JP3133067B2 - Multilayer diaphragm with leak outlet for diaphragm pump - Google Patents

Abstract

A multi-layered diaphragm with leakage offtake for diaphragm pumps, in particular hydraulic pumps, has at least two superposed individual diaphragms (1, 2) fixed to a rotating clamping site. A space (10) is located between adjacent individual diaphragms (1, 2). At least one space (10) contains at least one fold-free and force-free layer (9) made of a nonwoven, knitted, or woven hard-filament fabric which follows the deformation of the individual diaphragms. When under pressure, this layer (9) is also permeable to liquid. The space (10) containing this (these) layer(s) is connected, in the region of the clamping site, to a leakage offtake (12, 13) surrounded by a housing. The layer (9) can, however, also consist of a fibre reinforcement consisting of a nonwoven, knitted, or woven hard-filament fabric which projects from the diaphragm surface facing the adjacent individual diaphragm. A combination of these types of layers is also possible.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises at least two individual diaphragms mounted on each other and fixed to a circling holding point,
An intermediate space is provided between the individual diaphragms,
The present invention relates to a multilayer diaphragm with a leak discharge for a diaphragm pump, in particular for a pump subjected to hydraulic pressure.

An advantage of this type of diaphragm is that if the diaphragm breaks, the diaphragm can be alerted before the working medium comes into contact with the transport medium. In particular, when using a pump that is affected by hydraulic pressure, it is extremely important for the user to notify the user of the diaphragm damage so that the entire pump unit does not stop when the diaphragm is damaged. In this case, the mixture of the transport medium and the hydraulic medium caused by the breakage of the diaphragm is:
Most often leads to the worst failure.

In a known multilayer diaphragm (U.S. Pat. No. 3,316,638), at least three multiple diaphragms are stacked. The central diaphragm is perforated and has a plurality of radially outwardly extending slits. One or some of the plurality of slits communicate with the periphery. If one of the two outer diaphragms in contact with the carrier or hydraulic medium breaks, the medium passing through the break is guided outwardly along the radial slit of the central diaphragm to provide appropriate monitoring and control. It is supplied to the notification device. Diaphragms that are superimposed on one another must be connected to one another by gluing in order to function as one diaphragm as a whole. However, this adhesive connection is subject to considerable shear forces during the operation of the pump, especially at high pressures, so that the load on the diaphragm during the suction stroke is very unfavorable, thus significantly impairing the operating stability of the pump. Also, increasing the rigidity must be considered.

Other known multilayer diaphragms (German Patent No. 1800)
No. 018), there are also provided three individual diaphragms overlapping each other. However, these individual diaphragms are not glued and are hydraulically connected by a hydraulic medium that completely fills the slits in the central diaphragm. This type of hydraulic connection is satisfactory even in the high pressure range when the diaphragm is a flat plate made of a relatively hard material, but the stroke of the diaphragm is very small. In the case of a diaphragm made of an elastomer, a problem arises at the sandwiching point of the diaphragm layer having the slit. This is because, in order to seal the diaphragm from the outside, a relatively large surface pressure in the high pressure range is required at the clamping portion. However, when the surface pressure is large, the slit of the central diaphragm is deformed, and the leaked liquid cannot be discharged through the closed slit.

In other known multilayer diaphragms (German Patent No. 3146)
No. 222), a porous intermediate layer is provided between the individual diaphragms to allow liquid to pass in the radial and axial directions. These intermediate layers are formed, for example, from wool. Such a relatively soft porous intermediate layer loses its porosity as the surface pressure increases, ie in the high pressure range.

The object of the present invention is to provide a multilayer diaphragm of the type mentioned at the outset in the following way: the discharge of leakage from the intermediate space of the multilayer diaphragm can be achieved by simple means, while at the same time ensuring a stable operation. Is to provide a multi-layer diaphragm that does not impair.

