JPS631011Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a reciprocating pump that handles slurry. In particular, it uses a reciprocating pump that prevents failures caused by solid matter adhering to the plunger packing, and also The present invention relates to a reciprocating pump system that can make the slurry concentration on the suction side and the discharge side the same.

Conventionally, in reciprocating pumps that handle slurry,
When the plunger, which was in contact with the pump handling liquid during the forward stroke, enters the seal and seal presser during the backward stroke, solid matter also enters, impairing the integrity of the seal and accelerating wear of the seal and plunger. .

From this point of view, in order to overcome the above-mentioned problems of the reciprocating pump, the applicant first proposed the following steps in the seal retaining portion of the plunger of the reciprocating pump:
When the plunger is retracted to the maximum, a flushing pipe is inserted through and opened in the cylinder part that is always located behind the retreating end of the plunger, and a packing is provided behind the opening of this pipe, and in front of the opening on the pump chamber side. By constructing a flushing part without providing any packing at all, and flushing a predetermined amount of flushing liquid from the flushing pipe under the action of a flushing pump at a discharge pressure slightly higher than the suction pressure of the plunger,
We have developed a reciprocating pump that flushes solid matter adhering to the plunger that enters the seal and the seal presser side to the pump chamber side, and has been registered as a utility model.
It was registered as a utility model as No. 1068288 (publication number 1068288 (publication of Utility Model Publication No. 49-3523)).

However, in the conventional reciprocating pump proposed earlier, the flushing liquid is injected from outside the slurry piping system as a clear liquid that is the same as the slurry, or a clear liquid that does not cause any process problems even if mixed into the slurry. Because of the heat, the slurry concentration in the pump discharge piping system was lower than the slurry concentration in the slurry supply piping system, that is, the concentration of the stock solution, which caused a process problem in slurry treatment. That is, in the previously proposed reciprocating pump, no consideration was given to means for controlling the slurry concentration on the discharge side of the main pump to always be the same as the concentration of the stock solution on the suction side.

However, in today's coal slurry treatment process, for example, there is a problem in that the slurry concentration is diluted unnecessarily by flushing liquid, so a pump that can pump slurry while maintaining the concentration of the undiluted solution has come to be required. It's on.

Therefore, the inventor of the present invention has conducted various studies in order to overcome the above-mentioned problems regarding slurry concentration in the conventional reciprocating pump, and as a result, it has been found that the amount of clear liquid required for flushing can be obtained by passing through the slurry. We focused on this and found that by using this effluent for flushing, it was possible to make the slurry concentration in the slurry supply piping system and the pump discharge piping system approximately the same.

On the other hand, in this case, the configuration of the reciprocating pump is to use a plunger-type reciprocating pump similar to the main pump as the flushing pump, and use the electric motor, which is the drive source of the crank mechanism that drives the main pump, as a common drive source. As a result, each rotating shaft is coaxially connected by a coupling via a crank mechanism, and the rotational phase difference between the main pump and the reciprocating pump for flushing liquid supply is set to 180°, and the flushing with respect to the flow rate of the liquid handled by the main pump is set. The ratio of the amount of liquid mixed in, that is, the dilution rate, is always constant regardless of the pump rotation speed, and the amount of flushing liquid supplied increases or decreases in proportion to the magnitude of the plunger retraction speed. The concentration of the liquid to be handled can be properly controlled, and the plunger can be cleaned efficiently and economically using the flushing liquid.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a reciprocating pump that can make the slurry concentration in the slurry supply piping system and the reciprocating pump discharge piping system the same using a simple mechanism in a slurry conveyance process.

