JP3349590B2 - Foam generator - 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 generator used for buffering and suppressing underwater shock waves in underwater blasting.

[0002]

2. Description of the Related Art As shown in FIG. 6, for example, as shown in FIG. 6, a tube (or bag) 101 having a large number of holes is submerged in water, and an air compressor or a cylinder mounted on a work boat 102 is used. A gas is supplied from a gas supply source to the tube 101 via the hose 103, and the gas is ejected from a hole of the tube 101 to generate bubbles B. As shown in FIG. Some of them generate bubbles B by sinking the basket 105.

[0003]

However, in the above-described conventional bubble generator, when the tube 101 is used, a gas supply source or a hose 103 on a ship is required.
For example, there is a problem that the whole apparatus becomes large and it is difficult to generate a large amount of bubbles. In the case of the one using dry ice 104, the handling is difficult and a storage provided with a freezing facility is required. There is a problem that it is indispensable, and solving these problems has been an issue.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and is intended to provide a foam generating apparatus which can generate a large amount of foams while being small in size, and which is excellent in handleability and storability. It is intended to provide.

[0005]

According to a first aspect of the present invention, there is provided a foam generating apparatus for generating a large amount of bubbles in water, wherein a predetermined range is provided from one end of a cylindrical case. A solid propellant, which has been made into an end face burning type grain, is charged, and at the other end of the case, an igniter for the solid propellant and a plurality of injection nozzles opened laterally at equal intervals in the circumferential direction of the case. In a second aspect, a propellant for imparting axial propulsion to the case is provided at the other end of the case, and a time delay agent is provided between the propellant and the solid propellant igniter. It is configured to be loaded,
The above configuration is a means for solving the problem.

[0006]

The bubble generating device according to the first aspect of the present invention is disposed in the water together with the case, ignites the end face of the solid propellant with the igniter, and injects the combustion gas to the side from the injection nozzle. Generates foam. At this time, in the foam generator, since the plurality of injection nozzles are provided at equal intervals in the circumferential direction at the other end of the cylindrical case, the combustion gas is radially injected, and thereby sinks. The foam is generated in place without applying lateral (radial) and axial propulsion to the case. Further, since the solid propellant is used, a large amount of bubbles is generated while being small, and the solid propellant is formed as an end face burning type grain, so that the burning time with respect to the amount of the solid propellant is prolonged.

[0007]

[0008]

Further, in the foam generating apparatus according to the second aspect of the present invention, the propellant is started by itself by igniting the propellant, and after the delay medicine is burned, the solid propellant is ignited by the igniter. Therefore, it is possible to generate bubbles by the combustion gas of the solid propellant when the case is caused to fly to the target position and settle down to a predetermined water depth.

[0010]

[0011]

1 and 2 are diagrams for explaining an embodiment of a foam generating apparatus according to the present invention.

A foam generator 1 shown in FIG. 1 has a cylindrical case 2 loaded with a solid propellant 3 for a rocket, which is a gas generating agent, and an igniter as an actuating means provided at an end of the case 2. 4, and at the same end of the case 2, an injection nozzle 5 that is opened laterally at equal intervals in the circumferential direction is provided.

The case 2 has a head plate member 6 screwed to one end and a female screw hole 7 smaller than the inner diameter of the case at the center of the other end. , Solid propellant 3 formed as end-burning grains is loaded via restrictor 8. The solid propellant 3 is completely fixed by a spacer 10 provided between the solid propellant 3 and the step 9 in the case 2.

A space 11 is formed in the other end of the case 2, and a plurality of (eight in this embodiment) injection nozzles 5 are provided on the side of the other end. Each injection nozzle 5
Has a tapered portion 12 extending outside the case, and is closed by a nozzle closure 13 detachably provided on the tapered portion 12. Therefore, the inside of the case 2 is in a sealed state, whereby the function of preventing the solid propellant 3 from deteriorating is further enhanced.

The igniter 4 has a configuration in which an igniter 16 and a squib 18 connected to a conductive wire 17 are mounted on a convex holder 15 having a gas discharge hole 14 at the tip. It is screwed into the female screw hole 7 so as to protrude into the space 11.

The foam generator 1 having the above configuration is used, for example, as a means for reducing impact pressure from blasting in water.
In this case, as shown in FIG.

The foam generator 1 is provided with a squib 1
The ignition of the igniting charge 16 is carried out by electrically igniting 8, and then the solid propellant 3 is ignited. Then, following the start of combustion of the solid propellant 3, each nozzle closure 13 is blown off by the internal pressure of the space 11, and each opened injection nozzle 5
, A combustion gas is simultaneously injected to generate bubbles B. As a result, for example, the impact pressure applied to the hull itself is reduced or suppressed.

At this time, the foam generating apparatus 1 opens the plurality of injection nozzles 5 radially, more specifically, opens the respective injection nozzles 5 laterally at equal intervals in the circumferential direction at the other end of the cylindrical case 2. Since the combustion gas is simultaneously ejected from each of the injection nozzles 5, no lateral (radial) and axial propulsion force is applied to the case 2 that sinks with the end plate member 6 facing downward. The posture of the case 2 is stabilized, and bubbles B are generated at fixed positions.

Further, since the above foam generating device 1 uses the solid propellant 3 for a rocket as a gas generating agent, it has a simple structure and excellent storage properties, and starts operating in a short time. It is possible to generate a large amount of foam B,
Further, since the solid propellant 3 is an end-face burning type grain, the burning time for the amount of the solid propellant is prolonged, and the foam B is generated for a long time.

