JPH02136590A - Screw pump - Google Patents

Abstract

PURPOSE:To suppress the generation of the closing trouble by increasing the discharge pressure of transported substance by gradually increasing the diameter of a screw towards the downstream side between a take-in port and a discharge port which are formed at the both edges of a screw pump. CONSTITUTION:The title screw pump 1 is constituted of a screw conveyor 2 having a take-in port 6 at the lower edge, pump 3 in the discharge part connected with the screw conveyor 2, and a hydraulic motor 4 as driving part. The screw conveyor 2 is constituted of a screw 8 which is installed onto a screw shaft 7 integrally formed with the shaft 3b of the blade 3a in the pump part 3 and whose diameter is gradually increased towards the discharge side from the take-in port 6, casing 5 for accommodating the screw 8, and a bearing 9 for bearing supporting the screw shaft 7 at the lower edge. Further, the pump part 3 has a blade 3a whose inner diameter is increased towards the discharge side, casing 3c having an annular part expanded on the downstream side, and a discharge port 15.

Description

[Detailed Description of the Invention] [Industrial Application Field] The invention is applicable to the transportation of transported objects, for example, soft mud such as sludge accumulated in water intakes of two submarine power plants, lakes, rivers, and ports. The invention relates to screw pumps.

[Prior Art] Conventionally used screw pumps are often used to transport materials using the screw effect, and while they can transport large particle size foreign materials, they have the property of being difficult to build up pressure.

In addition, centrifugal pumps have a small gap between the casing and impeller, which makes it easy for pressure to build up, but it also has the disadvantage of being easily clogged with foreign matter.

[Problems to be Solved by the Invention] Therefore, conventional screw pumps have a structure in which the material to be transported is simply introduced into the screw pump from the intake port, and the discharge pressure is relatively small and the high The drawback was that it was unsuitable for long-distance transportation.

[Means for Solving the Problems] The screw pump according to the present invention has an intake port at one end, a discharge port at the other end, and is provided with at least two bearings for supporting the screw shaft. The screw diameter was configured to gradually increase from the inlet to the discharge port.

Second, the screw pump is composed of a screw conveyor section having an equal diameter from the intake side to the downstream side, and a pump section whose diameter increases toward the discharge side.

[Function] Since the screw diameter of the screw pump of the present invention gradually increases from the suction port toward the discharge port, the conveyed material is not consolidated in the screw conveyor and goes to the discharge port, and the screw is not compressed at the discharge port. Since the diameter is the maximum, the circumferential speed is the maximum for the same number of rotations, and a high pumping force can be obtained.

Moreover, since the diameter of the screw in the middle increases gradually rather than stepwise, smooth flow of the transported material is achieved.

Further, even if the screws are of equal diameter after the suction port and only the pump portion of the discharge portion is enlarged in diameter, the discharge pressure can be increased.

[Example] Hereinafter, the present invention will be described in detail using examples shown in the drawings.

1 to 3 show one embodiment of the screw pump according to the present invention, FIG. 1 is an overall longitudinal sectional view, and FIG. 2 is an I of FIG.
FIG. 3 is an overall vertical sectional view showing another embodiment.

The screw pump 1 includes a screw conveyor 2 having an intake port 6 at the lower end, a pump 3 at a discharge section connected to this,
It is composed of a hydraulic motor 4 as a drive section. The screw conveyor 2 includes a screw 8 which is attached to a screw shaft 7 formed integrally with the shaft 3b of the vane 3a of the pump 3, and whose diameter gradually increases from the intake port 6 toward the discharge side, and this screw 8. It consists of a casing 5 that covers the screw shaft 7, and a bearing 9 that pivotally supports the screw shaft 7 at the lower end.

As shown in FIG. 2, the intake ports 6 are formed by drilling a plurality of rectangular holes at the same pitch in the lower end of the casing 5.

On the other hand, the pump 3 includes a blade 3a that is attached to a shaft 3b integrally formed with the screw shaft 7 and whose diameter increases toward the discharge side, and an annular portion that covers the blade 3a and expands at the most downstream side. and a discharge port 15 for discharging the transported material in the tangential direction of the vane 3a and the annular portion, and is connected to the screw conveyor 2 and the transport pipe (not shown) by flanges on both the upstream and downstream sides. It is concluded.

