JPH0781477B2 - Bubble generating method and apparatus thereof - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bubble generating method and apparatus used in an air drilling drilling operation.

[0002]

2. Description of the Related Art Conventionally, during drilling work, an air digging method in which bubbles are sent into the hole together with air in order to cool the tip of the sampler tube inserted into the ground and to carry rock powder out of the hole smoothly. It has been known. As an air drilling machine using such bubbles, the inventor of the present invention has shown in FIG. 4 and FIG.
No. 43552 proposes a bubble generator. This device is equipped with a digging air hose that sends compressed air into the hole and a bubble generation air hose of another system in order to send bubbles with air to the sampler tube, and a constant pressure valve is provided in this bubble generation air hose. By supplying the foaming agent from the tank provided with a constant pressure, a fixed amount of air and foaming agent are obtained.

That is, FIG. 4 shows an example of an air bubble generating device and an air drilling device using the same. 31 is a boring machine for drilling, 32 is its rod, and 33 is a boring machine attached to the tip of 32. It is a sampler tube (generally called a cone). A drilling air hose 35 extending from the main compressor 34 is connected to the upper end of the rod 32, and compressed air is supplied to the tip of the sampler tube 33 by this air hose 35.
A foam supply air hose 37 extending from a foam generation compressor 36 is connected in the middle of the digging air hose 35, and a bubble generator 40 is provided in the middle of the foam supply air hose 37.

This bubble generating device 40 has a structure as shown in FIG. 5, and is provided with a foaming agent tank 41 supported by legs 41a. This foaming agent tank 4
1, a foaming agent injection port 42, a drainage port 43, a flow meter 4
4 and an air bleeding cock 45 are provided, and the foam supply air hose 37 is supported by a support member 46 provided on the upper part thereof.

A pressure valve 47 having one end connected to a foam supply air hose 37 is provided above the liquid level of the foaming agent tank 41, and the pressure valve 47 is provided.
A constant pressure valve 48 is provided on the pipeline. On the other hand, the lower end of the liquid supply pipe 49 opens near the inner surface of the bottom of the foaming agent tank 41, and the upper end of the liquid supply pipe 49 penetrates the upper part of the tank 41 and opens into the foam supply air hose 37. . The opening portion of the liquid supply pipe 49 in the bubble supply air hose 37 is a venturi 50 having an inner diameter smaller than that of the other portions, and the tip end is inserted into the liquid supply pipe 49 outside the venturi 50. 51 is provided. In addition, a window 52 for monitoring the foam state of the foam supply air hose 37 is provided at the foam discharge side of the venturi 50.

In such a bubble generating apparatus, as shown in FIG. 4, compressed air is sent to the sampler tube 33 through the digging air hose 35 by the action of the main compressor, and at the same time, compressed by the bubble generating compressor 36. The air is sent to the bubble generating device 40, and the bubbles generated here are supplied to the inside 35 of the digging air hose through the bubble generating air hose 37 and are sent to the tip of the sampler tube 33 together with the compressed digging air therein. , Carry out the rock powder from the drilling hole.

In this case, in the bubble generator itself, as shown in FIG. 5, the compressed air from the dedicated compressor 36 is supplied to the foaming agent tank 41 through the pressurizing valve 47 provided with the constant pressure valve 48 on the way. It Therefore, the foaming agent tank 4
Since a constant pressure is always applied to the upper space of 1, the foaming agent is supplied to the venturi 50 portion through the liquid supply pipe 49 at a constant pressure. In the Venturi 50 portion, the flow of air in the bubble supply air hose 37 is fast, so the foaming agent discharged from the liquid supply pipe 49 is sprayed in a mist state and immediately foams.

As described above, since the amounts of the foaming agent and the air supplied in the foam supply air hose 37 are always kept constant,
It is possible to generate bubbles of uniform diameter.

