DE3347444A1 - Plastic well filter pipe - Google Patents

Abstract

Plastic well filter pipes have a slitting, which runs either parallel or at an angle to the filter axis (pipe axis). It is rectilinear and longer - usually also wider - on the outside then on the inside, because it is made by a circular-saw cut. In contrast to this conventional form, the invention envisages slits which run in a zig-zag or wave form (Fig. 2-h) and are longer (Fig. 2-m/n) and wider (Fig. 2-k/l) on the inside then on the outside, which is made possible by production in injection moulds. <IMAGE>

Description

RUDOLF BARAINSKY Ringstrasse 5

4973 Ulotho

December 23, 1983

Well filter pipe made of plastic

Well filter tubes are usually made of plastic from extruded tubes - preferably PUC -, which after their production in separate operations Cut to length, provided with sleeves and these in turn with threads. The opposite of the threaded socket The end is usually provided with an external thread that matches the socket thread. The for use of the pipe as a well filter pipe, however, the decisive processing is the slitting with a circular saw or Disc. These slots, usually cut at an angle of 90 ° to the pipe axis, must have a certain open area in relation to the total area of the filter (according to DIiM). By sawing in with a circular saw blade or Circular disk, however, creates disadvantages which are evident in that the slots in the interior of the tube are always shorter than outside, although the reverse state would be preferable for reasons of flow behavior, In addition, the width of the slots corresponds to the thickness of the saw blade, ideally inside and outside the same distance, but usually even further on the outside than on the inside. This leads to the fact that z. B. grains of sand, the one hand because of their small size, easily pass through the slot in one dimension, and the other Gradually clog the slot as the grain rotates during its passage, so that another, larger dimension of the grain, exceeding the slot width, becomes effective when there is an elongated grain erects during the passage and jammed in the slot.

Such filter tubes are also known which have longitudinal ribs on their outside, whereby the outer slot length is increased.

The present invention solves the problem of overcoming the above deficiencies and drastically enlarging the open area, especially inside, as well as increasing the slot width from the outside to the inside by not making the slots with the saw or the like naturally results in straight cuts, but because the slots run in a zigzag, which can be achieved in the manufacture of the filter in a mold (injection mold). Due to the zigzag course of the slots, a considerable increase in the effective slot length is achieved while the pipe diameter remains the same. A zigzag run of the slot with BD ⁰ upwards and 60 ° downwards, for example, results in a doubling of the effective slot length. This ensures that the inflow rate per unit length of the tube increases accordingly, so that a much shorter filter tube of the new design, which is only half as long as in the above example, is required for the same throughput.

The production of the pipes in casting molds (injection molds) also enables the slots in the pipe interior to keep going longer and at the same time than outside. This not only improves the flow behavior, it also reduces the risk of clogging the filters.

33474U

Figure 1 shows the previous version shown, and it means:

a = filter tube

b = inner slot length (shorter than outer) c = outer slot length

d = Rohrujand thickness

e = Schlitziueite (inside and outside the same) f = saw blade

Figure 2 shows the embodiment according to the invention; in which + means:

g = wall of the filter tube shown in development h = zigzag slot

i = section through the pipe wall with a slot k = outside slit

1 = slot width inside (larger than outside) m = outer slot length

η = inner slot length (longer than outer) ο = pipe edge thickness

In addition to this design the well filter can the pipe is ripped in such a way that that not only on the outside, but also on the inside of the tube, ribs with a preferably triangular or rounded cross-section run that they cross the slots, so in the case of the zigzag slot preferably also running in a zigzag .

Claims (11)

334W4 claims 1. Well filter tube, preferably made of plastic, characterized in that the filter slots run in a zigzag. 2. Well filter tube, preferably made of plastic, characterized in that ribs inside the tube are present which cross the slots. 3. Well filter tube according to claim 1 and 2, characterized in that the zigzag Slits are crossed by outer ribs, which also run in a zigzag. 4. Well filter tube according to claim 1 and 2, characterized in that the outer ribs in per se as is known, running parallel to the pipe axis, crossing the zigzag slots. 5. Well filter tube according to claim 1 and 2, characterized characterized in that the outer ribs running in the circumferential direction of the tube, the zigzag slots cross. B. well filter pipe according to claim 1, characterized in that that the slots are wavy. 7. Well filter tube according to claim 1 to B, characterized in that the ribs are undulating. 8. Well filter tube according to claim 1 to 7, characterized characterized in that the ribs have an angular cross-section. 9. Well filter tube according to claim T to 7, characterized characterized in that the ribs have a rounded cross-section. 10. Well filter tube according to claim 1 to 9, characterized characterized in that the Schlitzujeite increases inward. 11. Well filter tube according to claim 1 to 10, characterized in that it is produced in injection molds are.