JP2004150315A - Reciprocating pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reciprocating pump wherein a trouble with the generation of gas is eliminated by naturally solving a discharge failure even if gas is generated from the transferred fluid during the transference of the pump. <P>SOLUTION: A pump body 1 is formed with a pump chamber 4 for sucking/discharging liquid with horizontal reciprocation of a plunger 3. A suction flow passage 5 is provided over the pump chamber 4, and a discharge flow passage 6 is provided under the pump chamber 4. The suction flow passage 5 is provided with an opening/closing valve 8 for closing a valve opening c with surface of a float-shape valve element e and for opening the valve opening c with lowering of the float-shape valve element e. The discharge flow passage 6 is provided with an opening/closing valve 13 for closing by pushing a valve element k to the valve opening c with a spring j. When sucking the fluid, the valve element e of the suction flow passage side opening/closing valve 8 opens the valve opening c, and the valve element k of the discharge flow passage side opening/closing valve 13 closes the valve opening h. When discharging the fluid, the valve element e of the suction flow passage side opening/closing valve 8 closes the valve opening c, and the valve element k of the discharge flow passage side opening/closing valve 13 opens the valve opening h, resisting the spring j. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reciprocating pump such as a plunger pump and a diaphragm pump.
[0002]
[Prior art]
A reciprocating pump generally sucks and discharges a liquid by reciprocating a plunger or a diaphragm and opening and closing a valve. Typical examples thereof include a plunger pump and a diaphragm pump.
[0003]
Although a known document cannot be specifically mentioned, for example, in a conventional plunger pump, a pump chamber for sucking and discharging a liquid by a horizontal reciprocating motion of a plunger is formed in a pump body, and a lower part of the pump chamber is formed. A suction channel is provided on the side, a discharge channel is provided on the upper side, and an on-off valve for opening and closing a valve port by, for example, a spherical valve body made of stainless steel is provided in each of the suction channel and the discharge channel. When the plunger is pulled, the valve element of the discharge flow path side on-off valve closes the valve port, the valve element of the suction flow path side on-off valve opens the valve port, sucks liquid, and when the plunger is pushed again. The valve element of the suction flow path side on-off valve closes the valve port, the valve element of the discharge flow path side on-off valve opens the valve port to discharge liquid, and thus repeats a certain amount of discharge by the horizontal reciprocating motion of the plunger. Has become.
[0004]
[Problems to be solved by the invention]
The plunger pump (or diaphragm pump) as described above is used for the fixed-rate injection of various chemical liquids. In recent years, among various liquid chemicals, for example, a gas such as sodium dichlorate that generates gas during pump transfer. The gas generated in this way accumulates inside the pump, and even if the plunger reciprocates, no vacuum pressure is generated inside the pump and liquid cannot be sucked up, making it impossible to discharge the pump. There is.
[0005]
An object of the present invention is to provide a reciprocating pump in which even if gas is generated from a liquid to be transferred during pump transfer as described above, a discharge failure is naturally eliminated and troubles due to gas generation are eliminated. And
[0006]
[Means for Solving the Problems]
According to the first aspect of the present invention, a pump chamber 4 for sucking / discharging a liquid by the horizontal reciprocation of the plunger 3 or the diaphragm 18 is formed in the pump body 1, and a suction flow path 5 is formed in an upper side of the pump chamber 4. An opening / closing valve 8 is provided on the lower side of the opening / closing valve 8 to close the valve port c by floating the float type valve element e having a lower specific gravity than the liquid to be used and to open the valve port c by descending. The discharge channel 6 is provided with an opening / closing valve 13 which closes the valve body k by pressing the valve body k against a valve port h with a spring j. When the liquid is sucked, the valve body e of the suction channel 5 side opening / closing valve 8 is closed. The valve port c is opened, the valve body k of the on-off valve 13 on the discharge flow path 6 side closes the valve port c, and the valve element e of the on-off valve 8 on the suction flow path 5 closes the valve port c and the discharge flow side That the valve body k of the on-off valve 13 opens the valve port h against the urging force of the spring j. And butterflies.