[0009]

However, in the conventional apparatus, the surfactant used as the foaming agent was an aqueous solution having an ideal solution concentration of 0.2 to 0.6%. This ideal solution concentration is a concentration that exhibits the highest effect of emulsifying property, which is a surface active action. However, high foamability is required during drilling work. That is, the reason why the rock powder is discharged by the bubbles is that the old foam having the rock powder on the surface is pushed up to the entrance of the hole by the new foam supplied to the bottom of the hole. The adsorption force largely depends on the foamability of the surfactant such as the amount, size, viscosity and surface tension of bubbles.

Therefore, in order to carry out the drilling work efficiently, it is conceivable to use the foaming agent as an aqueous solution having a high foaming property, but the concentration exhibiting a high effect on the foaming property is 3 to 10%, which is ideal. It is considerably higher than the solution concentration. At this concentration, it becomes a hydrosol close to a highly viscous gel in a micelle state. It is necessary to eject the foaming agent in this state to the air hose for foam generation in the form of aerosol to foam. It is difficult for a conventional foaming apparatus to constantly supply a fixed amount of such a high-concentration foaming agent having high viscosity as foam.

That is, one of the problems is that a stirring means is not provided in the tank of the conventional bubble generator. Therefore, the concentration of the foaming agent is not constant, which affects the foamability of the supplied foam. This is because there is a difference in the surfactant concentration between the upper layer and the lower layer in the tank because the foaming agent is an aqueous solution. In particular, when the foaming agent has a high concentration, the difference becomes remarkable.

Further, since the opening 49a of the liquid supply pipe 49 opens downward near the inner surface of the bottom of the foaming agent tank 41, the foaming agent is sucked from near the bottom of the tank 41. For this reason, an irregular water flow is generated around the opening 49a, and the amount of suction is small for a high-concentration foaming agent having a particularly high viscosity, so it is difficult to maintain a constant flow rate. Further, since it is opened downward, impurities such as dust settled on the bottom surface of the tank are sucked.
Conventionally, these impurities are caught in the venturi 50 portion and the drilling hole at the tip of the sampler tube 33 when the foaming agent is supplied from the liquid feeding tube into the foam supply air hose 37, and the supply amount of the foaming agent is further reduced. Had a problem that the device itself was disabled.

Further, in the conventional foam generating compressor 36, since the flow velocity of the compressed air in the foam generating air hose 37 and the pressure in the tank 41 are not sufficient, the foaming air hose 37 with a high concentration of foaming agent is used. It is difficult to inhale it and turn it into an aerosol.

By the way, since the foaming agent is difficult to recover, it is necessary to be one that is extremely safe for the global environment and one that reacts promptly to changes in the environment and decomposes to become stable. However, such blowing agents are chemically unstable. Therefore, it is necessary to store such a foaming agent in the tank 41 in a chemically stable state, but the foaming agent tank 41 of the conventional apparatus has no means for providing a constant storage environment. . For this reason, what was stored in a stable state was repeatedly added to the tank 41 little by little, and the work efficiency was poor.

On the other hand, in the conventional device, in addition to the drilling device, devices such as the foam generating compressor 36 for supplying bubbles are provided, so the device for drilling becomes large and drilling is performed. A sufficient installation area is required in the surrounding area. Also,
The large number of devices complicates the operation, and requires a high level of working technique for the amount of air suitable for the ground, the amount of foaming liquid, the air pressure for these, the tank pressure, and other drilling tests.

The present invention has been proposed to solve the above-mentioned drawbacks of the prior art, and its purpose is to provide means for stirring in the foaming agent tank,
It is possible to always supply a constant concentration of foaming agent, and a liquid supply pipe that can suck a constant amount of high-concentration foaming agent is provided. Furthermore, even this high-concentration foaming agent can be sucked into compressed air. It is an object of the present invention to provide a bubble generating method and an apparatus therefor in which the fine and uniform bubbles are formed, and the bubbles are supplied to the tip of the sampler tube so that the rock powder can be smoothly discharged and the drilling work is efficiently performed.

Further, it is another object of the present invention to provide a bubble generator having a foaming agent tank which can store a foaming agent which is extremely safe against the global environment in a stable state and has a good working efficiency.

