JP2538230B2 - Submersion type air driven pump - Google Patents

Description

Description: (a) Technical field to which the present invention pertains The present invention relates to, for example, a submerged air used by being immersed in a strongly corrosive chemical solution such as a strong acid or a strong alkali solution by being immersed in the solution. The present invention relates to a drive pump, and more specifically, to a submerged air drive pump that pumps a movable valve body such as a bellows or a diaphragm by reciprocatingly driving the back valve with air.

(B) Conventional technology Since most of the above liquid immersion type air driven pumps are used for transferring a strongly corrosive pharmaceutical liquid, as shown in FIG. 5, a pump main body 16 constituting the air driven pump 15, The bellows 17 installed inside the liquid suction chamber 16a of the pump body 16 and the liquid suction chamber 1
Each of the liquid contact members such as the housing 18 for fixing the bellows 17 by screwing to the 6a, or the liquid contact surface is formed of a fluororesin.

However, when the transfer pressure for transferring the chemical solution or the heat of the chemical solution due to the chemical reaction is applied to the liquid contact member, stress is relaxed in the screwed portion of the housing 18, and a gap is created at the joint surface between the bellows 17 and the housing 18. The sealing function deteriorates, and the O-ring 19 is fitted to the cylindrical portion 18a at the bottom of the housing 18 to seal the back pressure chamber 17a in the bellows 17.
9 also uses a material such as Kalrez that has corrosion resistance, so it has a larger compression creep than materials such as NBR (acrylonitrile butadiene rubber) and the problem that the sealing function deteriorates due to transfer pressure and heat. have.

Further, when the pump is used by being immersed in a chemical solution, stress is also relaxed in the threaded portion of the air tube 20 connected to the upper part of the housing 18, and the chemical solution outside the pump may penetrate into the back pressure chamber 17a. are doing.

Therefore, when the chemical liquid that has penetrated into the back pressure chamber 17a is sucked into the vacuum device through the air tube 20 together with the air in the back pressure chamber 17a, the metal part of the device is corroded and the drive system is damaged. However, there is a problem in that the pump operation is impaired.

(C) Problem to be Solved by the Invention The present invention is designed to weld a joint between a movable valve body and a housing, and weld a joint between a housing and an air tube. The formed back pressure chamber is completely sealed, liquid is surely prevented from penetrating into this back pressure chamber, and smooth pump operation is obtained.
By substituting the housing with the movable valve element welded to the pump body in a detachable manner, it is possible to achieve accurate welding workability and greatly improve maintainability. The purpose is to provide a drive pump.

(D) Structure of the Invention The present invention is a submerged air drive pump in which a movable valve body driven by back pressure of air is incorporated in a pump body, and liquid is sucked and discharged by reciprocating movement of the movable valve body. Each of the liquid contact members constituting the air driven pump is made of a fluororesin, and the movable valve body, the annular projection formed on the lower surface of the housing for fixing the movable valve body to the pump body, and the opening of the movable valve body. The flange part formed on the outer peripheral edge of the part is fitted, and the outer periphery of the flange part and the annular projection are welded in the circumferential direction, and the joint part of the housing and the air tube inserted into the housing is surrounded by the circumference. It is characterized in that it is an in-liquid submersible air drive pump that is welded in the same direction and the housing is detachably screwed and fixed in the pump body.

(E) Action When the present invention applies a back pressure to the movable valve body in the pump body to transfer the liquid, the movable valve body is provided in the back pressure chamber formed by joining the movable valve body and the housing. The liquid is transferred by the pump operation by preventing the liquid from permeating through the joint with the housing and by preventing the liquid outside the pump from permeating through the joint between the housing and the air tube.

(F) Effect of the Invention According to the present invention, the annular projection formed on the lower surface of the housing and the flange portion formed on the outer peripheral edge of the opening of the movable valve body are fitted to each other, and the outer periphery of the flange portion and the annular projection are formed. Since the back pressure chamber is completely sealed by welding in the circumferential direction, the relative minute movement between the annular projection and the collar portion of the two parts is restricted against air pressure and vibration of the movable valve body, Moreover, peeling of the welded part can be prevented, and liquid can be securely prevented from penetrating into the back pressure chamber.
The safety of the pump can be ensured, and at the same time, when the pump is immersed in the liquid and used, it can be surely prevented that the liquid outside the pump permeates into the back pressure chamber, and the predetermined transfer pressure Therefore, there is an effect that a liquid having a constant flow rate can be continuously transferred and a smooth pump operation can be performed.

In addition, the pump structure is strengthened by welding the joints of the respective members, and sufficient strength for transfer can be obtained even when the transfer pressure is high corresponding to the viscosity of the liquid, and the durability and transfer function of the pump can be improved. There is an effect that can be done.

Moreover, since the above-mentioned housing to which the movable valve body is welded is detachably screwed to the pump main body, each welding portion, that is, the welding portion between the housing and the air tube and the welding portion between the housing and the movable valve body are attached to the housing. The structure concentrates on the side.

As a result, it is possible to perform the welding work of each component independently of the housing side, which enables accurate welding work, reduces the occurrence of welding defects, and improves the welding workability. .

In addition, the movable valve body and the air tube are assembled to the above-mentioned housing, and the integrated housing is screwed to the pump body in a detachable manner. In the case of damage such as drilling, the unit on the housing side can be easily removed and replaced, which has the effect of greatly improving maintainability.

In particular, this type of submersion type air-driven pump for transporting a strongly corrosive chemical liquid is required to have maintainability, which is convenient for practical use.

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

The drawing shows a vertical air-driven pump having a pump of the same structure, and in FIG. 1, the air-driven pump 1 is provided on the left and right sides of a pump body 2 having a prismatic outer shape.
The liquid suction chambers 3,3 having a bottomed cylindrical shape are formed from the upper surface side of the pump main body 2 toward the inside, and bellows 4,4 as movable valve bodies are provided in the respective liquid suction chambers 3,3. , The housings 5 and 5 are detachably screwed and fixed to the upper openings of the liquid suction chambers 3 and 3, and the bellows 4 and 4 are fixed in the liquid suction chambers 3 and 3, respectively. The air tubes 6, 6 are inserted through the center of the structure.

A suction passage 3a for sucking the liquid is formed in the bottom of the liquid injection chamber 3, and the check valve 7 inserted into the suction passage 3a is retained by a valve seat 8 screwed into the suction passage 3a. At the same time, the check valve 7 and the valve seat 8 are brought into and out of contact with each other to allow only the suction of the liquid.

Further, a discharge passage 3b for discharging the liquid is formed on the upper side surface of the liquid suction chamber 3, and a check valve 7 inserted into the discharge passage 3b is provided with a valve seat 8 screwed into the passage.
The check valve 7 and the step portion in the discharge passage 3b are brought into contact with and separated from each other to allow only the liquid to be discharged.

In the bellows 4 described above, a cylindrical portion 5a vertically extending from the central portion of the lower surface of the housing 5 is inserted into the back pressure chamber 4a by a predetermined length, and the collar portion 4b formed on the outer peripheral edge of the opening of the bellows 4 is attached to the housing. 5, the bellows 4 and the housing 5 are brought into close contact with each other by fitting an annular projection 5b formed on the lower surface of the collar 5, and as shown in FIG.
The joint with 5b is welded in the circumferential direction and sealed.

In the housing 5, the male screw 5c formed on the large-diameter outer peripheral surface of the housing 5 is detachably screwed to the female screw 3d formed on the inner surface of the opening of the liquid suction chamber 3 of the pump body 2, and , The flange 4b of the bellows 4 to the step 3c of the liquid suction chamber 3
Is in contact with

Further, as shown in FIG. 3, in the above-mentioned housing 5, the air tube 6 is provided at the center of the cylindrical portion 5a vertically extending from the center of the threaded portion 5d projecting at the center of the upper surface. The outer peripheral edge of the tip of the air tube 6 and the inner peripheral edge of the cylindrical portion 5a are welded in the circumferential direction and sealed.

In the air tube 6 described above, the conical ferrule 9 inserted into the outer surface is fitted into the threaded portion 5d of the housing 5, and the union nut 10 is screwed into the threaded portion 5d.
The ferrule 9 is tightened so that it is in close contact with the outer peripheral surface of the air tube 6 and the conical surface of the threaded portion 5d.

In the air-driven pump 1 configured as described above, the liquid contact members such as the pump body 2, the bellows 4, the housing 5, and the valve seat 8 are made of PTFE resin (tetrafluoroethylene resin).
And the air tube 6 and the check valve 7
Is made of PFA resin (perfluoroalkoxy fluororesin). If necessary, PCTFE resin (polychloro 3
(Fluorinated ethylene resin) or the like, or only the liquid contact surface of the air-driven pump 1 may be resin-coated.

An air supply source is connected to each of the air tubes 6 and 6 of the air-driven pump 1. One of the air supply sources is pressurized air and the other is vacuum. Are alternately switched and supplied by the air switching device 11.

That is, as shown in FIG. 1, a state in which a vacuum source is connected to the right pump via the air tube 6 and a pressurized air source is connected to the left pump via the air tube 6. By alternately switching the air source from these states, the bellows 4 alternately repeats contraction and extension to perform pumping movement.

Then, the negative pressure in the liquid suction chamber 3 due to the contraction of the bellows 4 separates the check valve 7 from the valve seat 8 to suck the liquid from each suction passage 3a, and then to the back pressure chamber 4a of the bellows 4. A check valve 7 on the discharge side is supplied by supplying air to provide back pressure and pressurizing the liquid suction chamber 3 by expanding the bellows 4.
Is separated from the step portion of the discharge passage 3b to discharge the liquid from each discharge passage 3b.

FIG. 4 shows an electromagnetically-operated air switching device 11, which has a pressurized air source connected to the C port, V1, V
A vacuum source is connected to each port of 2.

The ports A and B are connected to the air tubes 6 and 6 via the filters 12 and 12, respectively.

Further, the left and right electromagnetic coils are alternately switched and controlled by the timer circuit 13.

Therefore, the above-mentioned air switching device 11 is switched and controlled by the timer circuit 13, so that the pressurized air source and the vacuum source are alternately connected to the respective air tubes 6 and 6, and the left and right bellows 4 and 4 are The expansion and contraction are alternately repeated to operate the pump.

When the air-driven pump 1 configured as described above is used for liquid transfer, the joint between the bellows 4 and the housing 5 is welded, the housing 5 and the air tube 6 are welded, and the back pressure chamber 4a is completely sealed. Therefore, the transfer liquid can be reliably prevented from penetrating into the back pressure chamber 4a.

Further, when the air-driven pump 1 is used by being immersed in the liquid, the liquid does not permeate through the insertion portion of the air tube 6, and a constant flow rate of the liquid is continuously applied at a predetermined transfer pressure. Can be transferred to, and a smooth pump operation can be obtained.

Furthermore, the welding of each member strengthens the pump structure, and the durability and transfer function of the pump can be improved.

Moreover, the housing 5 to which the above-mentioned bellows 4 is welded
Since the pump is detachably screwed to the pump body 2, each welded portion, that is, the welded portion between the housing 5 and the air tube 6 and the welded portion between the housing 5 and the bellows 4 are concentrated on the housing 5 side.

As a result, it is possible to perform the welding work of each component independently of only the housing 5 side, the accurate welding work becomes possible, the occurrence of welding defects is reduced, and the welding workability is improved. is there.

In addition, since the bellows 4 and the air tube 6 are assembled to the housing 5 and the housing 5 integrally formed as a unit is detachably screwed to the pump body 2, the bellows 4 which is the most easily damaged is formed. When a damage such as a hole is formed, the unit on the housing 5 side can be easily removed and replaced, and the maintainability can be greatly improved.

In particular, an air-driven pump of this type for transporting a strongly corrosive chemical liquid is required to have maintainability, which is practically convenient.

In the correspondence between the configuration of the present invention and the above-described embodiment, the movable valve element of the present invention corresponds to the bellows 4 of the embodiment, but the present invention is not limited to the configuration of the above-described embodiment. A diaphragm may be used instead of the bellows 4.

[Brief description of drawings]

The drawings show one embodiment of the present invention, FIG. 1 is a vertical sectional view of an air-driven pump, FIG. 2 is an enlarged sectional view showing a bellows welded portion, and FIG. 3 is an enlarged sectional view showing an air tube welded portion. FIG. 4 is a circuit diagram of the air switching device, and FIG. 5 is a vertical cross-sectional view of an air driven pump showing a conventional example. 1 ... Air driven pump, 2 ... Pump body 4 ... Bellows, 4b ... Collar part 5 ... Housing, 5b ... Annular protrusion 6 ... Air tube

Claims (2)

(57) [Claims] 1. A liquid immersion type in which a movable valve body (4) driven by a back pressure of air is incorporated in a pump body (2) and liquid is sucked and discharged by reciprocal movement of the movable valve body (4). An air-driven pump, wherein each liquid contact member constituting the air-driven pump (1) is made of a fluororesin, and the movable valve body (4) and the movable valve body (4) are provided in a pump body (2). The annular projection (5b) formed on the lower surface of the housing (5) fixed inside is fitted to the collar portion (4b) formed on the outer peripheral edge of the opening of the movable valve body (4), and the collar portion (4b) The outer periphery of the base and the annular projection (5b) are welded in the circumferential direction, and the joint between the housing (5) and the air tube (6) inserted into the housing (5) is welded in the circumferential direction, A submersion type air driven pump in which a housing (5) is detachably screwed and fixed in a pump body (2). 2. A liquid contact surface inside and outside the pump body (2) and a liquid contact surface of each liquid contact member are formed of a fluororesin. The submerged air-driven pump according to claim 1.