[0007]
According to a second aspect of the present invention, in the reciprocating pump according to the first aspect, on-off valves 8 and 9 are connected to the suction passage 5 in a plurality of upper and lower stages.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is an external perspective view of a plunger pump which is one embodiment of a reciprocating pump according to the present invention, and FIG. 2 is an enlarged vertical sectional view of a main part of the plunger pump. In these figures, reference numeral 1 denotes a pump body which is connected to a pump drive unit 2 provided on a base K and extends horizontally. As shown in FIG. A variable displacement pump chamber 4 for sucking and discharging liquid by movement is formed, and an upwardly extending suction flow path 5 is provided on the upper side of the pump chamber 4, and a downwardly extending discharge flow is formed on the lower side thereof. Road 6 is provided.
[0009]
The suction passage 5 includes a suction port 7 formed at an upper part on the distal end side of the pump chamber 4, a first opening / closing valve 8 on a lower side and a second opening / closing valve 9 on an upper side connected to the suction port 7, The first opening / closing valve 8, the second opening / closing valve 9, and the inlet nozzle 10 are integrally connected by a tubular holder 11. The inlet nozzle 10 is connected to the upper second opening / closing valve 9. The discharge passage 6 includes a discharge port 12 formed at a lower portion on the distal end side of the pump chamber 4, an on-off valve 13 connected to the discharge port 12, and an outlet nozzle 14 connected to the on-off valve 13. The on-off valve 13 and the outlet nozzle 14 are integrally connected by a cylindrical holder 15.
[0010]
The first on-off valve 8 on the suction flow path 5 side has a cylindrical wall portion a and a plurality of communication holes o having small diameters (see FIG. 2B), and is attached to a lower end portion of the cylindrical wall portion a. A lower end plate b, a valve port c, an upper end wall d provided at the upper end of the cylindrical wall portion a, and a float type valve body disposed in the cylindrical wall portion a for opening and closing the valve port c. The float type valve element e is made of, for example, a synthetic resin having a specific gravity of 1 or less, that is, a specific gravity smaller than the liquid used. In mounting the first on-off valve 8, the lower end portion of the cylindrical wall portion a is fitted and fixed to the upper concave portion n of the pump body 1. The second on-off valve 9 is made of exactly the same components as those of the first on-off valve 8. The lower end plate b of the second on-off valve 9 is attached to the upper end wall d of the first on-off valve 8 by the cylindrical holder 11. Are connected to the first opening / closing valve 8 by the cylindrical holder 11 in a state where they are overlapped.
[0011]
The on-off valve 13 on the discharge channel 6 side has a cylindrical wall portion f and a plurality of communication holes o having small diameters (see FIG. 2C), and a lower portion attached to a lower end portion of the cylindrical wall portion f. An upper end wall i provided at the upper end of the cylindrical wall f and having an end plate g, a valve opening h, and a spherical valve body disposed in the cylindrical wall a and pressed against the valve opening h by the coil spring j. The spherical valve body k is formed of a ceramic material or a stainless material having a higher specific gravity than the liquid used, and the coil spring j is formed of a stainless material or the like. In mounting the on-off valve 13, the upper end portion of the cylindrical wall portion f is fitted and fixed to the lower concave portion m of the pump body 1.
[0012]
The plunger 3 is connected to a crank mechanism (not shown) of the pump drive unit 2 via a crosshead 16 so as to reciprocate a predetermined stroke. Note that the crank mechanism is driven by a motor of the pump drive unit 2. In FIG. 2A, reference numeral 17 denotes a gland packing interposed in a sliding portion of the plunger 3 inside the pump body 1.
[0013]
In the use of the plunger pump configured as described above, when the liquid flows from the inlet nozzle 10 of the suction flow path 5, the liquid enters the cylindrical wall portion a through the valve port c of the second on-off valve 9, and enters the lower end portion. From the communication hole o of the first opening / closing valve 8 into the cylindrical wall a through the communication port o of the first opening / closing valve 8, and flows into the pump chamber 4 through the suction port 7 from the communication hole o at the lower end thereof. Since the spherical valve body k is pressed against the valve port c by the coil spring j and the valve is closed, the liquid from the suction flow path 5 is in the pump chamber 4 in the discharge flow path 6 side opening / closing valve 13. . At this time, the float type valve element e of each of the on-off valves 8 and 9 on the suction flow path 5 side is lowered and grounded on the lower end plate b until the liquid flows in. When the liquid is filled in the valve 5, the valve body e of each of the on-off valves 8 and 9 floats and closes the valve port c.
[0014]
When the power of the motor of the pump drive unit 2 is turned on from this state, the plunger 3 reciprocates. First, when the plunger 3 is pushed, that is, when the plunger 3 moves to the left with respect to FIG. 3A, the liquid in the pump chamber 4 is pressurized, and the first open / close valve 8 and the second open / close The valve 9 is closed in a state where the float type valve body e floating in the liquid is strongly pressed against the opening end face of the valve port c, and the on-off valve 13 on the discharge flow path 6 side is a spherical valve body k in which a coil spring is used. It is pushed down against the urging force of j to open the valve. As a result, the liquid in the pump chamber 4 passes from the discharge port 12 through the valve port h of the on-off valve 13, passes through the communication hole o, and is discharged from the outlet nozzle 14.
[0015]
Next, when the plunger 3 is pulled, that is, when the plunger 3 is moved rightward with respect to FIG. 3A, the pressure in the pump chamber 4 is reduced. The spherical valve body k is pressed against the valve opening h by the urging force of the coil spring j to close the valve, and the first opening / closing valve 8 on the suction flow path 5 side is lowered by the float type valve body e to open the valve opening c. As a result, the second opening / closing valve 9 is opened in the same manner, whereby the liquid flows into the pump chamber 4 from the suction port 7 by the movement of the plunger 3. By repeating such an operation, a fixed amount of liquid is discharged from the outlet nozzle 14.
[0016]
According to this plunger pump, the suction passage 5 is provided on the upper side of the pump chamber 4 and the discharge passage 6 is provided on the lower side, so that when gas is generated from the liquid inside the pump body 1, The gas naturally rises upward naturally because it is lighter than the liquid, and escapes to the inlet nozzle 10 side through the suction flow path 5 on the upper side of the pump chamber 4, so that gas accumulation inside the pump body 1 is eliminated. This naturally eliminates the discharge failure caused by the generated gas.
[0017]
Further, according to this plunger pump, since the valve element e of the on-off valve on the suction flow path 5 side is a float type valve element e formed of a material having a lower specific gravity than the liquid used, the gas generated inside the pump is sucked. When the flow path 5 is filled, the float-type valve body e descends, and the liquid flows into the inside from the valve port c. Is closed, so that the discharge action of the pump can be immediately restored. Further, since the valve element e of each of the on-off valves 8 and 9 on the suction flow path 5 side is a float type valve element e, the closing force or the sealing force with respect to the valve port c increases, and the quantitativeness of the discharge amount is secured. Is done.
[0018]
Also, in this plunger pump, two on-off valves 8, 9 of a first on-off valve 8 and a second on-off valve 9 are connected to the suction flow path 5, and the suction flow path 5 is doubled during liquid suction. , It is possible to further ensure the quantitativeness of the discharge amount. In this embodiment, two on-off valves 8 and 9, that is, a first on-off valve 8 and a second on-off valve 9, are connected to the suction passage 5, but three or more on-off valves may be connected. .
[0019]
FIG. 3 shows a diaphragm pump which is another embodiment of the reciprocating pump according to the present invention. In this diaphragm pump, a pump chamber 4 for sucking and discharging a liquid by horizontal reciprocation of a diaphragm 18 is formed inside a pump body 1, and an upwardly extending suction flow path 5 is provided above the pump chamber 4. At the same time, a downwardly extending discharge flow path 6 is provided on the lower side thereof. The diaphragm 18 is used instead of the plunger 3 of the plunger pump shown in FIG. It is similar to the case of the jar pump. Therefore, the same components as those of the plunger pump are denoted by the same reference numerals, and description thereof will be omitted.
[0020]
The diaphragm 18 is attached to the tip of a crosshead 19 via a diaphragm receiver 20 and fixed with a lock nut 21, and the outer peripheral edge of the diaphragm 18 is arranged at the tip of a crosshead guide 22. It is pressed against the open end face of the pump chamber 4 by the diaphragm holder 23.
[0021]
【The invention's effect】
According to the reciprocating pump according to the first aspect of the present invention, by providing a suction flow path on the upper side of the pump chamber and providing a discharge flow path on the lower side, when gas is generated from the liquid inside the pump body, Since the gas is lighter than the liquid, it naturally rises upward and escapes through the suction channel on the upper side of the pump chamber, eliminating gas accumulation inside the pump body and naturally eliminating discharge failure due to generated gas. You.
[0022]
In addition, since the valve element of the suction flow path side on-off valve is a float type valve element formed of a material having a lower specific gravity than the liquid used, when the gas generated inside the pump fills the suction flow path, this valve element is used. Since the liquid descends and the liquid flows into the inside from the valve port, the valve element floats up after the flow and closes the valve port instantaneously, so that the discharge action of the pump can be immediately restored. Further, since the valve element of the suction flow path side on-off valve is a float type valve element, the closing force or the sealing force with respect to the valve port is increased, and the quantitativeness of the discharge amount is secured.
[0023]
As in the reciprocating pump according to the second aspect of the present invention, the on-off valves are connected to the suction flow path in a plurality of upper and lower stages, so that the suction flow path is sealed in a plurality of layers when the liquid is suctioned. Can be further ensured.
[Brief description of the drawings]
FIG. 1A is an external perspective view of a plunger pump which is an embodiment of a reciprocating pump according to the present invention.
2 (A) is an enlarged vertical sectional view of a main part of the plunger pump, FIG. 2 (B) is a bottom view of a lower end plate of a suction flow passage side opening / closing valve, and FIG. 2 (C) is a lower end plate of a discharge flow passage side opening / closing valve. FIG.
FIG. 3 is an enlarged longitudinal sectional view of a main part showing a diaphragm pump which is another embodiment of the reciprocating pump according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pump body 3 Plunger 4 Pump chamber 5 Suction channel 6 Discharge channel 8 First on-off valve on suction channel side 9 Second on-off valve c on suction channel side First and second opening / closing valves e, 1 Valve element 13 of second on-off valve Discharge channel side on-off valve h Discharge channel side on-off valve valve port k Discharge channel side on-off valve valve body j Discharge channel side on-off valve spring 18 Diaphragm

Claims (2)

A pump chamber for sucking and discharging liquid by a horizontal reciprocating motion of a plunger or a diaphragm is formed in the pump body, and a suction flow path is provided on an upper side of the pump chamber, and a discharge flow path is provided on a lower side thereof. An open / close valve that closes the valve port by floating a float-type valve element having a lower specific gravity than the liquid used and opens the valve port by descending, and closes the discharge channel by pressing the valve element against the valve port with a spring An on-off valve for providing a valve, wherein the valve body of the suction passage-side on-off valve opens the valve port when the liquid is sucked, and the valve body of the discharge passage-side on-off valve closes the valve port when the liquid is discharged; A reciprocating pump in which a body closes a valve opening and a valve body of a discharge passage side opening / closing valve opens the valve opening against the urging force of a spring. 2. The reciprocating pump according to claim 1, wherein an on-off valve is provided in a plurality of stages in the suction flow path.

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