It is another object of the present invention to provide an air bubble generating device which has a small size, enables drilling work even in a limited place, is easy to operate, and has improved workability.

[0019]

According to the present invention as set forth in claim 1, compressed air is caused to flow to the upper portion of the foaming agent tank through a pressure pipe to pressurize the inside of the foaming agent tank and to generate bubbles through which the compressed air flows. By connecting a Laval pipe to a part of the pipe and sucking the foaming agent in the foaming agent tank through the liquid supply pipe, the foaming agent is ejected into the compressed air to foam, and this foam is used as an air hose for digging. It is characterized in that it is supplied up to the tip of the attached sampler tube, and the rock powder is carried out of the hole from the tip of the sampler tube inserted into the ground by this foam.

According to a second aspect of the present invention, there is provided a foaming agent tank for supplying air bubbles to a digging air hose through which compressed air flows, and a main pipe connected to a part of the digging air hose. A bubble generating pipe that branches from the main pipe and joins again, a pressurizing pipe that has one end opening to the main pipe and the other end opening to the top of the foaming agent tank, and air that is provided in the main pipe and can adjust the internal pressure. A quantity control valve and a liquid feed pipe having one end in the liquid inside the foaming agent tank and the other end opening into the bubble generation pipe are provided.

According to a third aspect of the present invention, in the bubble generating apparatus according to the second aspect, one end is provided with a main pipe and the other end is provided with a stirring pipe having an opening in the liquid in the foaming agent tank.

The present invention according to claim 4 is characterized in that a Laval pipe is provided at an opening portion of the liquid feeding pipe in the main bubble generating pipe of the bubble generating apparatus according to claim 2.

The present invention according to claim 5 is characterized in that the opening of the liquid feed pipe in the liquid of the foaming agent tank of the bubble generator according to claim 2 is provided spirally on the side face of the liquid feed pipe. To do.

The present invention according to claim 6 is characterized in that a liquid temperature adjusting device for keeping the liquid in the foaming agent tank at a constant temperature is provided around the foaming agent tank of the bubble generating apparatus according to claim 2. To do.

[0025]

The operation of the present invention having the above construction is as follows.

That is, according to the first aspect of the present invention, the foaming agent is ejected from the foaming agent tank at a high speed to the bubble generating pipe through the liquid supply pipe by the suction force of the Laval pipe together with the pressure applied inside the foaming agent tank. Furthermore, since this foaming agent is mixed with the high-speed compressed air jetted from the Laval tube and immediately foams and is supplied to the tip of the sampler tube, even the high-viscosity foaming agent is sufficiently foamed to the tip of the sampler tube. The rock powder can be smoothly carried out of the hole.

According to the second aspect of the present invention, the compressed air flows into the main pipe connected to the digging air hose, flows from the main pipe to the pressurizing pipe, and the inside of the foaming agent tank has a high pressure. This pressure is adjusted together with the internal pressure of the main pipe by the air amount adjusting valve provided in the main pipe. This pressure is applied to the foaming agent, and the foaming agent is discharged from the liquid supply pipe into the bubble generating pipe. Here, the blowing agent is foamed by the flow of the compressed air supplied from the main pipe, and further, the foam passes through the main pipe,
It is sent to the air hose for drilling. Therefore, foaming can be obtained with a simple device.

According to the third aspect of the present invention, since the foaming agent tank of the second aspect is provided with the stirring pipe, the compressed air is blown into the foaming agent to stir the foaming agent so that the foaming agent is constantly constant. It becomes the concentration.

According to the present invention as set forth in claim 4, since the Laval pipe is provided at the opening portion of the liquid supply pipe in the bubble generating pipe of the invention as set forth in claim 2, the foaming agent can be applied together with the pressure applied in the foaming agent tank. Due to the suction force due to the differential pressure of the Laval tube, it is discharged into the bubble generating pipe and foams. Furthermore, the foam of the foaming agent is supplied to the digging air hose at high speed by the compressed air that becomes a high-speed air flow by the Laval tube.

