JPS63263023A - Irrigation system - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to seawater systems, and more particularly to seawater systems in the field of agriculture and horticulture.

[Conventional technology]

In recent years, many proposals have been made for seawater systems in the field of agriculture and horticulture. In the past, most hydroponic cultivation methods used a nutrient solution circulation method, but recently, many continuous flow methods such as sand cultivation and rock wool cultivation have become popular. A typical example is the drip method using a microtube.

In the drip method using a microtube, as shown in Figure 3, the drip amount is adjusted manually by keeping the secondary pressure constant with a constant pressure valve 7 and visually checking the height of the water column with a water column gauge (pressure gauge) 9. There is a system in which the secondary pressure is adjusted and the drip is carried out from a microtube 6 inserted into the drip unit 4 arranged in series in the irrigation pipe 5, or a flow rate limiting tube from the main irrigation pipe 5 as shown in Fig. 4. A method is known in which drips are dripped from a microtube 6 inserted into a drip unit 4 arranged in parallel to a main irrigation pipe 5 via a microtube 3 .

On the other hand, as shown in FIG.
A method is also known in which the drip is carried out from a microtube 6 inserted into a drip unit 4 arranged in series. In each of the above figures, 1 indicates a solenoid valve, and water or nutrient solution moves in the direction of the arrow. In addition, 4B# and others proposed a pond water fertilization system that takes advantage of the features of the system shown in Figure 5 to control the total amount of dripping. (Refer to Utility Model Application No. 57-176921 and Utility Model Application No. 59-81348.) [Problems to be Solved by the Invention] In the above-mentioned through-hole microtube drip method, two methods are known for adjusting the drip volume. ing. One is to keep the secondary pressure constant with a constant pressure valve as shown in Figures 3 and 4, and manually adjust the secondary pressure while visually checking the water column gauge (pressure gauge). This method adjusts the amount of drip from the tube.

In the case of the system shown in Fig. 3, in order to increase the drip volume from one microtube to 5 cc/min, the internal pressure of the drip unit 4 must be 0.05 Kf/cm! However, since the drip unit 4 and the main irrigation pipe 5 are arranged in series, and the pressure inside the main irrigation pipe 5 and the drip unit 4 is the same, it is necessary to maintain the level (height) of the irrigation point. At the same time, the amount of drip from the microtube 6 attached to the drip unit 4 placed higher is greatly affected by the height difference in the arrangement of the main water pipe 5, and the amount of drip from the micro tube 6 attached to the drip unit 4 placed lower is significantly affected. The amount of infusion from the attached microtube 6 will be smaller.

In addition, the viscosity coefficient of the water changes due to changes in the water temperature in the main irrigation pipe 5, which affects the drip rate. If the sluice valve 8 is not adjusted each time, the amount of drip from the microtube 6 will be greater when the water temperature is high than when it is low.

Also, one of the problems with the drip system is the air lock, but in the case of the system shown in Figure 3, if air enters from the negative side, the irrigation main pipe 5 and the drip unit 4 are arranged in series. During the air movement process, air may get mixed into one of the microtubes G, causing an air lock and making it impossible to drip.

Possible mechanisms for air intrusion are as follows. That is, in the method shown in FIG. 3, when the solenoid valve 1 is closed, the water inlet side of the main irrigation pipe 50 temporarily becomes negative pressure due to the inertia of the fluid in the main irrigation pipe 5, and the shear from the microtube 6 is drawn in. . On the other hand, the terminal portion continues dripping during this time, but when the inertia disappears, the negative pressure is reduced and air is drawn in from the microtube 6 in the same manner as described above.

These are thought to be the cause of airlock.

