JP2746795B2 - Bubble generator for borehole - 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 in an air drilling drilling operation.

[0002]

2. Description of the Related Art FIG.
As shown in the figure, foam is sent together with air from the bubble generator P to the borehole machine M by the foam sending hose 4, and is discharged from the bore 3 at the lower end through the rod 2 in the borehole machine M. When the foam is released from the lower end of the cone 3 in this manner, slime such as crushed rock or soil is absorbed by the foam and floats up, and is discharged from the top of the drill hole. Is reasonably promoted.

[0003] Conventionally, as shown in FIG. 3, a foam generating apparatus used in this drilling operation is based on the principle of Venturi, and an air feeding hose 35 and a foam generating hose 37 to which air is sent from different compressors. Among them, the principle of Venturi is applied between the foam generating hose 37 and the liquid storage tank 41.

[0004] That is, a narrow portion 50 having a narrow passage is provided in the foam generation hose 37, and the air in the liquid storage tank 41 is made to flow from the foam generation hose 37 through the valve 47 to the inside of the liquid storage tank 41. Feed pipe 49 immersed in the foaming liquid
Is opened at the narrow portion 50. Then, the air pressure for pressing the water surface of the foaming liquid in the liquid storage tank and the narrow portion 5
Due to the pressure difference from the air pressure at 0, the foaming liquid in the liquid storage tank 41 is pushed up to the liquid sending pipe 49, and is ejected from its tip to the narrow portion 50, where it is foamed.

[0005]

However, the conventional foam generator as described above has drawbacks in the suitability of the use concentration of the foaming liquid and the stability of the foam supply.

[0006] Regarding the use of a foaming liquid, a foaming liquid is jetted into a foaming hose by a pressure difference based on the principle of Venturi, and a large force cannot be expected for the pressure difference. If the concentration of the foaming liquid is high and the viscosity is high due to the weak force of pushing up the foaming liquid, the supply of the foaming liquid will be obstructed, such as clogging of the liquid supply pipe. Did not.

[0007] In this regard, when a surfactant is used as a foaming material, its concentration can be used in the range of about 0.2 to 0.6%, which is suitable for foam required for borehole work. An aqueous solution having a concentration of about 3 to 10% could not be used.

As for the stability of the foaming supply, as the water level in the liquid storage tank decreases, the pressure required to raise the foaming liquid in the liquid supply pipe increases. However, since the pressure in the liquid storage tank is always constant, When the water level decreases, the supply amount of the foaming liquid decreases, and accordingly, the amount of generated bubbles also decreases. Also, in order to keep the venturi principle working, it is necessary to keep the storage tank closed at all times.However, when the lid of the storage tank is opened because the foaming liquid needs to be replenished, However, there is a problem that the drilling operation is interrupted and the generation of bubbles is stopped, so that the borehole operation is hindered.

The present invention has been made in view of the above situation,
Highly concentrated foaming liquid can be stored and used in the storage tank, and not only can the amount of foaming generated be kept constant at all times. It is an object of the present invention to provide a bubble generator for a borehole in which the supply can be continued.

[0010]

In order to achieve the above object, the present invention provides a main pipe through which air is pressure-fed to a borehole, and a bypass pipe for branching and returning from the main pipe. The liquid storage tank is equipped with a liquid feed pump that sucks the foaming liquid in it and supplies it to the foam generation nozzle, and attaches the foam generation nozzle to the bypass pipe so that the foaming liquid blows out to the downstream side. The generator was constructed.

[0011]

The foaming liquid is ejected from the foaming nozzle into the bypass pipe to generate foam. The generated foam is sent from the bypass pipe to the main pipe by air pressure, and then sent to the drilling machine together with the air.

Since the foaming liquid is sent from the liquid storage tank to the foam generating nozzle by the liquid feed pump, even if the concentration of the foaming liquid is high and the viscosity is high in a gel state, there is no problem in sending the liquid. Even if the foaming liquid decreases in the tank and the water level drops, the supply amount of the foaming liquid alone does not change,
The supply of the foaming liquid to the foam generating nozzle can be continued even while the foaming liquid is being replenished to the liquid storage tank.

[0013]

Next, the present invention will be described based on embodiments.

As shown in FIG. 1, a bubble generator P
Is used for drilling work. In the drilling machine M,
A cone 3 serving as a tip of the excavation is attached to the lower end of the rod 2, and air and bubbles required for excavation are pumped from the rod 2 to the cone 3. Therefore, the foam sending hose 4 from the foam generator P
Is connected to the upper end of the rod 2, and the first compressor 6 and the second compressor 8 are used for pumping.

The main part of the foam generator P is a box 1
As shown in FIG. 2, a bypass pipe 12 is provided along with the main pipe 5 for foaming, and a foaming liquid is sucked up from a liquid storage tank 21 by a liquid feed pump 15 for the foaming. Bubble generating nozzle 13 inside
It is made to squirt from.

