JP2729455B2 - Foam injection 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 foam ejecting apparatus for ejecting a liquid containing a foaming agent into foam.

[0002]

2. Description of the Related Art In operations such as cleaning, disinfection, weeding, and sterilization of crops, a foaming agent is mixed with a diluted drug to form a foam, and the foam is sprayed on an object in order to enhance the effect of the drug. ing.

FIG. 2 is a longitudinal sectional view of a conventional foaming nozzle 100. Body 102, pipe 104 and flat nozzle member 10
Numerals 6 are arranged in order from the base end side to the front end side along the center line of the foaming nozzle 100, and adjacent ones are mutually connected by screwing. The cover 108 extends from the base end of the body 102 to the pipe 104
Body 102 so that the area up to the base end of the
Is screwed on. The connection port 110 is formed in the base end of the body 102, and is screwed with a distal end such as a valve cock and a stop gun (both not shown).
An injector nozzle 112 is housed and disposed in a nozzle case 114. The diluent pumped from a pump (not shown) is supplied to the injector nozzle 112 via a valve cock and a stop gun, and is ejected from the tip of the injector nozzle 112 into the nozzle case 114. Negative pressure is generated around 114. The check valve 116 is connected to the foaming agent tank via a pipe (not shown), and allows a one-way liquid flow from the foaming agent tank to the nozzle case 114. The foaming agent in the foaming agent tank
Suctioned by the negative pressure in the nozzle case 114, the check valve 116
Through the nozzle case 114. The liquid ejected from the injector nozzle 112 sucks the foaming agent from the check valve 116, flows into the center hole 118, mixes with the foaming agent, and then ejects to the enlarged diameter portion 120. By blowing out the diluting agent containing the foaming agent to the enlarged diameter portion 120, a negative pressure is generated around the enlarged diameter portion 120. The air outside the foaming nozzle 100 is taken in from the air suction port 122 between the outer peripheral surface of the pipe 104 and the inner circumference of the tip of the cover 108 due to the negative pressure in the enlarged diameter portion 120, and passes through the introduction hole 124. It is introduced into the enlarged diameter section 120. The diluted chemical containing the foaming agent mixed with the air is diffused from the expanded portion 120 to the diffuser 126.
Then, mixing with air is promoted in the diffuser 126 and the diffuser 126 enters the net 128. The punching metal 130 serves to prevent the mesh 128 from slipping out of the pipe 104 in the distal direction. Is generated. In this way, the foamed drug passes through the punching metal 130 and is injected into the injection hole 13 at the tip of the flat nozzle member 106.
Squirt from two.

[0004]

SUMMARY OF THE INVENTION A conventional foaming nozzle 100
The problems are listed as follows. (A) In the foaming nozzle 100, a negative pressure is generated by injection from the injector nozzle 112, and the foaming agent is sucked from the foaming agent tank by the negative pressure. Must be installed, which is a constraint. (B) The mixing of the blowing agent-containing diluent agent and air in the diffuser 126 is insufficient, and the foamability is low. In order to avoid this, if the diffuser 126 is made longer, the length of the foaming nozzle 100 increases. (C) This is a mechanism in which a mixture of the diluting agent containing a foaming agent and air is passed through the mesh 128 to generate bubbles. However, when the density of the mesh 128 is low, the deceleration effect is reduced and the injection hole is reduced. When the fluid from 132 is not foamed but becomes mist, and the density of the net 128 is high, the deceleration effect increases,
There are problems that the bubbles are reduced and the ejection power from the ejection holes 132 is weakened. (D) Foam generation performance fluctuates depending on the manner of assembling the net 128, and there are many variations among products. (E) The bubbles are ejected from the injection holes 132,
Due to the presence of the net 128, the ejection speed is reduced, and the reach is shortened.

[0005] It is an object of the present invention to provide a foam injection apparatus which can overcome the above-mentioned problems. Claim 2
Another object of the present invention is to provide a foam ejecting apparatus capable of improving the reach of foam. A third object of the present invention is to reduce the intake resistance against air taken in from outside for introducing air from the first air introduction hole and the second air introduction hole.