In the case of the prior art system shown in FIG. 4, as can be easily understood from the figure, from the irrigation main pipe 5 to the drip unit 4
are arranged in a branched manner, and each drip unit is connected to the irrigation main pipe 5 by a flow rate restriction tube 3 that allows a total flow rate of the drip volume from the microtubes 6 attached to each drip unit 4 to flow. At this time, the diameter and length of the flow rate restriction tube 3 are determined depending on the pressure inside the irrigation main pipe 5. The method shown in Fig. 4 allows the pressure inside the main irrigation pipe 5 to be higher than that shown in Fig. 3, so when the seawater point level is the same, the difference in height of the arrangement of the main irrigation pipe 5 is It is not easily affected and it is possible to make the pond water uniform. Also,
Regarding the air lock problem of micro tube 6,
The invading air moves through the irrigation main pipe 5, which has less resistance than the flow rate restriction tube 3, and the probability of it invading the drip unit 4 is extremely low.

However, even if it is possible to increase the pressure inside the main irrigation pipe 5, considering the height limit of the installation of the water column meter 9, it is only possible to secure pressure up to about 1 m, that is, about 0.1 Kf/cm. Although it is difficult to be affected by the height difference in the arrangement of the main irrigation pipe 5, it is only a few centimeters.Furthermore, as with the method shown in Fig. 3, the increase in dripping of the microtube 60 due to changes in water temperature in the main irrigation pipe 5 is Since it does not have a restriction function, it is inevitable that the amount of drip infusion will increase due to temperature rise.

FIG. 5 shows a conventional method in which a constant flow valve 2 is installed to introduce a constant amount of water or nutrient solution into the main irrigation pipe 5 regardless of fluctuations in the water pressure to adjust the amount of drip from the microtube 6. This shows that.

FIG. 5 shows an example in which the main pipe 5 and the drip unit 4 are arranged in series.

In the method shown in FIG. 5, the air lock of the microtube 6 cannot be prevented as in the method shown in FIG. When considering irrigation accuracy, the effect of the difference in height of the irrigation main pipe 5 when the seawater point level is the same shows a tendency similar to that in Fig. 3; however, the water temperature at the inlet of the constant flow valve 2 Since there is no exposure and the water is supplied at a constant temperature, there are few changes in water temperature, and the total amount of water flowing into the hot water main pipe 5 is almost constant.
The drip volume of the microtube 6 installed in the drip unit installed at a high position was slightly smaller than that of the microtube 6 installed in the drip unit 4 installed at a low position. The difference is that the amount of drip from the microtube 6 provided in the drip unit (4) at a lower position is increased.

In addition, in the system shown in Fig. 5, when the water temperature in the hot water main pipe 5 rises, the fluid resistance of the microtube 6 becomes smaller compared to when the water temperature is low, so the pressure in the hot water main pipe 5 decreases, and the drip amount increases. is suppressed, and the supply amount from the constant flow valve 2 and the drip amount from the microtube 6 are maintained, but the difference in the drip amount between the water inlet side and the terminal side of the main irrigation pipe 5 increases.

As described above, the conventional seawater system is affected by the difference in height between the drip point and the irrigation main pipe 5, the effect of changes in water temperature in the hot water main pipe 5, the influence of air locks, etc. In order to effectively perform small amounts of water, which is a feature of the drip method, it is necessary to
There was a problem that the change in f was large.

It is an object of the present invention to solve the above-mentioned problems and provide a drip system using a microtube with less variation in drip volume.

[Means for solving problems]

According to the present invention, the above-mentioned problems can be solved by providing a main irrigation pipe that receives water or nutrient solution through a constant flow valve, and a main water supply pipe that receives water or nutrient solution at appropriate intervals downstream of the constant flow valve of the main hot water pipe. Equipped with a drip unit that is branched using a restriction tube 2
The problem is solved by an irrigation system characterized in that a plurality of microtubes are attached to the drip unit, and water is dripped from the tip of the microtube in the longitudinal direction.

[For production]

The irrigation main pipe receives water or nutrient solution through a constant flow valve, and a drip unit is installed downstream of the constant flow valve in the irrigation main pipe via a flow restriction tube, and the pressure inside the irrigation main pipe is set high. It is something.

Therefore, even if there is a slight difference in height when installing the drip unit, the difference in the amount of drip from the microtube inserted into the drip unit will be negligible, and even if the water temperature in the main irrigation pipe increases, the microtube and flow rate will be restricted. The fluid resistance of the tube is reduced, and the internal pressure of the main irrigation pipe and drip unit is automatically lowered, making it possible to maintain a constant drip volume.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing the overall outline of the irrigation system according to the present invention, and FIG. 2 is a perspective view showing details of the irrigation system according to the invention.

