JP3168989U - Gas lock avoidance structure in reciprocating pump - Google Patents

Abstract

A gas lock avoiding structure for a reciprocating pump is provided. SOLUTION: The pump head 1 is provided with a pump chamber 6 having outflow inlets 4 and 5 and a diaphragm 2, and an inflow communication passage having an inflow check valve 9 between the outflow inlets 4 and 5 and the pump chamber 6. A reciprocating pump is constructed by providing an outflow communication passage 8 having an outflow check valve 7 and an outflow check valve 10. Further, the inflow communication passage 7 is provided with a gas vent passage 13 which vertically branches upward downstream of the check valve 9 for inflow and communicates with a gas vent 12 formed at an upper end of the pump head 1. A lower valve seat 14 provided at the lower end opening of the gas vent passage 13 is provided with a check valve 15 for degassing, which can be seated from above and has a larger specific gravity than the transfer liquid, and an inflow downstream from the check valve 15 for degassing. The communication passage 7 is provided with a section 7c that is bent vertically downward. Further, a downstream side check valve 17 which is a spherical ball check valve that can be seated from below and is made of a material having a larger specific gravity than the transfer liquid is provided on the upper valve seat 16 provided at the upper end opening of the vertical descending section 7c. Set up. [Selection diagram] Figure 1

Description

  The present invention relates to a gas lock avoidance structure in a reciprocating pump.

  Conventionally, when a liquid that tends to generate bubbles (gas) such as sodium hypochlorite solution is transferred by a reciprocating pump, the gas generated from the liquid stays in the pump chamber and reduces the compression efficiency of the reciprocating pump. A so-called gas lock phenomenon in which liquid cannot be transferred may occur, and for this reason, reciprocating pumps having various gas venting mechanisms have been proposed.

  For example, in the reciprocating pump disclosed in Patent Document 1, the upper side of the check valve of the discharge flow path connected to the upper side of the pump chamber is branched into a horizontal discharge liquid passage and a vertical gas release passage. A gas vent valve constituting an incomplete seal is inserted in the passage so that liquid and gas are slightly discharged to the outside during the discharge stroke.

  Further, in the reciprocating pump disclosed in Patent Document 2, a suction flow path is connected to the upper side of the pump chamber and a discharge flow path is connected to the lower side. A stop valve is arranged, and gas is discharged out of the pump by opening a check valve on the suction side that floats in the processing liquid.

Japanese Patent No. 2848807 Japanese Examined Patent Publication No. 61-48633

However, the reciprocating pump of Patent Document 1 is configured so that a trace amount of liquid always leaks from the gas vent passage, and in this way, a part of the handling liquid is leaked. The discharge amount is irregular and unstable.
In the reciprocating pump of Patent Document 2, since the check valve floats, the gas accumulated in the pump chamber is surely discharged from the upper suction passage through the check valve during the pump operation. Since gas adheres to the valve, the adhesion with the valve seat is deteriorated, and the transfer of the processing liquid may become impossible.
In addition, when the pump is stopped, the gas that is generated from the processing liquid and rises in the suction channel presses the check valve against the valve seat located above it from the bottom, keeping the valve closed firmly. Stays in the pump chamber and easily falls into a gas lock phenomenon.
Therefore, an object of the present invention is to provide a gas lock avoidance structure capable of exhibiting stable degassing in a reciprocating pump.

In view of the above problems, the gas lock avoidance structure in the reciprocating pump according to the present invention has an inlet and an outlet in the pump head and a recessed pump chamber, and the opening of the pump chamber is opened by operating the drive source. The inflow communication path provided between the inflow port and the pump chamber is provided with an inflow check valve that allows only the inflow of fluid into the pump chamber. In the reciprocating pump provided with an outflow check valve that allows only the outflow of fluid from the pump chamber in the outflow communication passage provided between the pump chamber and the pump chamber, Downstream vertically and vertically branching, and a venting passage that communicates with the venting port established at the upper end of the pump head is provided, and can be seated from above on the lower valve seat provided at the lower end of the venting channel The specific gravity is larger than that of the transferred liquid. A degassing check valve is provided, and an inflow communication path downstream from the degassing check valve is provided with a vertically bent section, and an upper valve seat provided at the upper end of the vertical descending section is viewed from below. A downstream inflow check valve is provided which can be seated and has a specific gravity greater than that of the transfer liquid.
Further, the downstream end port of the inflow communication path facing the pump chamber and the upstream end port of the outflow communication path may be connected to form a flow port through which fluid can enter and exit.

