Method And Apparatus For Introducing Liquid Into Root Zone Of Plants In Soil

Abstract

Liquid under high pressure is injected into the root zone of plants in soil by the action of accumulated impact energy in the form of continuous pulse jets. A device for effecting injection of liquid comprises a chamber adapted to accumulated the liquid, and a nozzle disposed in the lower portion of the chamber and adapted to discharge liquid as pulse jets. A plunger is accommodated in the chamber, the plunger being reciprocated to transmit an impact to the liquid and being connected to a resilient compression member adapted to accumulate energy.

Parent Case Text

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is essentially a continuation-in-part application of U.S. Pat. Application Ser. No. 203,500 filed on Nov. 30, 1971, now abandoned. This latter application, in turn, is a Continuation Application of the parent application Ser. No. 849,452 filed on Aug. 12, 1969 and is now abandoned.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to fertilizing and more particularly, it relates to a method of introducing highly pressurized liquid into root zone of plants in soil and to an apparatus for accomplishing the same.

This invention may be successfully used in growing large-and-small fruits, vineyards etc., when deep subsoil injection of liquid fertilizers directly into the root zone of a plant is required in order to provide a vast subsoil nourishing zone without destroying the root system of the plant. The invention may also be used for subsoil irrigation of plants, for protection of plants from pests, as well as for stimulating growth of the former.

Methods of injecting liquids into soil are known, such methods comprising the step of introducing liquid into soil in the form of separate intermittent jets which penetrate into the soil to a negligible depth of about 6-8 inches under pressures ranging from 35 to 105 atm. The device used for accomplishing the method comprises a measuring tank receiving pressurized liquid supplied by a pump and a cylinder disposed under the tank and containing a plunger reciprocating in the cylinder under the action of a cam and connected to a valve (cf. U.S. Pat. No. 3,012,526, Cl111-6). The process of injecting liquid into soil is carried out in the following way. Liquid is supplied from the pump to the measuring tank. During the downward stroke of the plunger the liquid is passed to a delivery pipe through a valve, while on the upward stroke of the plunger the pressure of the liquid in the pipe and in an outlet cavity gradually increases. The outlet of the nozzle is ovelapped by a spring-loaded needle valve. When pressure of the liquid contained in the pipe exceeds the force of the spring, the needle valve is raised to open the outlet of the nozzle, whereby the liquid goes out of the nozzle under pressure and penetrates into soil. After the dropping of pressure in the chamber, the needle valve is lowered to overlap the nozzle outlet, whereupon the cycle is repeated. From the above-said it is clear, that the possibilities of the conventional device are extremely limited with respect to discharge pressure of the liquid coming out of the nozzle. To build up high pressure of an order of 3,000 atm. which is necessary for penetration of liquid to a relatively great depth of about 1 meter without destroying the root system of plants, it would be necessary to substantially increase the overall dimensions of the deivce, which is undesirable from the structural point of view.

Devices for injecting liquids into soil are also known in the art, comprising a spring-loaded piston disposed in a chamber and reciprocating therein due to engagement with a cam; a nozzle fixer in the lower part of the chamber, and a valve positioned in a pipe supplying liquid to the chamber (cf. U.S. Pat. No. 2,930,334, Cl.111-6). The injection of liquid is carried out in the following way. The piston reciprocates in the chamber (moving downwardly under the action of the cam and upwardly under the action of the spring). During the upward stroke of the piston, the chamber is vacuumized and the valve is caused to operate due to the vacuum and under the action of the liquid gravity, whereby the space defined by the piston and sleeve is filled with the liquid.

During the downward stroke, the piston compresses the liquid and thereby gradually increases the pressure in the cavity. Due to the fact that there is no space between the piston and the liquid, the latter is gradually forced out of the cavity during the rotation of the cam and movement of the piston. The opening provided in the sleeve is normally closed by the spring-loaded valve. When the pressure of the liquid acting on the valve exceeds the force of the spring, the valve is displaced downwardly permitting the liquid to come out of the nozzle through the openings. It is absolutely clear that the liquid pressure depends on the cam stroke and, therefore, the conventional device is limited with respect to the possibilies of increasing the pressure, and hence, the depth of injection.

The injection depth may, however, be increased by using a device with working units mounted on the tine of a cultivator and deepened together therewith into soil down to a required depth. While travelling along a furrow, the working unit of these devices introduces liquid into soil. However, in the case of use of the aforesaid device a split is formed in the soil, which results in damage and desiccation of the root system of plants, as well as in a partial wear of the working units due to the soil abrasive action.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide such a method and an apparatus for introducing liquid into soil that will provide for injecting highly pressurized intermittent liquid into soil to a considerable depth without destroying the root zone of plants.

