JPH0137032Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a slurry pump system used when excavating a mine shaft using a high-pressure water jet.

BACKGROUND ART A jet rock crushing method using a high-pressure water jet is sometimes used for tunnel excavation, etc. Pump systems used in such applications require a loop for circulating water and a high-pressure slurry pump for muddy water to prevent environmental pollution.

Problems to be solved by the invention In high-pressure slurry pumps used in pump systems such as those described above, it is important to reduce slurry wear on internal parts. In particular, the sand particle size of the slurry has a large effect on the wear of the pump impeller and shaft seal. According to Wong, the influence is expressed as follows.

Wear rate due to slurry e(t) = κ・d ³・υ ^1~3 d: Particle size υ: Collision speed κ: Constant Therefore, it is necessary to send slurry with as small a particle size as possible to the high-pressure slurry pump that rotates at high speed. However, this usually requires a large settling basin and cannot be used as a system at construction sites. Furthermore, since the wear rate increases when a slurry pump is operated under partial load, it is important to ensure that the pump is always operated at its rated point.

In addition, since the equipment is moved forward as the face is excavated, it must be constructed so that it can be easily relocated.

Measures to solve the problem A low differential pressure separator is installed on the suction side of the high-pressure slurry pump to remove coarse particles, and a pressure regulating switching valve prevents the slurry pump from operating at a partial flow rate.
The entire structure was divided into three blocks to facilitate transportation.

Effect: Use of a low differential pressure separator prevents a drop in pressure at the outlet of the water pump, and removes coarse particles in the slurry reaching the inlet of the high-pressure slurry pump, thereby preventing excessive wear of the slurry pump.

Embodiment In Fig. 1, 1 is a high-pressure slurry pump for muddy water slurry, 2 is a motor, 3 is a muddy tank, 4 is a low differential pressure separator, 5 is a discharge line, 6 is a slurry supply line, and 7 is a coarse particle discharge line. , 8 is a flexible hose, 9 is a discharge control valve, 10 is a water pump, 11 is a pressure adjustment switching valve, 12 is a nozzle, 13
1 is a jet flow, 14 is a face, 15 is a portable platform, 1
6 is a pump supply line, and 17 is a vacuum orifice.

In FIG. 2, 21 is a slurry supply line;
22 is a rotating plate, 23 is a perforated plate, 24 is a concentration cylinder, 2
5 is a pump supply line, 26 is a coarse particle discharge line, and 27 is a discharge control valve.

The centrifugal high-pressure slurry pump 1 is capable of pressurizing a large volume of muddy slurry to a high pressure, and the pressurized slurry is guided to a face 14 through a conduit 5.
At the face 14, a high-speed jet stream 1 from the nozzle 12
3 performs rock crushing, and the slurry flow after rock crushing is guided to the mud tank 3.

Coarse particles settle in the muddy water tank 3, but since the capacity is usually not large enough, a large amount of coarse particles are sent to the slurry pump 1 via the water pump 10. A separator 4 is installed on the discharge side of the water pump 10 to remove coarse particles. If a conventional cyclone type separator 4 is used, there will be a large pressure drop, which will cause problems such as larger and faster water pumps (increasing costs and wear rate) or cavitation of slurry pumps (reduction in suction pressure). Therefore, a low differential pressure type as shown in FIG. 2 is used. Pressure adjustment switching valve 11 upstream of nozzle 12
In order to prevent the slurry pump 1 from operating at a partial flow rate and causing severe wear, the slurry is returned to the mud tank 3 through the vacuum orifice 17 when rock is not crushed. Note that the pressure reducing orifice 17 is necessary to prevent wear of the pressure adjustment switching valve 11 due to cavitation.

The above system configuration makes it possible to apply the jet rock crushing method to construction work that is impossible with conventional methods.

In the low differential pressure separator shown in FIG. 2, the slurry is given a swirl by a swirling plate 22, and the centrifugal force exerted by the swirling flow forces the particles against a porous plate 23 on the wall. A large number of holes are bored in the wall, through which the coarse particles are led to the concentration cylinder 24, from which they are returned to the mud tank 3 via a coarse particle discharge line 26. With this device, there is no change in flow direction from the inlet to the outlet, making it possible to reduce pressure loss.

Effects of the invention The use of a low differential pressure separator prevents coarse particles from going to the slurry pump and reduces pressure loss. The use of pressure regulating switching valves prevents the slurry pump from operating at partial flow rates and prevents excessive wear. The entire system is divided into three components (high-pressure slurry pump/motor unit, mud tank/water pump/low differential pressure separator unit, nozzle/pressure adjustment switching valve unit) to facilitate transportation and improve practicality.

[Brief explanation of drawings]

FIG. 1 is a system diagram of an embodiment of the high-pressure jet rock crushing system of the present invention, and FIG. 2 is a schematic sectional view of an embodiment of the low differential pressure separator used in the present invention. 1...High pressure slurry pump, 2...Motor, 3
... Mud water tank, 4 ... Low differential pressure separator, 10 ... Water pump, 11 ... Pressure adjustment switching valve, 12 ... Nozzle, 13 ... Jet flow, 14 ... Face.

Claims (1)

[Scope of utility model registration request] A closed-loop system that features a high-pressure slurry centrifugal pump and motor installed on a portable platform, a nozzle and pressure adjustment switching valve installed in the excavation section, and a water pump and low differential pressure separator installed in the mud tank. Portable high pressure jet rock crushing system.