The bypass pipe 12 has a U-shaped refraction form that branches off from the upstream part of the main pipe 5 and returns at the downstream part. A bag portion 23 that opens toward the front is provided, and the bubble generation nozzle 13 is attached to the base end of the bag portion 23.

The main pipe 5 has a bypass pipe 12
A pressure reducing valve 10 is provided downstream of the branch portion, and a pressure reducing valve 11 is also provided in the bypass pipe 12 near the branch portion. By adjusting both of the pressure reducing valves 10 and 11, the amount of air sent to the bypass pipe 12 is adjusted.

The adjustment of the amount of air to the bypass pipe 12 is performed so that a good mixing state of bubbles and air can be obtained even when the concentration of the foaming liquid, the injection amount, and the like are different. The state of the bubble generation is observed from a bubble generation monitoring window 22 provided in the bypass pipe 12.

The liquid storage tank 21 is received by a support base 20, and the liquid storage tank 21 is provided with a liquid level gauge 16, a liquid inlet 17, a drain valve 19 and the like. Further, the tip of the suction hose 25 of the liquid feed pump 15 is immersed in the foaming liquid, and the strainer 18 is attached to the tip so as not to suck impurities.

The liquid feed pump 15 is installed above the liquid storage tank 21, and the bubble generating nozzle 13 is connected to the end of a liquid feed hose 29.

The main pipe 5 has an upstream side connected to the air hose 31 of the second compressor 8 and a downstream side joined with the air hose 30 of the first compressor 6. Machine M
Supplied to

With respect to the operation of the above-mentioned foam generator P, the first compressor 6, the second compressor 8, the liquid feed pump 1
5 is operated, air passes through the bypass pipe 12, and the foaming liquid is ejected from the foam generating nozzle 13 into the air to generate foam. The generated foam enters the main pipe 5, and then enters the main pipe 5. And the air sent by the air hose 30 of the first compressor 6 is joined to the borehole M by the foam sending hose 4.

In the drilling machine M, foam is injected into the rod 2 together with air from the upper end by the foam sending hose 4 and discharged from the lower end of the lower end cone 3, so that the slime floats with the foam and Exhausted from above.

When the concentration of the foaming liquid is high, more bubbles are generated after being discharged from the cone 3 by mixing with groundwater or air, and the ability to adsorb and float slime is improved.

When the amount of the foaming liquid in the liquid storage tank 21 decreases, the liquid is supplied from the liquid inlet 17 while the operation is continued. That is, foaming is not interrupted for replenishing the foaming liquid.

Unlike the above embodiment, the air hose 30 of the first compressor 6 and the air hose 31 of the second compressor 8 may both be connected to the upstream side of the main pipe 5. In that case, one compressor is auxiliary. Further, it is also possible to use only one compressor 8 for pumping air to the main pipe 5 and omit the other compressor 6.

[0027]

As described above, according to the present invention, the main pipe is provided with the bypass pipe for branching and returning from the main pipe, and the foaming liquid is injected from the foam generation nozzle into the bypass pipe. As a result, bubbles were generated, so that the bubbles could be sent to the borehole through the main pipe, and of course, the liquid supply pump was used to supply the foaming liquid to the bubble generation nozzle. Even if a highly concentrated foaming liquid is stored in the tank, there is no problem in the supply of the foaming liquid.
By using a foaming liquid having a high concentration, it is possible to generate a foam having a high functionality for eliminating slime.

Since the supply of the foaming liquid to the foam generating nozzle is always kept constant by the liquid feed pump, a uniform bubble generating state is obtained even when the foaming liquid is refilled into the liquid storage tank. Since the supply of the foaming liquid to the bubble generating nozzle is not interrupted, a constant amount of foam having an appropriate concentration of the foaming liquid can be continuously and stably supplied to the borehole.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing a use state of a bubble generating device for boreholes.

FIG. 2 is an explanatory sectional view showing a main part of a bubble generator for boreholes.

FIG. 3 is an explanatory diagram of a conventional example.

[Explanation of symbols]

 P Bubble generator for borehole M Borehole machine 5 Main pipe 12 Bypass pipe 13 Bubble generation nozzle 15 Liquid feed pump 21 Liquid storage tank

Claims (1)

(57) [Claims] 1. A main pipe (5) through which air is pressure-fed to a borehole drill (M), and a bypass pipe (12) branching and returning from the main pipe (5) for foam generation.
In 1), the foaming liquid therein is sucked and a foam generating nozzle (13)
Bubble generating device for a borehole, characterized in that a liquid feed pump (15) for supplying the liquid to the nozzle is provided, and a bubble generating nozzle (13) is attached to the bypass pipe (12) so that the foaming liquid is ejected toward the downstream side. .