In order to achieve the above purpose, in the present invention,
A flushing pipe is installed in the cylinder part that supports the plunger that performs the main pump operation, behind the maximum retracted position of the plunger where it comes into contact with the pump handling liquid (slurry), and a flushing area is located in front of the flushing pipe toward the pump chamber. A reciprocating pump is configured such that a packing is provided on the rear drive source side and a flushing pump is connected to the flushing pipe so that the flushing liquid flows into the pump chamber while cleaning the plunger surface. A filtration device is provided in the slurry storage tank of the suction piping system of the pump, and a flushing liquid storage portion is provided to store the clarified liquid obtained by passing the slurry through the filtration device, and a flushing pipe is connected to the flushing liquid storage portion. It is characterized by connecting.

Further, it is preferable to provide the slurry storage tank with a stirring mechanism.

On the other hand, the flushing pump is configured with a reciprocating pump, and the rotational phase difference between the main pump and the flushing pump is set to 180°, so that the ratio of the amount of flushing liquid mixed in to the flow rate of the liquid handled by the main pump (slurry) is determined by the pump rotation. Even higher accuracy can be achieved by connecting the main pump and the flushing pump to a common drive source so that the amount of flushing fluid supplied is always constant regardless of the number of pumps, and furthermore, the amount of flushing fluid supplied increases or decreases in proportion to the magnitude of the plunger retraction speed. This is suitable because concentration can be controlled.

Next, embodiments of the reciprocating pump according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a system diagram showing the piping configuration of the pump of the present invention. That is, in FIG. 1, slurry is injected into a storage tank 12 via a supply pipe 10. The storage tank 12 is provided with a stirring mechanism 14 to prevent solid matter from settling in the slurry.
A filtration device 16 is provided in a part of 2 to form a reservoir for a flushing liquid obtained by filtrating the slurry. In this case, various devices such as a liquid cyclone separator, a filter, a paper filter, and a magnetic separator can be used as the filter device 16.

In this way, the slurry stored in the storage tank 12 and stirred is sent to the discharge pipe 22 via the suction pipe 18 under the action of the main pump 20. On the other hand, in the storage tank 12, the filter device 1
The flushing liquid obtained through the pump 6 is sent to a flushing pipe 28 connected to the flushing section of the main pump 20 through a suction pipe 24 under the action of a flushing pump 26 . Therefore, the liquid flushed in the main pump 20 directly flows into the pump chamber of the main pump 20 and is discharged to the discharge pipe 22 together with the slurry to be handled.

That is, the configuration for flushing the flushing liquid to the main pump 20 is such that a flushing pipe is installed behind the maximum retracted position of the plunger that contacts the pump handling liquid (slurry) in the cylinder part that supports the plunger that performs the main pump operation. This can be realized by arranging a flushing area, forming a flushing area on the front pump chamber side of the flushing pipe, providing a packing on the rear drive source side, and connecting a flushing pump to the flushing pipe. With this configuration, the flushing liquid is caused to flow into the flushing region through the flushing pipe at a predetermined pressure so that a flushing action is performed on the flushing region during the suction process of the main pump. As a result, solid matter adhering to the plunger is washed away into the pump chamber, preventing solid matter from entering the seal, and allowing stable and smooth operation of the main pump to continue.

However, in the pump according to the present invention configured as described above, the slurry sucked into the main pump 20 is concentrated, but the concentration ratio in this case is not such that it actually supports the operation of the main pump 20. do not have. That is, in FIG. 1, the flow rate of the slurry supplied to the supply pipe 10 is Al/min., and the concentration is awt%.
The flow rate of the slurry supplied to the suction pipe 18 of the main pump 20 is Bl/min, the concentration is bwt%, and the flow rate of the flushing liquid supplied to the suction pipe 24 of the flushing pump 26 is Fl/min, the concentration is If fwt% is fwt%, f≈0, and the following relationship holds true for the concentration a of the slurry.

a=Bb/B+F (1) On the other hand, if the ratio of the flushing liquid amount F to the suction amount B of the main pump 20 is φ, then F=φB, so the concentration of the slurry can be calculated based on the above equation (1). The following relationship holds true for b.

b=(1+φ)a (2) From the above equation (2), it is generally sufficient that the ratio φ is 0.1 or less, so b≦1.1a. That is, if the concentration of the slurry stock solution is, for example, 20%, the slurry sucked into the main pump 20 will have a concentration of only 22% at most.

