JPH04354503A - Device for preventing nozzle block in sand lifting device - Google Patents

Abstract

PURPOSE:To prevent the block of a jet nozzle even at the time of the stoppage of a sand lifting operation by providing a fluid supply part, which can supply and stop a fluid, between a sand lifting part and a sand intake port. CONSTITUTION:The sand lifting part 130 is provided in the middle of a sand lifting pipe 114, and the fluid supply part 132 is provided between the sand lifting part 130 and the sand intake port 131. To the fluid supply part 132, a fluid pipe 139 is connected via a valve 138. At the time of the stoppage of the sand lifting, while continuing a jet stream supply upward by a high pressure water via the high pressure pipe 142 of the sand lifting part 130, a fluid such as air and water is supplied from the fluid supply part 132. Since the fluid has a lighter specific gravity than the water containing sand, only the fluid is lifted through the sand lifting pipe 114 and the sand lifting operation is not performed. Consequently, the sand inside the sand lifting pipe 114 is discharged together with the fluid, and the inside of the sand lifting pipe 114 is the fluid only which is supplied from the sand supply part 130 and the fluid supply part 132. When the sand lifting operation is stopped in this state, the jet nozzle 140, etc., is not blocked by the back flow of the sand inside the sand lifting pipe 114.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle clogging prevention device for a sand pumping device, and more particularly to an improvement in its sand pumping stop mechanism.

0002

[Prior Art] Various wastewater treatment facilities are equipped with settling basins in order to prevent contamination of discharge areas and accumulation of sediment, prevent wear and tear and closure of pumps and treatment facilities, and facilitate treatment operations. There is. Then, the gray water mixed with sand is introduced into this settling pond and left to stand, the sand contained in the gray water is allowed to settle, and the supernatant liquid is discharged or sent to a treatment process such as the activated sludge method. ing.

[0003] By the way, when sand accumulates at the bottom of the settling basin,
It is necessary to suck up the sediment with a pump or the like and dispose of it. Conventionally, devices such as a vacuum pump type, a jet pump type, etc. have been used as a sand pumping device for sand accumulated at the bottom of a sand settling basin. The vacuum pump type sand pumping device shown in FIG.
This is to cause sand to be released.

However, depending on the quality of the sand, it may become very hard at the bottom of the settling basin, and in this case, the vacuum pump 16
Even if an attempt was made to suck up the sand, the sand pumping pipe 14 would become clogged and no longer function. In other words, the vacuum pump type cannot generate a suction force higher than atmospheric pressure, and furthermore, once a blockage occurs, no water flow is generated, and the sand suction function is completely paralyzed. For this reason, conventional vacuum pump type sand pumping equipment requires a high degree of skill to operate.

[0005] On the other hand, such problems are relatively less likely to occur in a jet pump type sand lifting device (Japanese Patent Application Laid-Open No. 62-204810, etc.) as shown in FIG. That is, Figure 6
In the jet pump type sand pumping device shown in Fig. 1, a sand pumping pipe 14 is disposed within the sand 12 collected at the bottom of a sand settling basin 10, and a jet nozzle 20 is provided slightly above the sand pumping pipe 14. The tip of the jet nozzle 20 is arranged to face upward inside the sand pumping pipe 14, and by supplying high pressure water or a mixed fluid of water and air from the jet nozzle 20, the sand settling pipe 12 along with the jet water flow is supplied. is drawn into the sand lifting pipe 14 to lift sand.

[0006] According to such a jet pump type sand lifting device, it is possible to obtain a much stronger sand lifting action than the vacuum pump type sand lifting device described above, and moreover, it is possible to obtain a sand lifting action that is much stronger than the above-mentioned vacuum pump type sand lifting device, and moreover, it can lift even relatively hard sand. It has the advantage of being less likely to cause blockages.

[0007]

[Problems to be Solved by the Invention] However, although such an improved jet pump type sand pumping device has an excellent sand pumping function itself, when the sand pumping operation is stopped, the nozzle hole of the jet nozzle 20 is closed. The problem was that it got stuck. That is, during sand lifting, no problem occurs because the sand moves up inside the sand lifting pipe 14 along with the jet water flow, but when the sand lifting operation is stopped, as shown in FIG. The sand flows backwards and clogs the jet nozzle 20. For this reason, conventionally, an opening/closing part was provided at the tip of the jet nozzle to prevent the nozzle hole from becoming clogged by the backflow of sand when the sand pumping operation was stopped, but the structure was complicated and Providing a mechanically moving part within the pipe itself could cause problems such as breakdowns during intense sand lifting operations.

The present invention was made in view of the problems of the prior art described above, and its object is to provide a sand lifting device which has an excellent sand lifting function and which does not block the jet nozzle even when sand lifting action is stopped. An object of the present invention is to provide a nozzle blockage prevention device.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the nozzle clogging prevention device of the sand pumping device according to the present invention has a sand pumping section that supplies fluid upwardly inside the sand pumping pipe, and a sand suction port. The present invention is characterized by comprising a fluid supply section capable of supplying and stopping fluid between the two.