The present invention according to claim 5 is characterized in that the opening in the foaming agent provided in the liquid supply pipe of the invention according to claim 2 is spirally opened on the side surface of the liquid supply pipe, and thus the liquid supply pipe is formed. The foaming agent sucked in becomes a spiral water flow in a certain direction. This makes it easy to suck even a small amount of the foaming agent in the tank.

According to the present invention of claim 6, the foaming agent tank of the invention of claim 2 is provided with a liquid temperature adjusting device for the foaming agent, so that the foaming agent which changes depending on the temperature can be kept stable. Can be stored.

[0032]

EXAMPLE A bubble generating method and apparatus according to the present invention will be described below.
Description will be made based on the embodiment shown in FIGS. 1 and 2.

The present embodiment includes the inventions according to claims 1 to 6.

That is, FIG. 1 shows an air bubble generator of the present embodiment and an air drilling device using the same. 1 is a boring machine for drilling, 2 is its rod, and 3 is a test drill attached to the tip of 2. It is a sampler tube (generally called a cone) for. At the upper end of the rod 2, a compressor 4
A drilling air hose 5 extending from is connected, and compressed air is supplied to the tip of the sampler tube 3 by this air hose 5. A main pipe 6 having the same diameter as the digging air hose 5 is partially connected in the middle of the digging air hose 5. In the middle of the main pipe 6, there is provided a bubble generator 10 for supplying bubbles to the tip of the sampler tube 3 together with compressed air.

This bubble generating device 10 has a structure as shown in FIG. 2, and a bubble generating pipe 7 is branched from the main pipe 6, a foaming agent tank 11 is connected in the middle thereof, and the main pipe 6 is connected again. I am joining. This merging portion is provided so as to form an acute angle with respect to the flow of compressed air.

The foaming agent tank 11 is supported by the legs 11a, and is provided with a foaming agent inlet 12, a water draining port 13, a flow meter 14, and an air vent cock 15. The air venting cock 15 has a foaming agent tank. A tank pressure monitor pressure gauge 16 is provided on the 11 side. On the other hand, the bottom surface of the tank 11 has a double structure, and a heater 26 with a thermostat is provided inside the tank 11 as a means for adjusting the liquid temperature.

Also connected to the tank 11 are two pipes 17.18 having one end opening to the main pipe 6 and one pipe 19 having one end opening to the bubble generating pipe 7. One of the pipes that opens to the main pipe 6,
The pressure pipe 17 that opens at the top of the tank 11
The book is a stirring pipe 18 that opens into the blowing agent. Also,
The pipe opened to the bubble generating pipe 7 is a liquid supply pipe 19 having the other end opened into the foaming agent.

The openings 19a in the liquid of the foaming agent tank 11 of the liquid supply pipe 19 are provided at three positions on the side surface of the liquid supply pipe 19, and the heights of the spirals are different, and each of them has a radial shape of 120. It is opened at a position with an angle of °.

On the other hand, the liquid feed pipe 1 in the bubble generating pipe 7
The opening portion of 9 is a Laval tube 20. In this Laval pipe 20, a wide pipe portion 20a having the same diameter as the bubble generating pipe 7 is formed.
A thin tube portion 2 formed with a smaller inner diameter than a part of this
0b, and the liquid supply pipe 19 is opened from the narrow pipe portion 20b to the enlarged portion of the discharge-side wide pipe portion 20a. A pipe having a diameter of about 1/2 to 2/3 of the main pipe 6 is used as such a liquid feeding pipe 19, and a foaming agent amount adjusting valve 21 and a flow meter are provided outside the foaming tank 11 on the pipe line. 22 is provided.

An air amount adjusting valve 23 is provided in the main pipe 6 near the compressor side from the confluence position of the main pipe 6 and the bubble generating pipe 7. Further, a compressed air pressure gauge 24 and a compressed air flowmeter 25 also serving as a bubble monitor are provided on the boring machine 1 side of the main pipe 6 from the confluence position.