[0006]

The present invention will be described with reference to the drawings corresponding to the embodiments. The foam injection device (10) of the first aspect has the following components (a) to (g). (A) Orifice (26) through which liquid containing foaming agent passes (b) Multistage diffuser (28, 30, 32) provided downstream of orifice (26) and increasing in diameter sequentially (c) Orifice (26) Orifice (26)
A first air introduction hole (46) for introducing air into the orifice (26) by the negative pressure of (d) communicating with the last stage diffuser (32) and the last stage diffuser (32) by the negative pressure of the last stage diffuser (32); (2) a second air introduction hole (48) for introducing air into the inside (e). (E) A foaming agent-containing liquid from the last-stage diffuser (32) provided downstream of the last-stage diffuser (32).
A foaming chamber (34) which collides with the liquid containing foaming agent reflected from the collision wall (50) and collides with a subsequent liquid containing foaming agent to agitate the foaming liquid (f) from the foaming chamber (34) through the communication hole (52). Expansion chamber (36) that expands the incoming bubbles by inflow (g) a foam injection unit (40) that injects bubbles from the expansion chamber (36)

According to a second aspect of the present invention, there is provided a foam injection device.
(40) is formed in a taper that gradually increases in diameter in the bubble injection direction, and a rectifying air passage (58) connects the upstream end of the bubble injection unit (40) to the outside of the bubble injection device (10). Communicate with each other.

According to the third aspect of the present invention, the air suction passages (42, 44) for guiding outside air to the first air introduction hole (46) and the second air introduction hole (48) are: An enlarged portion (44) having an increased flow path cross-sectional area is provided in the middle.

[0009]

According to the first aspect of the present invention, the liquid containing a foaming agent is fed under pressure, passes through the orifice (26), and proceeds to the diffusers (28, 30, 32) having a plurality of stages. The first air introduction hole (46) opening to the orifice (26) has a negative pressure as the liquid containing the foaming agent passes through the orifice (26), and the air is
It flows into the orifice (26) through the first air introduction hole (46) and mixes with the liquid containing the foaming agent. When passing through the multi-stage diffuser (28, 30, 32), the liquid containing the blowing agent maintains the flow velocity and increases the flux diameter corresponding to the cross-sectional area of the diffuser (28, 30, 32). . When the liquid containing the blowing agent passes through the last-stage diffuser (32), a large negative pressure is generated in the last-stage diffuser (32), and air is generated in the second-stage diffuser (32).
A large amount is introduced into the last-stage diffuser (32) from the air introduction hole (48) of the first stage, and is mixed with the liquid containing a foaming agent in the last-stage diffuser (32). In the last-stage diffuser (32), the flow rate of the liquid containing the foaming agent is maintained high and the cross-sectional area is large, so that a large negative pressure is generated and the first air introduction hole (46)
A sufficiently large amount of air is introduced from the air into the orifice (26). When the foaming agent-containing liquid enters the foaming chamber (34), it collides with the collision wall (50) of the foaming chamber (34), is reflected, and further collides with the subsequent foaming agent-containing liquid to be in a stirring state. . As a result of stirring the liquid containing the foaming agent while being mixed with sufficient air, foam is generated in the foaming chamber (34), and the foam reaches the expansion chamber (36) through the communication hole (52), It expands further. The expansion of the foam in the expansion chamber (36)
It functions as a pushing force of the foam toward the foam ejecting section (40), and the foam is ejected from the foam ejecting section (40) toward the object to be dispersed.

According to the second aspect of the present invention, the bubbles are discharged to the outside through the tapered bubble ejecting section (40) whose diameter gradually increases. Further, the air outside the bubble injection device (10) is sucked into the bubble injection unit (40) through the rectifying air passage (58) by the negative pressure in the bubble injection unit (40), and the bubble injection unit (40) To the upstream end. This supply air flows in the taper-shaped foam injection section (40) to the exit side in a rectified state, and prevents scattering of the bubbles at the exit while increasing the flight distance.