In short, since the present invention is configured as described above, the downstream inflow check valve has a specific gravity greater than that of the liquid to be transferred, and is located in a vertically descending section having a valve seat at the upper end in the inflow communication path, and is reciprocated. While the pump is stopped, the valve is kept open from the upper valve seat due to its own weight, so that the gas generated from the liquid in the pump head does not stagnate in the pump head, and the upward degassing flow upstream. Naturally flowing to the path, the degassing check valve seated from above is pushed up by the gas pressure because the specific gravity is larger than the transfer liquid in the lower valve seat provided at the lower end of the degassing flow path, By opening the degassing check valve so as to be lifted and separated from the lower valve seat, the gas can be naturally discharged smoothly from the degassing flow path to the outside.
Therefore, according to the present invention, even if gas is generated in the pump head while the reciprocating pump is stopped, the internal pressure does not increase and can be maintained at almost the atmospheric pressure at all times, and the gas lock phenomenon can be avoided during operation. .
Also, since the downstream inflow check valve sits on the upper valve seat and closes in the discharge stroke of the reciprocating pump, the backflow of the transferred liquid occurs in the vertical descending section downstream from the degassing check valve in the inflow communication path. Is prevented, liquid does not leak from the gas vent flow path, and the discharge amount is not irregular and stable operation is possible as in the prior art.

  The downstream end of the inflow communication passage facing the pump chamber and the upstream end of the outflow communication passage are connected to form a flow port through which fluid can enter and exit, so the total length of the inflow communication passage and the outflow communication passage in the pump head is shortened. In addition, the volume in the pump head can be further reduced, thereby increasing the compression ratio in the pump chamber and further avoiding the gas lock phenomenon.

It is a simplified sectional view showing the degassing state of the pump head of the reciprocating pump. It is a simplified sectional view showing an inhalation state same as the above. It is a simplified sectional view showing a discharge state same as the above. It is a simplified sectional view showing a modification.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A reciprocating pump according to the present invention mainly transfers a sodium hypochlorite solution, and is a diaphragm pump (hereinafter simply referred to as a pump) mainly composed of a drive unit (not shown) and a pump head 1 connected to the drive unit. ).
The drive unit transmits the rotational movement of the output shaft of a drive source (not shown) composed of an electric motor to a drive shaft 3 whose tip is connected to the center of the diaphragm 2 via a series of conversion mechanisms (not shown). It is configured to reciprocate linearly in the horizontal direction.

In the drawing, the pump head 1 has an inlet 4 at the upper left side and an outlet 5 at the lower left side, and a pump chamber 6 that is partitioned from the drive unit via the diaphragm 2 at the center of the right side. .
Then, the opening formed on the right side of the pump head 1 by the recess is hermetically closed by the diaphragm 2, so that the pump chamber 6 is moved by the diaphragm 2 that is displaced via the drive shaft 3 that reciprocates linearly by the operation of the drive source. The volume is changed.

In the pump head 1, an inflow communication path 7 is provided between the inlet 4 and the pump chamber 6, and an outflow communication path 8 is provided between the outlet 5 and the pump chamber 6.
The inflow communication path 7 is provided with an inflow check valve 9 that allows only fluid to flow into the pump chamber 6, and the outflow communication path 8 is provided with an outflow check valve that allows only fluid outflow from the pump chamber 6. 10 is provided.
The inflow check valve 9 and the outflow check valve 10 are spherical ball check valves made of a material such as ceramic or metal having a higher specific gravity than the transfer liquid (sodium hypochlorite solution).

