JPH0823800A - Watering system by difference in negative pressure - Google Patents

Abstract

PURPOSE:To provide a compact and inexpensive watering system by difference in negative pressure, not damaging merits of a watering system by difference in negative pressure. CONSTITUTION:In a container 1 charged with a soil layer 2 at the upper part and a water storage part below the soil layer, a porous pipe is embedded in the soil layer. Water from the water storage part 3 is saturated under negative pressure in the porous pipe 4 and water in the porous pipe 4 is oozed through capillarity by difference between negative pressure of soil water in contact with the porus pipe and negative pressure in the porous pipe 4 to provide a watering system by the difference in negative pressure. Water in a flow channel intermittently flowing between the porous pipe and the water storage tank is forcibly made to flow and free air in the water channel can be removed to provide the objective watering system by difference in negative pressure provided with a free air removing means.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a negative pressure differential irrigation system.

[0002]

2. Description of the Related Art A negative pressure differential irrigation system saturates water in a porous pipe buried in soil and uses the water pressure in this pipe as a negative pressure to divide the negative pressure of soil water in contact with the porous pipe into a negative pressure inside the pipe. Watering is performed by the difference, which can be said to be a suitable method for controlling soil moisture. And, in the conventional negative pressure differential irrigation system, the cost of the basic system is reduced due to the expansion of the scale.

[0003]

However, if a very small scale, for example, a flowerpot is cultivated and managed by this negative pressure differential irrigation system, it will be extremely expensive. In other words, in order to maintain this system continuously, it is essential to remove the generated free air. Therefore, it is generally a fixed idea to always circulate and circulate water by a pump, and the useful life of the pump, etc. There was also a problem.

Therefore, the present inventor has conducted various studies to solve the above problems and found a system that is compact and inexpensive and does not impair the advantages of the negative pressure differential irrigation system, and arrived at the present invention. That is, the gist of the present invention is
In a container that stores a soil layer in the upper part and a water storage part below it, a porous pipe is embedded in this soil layer, and the water from the water storage part is saturated in this porous pipe under negative pressure, A negative pressure differential irrigation system configured to leach the water in the porous tube into the soil by the difference between the negative pressure of soil water in contact with the soil and the negative pressure in the porous tube. And a negative pressure differential irrigation system including free air removing means for removing free air in the flow path by forcibly flowing water in the flow path that connects the water storage tank. Hereinafter, the present invention will be described in detail.

First, in the present invention, the soil layer is stored in the upper portion of the container, and the water storage portion is stored below the soil layer. The soil of the soil layer, natural soil, and artificial soil such as culture soil is generally, as long as it can be used for plant cultivation by the negative pressure differential irrigation system of the present invention even if it does not contain organic matter. , Not particularly limited. In the present invention, since the essential water can be constantly supplied to the plant, the soil as the water retaining layer may be relatively small. Therefore, the space for that amount can be used for housing a control device or the like which will be described later. The thickness of the soil layer can be appropriately selected according to the size of the container.

The water storage section is for storing water to be leached into the soil by the method described later, and the kind of water is not limited as long as it is suitable for plant growth. In this case, fertilizer and the like can be dissolved as needed. The size of the water storage part can be appropriately selected according to the size of the container, or can be divided into a plurality of parts that are electrically connected to each other. The shape of the container can be arbitrary, such as various planters and flower pots, and the size can be appropriately selected according to the purpose. Further, the material thereof is not particularly limited, but plastic or the like is preferable.

In the present invention, a porous tube is buried in the soil layer. The depth to be buried is not particularly limited, but it is usually preferably about 5 to 50 cm from the soil surface, although it depends on the thickness of the soil layer. If it is too shallow, it is disadvantageous in that it is easily affected by the temperature of the surface of the earth and water easily evaporates, and if it is too deep, it is difficult to allow water to reach the root region of the plant, which is not preferable.

In general, the material of the porous tube is preferably ceramics, concrete or porous glass, but it is used as a porous material made of a plastic material such as a metal sintered body, polyethylene, polypropylene or rubber, and as a filter material. It is possible to use a material that is formed into a tubular shape from the available materials.
From the viewpoint of allowing water vapor or water to pass through, a hydrophilic material or a hydrophilized material is preferable. It is desirable that these porous materials have pores having a pore diameter in the range of about 0.01 to 200 μm. If they are smaller than this, clogging easily occurs during use and the flow resistance of the fluid is large, so that water flowability is high. If it is bad, or if it is rougher than this, air will flow in, and it will be difficult to maintain the negative pressure. A particularly desirable pore size is 0.
Those having a narrow pore size distribution in the range of about 1 to 50 μm are particularly suitable. In particular, a cylinder having a pore diameter of about 10 μm, which is obtained by molding and firing porcelain clay having a large amount of quartz, is preferable.

These porous materials are usually formed into a cylindrical shape and used as a porous tube. The inner diameter, wall pressure, and length are not particularly limited, but if they are too small, the resistance when water flows is large, and if they are too large, a large amount of water is circulated in order to flush out the bubbles generated or mixed in inside. Will be required. Therefore, usually, the inner diameter is about 3 to 100 mm, preferably 5 to 50 mm, the wall pressure is about 1 to 30 mm, preferably 3 to 15 mm, and the length is not particularly limited, but it is flexible such as ceramics depending on the material. It is possible to reduce the number of connection points by making it short if it is scarce and easily damaged by a flexural stress, and lengthening a flexible material such as a plastic material. To connect a plurality of porous pipes, it is common to use a tube such as polyvinyl chloride or polyethylene, or a pipe material, and it is convenient to use a metal pipe, a pipe connector or the like. At the time of connection, it is preferable to use a tube or the like having a smooth inside and to prevent the diameter of the tube from abruptly changing so that pressure loss is unlikely to occur.