According to the third aspect of the present invention, the outside air is supplied to the first air introduction hole (46) and the second air introduction hole (48).
The air is supplied through the air suction passages (42, 44) by a negative pressure to the enlarged diameter portion (44) in the middle of the air suction passages (42, 44).
Is to go through.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiment shown in FIG. FIG. 1 is a longitudinal sectional view of the foam injection device 10. Body 1
2. The pipe 16 and the injection port member 18 are arranged in order along the center line of the foam injection apparatus 10, and the adjacent ones are mutually connected by screwing. The cover 20 is screwed to the base end of the body 12 so as to cover the outer peripheral side of the body 12. Connection 22
Is formed on the inner peripheral side of the base end portion of the body 12, and is adapted to be screwed to a distal end portion such as a valve cock and a stop gun (both not shown). Inside the body 12, a tapered portion 24, an orifice 26, a first-stage diffuser 28, and a second-stage diffuser are sequentially arranged from the connection portion 22 side along the center line of the body 12.
30 are drilled. The tapered portion 24 gradually decreases in diameter in the downstream direction, and is supplied with a blowing agent-containing diluent from a pump (not shown) via a valve cock and a stop gun connected to the connection portion 22. On the downstream side of the second-stage diffuser 30,
Along the center line of the foam injection device 10, a third-stage diffuser 32 and a foaming chamber 34 are provided in the pipe 16, and an expansion chamber 36 is provided in the injection port member 18, in order from the second-stage diffuser 30. A discharge port 38 and a tapered portion 40 are formed respectively.

The annular suction port 42 is formed between the distal end of the cover 20 and the proximal end of the pipe 16, and
Is exposed to the outside. The annular air chamber 44 covers the cover 20.
Formed between the inner peripheral side of the body and the annular concave portion of the body 12, communicates with the annular suction port 42, and adjusts the cross-sectional area of the flow path to the annular suction port 4.
2, which is much larger than that of 2. Annular inlet 42
By screwing the cover 20 with respect to the body 12,
The opening area is adjustable. One introduction hole 46
Extend in the radial direction of the foam injector 10 and open into the annular air chamber 44 and the orifice 26 at radially outer and inner ends, respectively. A plurality of through holes 48 are formed at the distal end of the body 12 in parallel with the center line, and
4 communicates with the upstream end side of the third-stage diffuser 32.

The partition wall 50 is formed at the upstream end of the injection port member 18 and partitions the foaming chamber 34 and the expansion chamber 36 from each other.
The four communication holes 52 are radially drilled at equal angular intervals in the circumferential direction on the peripheral wall defining the expansion chamber 36, and communicate the downstream end of the foaming chamber 34 to the upstream end of the expansion chamber 36. Let the foaming room
The fluid containing the foaming agent at 34 and the large amount of air sucked by the third-stage diffuser 32 are set to positions that do not interfere with sufficient mixing, stirring, and foaming. The O-rings 54 and 56 are fitted to the threaded portion between the body 12 and the pipe 16 and the threaded portion between the pipe 16 and the injection port member 18 to seal the threaded joint. The discharge port 38 has a smaller diameter than the expansion chamber 36,
The diameter of the tapered portion 40 gradually increases in the downstream direction from the diameter of the discharge port 38 at the upstream end. The four through holes 58 are formed at equal angular intervals in the circumferential direction of the injection port member 18, extend in the radial direction, and connect the outer peripheral portion of the injection port member 18 and the upstream end of the tapered portion 40 to each other. They are communicating.