The inflow communication path 7 is provided with an upright section 7a having a predetermined length by being bent upright at the upstream side near the inlet 4 and serving as a starting point (upstream end) of the upright section 7a. An inflow valve seat 11 is provided around the lower end of the small diameter, and an inflow check valve 9 is provided on the inflow valve seat 11 so as to be seated from above.
In the inflow communication passage 7, downstream of the inflow check valve 9, a continuous section 7 a is provided with a horizontal section 7 b having a predetermined length that is reduced in diameter, and the horizontal section 7 b is vertically branched upward. At the same time, a gas vent channel 13 communicating with a gas vent 12 provided at the upper end of the pump head 1 is provided.

The degassing flow path 13 is provided by expanding the diameter above the lower end opening having the same diameter as the horizontal section 7b, and can be seated from above on the lower valve seat 14 provided around the lower end opening. Similar to the above, a spherical degassing check valve 15 having a specific gravity greater than that of the transfer liquid is provided.
In the inflow communication path 7 downstream from the degassing check valve 15, a section 7c bent in a vertical drop shape from the downstream end of the horizontal section 7b is provided with a predetermined length, and the vertical drop section 7c has the same diameter as the horizontal section 7b. The lower part of the vertical descending section 7c is provided with an enlarged diameter below the upper end opening, and can be seated from below on the upper valve seat 16 provided around the upper end opening of the vertical descending section 7c. A spherical downstream inflow check valve 17 (hereinafter simply referred to as inflow check valve 17) is provided.

  In the inflow communication passage 7 downstream from the inflow check valve 17, the downstream end port 18 of the inflow communication passage 7 having a smaller diameter than the downstream end of the vertical descending section 7 c and facing the pump chamber 6 is formed on the pump chamber wall surface 6 a facing the diaphragm 2. Opened.

Further, the outflow communication path 8 is provided with an enlarged diameter of a drooping section 8a having a predetermined length by bending the downstream side near the outflow outlet 5 in a vertically descending manner, and the end point (upstream end) of the dripping section 8a is provided. The inflow valve seat 19 is provided around the lower end opening, and the outflow check valve 10 is provided on the inflow valve seat 19 so as to be seated from above.
In the outflow communication passage 8 upstream from the outflow check valve 10, the upstream end port 20 of the outflow communication passage 8 facing the pump chamber 6 is opened in the pump chamber wall surface 6 a below the downstream end port 18.

Next, a modification of the present invention applied to the pump of FIG. 4 will be described.
FIG. 4 shows a simplified cross-sectional view of a diaphragm pump head as in FIGS.
In this pump head 1, the downstream end port of the inflow communication passage 7 facing the pump chamber 6 and the upstream end port of the outflow communication passage 8 are connected to form a flow port 21 through which fluid can enter and exit. Are the same as those described above, and the same or corresponding parts as those described above are denoted by the same reference numerals in the drawing and description thereof is omitted.

In the pump configured as described above, in the pump head 1, the upright section 7 a in the inflow communication path 7, the vertical descending section 7 c, the gas vent flow path 13 branched from the inflow communication path 7, and the outflow communication path 8 is arranged in the vertical direction, and in each of the sections 7a, 7c, 8a and the gas vent channel 13, a sodium hypochlorite solution (hereinafter simply referred to as liquid) Inflow check valves 9 and 17, an outflow check valve 10 and a degassing check valve 15 which are ball check valves formed of a material having a higher specific gravity than the above are respectively provided.
Therefore, when the pump shown in FIG. 1 is in a stopped state, the check valves 9, 10, and 15 other than the vertical lowering section 7c having the upper valve seat 16 at the upper end are respectively corresponding to the corresponding valve seats by their own weight. 11, 19 and 14 are seated and closed to prevent the flow of liquid from the outflow inlets 4, 5 and the gas vent 12.

On the other hand, the inflow check valve 17 in the vertical descending section 7c is opened, and the pump chamber 6 and the downstream of the inflow communication passage 7 are in communication with each other.
In such a state, the gas generated from the liquid in the pump head 1 does not stagnate in the pump head 1 and naturally flows to the lower end of the upward gas vent channel 13 upstream thereof as shown by an arrow in FIG. To flow.