In FIG. 1, 1 is a solenoid valve, 2 is a constant flow valve, 3 is a flow rate limiting tube, 4 is a drip unit, 5 is a main irrigation pipe, and 6 is a microtube.

When the solenoid valve 1 opens, water or nutrient solution on the primary side passes through the constant flow valve 2 and flows into the irrigation main pipe 5. The hot water main pipe 5 is branched at regular intervals using flow rate restriction tubes 3 of a constant length and connected to the drip unit 4.

This drip unit 4 has a cylindrical shape, for example, and has a plurality of microtubes 6 inserted therein. The water or nutrient solution flowing through the irrigation main pipe 5 is divided into each flow rate control tube 3, sent to the microtube 6 via the drip unit 4, and dripped from its tip.

The constant flow valve 2 has a mechanism that changes the orifice diameter in conjunction with the difference between the water supply pressure on the negative side and the pressure determined by the load on the secondary side, that is, the pressure difference, and allows a constant flow rate to flow to the secondary side. ing.

The flow rate of the constant flow valve 2 is determined from the product of the expected drip volume from one microtube 6 and the total number of microtubes that receive water or nutrient solution from the constant flow valve 2. In addition, the flow rate restriction tube 3 has a diameter such that the flow rate flowing through the tube 3 is the product of the drip volume from one microtube 6 and the total number of microtubes 6 inserted into one drip unit. and determine the length.

With the above structure, the internal pressure of the drip unit 4 is
In order to infuse a flow rate of around 5 cc/min from one microtube, 0.05 Kfl am is required. If the design is such that the internal pressure required to supply water from one pipe is approximately 0.45 Kfl cm, the internal pressure of the main irrigation pipe 5 will be 0.5 of the above total.
Kfl cm", and higher internal pressure can be applied to the irrigation main pipe 5 than in the conventional system. Therefore, the drip unit 4
Even if there is some height difference in the installation, the difference in the amount of drip from the microtube 6 is so small that it can be ignored.

In response to changes in the water temperature inside the main irrigation pipe s, the above-mentioned through and constant flow valve 2 has a mechanism to flow a constant flow rate, so even if the temperature inside the main irrigation pipe 5 rises, the micro tube 6 and the flow rate The fluid resistance of the restriction tube 3 is reduced, and as a result,
The internal pressure within the main pipe 5 and drip unit 4 is automatically reduced, and the amount of drip from the microtube 6 can be kept constant.

For the air lock, the drip unit 4 is connected in parallel to the irrigation main pipe 5 via the flow rate control tube 3, so air from the negative side is controlled in the same way as in the system shown in Fig. 3.
There is an extremely low probability that the water will move through the main pond water pipe 5, which has less resistance, and enter the drip unit 4 via the flow control tube 3, which has higher resistance.

Furthermore, even if there is air in the microtube 6, when the air moves from the reservoir main pipe 5, which has a high internal pressure, to the drip unit 4, which has only a pressure equal to the pressure loss of the microtube 6, it expands rapidly and instantaneously. It is expected that the internal pressure of the drip unit 4 will be increased and the air inside the microtube 6 will be eliminated.

Air being drawn in from the microtube 6 when the solenoid valve 1 is closed can be prevented because the internal pressure of the irrigation main pipe 5 is high.

FIG. 2 is a perspective view of an example in which the irrigation system according to the present invention is incorporated into rock wool cultivation in agricultural cultivation. In the figure, the numbers attached to the figure are the same as those in Figure 1, and 10 is a rock wool bed, and 11 is a stainless steel wire with a level that is fixed to the stakes 12 at both ends of the rock wool bed 10. Only a part of the rock wool bed 10 is shown, and only one drip unit (41F) is shown, and the others are omitted from the figure.