In the present embodiment constructed as described above, as shown in FIG. 1, compressed air is sent to the sampler tube 3 through the digging air hose 5 by the action of the compressor 4. At this time, compressed air is sent from the main pipe 6 connected in the middle of the digging air hose 5 to the bubble generation device 10, and the bubbles generated here pass through the digging air hose 5 together with the compressed air, and the sampler tube 3 It is sent to the tip and discharges rock powder from inside the drilling hole.

In this case, in the bubble generator 10, as shown in FIG. 2, the compressed air is sent from the stirring pipe 18 provided in the main pipe 6 into the foaming agent inside the tank 11, and the compressed air is discharged. The foaming agent is agitated.

The compressed air is supplied to the upper part of the foaming agent of the foaming tank 11 from the pressure pipe 17 provided in the main pipe 6. Therefore, a constant pressure is always applied to the upper space of the foaming agent tank 11, so that the foaming agent is supplied to the Laval pipe 20 through the liquid supply pipe 19 at a constant pressure. It is generally known that the Laval tube 20 can create a supersonic flow by passing a high-pressure compressed gas through the thin tube portion 20a and expanding it at the outlet. At this time, the discharge-side wide pipe portion is in a reduced pressure state. With such a Laval tube 20, the compressed air flowing from the main pipe 6 to the bubble generating pipe 7 is further compressed by the narrow tube portion 20b and becomes a high-speed air stream. This compressed air is jetted from the narrow pipe portion 20b to the wide pipe portion 20a at a high speed, and the wide pipe portion 20a on the discharge side is depressurized, so that the foaming agent in the tank 11 under high pressure is opened to the wide pipe portion 20a. The liquid is sucked toward the bubble generation pipe 7 having a low pressure through the liquid supply pipe 19. That is, the foaming agent is sprayed at high speed from the liquid supply pipe 19 to the bubble generating pipe 7 by the pressure applied inside the tank 11 and the suction force due to the differential pressure of the Laval pipe 20, and becomes a mist-like aerosol. Immediately foams when mixed with the high-speed compressed air jetted from the portion 20b.

Further, the opening 19 in the foaming agent of the liquid supply pipe 19
a is spiral on the side, and each opening is 120 ° radially.
Since it is opened at the position where the
The foaming agent in 1 becomes a spiral water flow toward the liquid delivery pipe 19.

Further, the bubble generating pipe 7 and the main pipe 6
Since the merging portion of is made an acute angle, it is possible to join the main pipe 6 in a high-speed airflow state without reducing the velocity of the compressed air.

The pressure in the foaming agent tank 11 at this time is adjusted by adjusting the air amount adjusting valve 23 provided in the main pipe 6, whereby the flow rate of the compressed air in the main pipe 6 is adjusted, and the inside of the main pipe 6 is adjusted. It is adjusted to any pressure together with the pressure.

On the other hand, since the heater 26 with a thermostat as a means for adjusting the liquid temperature is provided at the bottom of the foaming agent tank 11 and is stirred by the stirring pipe 18, the foaming agent in the tank 11 is always kept at a constant temperature. ing.

The effects of this embodiment as described above are as follows.

That is, in the bubble generator, the foaming agent tank 1
Since the foaming agent in 1 is sucked by the Laval pipe 20 together with the pressure applied to the tank 11, a sufficient amount can be supplied into the bubble generating pipe 7 at high speed. Moreover, since the velocity of the compressed air is further increased by the Laval tube 20, the high-viscosity, high-concentration foaming agent can also be discharged as an aerosol, and fine uniform bubbles can be formed. In addition, since the main pipe 6 and the bubble generating pipe 7 can be joined at a high speed without reducing the speed, a sufficient amount of bubbles can be supplied to the tip of the sampler tube 3 at a high speed. Therefore, the rock powder can be smoothly carried out from the drilling hole by the bubbles.

In addition, since the foaming agent is sufficiently stirred in the tank 11 by the stirring pipe 18, even when the foaming agent has a high concentration, a constant concentration can be always maintained.