On the other hand, in addition to the above-mentioned flushing liquid supply means, in the suction stroke of the main pump, which operates the pump by reciprocating the plunger, the flushing liquid can be flushed according to the flow rate of the slurry handled by the main pump without providing any special control means. The concentration of slurry handled by the main pump is maintained constant by keeping the amount of liquid mixed in constant.
Moreover, in order to obtain an efficient and economical cleaning effect using the minimum necessary amount of flushing liquid, the following pump configuration is suitable.

That is, in FIG. 2, reference numeral 30 indicates a cylinder that supports a plunger 32 that performs a pumping operation of the main pump 20, and a flushing pipe 28 is inserted through a part of this cylinder portion 30.
The flushing pipe 28 is installed at a position rearward from the position (indicated by a chain line) where the most extreme end 32a of the plunger 32 retreats to the maximum during the suction stroke, and the flushing pipe 28 is installed at the opening in the cylinder 30. A flushing area 34 in which no packing is provided is formed at and in front of this, and a packing 36 and a packing presser 38 are attached behind the flushing pipe 28. In this case, a sleeve 40 for smoothly guiding the flushing liquid to the outer peripheral surface of the plunger 32 is installed in the flushing region 34, and a through hole 42 is appropriately formed in the portion of the sleeve 40 facing the flushing pipe 28. to drill. Further, the length l of the sleeve 40 is preferably set longer than the maximum stroke displacement length of the plunger 32 so that the liquid-contacted portion of the plunger 32 does not enter into the gasket 36. Furthermore, the gap between the outer circumferential surface of the plunger 32 and the inner circumferential surface of the sleeve 40, which forms the flushing region 34, is preferably set to a size such that the flushing liquid flows at a flow rate faster than the average speed at which the plunger 32 retreats. be.

On the other hand, the flushing pipe 28 communicates via a check valve 44 with the discharge side of a flushing liquid supply reciprocating pump 26 that performs a flushing pump operation by reciprocating a plunger in the same manner as the main pump, The suction side of the flushing pump 26 is connected to the aforementioned storage tank 1 via the suction pipe 24.
It communicates with a flushing liquid reservoir formed by providing a second flushing device 16.

However, in the above-described reciprocating pump of this type, as a means for causing the reciprocating movement of the plunger 32, the rotational movement of the electric motor 46 is generally controlled by the crank device 48 via an appropriate speed reducer (not shown).
A configuration that transmits information is adopted. Therefore, in this embodiment, a coupling electrically couples the drive shaft 50 of the crank device 48 that drives the plunger 32 of the main pump with the drive shaft 54 of the crank device 52 that drives the flushing pump 26; The connection is made by a mechanical coupling means 56 such as a coupling, chain, or belt. In this case, the rotational phase difference is set to 180 degrees so that the flushing pump 26 has a discharge stroke in accordance with the suction stroke of the main pump. As a result, in the present invention, as shown in FIG. 3, the main pump plunger 3
The speed characteristic () during the reciprocating stroke of No. 2 and the flushing liquid discharge amount characteristic () of the flushing pump 26 have a certain proportional relationship. Therefore, since the supply amount of the flushing liquid increases or decreases in proportion to the magnitude of the plunger retraction speed, it is possible to control the concentration of the main pump handling liquid, that is, the slurry, to always be constant.

By configuring the reciprocating pump in this way, the rotational phase difference between the main pump and the reciprocating pump for flushing liquid supply is set to 180°, which allows for proper flushing of the plunger in synchronization with the suction stroke of the main pump. can be done. In addition, by keeping the ratio of the amount of flushing liquid mixed in to the flow rate of the liquid handled by the main pump always constant regardless of the pump rotation speed, concentration control is achieved that allows the concentration of the liquid discharged from the main pump to be kept constant at all times. can. Furthermore, by making the amount of flushing fluid supplied increase or decrease in proportion to the magnitude of the plunger retraction speed, the minimum amount of flushing fluid required is always flushed, allowing the flushing fluid to be used economically and in the most efficient manner. Good flushing cleaning can be achieved.

In particular, by employing a reciprocating pump as the flushing pump as in the above-described embodiment, it is possible to maintain a constant amount of flushing fluid and also to use a flushing fluid with high viscosity. In addition, a reciprocating pump used as a flushing pump has the function of preventing backflow of flushing liquid, but it is also possible to install a check valve between the flushing pump and the flushing pipe. Therefore, it is possible to reliably prevent backflow even if the pressure on the main pump side becomes excessive, and the flushing pump can be easily designed because it can withstand pressure comparable to the suction pressure of the main pump. There are some advantages.

As is clear from the above-mentioned embodiments, according to the present invention, the slurry handled by the main pump is used as the flushing fluid, so even if it gets mixed into the slurry handled by the main pump, there is no problem in the process. Moreover, it can be easily handled in cases where maintaining the concentration of coal fine particles is strictly required in, for example, coal liquefaction and gasification processes. Furthermore, since there is no need to separately prepare a flushing liquid, there is an advantage that operating costs can be significantly reduced.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing the piping configuration of the reciprocating pump according to the present invention, and Fig. 2 shows an example of the specific connection relationship between the main pump and flushing pump that can be suitably applied to the pump of the present invention. FIG. 3 is a waveform diagram showing the speed characteristics ( ) of the plunger in the main pump of the pump of the present invention and the flushing liquid discharge flow rate characteristics ( ) of the flushing pump. 10... Supply pipe, 12... Storage tank, 14... Stirring mechanism, 16... Filter device, 18... Suction pipe,
20...Main pump, 22...Discharge piping, 24...
Suction piping, 26...Flushing pump, 28...
...Flushing pipe, 30...Cylinder, 32
... Plunger, 34 ... Flushing area, 3
6...Putkin, 38...Putkin presser, 40...
...Sleeve, 42...Through hole, 44...Check valve, 4
6...Electric motor, 48...Crank device, 50
... Drive shaft, 52 ... Crank device, 54 ... Drive shaft, 56 ... Coupling means such as coupling.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A flushing pipe is provided in the cylinder part that supports the plunger that performs the main pump operation, behind the maximum retracted position of the plunger that contacts the pump handling liquid (slurry). A flushing area is formed on the front pump chamber side of the flushing pipe, and a packing is provided on the rear drive source side.
In a reciprocating pump configured such that a flushing pump is connected to the flushing pipe so that the flushing liquid flows into the pump chamber while cleaning the plunger surface, a filtration device is installed in the slurry storage tank of the suction piping system of the main pump. 1. A reciprocating pump characterized in that a flushing liquid storage section is provided for storing a clarified liquid obtained by passing the slurry through the filtration device, and a flushing pipe is connected in communication with the flushing liquid storage section. (2) The reciprocating pump according to claim 1 of the Utility Model Registration Claim, wherein the reciprocating pump is provided with a stirring mechanism in the slurry storage tank. (3) Scope of Utility Model Registration In the reciprocating pump described in claim 1 or 2, the flushing pump is composed of a reciprocating pump, and the rotational phase difference between the main pump and the flushing pump is set to 180°. ,
The ratio of the amount of flushing liquid mixed in to the flow rate of the liquid handled by the main pump (slurry) is always constant regardless of the pump rotation speed, and the amount of flushing liquid supplied increases or decreases in proportion to the magnitude of the plunger retraction speed. A reciprocating pump that connects a pump and a flushing pump to a common drive source.