An important object of the present invention is to provide a vast subsoil nourishing zone for plants.

Still another object of the invention is to simplify the design and to raise the reliability of the above-mentioned device.

In the accomplishment of these and other objects of the invention, periodically accumulated portions of liquid are introduced into the root zone of plants in soil under the action of impact as pulse jets, the pulse pressure in this case ranging from 1,000 to 3,500 atm. The lower limit of this range (1,000 atm) is dictated by the requirement to inject liquid to the depth of not smaller than 30- 50 cm. At pressures lower than 1,000 atm. the required depth of penetration cannot be achieved. In soil dressing of fruit crops and vineyards the required depth of liquid injection into soil is increased up to 1 m. This depth is achieved only at pressures of about 3,500 atm. A further increase in the pressure is not advisable because the main part of the hole is made by the first portions of the liquid jet, while the rest portions thereof lose a considerable part of their energy in passing through the previously delivered liquid and only thereafter can they reach the soil to increase slightly the depth already obtained.

It should be borne in mind that the soil resistance increases in proportion to the depth of the jet penetration and therefore, the critical moment is inevitable, when a further increasing of the pressure does not ensure an increment of the injection depth due to the loss of energy in the subsequent portions of the jet and due to the increase in the soil resistance.

In accordance with the present invention, the device for accomplishing the above-mentioned method is provided with means for delivering forces by a compressible elastic body disposed in the upper portion of the cylinder and adapted to accumulate the energy after the plunger leaves the chamber. The energy, thus accumulated, aids in further acceleration of the plunger, necessary for delivering an impact upon the surface of the liquid contained in the chamber. The elastic body is pressed by its one end to the plunger and by the other end to the stop disposed in the cylinder, the stop being made adjustable to control the energy accumulated by the elastic body.

Such a method and constructive embodiment of the device make it possible to inject liquid into soil in the form in high-speed pulse jets under a pressure of the range from 1,000 to 3,500 atm to the depth of about 0.3-1 m without destroying the root zone of plants.

The above-mentioned results were obtained by use of a device built in accordance with the main principles of the present invention which consist in a relatively slow accumulation of energy and in a very fast (some milliseconds) transmission of this energy to a definite volume of liquid contained in the chamber.

It is preferable that means provided for reciprocation of the plunger are made as an elongated bar having a projection at one end adapted to receive a spring forced against this projection, while the other end of the bar is bent and connected to a traverse member driven from a power unit, the bent end of the bar is also connected by means of a pivot to another rod the free end of which is equipped with rollers periodically engaging a locking clamp secured to the plunger. Such a specific embodiment of the device, in accordance with the invention, ensures reliable operation of the device as a whole, and, at the same time, makes it possible to simplify its structure.

In order to ensure the predetermined release height of the piston and the fixation of the amount of energy accumulated, it is expedient that the means used to reciprocate the plunger comprise a wedge-shaped projection secured to the cylinder and have a chamfer surface directed from the traverse member towards the nozzle to ensure disengagement of the rollers and the locking clamps, as well as to ensure the entrance of the plunger into the chamber under the action of the force of the compressing elastic body.

In order to ensure reliability of the device operation and for the sake of simplicity, it is preferrable to make the compressing elastic body in the form of a compression coil spring.

BRIEF DESCRIPTION OF THE DRAWINGS

For further details of the invention, reference may be made to the drawings, in which:

FIG. 1 schematically shows the method of injecting liquid into soil in accordance with the invention;

FIG. 2 is a general sectional view of a device for accomplishing the method according to the present invention;

FIG. 3 is a view taken in the direction of arrow A in FIG. 2;

FIG. 4 is a cross-sectional view taken along line IV--IV in FIG. 2;

FIG. 5 is a view similar to FIG. 4, at the beginning of the downward stroke of the plunger;

FIG. 6 shows a cross-sectional view of a nozzle with a valve.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The method of introducing liquid into the root zone of plants in soil comprising the steps of: periodically accumulating liquid inside a nozzle 1 (FIG. 1) disposed above the soil surface; periodically accumulating energy in means transmitting a force to deliver an impact to the liquid; subsequent periodical injection of the liquid into the root zone (2) of plants in a form of a high-speed pulse jet (3) developed under the action of the impact. The pressure generated at the moment of impact upon the liquid surface, in this case, may be from 1,000 to 3,500 atm depending on breed of plants, kind of soils and the required depth of injection.