The operation of the embodiment will be described. The foaming agent-containing diluent pumped from a pump (not shown) is supplied to the tapered portion 24 via a hose or the like. The blowing agent-containing diluent is squeezed and accelerated at the orifice 26,
A negative pressure is generated around the orifice 26. Air outside the foam injection device 10 is sucked by the negative pressure around the orifice 26 and the negative pressure described later around the third-stage diffuser 32, is taken in from the annular suction port 42, and flows into the annular air chamber 44. After that, it is introduced into the orifice 26 through the introduction hole 46, and is mixed in a small amount into the diluent medicine containing the blowing agent in the orifice 26. The mixed fluid of the blowing agent-containing diluent and air passes through the first-stage diffuser 28, the second-stage diffuser 30, and the third-stage diffuser 32 sequentially. First stage diffuser 28 and second stage diffuser 30
Has a stepwise increase in diameter, and the mixed fluid
The flow rate is maintained without being substantially reduced due to the incorporation of a small amount of air from the introduction hole 46 in 26, and the diameter of the mixed fluid increases as the flow proceeds to the first-stage diffuser 28 and the second-stage diffuser 30. It has been found that it increases with the diameter of the diffuser in the step. In the experiment, when the introduction hole 46 was closed and the mixing of air from the introduction hole 46 was stopped, the flux of the diluting agent containing the blowing agent was maintained at the diameter of the orifice 26 and the first-stage diffuser 28 was maintained. Passed through the second stage diffuser 30 and the third stage diffuser 32. Further, when a taper passage is provided instead of the first-stage diffuser 28, the second-stage diffuser 30, and the third-stage diffuser 32 whose diameters are increased stepwise, each stage diffuser 28, 30,
At a distance as short as 32, no sufficient increase in flux diameter occurred.

As the mixed fluid having the increased flux diameter blows out from the second-stage diffuser 30 to the third-stage diffuser 32, a large negative pressure is generated around the third-stage diffuser 32. This negative pressure causes the air in the annular air chamber 44 to pass through the through-hole.
After passing through 48, it is introduced into the third-stage diffuser 32 from the outer peripheral side of the distal end portion of the body 12, and further mixed into the mixed fluid in the third-stage diffuser 32. The diameter of the third stage diffuser 32 is large,
In addition, despite the increase in the diameter, the flow rate of the mixed fluid is maintained high, so that the amount of air mixed into the third-stage diffuser 32 from the through hole 48 is reduced by the amount of air flowing from the introduction hole 46 to the orifice 26. It is much larger and larger. Cover 20
Is formed by covering the enlarged diameter portion 44 so that unstable outside air does not directly reach the first and second air introduction holes 46 and 48,
Enables stable air supply.

The diluted agent containing the foaming agent sufficiently mixed with air enters the foaming chamber 34 from the third-stage diffuser 32,
It collides head-on with the partition wall 50, is greatly decelerated, and is agitated by the subsequent mixed fluid to generate foam in the foaming chamber 34.
The foamed mixed fluid bypasses the partition wall 50 and has a plurality of communication holes.
52 passes radially from the outside to the inside and is compressed and
Enter into 36. The foam expands due to an increase in the flow path diameter in the expansion chamber 36. The increase in bubbles in the expansion chamber 36 is a driving force that pushes downstream bubbles toward the tapered portion 40 and pushes the bubbles out of the tapered portion 40.

After the bubbles are squeezed at the discharge port 38, they flow through the tapered portion 40 whose diameter gradually increases in the downstream direction. Tapered part 40
A negative pressure is generated at the base end side of the nozzle, and the negative pressure sucks air outside the injection port member 18 through the through hole 58. This suction of air eliminates the slowing effect of the velocity towards the outlet of the foam due to the gradual increase in diameter at this point. Air introduced from the through holes 58 arranged at equal angular intervals in the circumferential direction to the downstream end of the tapered portion 40 travels downstream in the tapered portion 40 by laminar flow, and as a result, the inside of the tapered portion 40 The foam is transported while being rectified,
There is no scattering of bubbles at the outlet of the tapered portion 40 due to the suction of air from the tapered portion 40 toward the target, and the flying distance of the bubbles increases.