Figure 2 shows a film being placed on a somewhat leveled ground.
This figure shows an example in which an irrigation system according to the present invention is placed along a rock wool bed with a width of 30 cm and a bed length of 50 m. The arrows indicate the direction of movement of water or nutrient solution within the irrigation main pipe 5. In this drought system, a solenoid valve 1 and a constant flow valve 2 are provided on the water inlet side of the main irrigation pipe 5. This constant flow valve 2 is arranged in a 50 m long rock wool bed 10 for cultivation, and each of 500 wires of polyethylene microtubes 6 with an inner diameter of 1 mm and a length of 1 m can irrigate 5 ec/min. So total 2.51/
We selected those that represented the total flow of minutes. On the secondary side of the constant flow valve 2, a PVC pipe with an inner diameter of 1613 mm was installed as the irrigation main pipe 5.
It was placed along a rock wool bed 10 with a length of m.

Furthermore, from the main irrigation pipe 5, polyethylene flow restriction tubes 3 with an inner diameter of 1 nm and a length of 700 mm are placed every 2 m.
are used to branch out and connect each to an infusion unit 4 composed of a cylindrical container. Only one drip unit 4 is shown in the figure, and the others are omitted.

Twenty microtubes 6 made of polyethylene are inserted into each drip unit 4 so as to face upward. However, only six of them are shown in the figure. The other end of the microtube 6 is a cultivation vera) 100
It is fixed to the stakes 12 at both ends and fixed to the level stainless steel wire 11.

Here, the water pressure on the negative side was set to 2 KW/cm", solenoid valve 1 was opened, and the water pressure immediately after constant flow valve 2 was checked and found to be 0.
, 5 KW/am”.

The results of measuring the drip from the microtube 6 over the length of 5 fJm of the rock wool bed 10 under the above conditions are as shown in Part 1.

In the measurement, five microtubes 6 inserted into the same infusion unit were bundled together to measure the total amount of infusion for 3 minutes. "Flow rate of one microtube υ" in Table 1 is the total flow rate per microtube.
This is the value converted to the actual flow rate.

Table 1 Next, the heights of the main irrigation pipe 5 and drip unit 4 are determined according to 2 in Table 1.
20cm at the point 5m + 49m and 1 at the point 37m
When 0 am was raised in each block and measured in the same manner as No. 1, the results were as shown in Table 2.

Table 2 From Tables 1 and 2, the drip system with the above structure is ±
Water is irrigated from each microtube 6 with an accuracy within 5 inches,
It was also found that a height difference of about 20 cm between the irrigation main pipes has almost no effect on the amount of irrigation.

Regarding the air lock of micro tube 6, we opened the solenoid valve l at the same time every day for 5 consecutive days and checked all the micro tubes 6, but there was only one tube that had an air lock and was not being irrigated. There was none. Furthermore, the drawing of air from the microtube 6 was visually observed with the solenoid valve 1 closed, but no such phenomenon was observed.

〔Effect of the invention〕

As described above, the flooding system according to the present invention has higher accuracy in drip volume in a lake water system using microtubes than irrigation systems using conventional technology.
The problem of air locks in microtubes has also been largely resolved. Therefore, it is effective for use in greenhouse horticulture, especially sand cultivation and rock wool cultivation that employ a continuous flow seawater system.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an overview of a seawater system according to the present invention, FIG. 2 is a perspective view showing details of a flooding system according to the present invention, FIG. 3 is a diagram showing an overview of a seawater system according to the prior art, and FIG. FIG. 5 is a diagram showing an outline of a different seawater system according to the prior art. FIG. 5 is a diagram showing an outline of a further different irrigation system according to the prior art. 1...Solenoid valve 2...Constant flow valve 3...Flow rate control tube 4...Drip unit 5...Irrigation main pipe 6...Micro tube

Claims (1)

[Claims] A main irrigation pipe that receives water or a nutrient solution through a constant flow valve, and a drip unit that is branched from the main irrigation pipe at an appropriate interval downstream of the constant flow valve using a flow restriction tube. An irrigation system comprising: a plurality of microtubes attached to the drip unit, and drip irrigation performed from the tips of the microtubes in the longitudinal direction.