A device for injecting liquid into the root zone of plants under a high pulse pressure comprises a cylinder 4 with an outlet nozzle 1 (FIG. 2) attached to the lower portion of the cylinder. Also in the lower portion of the cylinder 4 there is provided a chamber 5. This chamber 5 is adjoined to the upper portion of the nozzle 1 and provided for periodical accumulation of liquid. A valve 6 is positioned in the nozzle, the valve preventing premature discharging of liquid from the chamber 5. Liquid is supplied to the chamber from a tank 7 through pipelines 8 and 9 and a non-return valve 10 preventing returning of liquid back to the tank 7. A cock 11 in inserted in the pipeline 9, which cock is adapted to control the rate of admission of liquid into the chamber 5. A plunger 12 is disposed in the cylinder 4, the plunger being capable of reciprocation for periodical entrance into the chamber 5 and transmission of an impact to the liquid accumulated in the chamber. The device is provided with means for ensuring reciprocation of the plunger 12 and with force transmitting means. The latter comprise a compression coil spring 13 which is rested by one end upon a plunger and by the other end upon an adjusting stop 14 screwed into the cylinder 4. This adjusting stop 14 makes it possible to control a force of the spring 13. A change in a force of the spring results in a change of energy used to accelerate the plunger 12 and to transmit an impact to the liquid.

Means for providing reciprocation of the plunger 12 comprise an elongated bar 15 having a projection 16 at one end, the projection being adapted to support a spring 17 embracing the bar. The other end of the spring 17 rests upon an adjusting stop 18 screwed into the cylinder 4. This stop 17 is adapted to control a force of the spring 18. The other end of the bar is rigidly connected to a traverse member 19. A cylinder 20 of an internal combustion engine 21 is mounted on the traverse element 19. Mounted coaxially with the cylinder 20 is a piston 23 of the internal combustion engine, the piston being mounted on a stationary plate 22. The internal combustion engine is adapted to provide the upward movement of the traverse member and other parts associated therewith. The downward movement of the traverse member and the associated parts is effected under the action of gravity and with the aid of the force of the spring 17. The role of the spring 17 grows at a tilted position of the device, when the effect of gravity of the traverse member and of the parts associated therewith on the downward movement thereof decreases. A power cylinder 24 with a stem 25 is secured to the stationary plate 22. This cylinder is adapted for the initial starting of operation of the device, i.e. to perform the initial lifting of the traverse member 19.

The upper end of the bar 15 (FIG. 3) is bent, a rod 26 being connected to the bent end of the bar. Rollers 27 engaging with a locking clamp 28 which is rigidly connected to the plunger 12 (FIG. 4) are pivotally mounted on the free end of the rod 26.

Welded to the cylinder 4 are plates 29 with holes 30 drilled therein. These holes are used for securing wedge-shaped projections 31 to the plates 29, the chamfers of these wedge-like projections being directed outwardly of the traverse member towards the nozzle. The wedge-shaped projections 31 are intended to adjust a height corresponding to the moment when the rollers 27 are disengaged from the locking clamp, whereby the plunger starts its downward stroke (the moemnt of disengagement is shown in FIG. 5).

The adjustment of a height of release of the plunger 12 is effected by moving the projections 31 along the plates 29 and securing them through different holes 30.

The valve 6 inserted into the nozzle 1 and adapted to prevent premature discharging of liquid from the nozzle is shown in more detail in FIG. 6. The valve comprises a valve body 32 which is spring-loaded by means of a spring 33 rested at one end upon the valve body and at the other end -- upon a stop 34 screwed into the nozzle 1. The stop 34 is provided with an opening 35 allowing the movement of the shank 36 of the valve body therethrough. In order to prevent rotation of the valve body 32 about the horizontal axes, the opening 35 and the shank 36 have a square cross-section.

The device according to the invention functions as follows. At the beginning of the cycle the power cylinder 24 is activated, whereby the stem 25 thereof comes into contact with the traverse member 19 raising it upwardly. At this moment the rollers 27 pivotally mounted on the rod 26 are in engagement with the locking clamp 28 of the plunger 12. The latter is moving up together with the rods 26, 15 and the traverse member 19, the springs 13 and 17 being compressed during this upward movement. As the plunger 12 raises, the liquid in the tank 7 is fed to the chamber 5 adjacent the nozzle 1. The rate of admission of liquid is adjusted by means of the cock 11 and is chosen so that at the moment, when the plunger begins its downward stroke, a predetermined space is defined between the end face of the plunger and the surface of the liquid. Liquid cannot flow out of the nozzle, as the outlet opening of the nozzle is closed by the valve body of the valve 6.

