowing through the main pipe, the main pipe is provided with a raw water flow rate detection means, and the flow path switching means is operated based on the detection result of the chemical liquid flow rate detection means described above. While appropriately selecting the branch flow path,
A chemical liquid flow enlarging device characterized in that a chemical liquid is mixed in proportion to the respective detection results of the chemical liquid flow rate detecting means and the raw water flow rate detecting means.