[0019]

The effects of the first aspect of the present invention are as follows. (A) Since the liquid containing the foaming agent is sent under pressure without sucking the foaming agent by the negative pressure due to the injection at the nozzle, there is a restriction that the foaming agent tank must be arranged near the foam ejecting apparatus. To be released. (B) Since a plurality of stages of diffusers are connected downstream of the orifice into which air can be introduced, the liquid containing the air blowing agent that has passed through the orifices becomes a mixed fluid with air, and a fluid flows between the plurality of stages of diffusers. The flow diameter can be increased rapidly without reducing the speed of the air, and a large negative pressure can be generated in the final stage diffuser. Further, by arranging the second air introduction hole here, a large amount of external air As a result, a large amount of air can be mixed into the liquid containing the foaming agent over a short distance, and the length of the foam injection device can be reduced. (C) deceleration in the foaming chamber due to the collision with the collision wall without allowing the mixture of the liquid containing the foaming agent and air to pass through the net;
Since the foam is generated by the agitation, the foam having an appropriate size is generated without being affected by the mesh size of the mesh body, without lowering the jetting force of the foam from the foam jetting unit. (D) Since the generation of bubbles does not change depending on the manner of assembly, it is possible to prevent variations among products. (E) Since the foam is not ejected from the nozzle but is ejected by the pushing force toward the foam ejection portion due to the expansion of the foam in the expansion chamber, the mist is scattered by the wind. Thus, the reaching distance is reduced, while the reaching distance is improved.

According to the second aspect of the present invention, the bubble injection section has a tapered shape whose diameter gradually increases toward the downstream side, and external air is introduced into the upstream end side of the bubble injection section through the air flow path for rectification. In this portion, the effect of reducing the speed toward the outlet of the foam due to the gradual increase in the diameter is cut off, and rectification is generated in the foam ejecting section, and the foam is conveyed. Reachability can be increased.

According to the third aspect of the present invention, the orifice and the second
The air suction passage leading to the first air introduction hole and the second air introduction hole for introducing air into the air introduction hole has an enlarged portion in the middle, and the air outside the bubble injection device is supplied through the enlarged portion. So that air intake resistance is reduced,
Air intake can be facilitated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a foam injection device.

FIG. 2 is a longitudinal sectional view of a conventional foaming nozzle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Foam injection device 26 Orifice 28 1st-stage diffuser (diffuser) 30 2nd-stage diffuser (diffuser) 32 3rd-stage diffuser (diffuser, last-stage diffuser) 34 Bubble chamber 36 Expansion chamber 40 Taper part (bubble injection part) 42 Annular Suction port (air suction passage) 44 Annular air chamber (air suction passage, enlarged diameter portion) 46 Inlet hole (first air inlet hole) 48 Through hole (second air inlet hole) 50 Partition wall (collision wall) 52 Communication Hole 58 Through hole (rectifying air passage)

Claims (3)

(57) [Claims] 1. An orifice (26) through which a liquid containing a foaming agent passes, and (b) a multistage diffuser (28, 30, 32) provided downstream of the orifice (26) and increasing in diameter sequentially. )
(C) a first air introduction hole (46) which is opened on the peripheral surface of the orifice (26) and introduces air into the orifice (26) by a negative pressure of the orifice (26); A) a second air introduction hole (48) communicating with the last-stage diffuser (32) and introducing air into the last-stage diffuser (32) by the negative pressure of the last-stage diffuser (32); The last stage diffuser (3) is provided downstream of the stage diffuser (32).
A foaming chamber (34) that collides the foaming agent-containing liquid from 2) with the collision wall (50) and collides the foaming agent-containing liquid reflected from the collision wall (50) with the subsequent foaming agent-containing liquid and stirs. ,
(F) an expansion chamber (36) for expanding bubbles flowing from the foam chamber (34) through the communication hole (52); and (g) the expansion chamber (3).
A foam ejecting unit (40) for ejecting the foam from (6). 2. The foam injection part (40) is formed in a taper whose diameter gradually increases in a foam injection direction, and a rectifying air passage (58)
The foam injection device according to claim 1, wherein an upstream end of the foam injection unit (40) and the outside of the foam injection device (10) communicate with each other. 3. The first air introduction hole (46) for external air.
And an air suction passage (42, 42) leading to the second air introduction hole (48).
The foam injection device according to claim 1 or 2, wherein the (44) has a diameter-enlarging portion (44) in which a flow path cross-sectional area increases.