Further, on the upper part of the pump 3, there is a bearing 10 that pivotally supports a shaft 14 connected to the pump shaft 3b by a coupling 12.
A hydraulic pump 4 is provided which connects a shaft 14 passing through the bearing 10 with a coupling 11 and drives and rotates the pump blades 3a and the screw 8 of the screw conveyor 2 as one unit. A mechanical seal 13 is provided at the lower part of the coupling 12 to prevent the transported material in the pump 3 from entering the drive section.

The operation of the screw pump of the present invention constructed as above will be explained next.

First, the screw conveyor 2 is gently lowered to a desired location where soft mud such as sludge is to be collected, and when it reaches the seabed, the hydraulic unit is turned on and the hydraulic motor 4 is driven to rotate. The transported items are taken in at the end of the screw conveyor 2 [via the rollers, and transferred to the screw conveyor 2].
The material enters the interior, rises as the screw 8 rotates, and eventually enters the pump 3. At this point, the transported material changes direction from the direction of the screw shaft 7 to the direction tangential to the rotation (circumferential direction) and becomes an annular shape. A discharge port 15 provided in the tangential direction of the casing 3C
Discharged at higher pressure.

In the above transportation process, in the screw pump 1 of the present invention, the diameter of the screw 8 and the blade 3a of both the screw conveyor 2 and the pump 3 gradually increases toward the discharge side, so that the outer circumference of the screw conveyor 2 and the pump 3 are gradually increased. Since the circumferential speed increases at the end, the discharge pressure is gradually increased, and a high discharge pressure is applied to the transported object. In particular, since the pump 3 has an annular casing shape that swells toward the most downstream side, the transported material is discharged at a high discharge pressure due to the same centrifugal effect as a centrifugal pump. Moreover, since the screw 8 and the blade 3a do not suddenly expand in diameter, the transported material within the screw pump 1 flows smoothly and without strain. At the same time, the blade ff13a inside the pump 3 and the casing 3
Since a wide space is confirmed between the device and the device C, there is very little risk of blockage by foreign objects and related troubles such as damage to the equipment.

Moreover, in another embodiment shown in FIG.
The screw conveyor 2 has a
This allows the discharge pressure of the transported object to be increased to a certain extent, so it can be easily used when the lift is relatively low and the distance is short.

Further, as shown in FIG. 3, a pressurized air injection pipe 22 is branched from the check valve 20 and the exhaust pipe 21, and can be used as a mixed pumping device using compressed air.

Note that the check valve 20 of this embodiment is provided to prevent backflow of compressed air, and the illustrated state is the valve flap 20a.
is rotatably taken up by the rotating bin 20b, and when there is no object to be transported, it is closed by gravity (solid line in the figure), and during operation, it is opened by the pressure of the object to be transported (double-dashed line in the figure).

[Effects of the Invention] As described above, according to the present invention, the diameter of the screw of the screw conveyor and the blades of the pump gradually expands toward the discharge side, so that the discharge pressure of the transported material can be increased. It has an excellent effect in that it can be transported over long distances or long distances, and at the same time, there is very little trouble in clogging the screw pump due to foreign objects such as large lumps. Furthermore, in the second aspect of the invention, the diameter of the pump blades can also be expanded to contribute to an increase in the discharge pressure.

[Brief explanation of the drawing]

1 to 3 show embodiments of the present invention, FIG. 1 is an overall vertical sectional view, FIG. 2 is an outline view of the main part seen from II-II in FIG. 1, and FIG. 3 is an overall vertical sectional view. It is. 1... Screw pump, 2... Screw conveyor, 3... Pump, 4...
...Hydraulic motor, 5...Casing, 6.
...Intake port, 7...Screw shaft, 8.
...Screw, 9,10...Bearing, 11
．． 12...Coupling, 13...Mechanical seal, 14...Shaft L5...
Discharge port, 20... Check valve, 21... Exhaust pipe, 22... Pressurized air injection pipe. Figure 1

Claims (2)

[Claims] (1) In a screw pump having an intake port at one end, a discharge port at the other end, and at least two bearings for supporting the screw shaft, the screw pump is provided between the intake port and the discharge port. A screw pump characterized in that its diameter gradually increases toward the downstream side. (2) In a screw pump having an intake port at one end, a discharge port at the other end, and at least two bearings for supporting the screw shaft, a screw conveyor portion of equal diameter after the intake port and A screw pump characterized in that it is comprised of a pump part whose diameter increases toward the discharge side.