As the rollers 27 are moving upwardly, they ride upon the wedge-shaped projections 31 and are gradually disengaged from the locking clamp 28 (FIG. 5). When this occurs, the rod 26 is rotated about its pivot relative to the bar 15. With the rollers disengaged from the locking clamp 28, the plunger 12 instantly moves down under the action of the spring 10 thus transmitting an impact to the liquid contained in the chamber 5. Under the action of pressure of the liquid upon the chamfered surface of the valve body 32, the latter will be displaced, whereby the liquid is permitted to flow out of the nozzle in the form of a high-speed pulse jet. When the whole charge of the liquid is exhausted, the valve body will be returned to its original position by means of the spring 33, thereby closing the outlet opening of the nozzle.

Upon disengagement of the rollers 27 from the locking clamp 28, the rods 15 and 26 together with the traverse 19 and the internal combustion engine 21 fall down under the action of gravity and the force of the spring 17. At this moment, the stem 25 of the power cylinder 24 is disengaged, whereby the power cylinder does not take part in the subsequent operation of the device. It should be noted that the spring 17 ensures the movement of the above-mentioned parts towards the locking clamp 28 of the plunger 12 at any position of the device (vertical, inclined or horizontal). At the extreme lower position the rollers again will come into engagement with the locking clamp 28, while the plunger 23 enters the cylinder 20 of the internal combustion engine 21.

When the piston 23 enters the cylinder 20 of the internal combustion engine, this causes the compression of the air in the cylinder, and at this moment fuel is injected into the cylinder. Under the action of pressure of gases formed upon combustion of the fuel, the cylinder 20 of the internal combustion engine moves upwards together with the traverse member 19 and the bars 15 and 26. The plunger 12, the locking clamp 28 of which is engaged with the rollers 27, also will be raised.

At the moment of disengagement of the rollers from the locking clamp 28, the plunger 12, the traverse member 19 and the parts associated therewith again will fall down, whereby the cycle is repeated.

Claims

What is claimed is:

1. A device for injecting liquid into the root zone of plants under pulse pressure comprising: at least one cylinder having an outlet nozzle mounted at the lower end of said cylinder and adapted to be positioned above the soil surface; a chamber disposed in said cylinder adjacent to said nozzle thereabove and adapted for periodical accumulation of liquid; a valve disposed in said nozzle and adapted to prevent premature discharging of the liquid from said chamber; means in fluid communication with said chamber for supplying the liquid thereto at an adjustable rate of flow; a non-return valve disposed in said means for supplying the liquid and adapted to prevent the return flow of the liquid; a plunger disposed in said cylinder and being capable of reciprocation for periodical entrance into said chamber in order to deliver an impact to the liquid accumulated in said chamber, whereby high pulse pressure is developed in said chamber, said pressure being utilized to discharge the accumulated liquid through said nozzle in the form of a high-speed pulse jet; means including a force transmitting element for ensuring reciprocation of said plunger; said force transmitting element comprising a compressible resilient member disposed in the upper portion of said cylinder and adapted to accumulate energy; the accumulated energy further accelerating said plunger when the latter enters said chamber to deliver an impact to the liquid accumulated in said chamber; said resilient member being mounted on one end upon said plunger and on the other end upon a stop disposed in said cylinder, said resilient member exerting a force on said plunger throughout the reciprocation thereof; said stop being adjustable to adjust an amount of energy accumulated in said resilient member.

2. A device as claimed in claim 1, wherein said means for ensuring reciprocation of said plunger comprise an elongated bar having a projection at its lower end, the other end of said bar being bent, a spring embracing said bar and resting upon said projection to move said bar to a lower initial position, a traverse member being connected to said bent end of said bar, means for imparting motion to said traverse member along with said bar, an additional bar being pivotally connected by one of its ends to said bent end of said elongated bar, rollers being disposed at the free end of said additional bar, and a locking clamp attached to said plunger and periodically interacting with said rollers to reciprocate said plunger.

3. A device as claimed in claim 2, wherein said means for ensuring reciprocation of said plunger comprise a wedge-shaped projection secured to said cylinder, the chamfer surface of which is directed outwardly of said traverse member towards said nozzle to ensure disengagement of said rollers from said locking clamp with the result that under action of said compression resilient member said plunger moves downward to deliver an impact to the liquid.

4. A device as claimed in claim 1, in which said compression resilient member comprises a compression coil spring.