In the present invention, the water in the water storage portion provided at the lower portion of the porous pipe is conducted to the porous pipe, and water flows in the water passage between the porous pipe and the piping material and the water storage portion. Is saturated, the water becomes stationary, and the pressure in the pipe becomes negative. The adjustment of the negative pressure may be carried out, for example, by providing a minimum height difference in which the negative pressure is generated in the target shape, and the change in the negative pressure difference due to the decrease in the water level of the water storage part due to water consumption is allowed in the target device. It can be solved as a problem within the possible range.

In the present invention, by adopting such a constitution, the water in the porous tube is leached into the soil by the capillary due to the difference between the negative pressure in the soil water in contact with the porous tube and the negative pressure in the porous tube. Can be made. In this case, as described above, the water in the flow path is in a stationary state, but only the amount of water that can be leached into the soil by the capillary is supplied from the water storage section. The water can be supplied to the water storage portion from a water supply port provided above the liquid surface of the water storage portion as appropriate (for example, once a month in summer and 3 to 4 months in autumn to winter). To 1
However, a means for giving an alarm by voice or display when the water level falls below a certain level may be adopted.

The present invention, in such a negative pressure differential irrigation system, comprises free air removing means capable of intermittently forcibly flowing the water in the flow path to remove the water in the flow path. . The free air can be discharged to the upper surface of the water storage unit, transmitted through the soil, and released into the upper atmosphere. Also, the air may be of some help in forming an air layer in the soil. Examples of such means for removing free air include a method in which water in the flow path is forced to flow using a pump or the like.
It is sufficient that the free air is removed and the time for giving the flow depends on the force for giving the flow, but for example, about 10 to 20 seconds is sufficient.

In order to operate such a removing means intermittently, for example, (i) a timer is used to set a time at which the negative pressure differential irrigation system is disturbed by the release of gas, and is periodically (For example, once / day) Automatically activate. (Ii) A gas is detected using a gas detection sensor, and a time difference is provided so that the gas is driven when it reaches a certain amount. (Iii) A level sensor is used to set the upper and lower limits of free gas and drive when the upper limit is reached. Although a method using a control device such as the above can be adopted, the method (i) is preferable in terms of simplicity. These free air removing means can be installed in, for example, a space portion provided between the soil layer and the water storage portion in the container described above. In this case, it is preferable that the partition between the soil layer and the water storage section has a structure that does not affect the operation of the removing unit. The control device is powered by direct current,
Any of alternating current can be adopted, but a battery is preferably selected from the viewpoint that wiring is not necessary, and a secondary battery such as a lithium battery or a solar battery can also be selected. Further, for convenience of battery replacement or the like, a detachable battery storage portion can be provided on the side surface of the container.

FIG. 1 shows an embodiment of the negative pressure differential irrigation system of the present invention. A soil layer 2 and a water storage section 3 are provided in a container 1, and the soil layer 2 has a porous structure. Tube 4
, And the porous tube 4 is electrically connected to the water in the water reservoir 3 by the tubes 5 and 5 '(11: water supply port, 1
2: Drainage port). The negative pressure is set by the difference in height between the water surface of the reservoir and the porous pipe in the soil by design. When the pump for flowing the water in the flow passage is operated, even if the positive pressure is temporarily generated, the negative pressure state is returned with the end of the operation, and the excessive supply amount is promptly discharged. Usually, water is supplied from the tube 5, and a portion corresponding to the capillary leaching from the porous tube 4 to the soil layer 2 is supplied from the tube 5 '.

A control device 6 and a power supply 7 are provided in the space.
Is provided and is configured to detect the amount of free air by the level sensor 9 that monitors the state of free air in the flow path at the bent portion 8 of the tube 5. When the level sensor 9 detects an allowable lower limit value of free air, the control device 6 causes the pump 10 to set, for example, 1
Run for 0 seconds to remove free air. In addition, for example, a cock (not shown) for adjusting negative pressure can be provided above the pump 10. Instead of the above level sensor,
When a timer is installed, regardless of the presence or absence of air generation, for example, once a day to three days, once every 10 to 20 days.
It can be set to operate for seconds. The setting can be made in consideration of climate, temperature, etc.

[0016]

According to the present invention, a compact and inexpensive negative pressure differential irrigation system can be obtained. That is, the advantages of the negative pressure differential irrigation can be utilized, and the labor of irrigation and the damage of over-irrigation can be prevented to facilitate plant cultivation. According to the present invention, for example, in the case of a small-scale planter, it is possible to suitably operate the CA battery without replacing it for one year or more by devising the power saving of the control device.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of a negative pressure differential irrigation system of the present invention.

[Explanation of symbols]

 1 Container 2 Soil Layer 3 Water Storage Section 4 Porous Pipe 5, 5'Tube 6 Control Device 7 Power Supply 10 Pump

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location A01G 25/06 D 9318-2B 27/02

Claims (1)

[Claims] 1. A container for accommodating a soil layer in the upper part and a water storage part in the lower part of the container, wherein a porous pipe is embedded in the soil layer, and the water from the water storage part is saturated in the porous pipe under negative pressure. A negative pressure differential irrigation system configured to allow the water in the porous tube to leach into the capillary by the difference between the negative pressure in the soil tube in contact with the porous tube and the negative pressure in the porous tube,
A negative pressure differential irrigation system comprising a free air removing unit capable of intermittently forcibly flowing water in a flow path connecting a porous pipe and a water storage tank to remove free air in the flow path.