GB2249136A

GB2249136A - Pump intake filter and casing combination.

Info

Publication number: GB2249136A
Application number: GB9117051A
Authority: GB
Inventors: Niels Due Jensen; Kristian F Nielsen; Jens Bilgrav Bach
Original assignee: Grundfos International AS
Current assignee: Grundfos AS
Priority date: 1990-08-11
Filing date: 1991-08-07
Publication date: 1992-04-29
Anticipated expiration: 2011-08-07
Also published as: FR2665643A1; ITMI912050A0; ITMI912050A1; GB9117051D0; DE4025498A1; DE4025498C2; IT1250704B; FR2665643B1; GB2249136B

Description

22491 3j- INTAKE FILTER This invention relates to an intake filter for a

submersible pump, in particular for a fountain pump.

Submersible pumps are used, for example, for operating fountains, aerating ponds or evacuating water from cellars, ponds or the like. Examples of industrial uses of such submersible pumps include the emptying of excavations on construction sites, etc. In all these cases the assemblies have to convey a liquid, usually water, which has solids mixed in it, and these solids can clog the impeller passages or other parts of the pump. It is therefore necessary to provide pump assemblies of this type with a filter arranged in front of the pump intake of the assembly.

The efficiency of the pump assembly is often impaired to a not inconsiderable degree by the flow resistance created by such filters, which need to be sufficiently fine-meshed to arrest suspended matter. This effect becomes more pronounced in the course of time owing to the fact that the suspended particles sucked on to the filter cause it to become increasingly obstructed. Filters for suction pump assemblies therefore have to be cleaned at regular intervals, which is a laborious operation and hence costly if done by a professional and tedious for the private individual. Usually the job involves removing the filter casing releasably attachpd to the pump assembly and cleaning and, if necessary, replacing the filter block contained in the casing.

Taking this situation as its starting-point the invention sets out to provide an intake filter for a submersible pump designed to prevent, or at least slow down, the clogging of the filter, and to be capable of being cleaned quickly and easily if the need arises.

Accordingly, the present invent;ioh consists in an intake filter for a submersible pump,, in particular for a fountain pump, wherein the filter is a casing which completely encloses the pump assembly with the pressure line of the pump assembly passing through the casing.

By the design according to the invention, the filter surface area, or at least the intake surface area of the filter, is increased by, for example, ten to twenty times that of known filters. Because of this extremely large intake surface area, the rate of flow is slowed down considerably as it passes through the filter surface, so that, if only because of the reduced rate of flow, considerably smaller quantities of suspended matter are sucked in than in known filters of this type. The result is that the servicing period, that is to say the time interval after which the filter needs cleaning, is usually increased several times over. Thus the use of the filter according to the invention reduces the operating costs of the submersible pump assembly. Also, because the filter is external, that is to say it surrounds the pump assembly, it is readily accessible and is easily cleaned if the need arises. A further advantage lies in the fact that the pump assembly itself is mechanically protected by the surrounding filter, so that in the event of damage due to some external mechanical cause the relatively cheap casing will be damaged first, before the unit itself becomes involved. Hence the casing may, depending on its construction, also form a transport packing or at least part of a transport packing for the assembly, both saving packing costs and reducing the environmental problems which the packing would otherwise cause.

The casing advantageously comprises at least two part-casings which are releasably connected to one another. For the purposes of the invention 'Ireleasablyll does not mean that the two part-casings need to be physically separated from one another, but that the casing can be opened and re-closed for cleaning or for replacement of the pump assembly.

I The pump assembly can conveniently be fixed in position inside the casing with a gap between the pump and the casing so as to establish a defined position of the pump assembly with respect to the casing and thus to obtain a uniform rate of flow over the whole of the casing surface. If the intake filter is designed as a kind of pad filter, this gap between pump assembly and casing can be filled with the corresponding filter material, but it may also be intended to provide an unobstructed space so as to settle the flow within the casing.

The casing is advantageously constructed in one piece, with part-casings joined together by at least one elastic bridge piece and preferably capable of being locked together in a form-fitting positive manner. Such locking devices are sufficiently known from the relatively simple shell boxes or more complex kinds of packings. The onepiece construction of the f ilter casing has the advantage, besides its benefits in terms of production cost, that individual parts of the filter cannot be lost, making it particularly easy to handle.

The casing can then be conveniently made as an injection moulding of polymer material, the material being selected to suit the intended uses of the pump assembly.

The invention will be described by way of example with reference to the accompanying drawings, in which:- Figure 1 shows an end view, half in cross-section, of one embodiment of an intake filter with a submersible pump; Figure 2 shows a side view on arrow II in Figure 1; Figure 3 shows another embodiment of an intake filter in the same representation as Figure 1; and Figure 4 shows a further embodiment of an intake filter also in the same representation as Figure 1.

The intake filter illustrated in Figures 1 and 2 comprises a casing 1 which is made up of two half-casings 2 and 3 which are joined at one side by two spaced-apart i elastic bridges 4, and on the other side possess a positively locking device 5 by which the two half-casings 2 and 3 can be joined together as illustrated to form the casing 1.

The half-casings 2 and 3 together with the bridges 4 and locking device 5 are manufactured in one piece as an injection moulding of a thermoplastic material.

The pump assembly arranged inside the casing 1 is shown merely in simplified form as a cylinder 6. Practically any suitable pump assembly can be used, the casing being if necessary suitably adapted in its internal configuration so that the pump assembly 6 is held within the casing 1 with a gap around it. In the embodiment which is being described, this is achieved by means of retaining devices or shackles 7 which extend from the inside of the casing 1 and clasp the pump assembly 6 in a form-fitting manner.

The pressure or delivery connection of the pump assembly 6 is not shown in detail in the Figures. The pressure or delivery nozzle of the pump by which the pump is connected to the pressure or delivery line is located in a casing nozzle 8 on the casing 1 through which the electrical supply lead can also be led into the casing 1. In the illustrated embodiment the supply lead is led through a cut-out 12 in the end face of the casing 1, located in the parting plane 13.

The casing 1 illustrated in Figures 1 and 2, which forms the filter for the pump assembly 6, is of essentially cylindrical designe with numerous slots 9 provided in its circumferential and end faces, through which the liquid for pumping passes on its way to the pump assembly 6. The slots 9 may-be designed like those of a strainer, or other suitable passageways can be provided in the casing.l. It is also possible to provide a fabric of suitable mesh size as a jacket for the casing 1 and a covering for the slots 9. The region between the casing 1 and the pump assembly 6 I 1 can also be filled with a suitable filter material, according to the requirement.

The casing 1 is designed as a carrying-case so that it can simultaneously serve as a packing; it has four feet 10 and a carrying-handle 11, and is otherwise of an essentially cylindrical shape.

Figures 3 and 4 show similar intake filters with other configurations and elements whose functions correspond to elements described above with reference to Figures 1 and 2 are identified by the same reference numbers but with different reference letters, for example an "all in the embodiment shown in Figure 3 and a 11b11 in the embodiment shown in Figure 4.

Claims

1. Intake filter for a submersible pump, in particular for a fountain pump, wherein the filter is a casing which completely encloses the pump assembly with the pressure line of the pump assembly passing through the casing.

2. Intake filter as claimed in Claim 1, wherein the casing comprises at least two part-casings which are releasably connected to each other.

3. Intake filter as claimed in Claim 1 or 2, wherein the pump assembly is fixed in position inside the casing with a gap between the pump and the casing.

4. Intake filter as claimed in Claim 1, 2 or 3, wherein the casing is constructed in one piece, with partcasings joined together by at least one elastic bridge piece and capable of being fastened with a positive lock.

5. Intake filter substantially as herein described with reference to Figures 1 and 2 or Figure 3 or Figure 4 of the accompanying drawings.

5. Intake filter as claimed in any one of the preceding Claims, wherein the casing is made of a polymer material and is formed as an injection moulding.

6. Intake filter substantially as herein described with reference to Figures 1 and 2 or Figure 3 or Figure 4 of the accompanying drawings.

1 107 - Amendments to the claims have been filed as follows 1. Intake filter for a submersible pump, in particular for a fountain pump, the filter consisting of a casing which completely encloses the pump assembly and secures the pump assembly in the casing with the pressure line of the pump assembly passing through the casing, wherein the casing comprises at least two part-casings which are re leasably connected to each other and the pressure line is located in the parting plane of the casing.

2. Intake filter as claimed in Claim 1, wherein the pump assembly is secured inside the casing so as to provide a gap between the pump and the casing.

3. Intake filter as claimed in Claim 1 or 2, wherein the casing is constructed in one piece, with the part casings being joined together by at least one elastic bridge piece and capable of being fastened with a positive lock.

4. Intake filter as claimed in any one of the preced ing Claims, wherein the casing is made of a polymer materi al and is formed as an injection moulding.