In this case, it is configured so that even the high-viscosity medium can pass through the intermediate space of the multilayer diaphragm even in the low-pressure range and the high-pressure range, so that the transporting medium or the hydraulic medium that enters between the layers of the diaphragm when the diaphragm is damaged is reduced. It is another object of the present invention to configure a multilayer diaphragm so as to flow out from the periphery of the diaphragm and to perform leakage monitoring or leakage notification.

The object of the present invention is to provide, according to the invention, in a multilayer diaphragm of the type mentioned at the outset, at least one intermediate space comprising at least one layer which follows the deformation of the individual diaphragm and allows the liquid to permeate even under pressure. , This layer consists of hard filaments, non-woven fabrics, knitted products, knitted goods,
Alternatively, the problem is solved by the fact that the intermediate space provided with the layer is in the region of the clamping point in communication with the leak discharge housed in the surrounding casing.

The materials used in the present invention (eg, metals or ceramics or plastics) can be loaded with almost any surface pressure and do not lose their porosity. As a result, even in the case of high pressure and high viscosity, leak notification from one or a plurality of intermediate spaces can be reliably and promptly made to the outside through the fastening area of the individual diaphragm.

According to the invention, the multilayer diaphragm can be configured such that the at least one layer is a multiaxial or multidirectional nonwoven, knitted product, knit or textile. The use of such a material allows the relatively thick layer to operate flexibly without wrinkling.

According to the invention, the multilayer diaphragm has at least one
It can be configured such that one layer is configured as a mesh product. This allows the layers to be advantageously adapted inexpensively to the curvature of the individual diaphragms.

According to the invention, the multilayer diaphragm has at least one
It can be configured such that one layer is configured as a polyamide mesh product. The hardness of the polyamide is chosen such that the layer allows the passage of liquid even at high pressures.
Even in this configuration, the layers are very inexpensive components.

According to the invention, the multilayer diaphragm has at least one
One layer is formed by fiber reinforcements made of non-woven, knitted, knitted or woven fabrics of hard filaments, the fiber reinforcements facing each other of the two superposed individual diaphragms It is configured to be arranged in.

When the elastomeric diaphragm is reinforced with a fabric, the reinforcement of the fabric reaches inside the diaphragm. However, in this configuration according to the invention, the plastic fabric,
For example, a plastic woven fabric made of polyester or polyamide is used as coarsely woven as possible. As a result, some of the fibers of the fabric are located outside the rubbery base material of the diaphragm. The fabric facilitates drainage of leaking liquid that accumulates between the layers of the diaphragm if the diaphragm breaks. The tissue structure of the fabric is sufficient to drain the leakage liquid, especially if the transport medium and the hydraulic medium are of low viscosity and not very high pressure. On the other hand, the fabric
It is also possible to use with layers made of nonwovens, knitted goods, knits or fabrics. In this case, the sliding becomes particularly good.

According to the invention, the multilayer diaphragm has at least one
One layer can be configured as a separate intermediate layer formed between two overlying individual diaphragms. In this case, the layer thickness and the material are adapted to the respective requirements. It is expedient to use the layer forming one such separate intermediate layer in combination with the layer formed by the reinforcement.

According to the present invention, the multi-layer diaphragm is filled in the intermediate space with a liquid that is inert to the conveying medium and the hydraulic medium, and the liquid transmits a leak notification to the outside by hydraulic pressure when the diaphragm is broken. Can be configured. Such an inert liquid in communication with the surroundings outside the pump casing allows for a quick response when the diaphragm breaks, thereby providing a leak alert long before the entire diaphragm becomes unsealed. .

According to the invention, the multi-layer diaphragm is a molded diaphragm made of elastomer, in which the individual diaphragms are mechanically connected to one another, for example via two diaphragm disks secured by screw connections. It can be configured as follows. In the case of a planar diaphragm, the stroke of the pump is effected by the diaphragm expanding in one direction and the other. Through repeated expansion, both the diaphragm and the fabric reinforcement are constantly exposed to internal stress. As a result, the diaphragm and the fabric reinforcement are more prone to tearing in the area of maximum stress, ie in the middle of the diaphragm. The life of such planar diaphragms is therefore short and must be replaced frequently. Another disadvantage of planar diaphragms is that they cannot be broken with plastics that can withstand high chemical loads, such as PTFE, due to their high internal stress. This is because the plastic cannot follow the expansion and separates from the elastomer.

If the diaphragm is already bent and manufactured in the manufacturing stage and clamped in this state, the stroke movement of the diaphragm is carried out by slack or rolling movement, and the internal stress is minimized. The diaphragm does not expand or hardly expands during this step.
Thus, a much longer life is obtained than with a PTFE coating.

The mechanical connection of a plurality of individual diaphragms is a particularly simple structural measure. Further, if one diaphragm disk is vulcanized to the diaphragm layer on the side of the transport medium and the other diaphragm disk fixes the two diaphragm layers via the screw connection, the mechanical connection will not leak. Not completely sealed.

According to the invention, the multilayer diaphragm is such that the individual diaphragms have, at their outer edges, respective round-ring-shaped ridges, which ridges are correspondingly fixed in orbiting grooves provided in the casing. Can be configured. The clamping points of the multilayer diaphragm are used, on the one hand, for centering and fixing the individual diaphragms, but on the other hand, the transport and hydraulic media must be sealed off to the outside. The simplest way of clamping the diaphragm in a sealed manner is based on the principle of a round packing ring having a semicircular or triangular cross section. For this purpose, a round ring-shaped protuberance is provided on the outer periphery of the individual diaphragm, and the holding point provided on the casing is configured as a correspondingly formed groove.

According to the present invention, the multilayer diaphragm can be configured such that the orbiting groove communicates with the outer periphery of the casing. Most simply, if a leak occurs, it can be visually detected by optical monitoring from outside the pump casing to enable monitoring of the leak.

According to the present invention, the multilayer diaphragm is configured such that the orbiting groove communicates with a hole provided in the casing so as to communicate with the outer periphery of the casing, and the leak notification device is housed in the hole. be able to. According to this configuration, the leak is automatically detected, for example, by an electronic evaluation of the liquid sensor.

According to the invention, the multilayer diaphragm can be configured such that the leak notification device is a pressure sensor or a pressure-sensitive switch. Basically, the leak notification may be performed continuously using a pressure sensor, or may be performed discontinuously using a pressure sensitive switch. The advantage of using a pressure sensor is that it can detect the gradual breakage of the diaphragm due to slowly rising pressure. The pressure sensitive switch is the cheapest automatic alerting device, but has the disadvantage that it can only be set to a fixed value such that leak notification can be made without warning.

Next, two embodiments of the multilayer diaphragm according to the present invention will be described with reference to the accompanying drawings.

The attached drawing is a longitudinal sectional view of the diaphragm pump. The diaphragm has a multilayer diaphragm consisting of two individual diaphragms 1,2. The multilayer diaphragm is sandwiched between casing parts 3 and 4. Both individual diaphragms 1 and 2 have two diaphragm disks 5 and 6
And a screw connection part, and are mechanically pinched. Each of the individual diaphragms 1 and 2 has, at its outer edge, a protruding portion 7 or 8 in the shape of a circular ring having a triangular cross section. The layer 9 which allows the liquid to pass through even under pressure makes the intermediate space 10 between the individual diaphragms 1 and 2 communicate with the grooves 11 provided in the casing parts 3,4. The layer 9 is embodied as a knitted fabric in the first embodiment and is located as a piece between the individual diaphragms 1 and 2. Layer 9 consists of 6.6 type of woven polyamide filament yarn. The groove 11 communicates through a hole 12 around the outside of the casing parts 3,4.
Hole 13 is provided for receiving a pressure sensor or pressure sensitive switch (not shown).

According to a second embodiment, the layer 9 is a textile reinforcement (Gewebevers
trkung). The fabric reinforcement is located on the facing surfaces of the two individual diaphragms. Therefore, the textile part (Texturieru
ng).

Two separate diaphragms 1, defining an intermediate space 10,
Such two textile parts may be provided on both surfaces facing each other.

The layer structures described above between the individual diaphragms adjacent to one another may be used in combination with one another according to the respective conditions, in particular according to the conditions relating to pressure and viscosity.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-206378 (JP, A) JP-A-49-34001 (JP, A) JP-A-1-200078 (JP, A) JP-A-49-49 4806 (JP, A) JP-A 53-69805 (JP, U) Patent 113002 (JP, C2) West German Patent Application Publication 2620228 (DE, A1) West German Patent Application Publication 3522711 (DE, A1) (58) Search Field (Int.Cl. ⁷ , DB name) F04B 43/02

Claims (12)

(57) [Claims] 1. At least two individual diaphragms, which are fixed to each other and are located around each other and are orbiting, are provided.
An intermediate space is provided between the individual diaphragms,
In a multilayer diaphragm with a leak discharge for a diaphragm pump, at least one intermediate space (10) follows the deformation of the individual diaphragms (1,2) and at least one layer (10) that is permeable to liquids even under pressure. 9), wherein this layer (9) comprises hard filaments, knitted goods, knits,
Or an intermediate space (10) provided with said layer (9) in the area of the clamping point in the area of the leakage discharge (11,12, 13) A multilayer diaphragm characterized by being in communication with 2. The method according to claim 1, wherein the at least one layer is multiaxial.
The multilayer diaphragm according to claim 1, wherein the multilayer diaphragm is formed from a multidirectional nonwoven fabric, a knit product, a knit, or a woven fabric. 3. The multilayer diaphragm according to claim 1, wherein at least one of the layers is constructed as a mesh product. 4. Multilayer diaphragm according to claim 3, wherein at least one layer (9) is constructed as a polyamide mesh product. 5. At least one layer (9) is formed by a fiber reinforcement made of a non-woven, knitted, knitted or woven fabric of hard filaments, said fiber reinforcement being superposed. 5. The multilayer diaphragm according to claim 1, wherein the multilayer diaphragm is arranged on mutually facing surfaces of two individual diaphragms. 6. The method according to claim 1, wherein the at least one layer is formed as a separate intermediate layer between two superposed individual diaphragms. A multilayer diaphragm according to any one of the preceding claims. 7. The intermediate space (10) is filled with a liquid which is inert with respect to the conveying medium and the hydraulic medium, and the liquid transmits a leak notification to the outside by hydraulic pressure when the diaphragm is damaged. The multilayer diaphragm according to any one of claims 1 to 6, wherein: 8. Two diaphragm disks (5, 6), wherein individual diaphragms (1, 2) are fixed by screw connections.
8. The multilayer diaphragm as claimed in claim 1, wherein the diaphragm is a spherically shaped, elastomeric diaphragm which is mechanically connected to one another by way of a diaphragm. 9. The individual diaphragm (1, 2) has, at its outer edge, a round ring-shaped ridge (7, 8), said ridge (7, 8) correspondingly corresponding to the casing (3, 8). The multilayer diaphragm according to any one of claims 1 to 8, wherein the multilayer diaphragm is fixed to a circumferential groove (11) provided in (4). The orbiting groove (11) is provided in the casing (3, 3).
4) The multilayer diaphragm according to claim 9, wherein the multilayer diaphragm is in communication with an outer periphery. The orbiting groove (11) is provided in the casing (3, 3).
4) The device is characterized in that it communicates with a hole (13) provided in the casing (3, 4) so as to communicate with the outside periphery, and the leak notification device is housed in the hole (13). Item 14. The multilayer diaphragm according to item 10. 12. The multilayer diaphragm according to claim 11, wherein the leak notification device is a pressure sensor or a pressure sensitive switch.