In the gas vent flow path 13, the gas vent check valve 15 is seated on the lower valve seat 14 as described above, but the gas vent check valve 15 is pushed up by the increase in gas pressure at the lower portion thereof. Is lifted and separated from the lower valve seat 14 to open the valve, and the gas is naturally discharged from the gas vent channel 13 to the outside.
As described above, since the gas generated in the pump head 1 is exhausted, the internal pressure of the pump head 1 does not increase, and can always be maintained at substantially atmospheric pressure, and a gas lock phenomenon can be avoided during operation.

When the drive source is operated, the diaphragm 2 moves forward and backward according to the drive shaft 3 that reciprocates in conjunction with the drive source.
That is, in the suction stroke of the pump in which the diaphragm 2 moves backward, the inflow check valves 9 and 17 are opened, the degassing check valve 15 is maintained closed, and the inlet 4 and the pump chamber 6 are inflowed. The liquid communicates through the communication path 7 and is sucked into the pump chamber 6 from the inlet 4 without flowing into the gas vent channel 13 as indicated by an arrow in FIG.

  Next, in the discharge stroke of the pump in which the diaphragm 2 moves forward, the inflow check valve 17 is seated on the upper valve seat 16 and closed, and the outflow check valve 10 is opened, and the outlet 5 and the pump chamber are opened. 6 communicates via the outflow communication path 8, and the liquid is pumped from the outlet 5 without flowing into the gas vent channel 13 as shown by the arrow in FIG.

Further, the pump shown in FIG. 4 is the same as the above except that the liquid and gas flow in and out through the flow port 21 formed in the pump chamber wall surface 6a.
In this way, the downstream end port of the inflow communication passage 7 and the upstream end port of the outflow communication passage 8 are connected to form a flow port 21 through which fluid can enter and exit, whereby the inflow communication passage 7 and the outflow communication in the pump head 1 are formed. Since the overall length of the passage 8 can be shortened, thereby reducing the volume in the pump head 1 and increasing the compression ratio in the pump chamber 6, the gas lock phenomenon can be further avoided.

DESCRIPTION OF SYMBOLS 1 Pump head 2 Diaphragm 4 Inlet 5 Outlet 6 Pump chamber 7 Inflow communication path
7c Vertical descent section 8 Outflow communication passage 9 Inflow check valve
10 Check valve for outflow
12 Gas vent
13 Gas vent flow path
14 Lower valve seat
15 Check valve for venting
16 Upper valve seat
17 Check valve for downstream inflow
21 Distribution outlet

Claims (2)

  An inlet and an outlet are opened in the pump head, and a pump chamber is recessed. The opening of the pump chamber is closed with a diaphragm that is displaced so as to change the volume of the pump chamber by the operation of the drive source, and the inlet and the pump chamber An inflow check passage that allows only the inflow of fluid into the pump chamber is provided in the inflow communication passage provided between the pump chamber and the outflow communication passage provided between the outlet and the pump chamber. In a reciprocating pump provided with an outflow check valve that allows only the outflow of fluid, the inflow communication path is vertically branched downstream from the inflow check valve, and gas opened at the upper end of the pump head A degassing flow passage communicating with the vent is provided, and a degassing check valve having a specific gravity greater than that of the liquid to be transported is provided on the lower valve seat provided at the lower end of the degassing flow passage and has a higher specific gravity than the transfer liquid. In the inflow communication path downstream from the check valve A section bent in a vertically descending manner is provided, and a check valve for inflow on the downstream side that is seated from below and has a higher specific gravity than the transfer liquid is provided on the upper valve seat provided at the upper end of the vertically descending section. Gas lock avoidance structure for reciprocating pumps   2. A gas lock avoidance in a reciprocating pump according to claim 1, wherein the downstream end port of the inflow communication channel facing the pump chamber and the upstream end port of the outflow communication channel are connected to form a flow port through which fluid can enter and exit. Construction.

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