0010

[Operation] Since the sand lifting device according to the present invention has the above-described means, during sand lifting, the fluid supply section does not supply fluid, and the sand lifting section carries out sand lifting. On the other hand, when sand pumping is stopped, fluid such as air and water is supplied from the fluid supply section while the sand pumping section continues to supply the jet water stream upward. Here, since the fluid has a lighter specific gravity than water containing sand,
Only the fluid rises in the sand pumping pipe, and no sand lifting action takes place. Therefore, the sand in the sand pumping pipe is discharged together with the fluid, and only the fluid supplied from the sand pumping section and the fluid supply section remains inside the sand pumping pipe. If the sand pumping action is stopped in this state,
Sand in the sand pumping pipe will not flow back and block the nozzle etc.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows the overall configuration of a sand lifting device according to a first embodiment of the present invention. Incidentally, parts corresponding to those in the conventional example are indicated by the reference numeral 100 and their explanations are omitted.

A feature of the present invention is that a fluid supply section is provided to prevent the jet nozzle from clogging, and for this reason, in this embodiment, a sand pumping section 130 is provided in the middle of the sand pumping pipe 114 to prevent the jet nozzle from clogging. A fluid supply section 132 is provided between the sand pumping section 130 and the sand suction port 131. Pressure water is supplied from a pump 134 to the sand pumping section 130, and the pressure water is passed through the sand pumping pipe 1.
The sand 112 is sucked up by being ejected upward into the tank 14, and the sand is conveyed to the tank 118 by the jet water flow.

On the other hand, the fluid supply section 132 has a tank 1.
A fluid pipe 139 is connected from 18 through a valve 138.

The main parts of the sand lifting device according to this embodiment are shown in FIG. As shown in the figure, the sand lifting section 130 is formed into a conical shape, and the end 114b of the lower sand lifting pipe 114a is inserted into the hollow part. Then, the sand pumping pipe end 11
4b is close to the inner wall of the conical sand pumping section 130, and a jet nozzle 140 is formed between the two. High-pressure water is supplied to the sand pumping section 130 via a high-pressure water pipe 142, and the high-pressure water is jetted upward from a jet nozzle 140. As a result, the end portion 114b of the sand lifting pipe 114 is brought into a reduced pressure state, and sand is sucked up through the sand lifting pipe 114. Incidentally, during this sand pumping, the valve 138 is closed, and air, water, etc. are not supplied through the fluid pipe 139.

On the other hand, when stopping this sand lifting operation,
Before stopping the supply of high-pressure water, the valve 138 is opened and air or the like is supplied via the fluid pipe 139. Here, since air has a lower specific gravity than water containing sand, suction of sand through the sand pumping pipe 114 is stopped, and instead air, etc. is transported by the jet water flow through the fluid pipe 139. . As a result, the suction force of the sand in the lower sand pumping pipe 114a is stopped and the sand falls, but the sand in the upper sand pumping pipe 114c is transported into the tank 118 with the jet water flow, and the sand in the sand pumping pipe 114 is kept. It almost ceases to exist. In this state, the high pressure water pipe 14
If the supply of high-pressure water from 2 is stopped, clogging of the jet nozzle 140 and the like due to backflow of sand in the sand pumping pipe will be reliably prevented.

In this embodiment, the fluid pipe 139 is connected to the sand washing tank 118, and air (fluid) is collected from the sand washing tank, so that the exhaust gas having a bad odor can be minimized. can. Furthermore, although the sand pumping device according to this embodiment has been described as one that lifts sand from a sand settling pond,
The invention is not limited to this, and can also be used, for example, in dredging work in ports.

FIG. 4 shows the main parts of a sand pumping apparatus according to a second embodiment of the present invention, and the parts corresponding to those in FIG. In this embodiment, the lower part of the sand pumping pipe 214 is formed into a gentle crank shape, one end of which is used as a sand suction port 231, and high pressure water is supplied from the lower part of the crank part through a jet nozzle 240.

The present invention can also be applied to such a sand lifting device, and as in the first embodiment, the jet nozzle 24
By providing the fluid supply section 230 between the sand suction port 231 and the sand suction port 231, it is possible to prevent nozzle clogging when sand pumping is stopped.

[0019]

[Effects of the Invention] As explained above, according to the nozzle clogging prevention device for a sand pumping device according to the present invention, a fluid supply section capable of supplying and stopping fluid is provided between the sand pumping section and the sand suction port. ,
When the sand pumping is stopped, the fluid supply section is opened and a fluid such as air is supplied to stop the new sand pumping operation, and all the sand in the sand pumping pipe can be removed. As a result, the jet nozzle etc. will not be clogged even if the sand lifting action is stopped.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of main parts of a sand lifting device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of the operation of the sand lifting device of the present invention.

FIG. 3 is an explanatory diagram of the overall configuration of the sand lifting device according to the present invention.

FIG. 4 is an explanatory diagram of main parts of a sand lifting device according to a second embodiment of the present invention.

FIG. 5 is an explanatory diagram of the overall configuration of a conventional sand lifting device.

FIG. 6 is an explanatory diagram of main parts of a conventional sand lifting device.

FIG. 7 is an explanatory diagram of problems with a conventional sand pumping device.

[Explanation of symbols]

10,110 Sand settling pond 14,114,214 Sand pumping pipe 131,231 Sand suction port 130,230 Sand pumping section 132, 232 Fluid supply part

Claims (1)

[Claims] 1. A sand pumping device comprising a sand pumping section that supplies high-pressure fluid upwardly inside a sand pumping pipe, wherein a fluid supply section capable of supplying and stopping fluid is provided between the sand pumping section and a sand suction port. A nozzle clogging prevention device for a sand pumping device, characterized by comprising: