JPS60261985A - Free piston pump for pressure sending slurry and its air bleeding device - Google Patents

Abstract

PURPOSE:To improve air bleeding operation by providing an air bleeding passage with a closing valve of which one end is placed close to the bottom face of a free piston which is in its lowest position while the other end is projected out of the a high pressure tank, in a pressure sending free piston pump for slurry. CONSTITUTION:A free piston 4-6 is provided in a high pressure tank 1-3, and an air bleeding device 26 having an air bleeding pipe 30 and an air bleeding port 32 is provided in such a way that its one end is placed close to the bottom face of the free piston 4-6 in its lowest position while the other end projects out of the high pressure tank. Accordingly, it does not take place as in the conventional cases that an air sump is compressed by the pressure of pressed-in slurry, varying the flow of the slurry.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a free piston pump for pumping slurry and an air venting device therefor.

Conventional structure and its problems For example, in a free piston pump for coal slurry, the coal slurry in the slurry tank is fed into a high pressure tank to raise the free piston in the high pressure tank, and then the drive liquid in the drive liquid tank is raised. The liquid is supplied into the high-pressure tank and the free piston is lowered, thereby forcing the coal slurry in the high-pressure tank to a designated location via the slurry flow line. However, the coal slurry in the slurry tank is Air gets mixed into the slurry during stirring, and air that has been attached to the coal from the beginning gets mixed into the slurry. Therefore, the formation of air bubbles under the free piston in the high pressure tank is unavoidable.

By the way, there are two methods for the state of the free piston in the high pressure tank.

The first method is to make the outer diameter of the free piston smaller than the inner diameter of the high-pressure tank (the gap between the inner diameter of the high-pressure tank and the outer diameter of the free piston is smaller than the maximum particle diameter contained in the slurry).
The second method is to make the inner diameter of the high-pressure tank and the outer diameter of the piston the same (but with a sealing material such as an O-ring). ) to completely separate the slurry and driving liquid. In the first method, air bubbles contained in the slurry float to the driving liquid side above the gap between the high-pressure tank and the free piston, and no air pockets are generated under the free piston. However, since the slurry is mixed with the driving fluid, the inner surface of the high-pressure pump is abraded. In order to prevent this, it is necessary to install fairly large-scale filtration equipment or to dispose of the driving fluid, which increases costs in either case. In the second method, since the driving liquid and the slurry are not mixed, even if the driving liquid is used in circulation, the inner surface of the high-pressure pump is not worn out, and filtration equipment is not required. However, an air pocket forms under the free piston. If such an air pocket is formed, when the slurry in the adjacent high-pressure tank is pressurized into the slurry flow line, the pressure of the injected slurry will compress the air pocket, and eventually the slurry will be pumped through the slurry flow line. The pressure on the slurry fluctuates and the slurry flow
) This causes fluctuations in the flow rate of the slurry, causing so-called pulsation, generating noise due to vibrations, and potentially causing leakage points in the slurry flow line.

OBJECTS OF THE INVENTION It is an object of the present invention to provide a free piston pump for pumping slurry and an air venting device therefor, which eliminates the above-mentioned conventional drawbacks.

Structure of the Invention In order to achieve the above object, the free piston for pumping slurry of the present invention supplies slurry into a high pressure tank in a slurry tank, raises the free piston in the high pressure tank, and then pumps slurry in a driving liquid tank. In a free piston pump for pumping slurry, the driving liquid is supplied into a high-pressure tank to lower the free piston, thereby pumping the slurry in the high-pressure tank to a predetermined location via a slurry flow line. An air vent path with an on-off valve is provided which approaches the lower surface of the free piston in the lowered state and whose other end faces the outside of the high pressure tank.

Further, the air venting device in the free piston pump for pumping slurry of the present invention supplies the slurry in the slurry tank to the high pressure tank, raises the free piston in the high pressure tank, and then pumps the driving liquid in the driving liquid tank to high pressure. In a free piston pump for pumping slurry, the slurry is supplied into the tank and the free piston is lowered, thereby pumping the slurry in the high pressure tank to a predetermined location via the slurry flow line. An air vent path with an on-off valve that approaches the lower surface of the free piston and the other end faces outside the high-pressure tank is provided, and a small detector section is provided to detect whether or not air exists under the free piston in its lowest position. The explanation will be based on the case where the opening/closing valve is opened by the air detection signal from the detector. In this cell example, the first to eighth high pressure tanks (1) to (3) 1! / Uses free pistons (4) to (6) among them.
are arranged so that they can be raised and lowered freely, and each free piston (4) ~
(6) is configured to move up and down by shifting the timing by 1/8 cycle. (7) is each free piston (
4) a sealing material (8) fitted into the grooves on the outer circumferential surface of the high pressure tanks (1) to (6) and abutting the inner circumferential surfaces of the high pressure tanks (1) to (3);
) is a slurry tank, (9) is a conveyor for supplying powdered coal etc. into the slurry tank (8), QO is a water supply pipe for supplying water into the slurry tank (8), One end of Q+) is connected to the lower end of the slurry tank (8), and the branch part (IIA) at the other end is connected to the i high pressure tanks (1) to (3), respectively.
A slurry supply pipe connected to the lower part of Q1), a slurry pump interposed in the slurry supply pipe Q1),
(to) is a driving liquid tank, and a and a are driving liquid tanks, one end of which is connected to the lower part of the driving liquid tank α, and the branch part (14A) of the other end connected to the upper end of each high pressure tank (1) to (3). Liquid supply pipe, 0!
9 is a fresh water pump interposed in the driving liquid supply pipe 04, αQ
The branch part (16A) at one end connects each high pressure tank (1) to (3).
] The driving liquid discharge pipe is connected to the upper end and the other end is inserted into the driving liquid tank (to), and the α force is connected to the branch part (17A) at one end.
) is connected to the lower end of each high-pressure tank (1) to (3), and the other end is extended to a predetermined location. Slurry flow line, (+8- (2])!, is connected to each branch 1 (IIA) y
(14A) (16A) The first to fourth opening/closing valves interposed in (17A), (support) is the piston upper limit detector, slope is the piston intermediate detector, (c) is the piston lower limit detector, and the handle is the air It is a removable device m and consists of the following:

That is, 2) is a holder that penetrates the bottom of the high pressure tanks (1) to (3), and the inside thereof is a partition plate (27A).
The first part is divided by 12m into an upper recessed part and an inner part. (to) 6 years old The main body part (80A) is the above partition plate (27A)
) is an air vent tube that is inserted into the inner chamber through the through hole 〇M and whose head (BOB) can be freely fitted into the upper recess (C), and the main body part is inserted from the side of the head (80B). (80
This is to form an air vent hole (toward) that passes through A) and exits downward. (to) is the flange formed in the center of the main body portion (80A), (b) is the spring interposed between the flange (to) and the partition plate (27A), and (to) is the flange formed at the center of the main body portion (80A). A sealing material (2) is fitted into the annular groove of the flange (end) and abuts against the inner surface of the inner chamber visor, and (2) is fitted into the annular groove of the head (80B) and abuts against the inner surface of the upper recess (2). (2) is a connecting tube whose upper part penetrates the bottom of the boulder and fits into the lower part of the main body part (80A) of the air vent pipe (through) through the sealing material (through). , (to) is the exhaust pipe connected to the lower end of the connecting tube (b), and (to) is the exhaust pipe (2) connected to the lower end of the connecting pipe (b).
), @D is the cleaning water supply pipe connected to the lower part of the connecting tube (b), and Opening/closing valve, (corporate) is a Samuta supply and discharge pipe connected to the bottom of the holder ■, - is an operating water supply pipe and drain pipe connected to the supply and discharge pipe ■ through a three-way switching valve), and θ is ( (goods) is an optical fiber for floodlighting whose tip extends from the lower end of the holder (support) through the inside of this holder (2) and faces into the high pressure tanks (1) to (3) from the upper end of the side of the holder (goods). It is an optical fiber for receiving light, and a light projector and a light receiver are connected to each base end of the optical fiber. @υ is each valve (g) ~ 0! ) and a control device that appropriately switches the three-way switching valve ■. - is the power cord.

Hereinafter, the operation of the above configuration will be explained based on FIG. 4. First, the free pistons (4) to (6) descend (a), and the piston lower limit detector (c) detects when they have descended to the lowest position (extension). Based on the detection signal, the control device i51 controls the second, eighth, Close the fourth on-off valve Q* w aυ (c), then open the first on-off valve (g)). Next, when light is emitted from the light projector, the light is projected into the high pressure tanks (1) to (3) through the light projecting optical fiber (b). If there is an air pocket under the free pistons (4) to (6) as shown in Figure 2, the light hits the inner peripheral surface of the high pressure tanks (1) to (3) and is reflected. The optical fiber is detected by the optical receiver, and the detection signal is input to the control device. On the other hand, if there is no air pocket under the free pistons (4) to (6), the slurry blocks the gap between both optical fibers, so the receiver does not detect light. (E). Next, the control device which received the detection signal from the light receiver closes the sixth opening/closing pulp 4.
Connect the three-way switching valve to the operating water supply pipe (g). Then, the working water is forced into the inner chamber (2) via the working water supply pipe ① and the supply/discharge pipe.

Raise the shaft of the air vent tube against the spring (2), and the upper end of the air vent hole (2) will be exposed outside the holder (2) (as shown in Figure 2). Next, open the fifth on-off valve (a). Then,
The air below the free pistons (4) to (6) is exhausted to the outside via the air vent hole (to), the connecting tube (b), and the exhaust pipe (to). As a result, the top surface of the slurry rises, blocking the gap between both optical fibers, and the receiver no longer detects the light, making it difficult to check the slurry. Next, due to the stop of the output signal from the light receiver, the control device value 1 closes the fifth on-off valve (Q).

This will prevent it from being exhausted. Next, the 6th on-off valve (
6) Open (6). This will allow the cleaning water supply pipe (b)
Cleaning water is supplied into the connecting tube (b) and the air vent hole (2) through the connecting tube (b) and the air vent hole (2), and the slurry F4 therein is discharged to prevent clogging. Then, after a certain period of time, connect the three-way switching valve) to the drain pipe). Then, the water pressure inside the inner chamber lowers, and the spring (b) lowers the air vent pipe (to), causing the head (8) to drop.
0B) is housed in the upper recess (c). Also close the 6th opening/closing valve @■. Next, open the third on-off valve (e). Then, the slurry (goods) supplied into the high pressure tanks (1) to (3) by the slurry pump (a)
The free pistons (4) to (6) are raised (b),
The driving liquid (2) above the free pistons (4) to (6) is returned into the driving liquid tank (to) via the driving liquid discharge pipe α6. When the piston upper limit detector (a) detects that the free pistons (4) to (6) have risen to the highest level, the control bag Wi51J receives the detection signal and controls the first and eighth opening/closing valves o.
4 (e) is closed, and the second and fourth on-off valves Q
l @1) can be opened. Then, the driving fluid supplied into the high pressure tanks (1) to (3) by the clean water pump (g) lowers the free bearings (41 to (6)), and the water in the high pressure tanks (1) to (3) is lowered. Slurry (goods) is transported to a predetermined location via a slurry flow line (b).

In (e) of FIG. 4, all that is required is to raise the control device (b) and free pistons (4) to (6) from the light receiver (b).

In the above F embodiment, the light emitted from the light emitting optical fiber (b) hits the inner surfaces of the high pressure tanks (1) to (3), is reflected, and enters the light receiving optical fiber (Incorporated). However, instead of kneading, as shown in Figure 6,
The ends of both optical fibers (2nd embodiment) may be made to face each other so that light enters directly from the light emitting side to the light receiving side. 1. Instead of the fiber hi (7), an electric wire Vη- is provided whose ends (57A) (58A) face each other at a certain distance, and the slurry causes the ends (57A) (58A) to The conduction signal may be used to confirm the existence of the slurry (goods) (eighth embodiment).

In addition, in the first embodiment, the lower surface of the free piston (■) is made flat, but as shown in FIGS. 7 and 8,
Air pocket recesses may be formed on the lower surfaces of 4) to (6) with the free piston. This allows the free piston (4
) to (6) Even if a small amount of air exists, the slurry can directly contact the free pistons (4) to (6), causing the free pistons (4) to (6) to (Fourth Example)

In the above embodiment, the control device hm automatically opens and closes the fifth and sixth on-off valves (2) and the three-way switching valve (2) based on the detection signal, but instead of this, it is possible to open and close them manually. Then, when an air pocket is formed under the free pistons (4) to (6), the fifth opening/closing valve may be manually opened to exhaust the air (fifth embodiment). ).

Effects of the Invention As described above, according to the free piston pump for pumping slurry of the present invention, by opening the opening/closing valve, the air pocket formed under the free piston can be discharged to the high pressure tank body through the air vent path. It is possible. Therefore, unlike in the past, the air pocket is compressed by the pressure of the press-fitted slurry, and the slurry flow 1 does not fluctuate, so there is no so-called pulsation, and there is no possibility of leakage points occurring in the slurry flow line due to vibration. do not have.

In addition, according to the air venting device of the free piston pump for pumping slurry, a detector detects the presence of air under the free piston, and a control device opens an on-off valve based on the detection signal. The resulting air pocket can be automatically discharged to the outside of the high-pressure tank via the air vent path.

[Brief explanation of the drawing]

1 to 4 show a first embodiment of the present invention, in which FIG. 1 is a process diagram, FIG. 2 is a longitudinal cross-sectional view of the vicinity of the air venting device, and FIG.
The figure is a schematic diagram of the detector, Figure 4 is a flowchart showing the air pocket discharge procedure, Figure 5 is a vertical sectional view of the main part of the detector showing the @2 embodiment of the present invention, and Figure 6 is the present invention. FIG. 7 is a vertical cross-sectional view of the main part of the detector showing the eighth embodiment of the present invention.
FIG. 8 is a longitudinal cross-sectional view of the lower part of the high-pressure tank showing this embodiment, and FIG. 8 is a view taken along the line ■-■ in FIG. (1) to (3)...first to eighth high pressure tanks, (4)
~(6)...Free piston, (8)...Slurry tank, 03...Opening liquid tank, as -aa...First~
Fourth opening/closing pulp, wire...air venting device, (a)...
・Air vent hole (air vent path), θO... 5th on-off valve, working... 6th on-off valve, θ... 3-way switching valve,
θ F... Optical fiber for light projection, (Foundation)...
Optical fiber for light reception, (to)... Emitter, phrase... Light receiver, Yuu... Control device, 關... Air pocket, 9jIl... Slurry, -... Driving liquid agent Morimoto Yoshihiro Figure 1 Figure 2 Figure 8 Figure 5 Figure 1 Figure 1

Claims (1)

[Claims] 1. The slurry in the slurry tank is supplied into a high-pressure tank to raise the free piston in the high-pressure tank, and then the driving liquid in the driving liquid tank is supplied into the high-pressure tank to create a free piston. In a free piston pump for pumping slurry, which lowers a piston and thereby pumps slurry in a high-pressure tank to a predetermined location via a slurry flow line, one end approaches the lower surface of the free piston in the lowest position, and A free piston pump for pumping slurry, characterized by having an air vent path with an on-off valve whose other end faces the outside of the high-pressure tank. 2. Supply the slurry in the slurry tank to the high pressure tank to raise the free piston in the high pressure tank, then supply the driving fluid in the driving liquid tank to the high pressure tank to lower the free piston, and then In a free piston pump for pumping slurry, which pumps slurry in a high-pressure tank to a predetermined location via a slurry flow line, one end approaches the lower surface of the free piston in the lowest position, and the other end approaches the bottom surface of the free piston, which is in the lowest position, and the other end approaches the outside of the high-pressure tank. An air vent path with an on-off valve facing the air is provided, a detector is provided to detect whether or not air exists under the free piston in its lowest position, and the air detection signal from the detector opens the on-off valve. An air venting device for a free piston pump for pumping slurry, characterized in that it is provided with a control device for controlling the air pressure.