JPH0689745B2 - Submersible air driven pump - Google Patents

Description

Description: (a) Field of the Invention The present invention relates to a submerged air-driven pump used for transporting a corrosive liquid, which is used by immersing the pump itself in the liquid.

(B) Background of the Invention Conventionally, as an air-driven pump that is provided with a bellows driven by back pressure of air in a cylinder and sucks and discharges liquid by the reciprocating movement of the bellows, for example, Japanese Patent Publication No. 56-50116.
There is a pump disclosed in Japanese Utility Model Publication No. 61-29078.

In order to use the above-mentioned pump as a pump for corrosive liquids such as strongly acidic or strongly alkaline liquids, the liquid contact surface inside the pump, that is, bellows, cylinder inner wall,
It can be used theoretically by coating the inner wall of the pipe with a resin that has liquid resistance that can withstand the above liquids, or by forming the above components with a resin that has liquid resistance. Becomes

However, generally, resin has a larger stress relaxation than metal, and if the movable part of the pump body is made of resin or a resin coating member, the risk of leakage of the transport fluid increases.

In a conventional corrosive liquid transportation system that uses a non-corrosive pump, the pump body should be located at a distant location in order to prevent corrosion by volatile substances generated from the liquid storage unit as much as possible. In order to avoid contact between the pump and corrosive liquid, the transportation system must be configured.

As mentioned above, since the pump body has moving parts, there is the highest possibility of liquid leakage in the corrosive liquid transportation system, the risk of liquid leakage from the pump itself and the volatility from the liquid storage part. In order to avoid corrosion of metal parts outside the pump due to substances, it is possible to immerse the pump itself in the liquid if possible, and if possible, eliminate the risk of leaking corrosive liquid and improve system safety. Will be the best configuration to increase.

However, conventionally commonly used pumps have connecting members (pipe fittings) that connect pipes to the intake and discharge ports of the cylinder, cylinders and bellows, and bolts and nuts for assembling other accessory parts. Furthermore, there are metal parts around the pump for giving rigidity to the parts that make up the pump, and these metal parts have the above-mentioned strong acidity,
It has a problem that it becomes unusable because it is corroded by a corrosive liquid such as a strong alkaline.

(C) Purpose of the Invention The present invention is to form all of the submerged portion of the pump in a fluororesin, so that even if the pump is immersed in a corrosive liquid such as strong acidity or strong alkali It is an object of the present invention to provide a submerged air-driven pump that prevents the pump from becoming unusable due to corrosion of the components by the liquid.

(D) Summary of the Invention According to the present invention, a movable valve made of bellows driven by back pressure of air is provided in a cylinder, and a reciprocating motion of the movable valve sucks in and discharges liquid, which is a liquid for transporting corrosive liquid. A submersion air-driven pump, in which all of the parts that make up the submersion part of the pump are made of a single fluororesin such as PTFE, PFA, CTFE or a composite of these. Is characterized in that.

(E) Effect of the Invention According to the present invention, even when the pump itself is immersed in a corrosive liquid for use, all the parts constituting the internal and external submerged parts are resistant to strong acid and Since it is made of a fluorine resin having strong alkalinity, the liquid contact surface inside and outside of the pump is not attacked by the liquid. In particular, the pump does not become unusable due to corrosion from the liquid contact surface outside the pump, and good operation can be obtained as a pump that is immersed in a strongly acidic or strongly alkaline corrosive liquid for use.

As described above, in the pump of the present invention, since the pump itself is immersed in the corrosive liquid and used, the pump portion of the corrosive liquid to be transported from the pump portion of the corrosive liquid to be transported is used as in the case where the pump is installed outside the liquid storage portion and used. The risk of leakage is completely avoided and the safety of the entire liquid transport system is significantly improved.

Further, for example, in the IC manufacturing process, a strong chemical, a strong corrosive chemical of strong alkali is used in the processing chemical, and it is extremely disliked not only for fine dust but also for the elution of ions, but the pump of the present invention is Since all the constituent parts are made of a fluororesin, it also has an effect of suppressing the elution of ions and transporting and supplying the treatment chemical liquid without lowering the purity of the chemical liquid.

(F) Embodiment of the Invention One embodiment of the present invention will be described in detail below with reference to the drawings.

The drawing shows a submerged air-driven pump for transporting corrosive liquids. The pumps shown in FIGS. 1 and 2 are vertical pumps, and pumps 10a and 10b having the same structure are provided side by side. .

Explaining the structure of one pump 10a, from the upper surface side of the cylinder 11 whose outer shape is formed in a prismatic shape, toward the inside,
A cylindrical cylinder chamber 12 having a bottom is formed, a bellows 13 is inserted into the cylinder chamber 12, and a flange portion 14 formed at the base of the bellows 13 is brought into contact with a step portion 15 of the cylinder chamber 12. There is.

Housing whose tip is inserted inside the bellows 13 described above
A male screw 17 is engraved on the base of 16 and the cylinder chamber 12
Screw in the female screw 18 engraved on the upper end of the bellows 13
Is fixed to the cylinder chamber 12.

An air passage 19 for applying a back pressure to the bellows 13 is formed in the center of the housing 16 described above. In addition,
The outer end of the air passage 19 is connected to an air supply source through an appropriate pipe.

A suction passage 20 is formed in the center of the bottom of the cylinder chamber 12 described above, and a check valve 21 that allows the suction of liquid is inserted into the passage, and a valve seat 22 is screwed to the outside of the valve 21. ing.

Further, the discharge passage 23 is provided on one side of the bottom portion of the cylinder chamber 12 described above.
Is formed, and a check valve 24 that allows liquid to be ejected is also provided in this passage.

The pipe joints 26, 26 are screwed to the ends of the discharge passages 23 of the two pumps 10a, 10b configured as described above, and the pipe joints 26, 26 are connected to the pipe 27 to form one pipe joint. The discharge port 28 is formed.

Furthermore, the above-mentioned two pumps 10a and 10b have two connecting plates 29.
Are fixed to each other by bolts 30 and 30 so as to be integrated.

In the pumps 10a and 10b configured in this way, all of the components that make up the submerged portion are made of fluororesin, but in particular, the cylinder 11, the bellows 13, the housing 1
6, connecting plate 29, bolt 30 is made of PTFE resin, check valves 21, 24, valve seat 22, pipe joint 26, pipe 27 is P
Made of FA resin. However, CTFE resin may be used if necessary.

The pump configured as described above is provided with the air passage 1 of the housing 16.
An air source is connected to 9,19. One of the connected air is pressurized air and the other is vacuum, and these air sources are alternately controlled to be supplied.

That is, in FIG. 2, the left pump 10a has a vacuum connected to the air passage 19, and the right pump 10b also has a vacuum connection.
Shows the state in which pressurized air is connected, and by alternately switching the air source from these states, the bellows 13,13
Alternately repeats compression and extension to perform pumping motion.

When this pump is used by being immersed in a corrosive liquid such as strong acid or strong alkali, the liquid sucked from the suction passage 20 through the check valve 21 is expanded and contracted by the bellows 13 and 13 to discharge the liquid. 23, check valve 24, pipe 27
Through the discharge port 28.

FIG. 3 shows an air source switching control device for driving the above-mentioned pumps 10a, 10b, which is an electromagnetically operated 5-port 2-position switching valve.
In reference numeral 31, a pressurized air source is connected to the C port, and a vacuum source is connected to each of the V1 and V2 ports.

Further, the ports A and B are connected to the air passages 1 of the pumps 10a and 10b.
It is connected to 9,19 via filters 32,32.

Further, the left and right electromagnetic coils of the switching valve 31 are alternately switched and controlled by the timer circuit 33.

Therefore, in the pumps 10a and 10b, the switching valve 31 described above is switched and controlled by the timer circuit 33, so that the air passages 1
Pressurized air and vacuum are alternately supplied to 9,19,
The left and right bellows 13, 13 alternately repeat expansion and contraction to operate the pump.

FIG. 4 shows another example of the pump, which is also a submerged air driven type pump, which is a horizontal type pump.

Circular recesses 41, 41 are formed on the left and right side surfaces of the housing 40, which is formed in a quadrangular shape in the central portion.
The collar portions 43, 43 of the recesses 41, 41 are inserted and female threads 44, 44 are engraved on the inner peripheral surfaces of the recesses 41, 41, and male threads 46, 46 engraved on the inner ends of the cylinder cylinders 45, 45. Screwed together, bellows 4
The collar parts 43 and 43 of 2,42 are fixed.

A connecting rod 47 is slidably inserted in the central portion of the housing 40 described above, and bellows 42, 4 are provided at both ends of the connecting rod 47.
Two heads are connected.

The connection is such that when one bellows is in a suction state, the other bellows is in a discharge state.

Further, external housings 48, 48 each having a quadrangular outer shape are attached to the outer ends of the cylinder cylinders 45, 45, and cylindrical recesses are formed inside the external housings 48, 48. Internal threads 49, 49 are engraved on the inner wall, and male threads 50, 50 engraved on the outer ends of the cylinder cylinders 45, 45 described above.
Screwed together and connected together, and these elements 40,4
Cylinder chambers 51, 51 are formed in the left and right lateral directions by 5,48 to form two pumps 10a, 10b.

A suction passage 52 and a discharge passage 53 are formed in the left and right outer housings 48, 48 described above, and a check valve 54 and a valve seat 55 which permit the suction of the liquid are provided in the suction passage 52, and the discharge passage 53 is also provided. Also, check valves 56 that allow the discharge of the liquid are respectively provided.

Further, pipe joints 57, 57 are screwed into the left and right suction passages 52, 52, and a pipe 58 is connected to both pipe joints 57, 57 to form one suction port 59. Discharge passage 5
The pipe joints 60, 60 are also screwed onto 3,53, and one discharge port 62 is formed.

The central housing 40 is formed with air passages 63, 63 communicating with the left and right bellows 42, 42, and the air passages 63, 63 have air sources for pressurized air and vacuum, respectively. This air source also drives the pump by controlling the switching of the pressurized air and the vacuum alternately by a switching valve as shown in FIG.

Furthermore, in the above-mentioned pump, the housing 4 in the central portion is
0, bellows 42 cylinder cylinder 45, connecting pipe 47, outer housing 48 are made of PTFE resin, and check valves 54, 56, valve seat 55, pipe joints 57, 60, pipes 58, 61 are made of PFA resin. However, CTFE resin may be used if necessary.

In the present invention, since the pump itself is immersed in the corrosive liquid and used, the risk of leakage from the pump portion, which is the most leaky in the liquid transportation system, is completely avoided, and the safety of the entire liquid transportation system is improved. Is improved.

[Brief description of drawings]

 The drawings show one embodiment of the present invention. FIG. 1 is a plan view of a submersible air driven pump, FIG. 2 is a sectional view thereof, FIG. 3 is an air switching control circuit diagram, and FIG. FIG. 5 is a plan view showing another example, and FIG. 5 is a sectional view thereof. 10a, 10b ... Pump, 11 ... Cylinder 12, 51 ... Cylinder chamber 13, 42 ... Bellows 16, 40 ... Housing 19, 63 ... Air passage 20, 52 ... Suction passage 23, 53 ... Discharge passage 26, 57, 60 ... Pipe Fitting 27,58,61… Pipe 48… External housing

Claims (1)

[Claims] Claims: 1. A bellows movable valve driven by back pressure of air is provided in a cylinder, and reciprocating movement of the movable valve sucks in and discharges liquid, and a submersible air driven type for corrosive liquid transportation. An air-immersed submersible pump in which all of the parts constituting the submerged part of the pump are made of a single fluororesin such as PTFE, PFA, CTFE or a composite of these.