As shown in FIG. 2, by using a plurality of bubble generators 1 in consideration of the timing of discarding, it is possible to form a bubble curtain having a certain surface state. Can further enhance the impact relaxation effect.

FIGS. 3 and 4 are views for explaining another embodiment of the foam generating apparatus according to the present invention. The same components as those in the previous embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The foam generator 21 of this embodiment has a case 2
The cylindrical member 22 is connected to the end of the igniter 4 side of
The case 2 has a configuration in which a propellant 23 for providing propulsion is provided, and a delay time drug 24 is loaded between the propellant 23 and the igniter 4 of the solid propellant 3. In addition, the cylindrical member 2
2 has four tails 25 urged outward by a spring (not shown). These tails 25 are held in a state of being housed in the cylindrical member 22 by a band 26 provided at an end of the cylindrical member 22.

The delay medicine 24 is housed in a tube 27 connected to the holder 15 of the igniter 4.
3 is loaded in a cartridge 28 connected to a tube 27. A squib 30 to which a conductive wire 29 is connected is attached to the cartridge 28.

The foam generator 21 having the above-described configuration is housed in a firing cylinder 31 as shown in FIG. 4, and when the ignition of the propellant 23 is performed by operating the ignition controller 32,
Following the start by itself, the restraint by the band 26 is released, and the tail fins 25 are made to protrude and fly to the target position.

Then, following the end of combustion of the propellant 23, the foam generator 21 ignites the delay medicine 24, and the delay medicine 2
Subsequent to the end of combustion of 4, the solid propellant 3 is ignited by the igniter 4. Thereby, each nozzle closure 13 is blown off by the internal pressure of the space 11, and each opened injection nozzle 5
, A combustion gas is simultaneously injected to generate bubbles B.

The above-mentioned foam generating device 21 can obtain the same effect as that of the above-described embodiment, and can set the flight distance of the case 2 according to the amount of the propellant 23. The ignition timing for the solid propellant 3 is set based on the amount of the postponing medicine 24, and when the solid propellant 3 is settled to a predetermined water depth, it is possible to generate bubbles B by the combustion gas.

FIG. 5 is a diagram for explaining an example of use of the foam generator according to the present invention.

That is, when blasting an underwater cliff as an offshore construction, the work vessel A sends a plurality of foam generators 1 (21).
And a bubble curtain BC having a certain surface state is generated facing the construction area 41 on which the explosive 40 has been set. This reduces the impact pressure (water pressure) at the time of the blast,
The effect on fish and the like can be reduced.

Further, in the case of the above-mentioned use example, if a foam generator provided with a propellant (see FIGS. 3 and 4) is used, the dumping operation can be performed at a position sufficiently distant from the construction area 41. The influence on the ship A can also be reliably avoided.

[0030]

As described above, according to the foam generating apparatus according to the first aspect of the present invention, the structure is extremely simple, it can be operated in a short time, and
It is small and can generate a large amount of foam. In addition, the appearance is constituted by a cylindrical case, and since it is discarded and used individually, it is easy to store, and the workability such as handling and maintenance management can be improved,
In addition, since bubbles are generated simultaneously from a plurality of injection nozzles in a radial manner, lateral (radial) and axial driving forces are not applied to the sinking case, and bubbles are reliably generated at a target position. Can be. In addition, since the solid propellant is an end-face burning type grain, the structure can be further simplified, and the combustion time can be increased with respect to the amount of the solid propellant. Can be generated.

[0031]

According to the foam generating apparatus of the second aspect of the present invention, in addition to the above-described effects, it is possible to perform self-starting, and by adjusting the amounts of the propellant and the delaying drug, the flying distance and the flight distance of the case are improved. Since the ignition timing of the solid propellant can be set and the ignition can be performed at a distant place, the evacuation action for underwater blasting or the like can be reliably performed at an early stage.

[0033]

Further, according to the foam generator according to the present invention, a bubble curtain having a certain surface state can be generated by using a plurality of foam generators. For example, when underwater blasting is performed, the impact pressure is reduced. Function can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining an embodiment of a foam generator according to claims 1 to 5 and 7 of the present invention.

FIG. 2 is an explanatory diagram showing a state in which the foam generator shown in FIG. 1 is discarded from a ship.

FIG. 3 is a cross-sectional view for explaining one embodiment of the foam generator according to claims 1 to 7 of the present invention.

FIG. 4 is an explanatory view showing a state in which the foam generator shown in FIG. 3 is fired and dumped in water.

FIG. 5 is an explanatory view showing another example of use of the foam generator according to claims 1 to 7 of the present invention.

FIG. 6 is an explanatory view showing a conventional bubble generator.

FIG. 7 is an explanatory view showing another example of a conventional bubble generating device.

[Description of Signs] 1,21 Bubble Generator 2 Case 3 Solid Propellant (Gas Generator) 4 Ignition Device (Activating Means) 5 Injection Nozzle 23 Propellant 24 Postponed Drug

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F42D 5/045 F41F 3/08

Claims (2)

(57) [Claims] 1. A device for generating a large amount of bubbles in water, wherein a solid propellant in the form of an end-face burning type grain is loaded into a cylindrical case over a predetermined range from one end of the case. A foam generator, comprising: an igniter for a solid propellant at an end thereof; and a plurality of injection nozzles that are laterally opened at equal intervals in a circumferential direction of a case. 2. A case wherein a propellant for imparting axial propulsion to the case is provided at the other end of the case, and a delaying agent is loaded between the propellant and a solid propellant igniter. The foam generator according to claim 1, characterized in that: