DE2421487A1 - DIAPHRAGM PUMP - Google Patents

Description

Diaphragm pump
(Priority: May 24, 1973, USA, Fr. 363 642)

The invention relates to a diaphragm pump.

Diaphragm pumps are widely used for metering flowable Materials used in processes. They also serve for promotion Corrosive or abrasive materials that are separated from the moving parts of the pump by the diaphragm.

An example of a diaphragm pump is described in US Pat. No. 3,551,076. This pump contains a hydraulically reciprocating membrane, which in turn drives a tubular membrane through which the material is pumped. This membrane consists of a flexible tube with a cylindrical shape and a uniform diameter. However, this pump does not have optimal efficiency. It also has the disadvantage that the wall loads are relatively are high and therefore fatigue of the material occurs relatively quickly.

AO9885 / 0340

-Λ.

The invention is based on the object of creating a diaphragm pump whose diaphragm has the most effective shape possible and where the wall loads are as low as possible.

According to the invention, this object is achieved in that the tubular or tubular membrane has an elliptical shape. the elliptical shape has various advantages over the known circular shape. It better approaches a flat one Membrane, which is the most effective form. At a certain size and displacement, the elliptical tube becomes less deflected than a circular one. Therefore, the wall stresses are reduced and the service life is increased. Furthermore is in the case of the elliptical hose the direction of deflection of the wall is predetermined, while the circular hose in the direction of the the weakest part of the wall is deflected. The direction of deflection is therefore indefinite in the case of circular hoses.

The elliptical tube is almost completely unidirectional deflected inwards. In contrast, the circular hose is inwardly in one plane and inward in the opposite plane deflected outside. This has the consequence that with circular hoses relatively larger housings are necessary so that he can Cannot touch the housing wall. Finally, the elliptical tube can inflate outward relatively easily when he gets out of step with the butt. The circular tube resists inflation under certain circumstances.

Preferably, the tubular membrane has circular end cross-sections, which makes it easier to attach the membrane to the membrane head will. Although the elliptical shape has many advantages, it is disadvantageous that an elliptically shaped hose is difficult to be attached to the membrane head and to be sealed against it. Therefore, according to the invention, a gentler or smooth transition from elliptical. Middle section to the circular sections provided at both ends of the hose.

409885/0348

Based on the embodiment shown in the drawing the invention is explained in more detail below. Show it:

1 shows the cross section of a pump;

Fig. 2 is the partially sectioned plan view of the end of the Pump;

3 shows the partially sectioned plan view from above; 4 shows the cross section of the elliptical tube membrane; Fig. 5 shows the cross section 5-5 of Fig. 4; 6 shows the plan view of the membrane from above; and Fig. 7 is a view of the end of the membrane.

The diaphragm pump shown in Figs. ■ 1 to 3 contains a back and movable piston 10 driven by an engine not shown is driven. A main flat disc diaphragm 12 becomes hydraulic bent between support blocks 14 and 16. The support blocks 14 and 16 limit the range of movement of the membrane. the flat disc membrane 12 is as small as possible and allows on the other hand the maximum displacement required without being subjected to excessive stresses during elongation. The profile the support blocks 14 and 16 must have a slightly larger displacement allow, als'der piston can reach, so that the pump during operations cannot be relieved.

The driving or control fluid connects the piston 10 with the one side of the flat membrane 12. The propellant liquid is through an oil refill valve, not shown, added. During the refilling, a safety valve 18 and a vent valve. 20 required.

During the exhaust stroke, the support block 16 limits and carries the flat Membrane 12 so that it cannot be overstretched and tear. If the outlet pressure exceeds the permissible pressure of the system, the safety valve 18 opens to protect the components of the pump.

409885/0348

242U87 -4-

During the suction stroke, the support block 14 limits and carries the flat membrane 12 so that it cannot be overstretched and tear. Exceeds the negative pressure is the pressure set on the oil-I refill valve, so this opens and the oil can enter the Yerschiebungskammer, so that oil losses, for example at the piston seal or replaced on the vent valve.

A tubular or hose-shaped membrane 22 is in the membrane head housing 24 attached, which forms an intermediate chamber surrounding the hose membrane 22. For filling and refilling the intermediate chamber a filling plug 26 and a drain plug 28 are used for propellant liquid which is compatible with the liquid to be conveyed. Water or other liquids compatible with the liquid to be pumped are suitable as the intermediate driving liquid.

The flexible hose membrane forms a channel for the material to be pumped. The material enters and exits through inlet 30 the pump through an outlet 32. Ball check valves 34 and 36, respectively, are arranged at the inlet and outlet, which the material- only allow flow through the hose membrane in one direction.

The hose meiabran 22 is shown in detail in FIGS. It includes an elliptical central section 38 and circular End sections 40 and 42. The middle section and the end sections, are connected to one another by smooth transition areas 44 and 46, respectively.

The pump works as follows. First, the membranes 12 and 22 are synchronized so that the hose membrane 22 is completely relaxed when the disk membrane 12 rests on the support block 14. This allows the full deflection of both membranes to be used with minimal stress on the tubular membrane 22 there is no danger of it collapsing in the full stroke position .

409885/0348

The propellant fluid is enclosed in the membrane head housing 24 Zwischenkainmer acts as a hydraulic coupling between the disc membrane 12 and the hose membrane 22. During the exhaust or working stroke the pump pushes the piston 10 the flat membrane 12 outward. This, in turn, causes the hose membrane 22 to be bent inwards, so that their cross-section is reduced. During the suction stroke is the direction of displacement reversed so that the tubular membrane 22 returns to its normal relaxed shape. Work on both membranes If the filling is correct, synchronously with one another, the wide walls of the tubular membrane only bend inward from their relaxed state. Because of the elliptical shape of the diaphragm 22, it will surely return to the relaxed elliptical shape.

The process liquid flows through the hose membrane 22 vertically up. With the help of the ball check valves 34 and 36, the Liquid can be pumped with each piston stroke in the same way as with a normal diaphragm pump.

Die.Schlauchmembran 22 can be made of any elastomeric material exist, which is resistant to the liquid to be pumped and has a high flexural strength. Such materials are including nitrile butadiene, chlorosulfonated polyethylene and Fluoroelastomers. The flat membrane 12 is made of molded urethane or a similar, just as tough, strong and flexurally resistant material. This is an elastomeric material that is chosen to be of displacement stretches. The membrane 12 can therefore be rigidly clamped at its edges will. In other known positive displacement pumps, a flexible, but more rigid material is used for the main diaphragm, that is chemically compatible with the fluid being pumped. Therefore, flat membranes with a larger diameter must be used, this material cold flowing during bending. The elastomeric disk membrane of the invention is smaller, more flexible, and has better sealing properties, with no cold flow occurring.

Claims 409885/0348

Claims (1)

PATTERN EXPRESSIONS .) Diaphragm pump, characterized by having a back and forth movable piston (10), through a main diaphragm (12), through a displacement chamber which is filled with a propellant fluid coupling the piston to one side of the main diaphragm is through a diaphragm head (24) which delimits an intermediate chamber and which is filled with propellant liquid, which the the other side of the main membrane couples with the intermediate chamber, and by a flexible one arranged in the intermediate chamber Hose membrane (22) * which forms a channel through the intermediate chamber for the material to be pumped, with a central section (38) the tube membrane has an elliptical cross-section in the undeformed state and in the case of one through the piston via the propellant liquid applied force is deformed inward and will certainly return to the undeformed elliptical shape. 2. Diaphragm pump according to claim 1, characterized in that that the hose membrane has two end portions (40, 42) with a circular cross-section, the attachment of the Lighten the membrane on the membrane head (24). J. Diaphragm pump according to claim 1, characterized in that that the main membrane (12) is flat and made of a during the displacement is made of stretchable material. 409885/0348 4. Diaphragm pump according to claim 3, characterized by a rigid seal for the edges of the flat membrane - (12). 5. Diaphragm pump according to claim 1, characterized by VentileiTirrichtungen (34, 36) for limiting the to be pumped Material through the hose membrane (22) on a predetermined flow direction. 6. Membrane pump according to claim 1, characterized by support blocks (14, 16), diarch which the main membrane (12) is held during the strokes of the piston (10). 409885/0348 Le e rs e ite