Moreover, the foaming agent in the tank 11 is used as the liquid delivery pipe 1.
Since a spiral water flow is directed toward the opening of 9, the liquid feed pipe 19 uses a high-concentration surfactant having a high viscosity as a foaming agent.
It can be sufficiently sucked even at a flow rate of 10 liter / h and can be ejected to the bubble generation pipe 7 as an aerosol. Further, even if the end of the liquid supply pipe is arranged near the bottom surface of the tank, impurities on the bottom surface of the tank 11 are not sucked in and are smoothly sucked.

Further, in the bubble generating apparatus of this embodiment, since the foaming agent in the tank 11 is always kept at a constant temperature, it is possible to store the foaming agent in a chemically stable state, so that it is suitable for the global environment. On the other hand, a foaming agent which is extremely safe can be used.

On the other hand, the compressed air flowing through the digging air hose 5 can be used to pressurize the inside of the foaming agent tank 11 and further agitate the foaming agent. A compressor for generation, an air hose,
Furthermore, without using a pressure pump or constant pressure valve,
The amount of bubbles required for drilling can be supplied to the tip of the sampler tube 3 together with compressed air.

Further, since the flowmeter 22 and the compressed air flowmeter 25 also serving as the bubble monitor are attached, the bubble generator of the present embodiment can arbitrarily set the air amount and the foaming agent amount suitable for the ground. It will be possible. Further, since the tank pressure monitor pressure gauge 16 and the compressed air pressure gauge 24 are attached, the pressure ejected from the tank 11 and the tip of the sampler tube 3 can be measured, and thus bubbles suitable for the ground can be arbitrarily selected. Obtainable. Moreover, the technique for obtaining the amount of air, the amount of foaming agent, and the bubbles suitable for these grounds depended on the experience and intuition of the operator in the past, but all can be easily controlled. Therefore, it is possible to operate the device with a small number of personnel, and the efficiency thereof is significantly improved.

The method and apparatus for generating bubbles of the present invention are not limited to the above-described embodiments, and the specific shapes of the respective members, or the mounting positions and methods of the respective members can be appropriately changed.

For example, the joint shape of the confluent portion of the bubble generating pipe 7 and the main pipe 6 is not limited. That is, the above-described embodiment is suitable for sand (mass sand / shirasu) ground, but can be changed according to the ground. As a result, when drilling at a depth below the groundwater level, such as gravel ground, in order to prevent the jetting phenomenon (boiling) of sand due to high air pressure, the joint angle is set at a substantially right angle as shown in FIG. The flow rate of the compressed air can be reduced by making the high-concentration foaming agent into an aerosol state sufficiently.

Furthermore, the liquid temperature adjusting device in the foaming agent tank 11 is not limited to the heater with a thermostat 26, and it is possible to flow a fluid heat retaining agent having a constant temperature around the foaming agent tank 11, for example. It is also an effective means to cover the periphery of the foaming agent tank 11 with a heat insulating agent. This is more effective by covering not only the periphery of the foaming agent tank but also the liquid supply pipe, the bubble generating pipe, and the like.

By the way, the foaming agent is not limited to a high-concentration solution, and even if the concentration is lower than that, the pressure adjusting valve 23
Can be adjusted to any pressure together with the pressure in the foaming agent tank 11 and the main pipe 6. Therefore, it can be used sufficiently efficiently by adjusting the pressure to the best foaming property at that concentration.

[0059]

As described above, according to the first aspect of the present invention, even a high-concentration foaming agent can be supplied to the tip of the sampler tube as fine and uniform bubbles in a constant amount necessary for drilling. Therefore, the rock powder can be discharged efficiently and smoothly.

According to the present invention as set forth in claim 2, since the bubble generating device is moved by the main compressor for drilling, the device is downsized, and further, a stable and arbitrary pressure can be applied to the foaming agent tank. Therefore, it is possible to provide the bubble generating device in which the amount of bubbles necessary for drilling is supplied to the tip of the sampler tube together with the compressed air.

According to the third aspect of the present invention, since the stirring pipe is provided, it is possible to provide the bubble generating device in which the foaming agent in the tank is kept at a constant concentration.

According to the present invention as defined in claim 4, the tank 1 is
By the Laval tube together with the pressure applied inside 1, a sufficient amount of foaming agent is supplied to the bubble generating pipe even with a high concentration of foaming agent.
It is possible to provide a bubble generation device in which a sufficient amount of bubbles are supplied to the cone at a high speed by the high-speed airflow ejected from the Laval tube.

According to the fifth aspect of the present invention, since the opening in the foaming agent of the liquid supply pipe is provided on the side surface in a spiral shape, the bubble generating pipe can be applied to the bubble generating pipe at a constant flow rate even with a high concentration of the foaming agent. It is possible to provide a bubble generating device in which sufficient bubbles are supplied to the sampler tube.

According to the sixth aspect of the present invention, since the foaming agent tank is provided with the liquid temperature adjusting device, the foaming agent can be stored in a chemically stable state.
It is possible to provide a bubble generating device in which a foaming agent that is extremely safe for the global environment can be used.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an outline of an air digging method using a bubble generating device of the present invention.

FIG. 2 shows an air bubble generator for gravel ground according to an embodiment of the present invention, in which (A) is a plan view and (B) is a side sectional view.

3A and 3B show a bubble generating device for gravel ground according to another embodiment, wherein FIG. 3A is a plan view and FIG. 3B is a side sectional view.

FIG. 4 is an explanatory view showing an outline of an air digging method using a conventional bubble generator.

FIG. 5 is a side sectional view showing a conventional bubble generator.

[Explanation of symbols]

 1,31 Drilling boring machine 2,32 Rod 3,33 Drilling sampler tube 4,34 Main compressor 5,35 Drilling air hose 6 Main pipe 7 Bubble generating pipe 10,40 Bubble generating device 11,41 Foaming Agent tank 12,42 Foaming agent inlet 13,43 Drain port 14,44 Flow meter 15,45 Air vent cock 16 Tank pressure monitor pressure gauge 17 Pressurizing pipe 18 Stirring pipe 19,49 Liquid transfer pipe 20 Laval pipe 21 Foaming agent amount adjustment valve 22 Flow meter 23 Pressure adjustment valve 24 Compressed air pressure gauge 25 Compressed air flow meter also used as bubble monitor 26 Heater with thermostat 36 Bubble generator compressor 37 Bubble supply air hose 47 Pressurization valve 48 Constant pressure valve 50 Venturi

Claims (6)

[Claims] 1. A foaming agent in which compressed air is caused to flow to the upper portion of the foaming agent tank through a pressure pipe to pressurize the inside of the foaming agent tank and a Laval pipe is connected to a part of a bubble generating pipe through which the compressed air flows. By sucking the foaming agent in the tank through the liquid supply pipe, the foaming agent is ejected into compressed air to foam, and the foam is supplied to the tip of the sampler tube attached to the digging air hose. A bubble generating method characterized in that rock powder is carried out of a hole from the tip of a sampler tube inserted into the ground. 2. An air bubble generator comprising a foaming agent tank for supplying air bubbles to a digging air hose through which compressed air flows, and a main pipe connected to a part of the digging air hose and a main pipe branched from the main pipe again. A bubble generating pipe that merges, a pressure pipe that has one end open to the main pipe and the other end that opens to the top of the foaming agent tank, an air amount adjustment valve that is provided in the main pipe to adjust the internal pressure, and one end that foams A bubble generating device, characterized in that, in the liquid of the agent tank, a liquid supply pipe having the other end opening into the bubble generating pipe is provided. 3. The bubble generating apparatus according to claim 2, wherein one end is provided with a main pipe and the other end is provided with a stirring pipe that opens into the liquid in the foaming agent tank. 4. The bubble generating device according to claim 2, wherein a Laval pipe is provided at an opening of the liquid supply pipe in the bubble generating pipe. 5. The bubble generating apparatus according to claim 2, wherein the opening of the liquid feed pipe in the liquid of the foaming agent tank is provided spirally on the side face of the liquid feed pipe. 6. The bubble generating apparatus according to claim 2, further comprising a liquid temperature adjusting device provided around the foaming agent tank to keep the liquid inside the foaming agent tank at a constant temperature.