DE1270533B - Screw filter press - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY GERMAN jßßWWl · PATENT OFFICE

EDITORIAL

Int. CL:

Number:
File number:
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BOId

German class: 12d-13

P 12 70 533.8-27
January 7, 1965
June 20, 1968

The invention relates to a screw filter press, its outer fixed cylindrical jacket as well an inner filter surface that rotates with the screw for dewatering a suspension a drain for the filtrates are provided, the solid residues through a closed one at the end Channel progressively smaller cross-section promoted and compressed against the discharge will.

In a known device of this type! Approximate shape is a vertically arranged, upwardly tapering screw provided in a cylindrical housing of constant internal diameter. One that rotates helically around the rotor The rib forms the individual screw flights, the pitch of which decreases in the conveying direction. At the foot the screw threads are provided with openings for drainage. The inner cylindrical surface of the The housing surrounding the screw body is also designed as a filter.

The suspension introduced into the device from above is carried by the individual screw flights added and conveyed down through the device. It is due to the increasing Screw diameter and the decreasing pitch exposed to a pressing pressure. The thereby The excreted liquid passes through the bores in the foot of the screw threads or through the filter jacket of the housing.

The main disadvantage of this known embodiment is to be seen in the fact that only a certain and always the same proportion of the suspension to be dewatered in direct contact with the filter surfaces comes. For example, the solid particles lying at the bottom of the screw threads remain on all the way through the device in contact with the drainage holes in the screw body, while the proportions lying between the screw and the housing wall are not possible have, at one point on their way through the press, in direct contact with a filter surface to get. The efficiency of this press is therefore proportional to the liquid to be separated small amount.

The invention was therefore based on the object of creating a screw filter press which has an increased Allow drainage of a suspension. In particular, the task was set, all Solid fractions of the suspension at some point during its passage through the device in direct Bring contact with a filter surface.

According to the invention, this object has become a screw filter press

Applicant:

G. A. Harvey & Co. (London) Limited,

Greenwich Metal Works, London S. E. 7

Representative:

Dr.-Ing. H. Jooss, patent attorney,

3300 Braunschweig, Steinweg 5

Named as inventor:

James Holden Clayton, London

Claimed priority:

Great Britain January 10, 1964 (1206)

solved by that in a screw filter press in

^a 5 inside in the conveying direction a slightly tapered screw and a jacket provided with the same inclination are provided, which comprise helical, turbid channels and zones with filtrate discharges on both sides with filter surfaces in between.

In a preferred embodiment, the cloud-guiding channel in the screw coincides that in the jacket, with the former channel decreasing in cross section seen in the direction of passage, while the channel arranged in the jacket has an increasing cross section.

It is expedient here for the zones having filter surfaces to be congruent, helical-shaped Grooves are formed.

In order to achieve an exact coverage of the individual channels, the axial displacement of the Adjustment device allowing a screw to be provided.

For the preparation of certain suspensions, at least part of the screw and / or the surrounding jacket are subject to heating.

The advantage of this new device is to be seen in the fact that now there is no longer one and the same solid material component against the filter surfaces. The solids are now from that in the Snail located channel in those of the

809 560/424

Passing the snail surrounding the mantle. The thin strips of the Solid components are pressed through between the individual filter surfaces. Through this ensures that all of the material is somewhere on its way through the press is pressed directly against a filter surface, so that an optimal drainage effect can be achieved.

In the drawing is an example

Embodiment of the invention shown. It shows F i g. 1 a screw filter press in longitudinal section,

F i g. 2, also in longitudinal section, the left part of FIG. 1 on an enlarged scale and

F i g. 3 shows a section of the device according to the line in FIG. 1.

According to FIG. 1, a filter device 2 is mounted on a frame, which consists of a number of brackets, U and angle irons 4 and can be screwed to the floor to achieve the required rigidity. The actual filter part of the device contains a screw 6 which rotates coaxially in a tubular jacket 8 corresponding to a cross section rigidly placed on the frame 4. A helical groove 10 is provided in the screw 6 and a corresponding groove 12 is provided in the casing 8. In addition to these grooves, the parts 6 and 8 also have further helical grooves 14 and 16 which are covered with filter surfaces 18 made of porous metal strips. A series of bores 20 connect the grooves 16 to a cavity 17 of the screw 6. The grooves 14 in the housing 8 are connected to a drain 22 (FIG. 3) through a series of bores 24 located in the housing 8.

At one end in the cavity 17 of the screw 6, a liquid outlet 26 is provided, which optionally connected either to an outlet 28 or to a tube 30 arranged centrally in the screw 6 can be.

The other end of the screw 6 has neither bores 20 nor porous metal strips covering them 18 and runs in a continuation of the shell 8 forming back pressure ring 32, which does not Has bores 24.

Coaxially on the shaft 34 of the screw 6, an end tube with flange 33 is placed, which through Piston 36 into the position shown in FIG. 1 position shown pressed or lifted from the front end 38 of the dynamic pressure ring 32nd can be.

The screw 6 is driven by a motor 40 via shafts 42, 44, the latter in the bearing 46 is running. ...

A set screw 48 allows axial displacement of the screw 6 such that its grooves with those can be brought exactly to cover in the jacket 8.

The bearing 46 is against the influence 52 for the mixture to be treated by a liquid seal 50 secured. A liquid drain 53 is attached to them.

In addition, there are seals in the form of O-rings 54 or also oil seals 56 are provided.

During operation of the device, the end tube with flange 33 is first displaced into the position shown in FIG. 1 by the piston 36. Then the material to be filtered is fed into the filter device 2 through the inlet 52. If the screw 6 is then set in revolutions by the motor 40, the filled material is conveyed up to the flange 33 through the channel which is formed by the helical grooves 10, 12 in the screw 6 or in its casing 8. In this way, the material is gradually completely discharged from the helical grooves 10 as a result of their progressive decrease in cross-section into the grooves 12, the cross-section of which increases accordingly and progressively. When a desired pressure has been reached in the device, the flange 33 can be lifted off the end face 38 of the dynamic pressure ring 32 (FIG. 1) by lowering the piston pressure.

The liquid from the mixture passes through the filter surfaces 18 and the bores 20 into the outlet 26 and through the bores 24 in the jacket 8 to the drain 22. From the outlet 26 it can either be in the Drain 28 and from here to the outlet 53, or into the pipe 30 and then discharged from the end of the shaft 34 a suction device must be provided at the shaft end 34. When the out The liquid separated from the mixture and the liquid used in the liquid seal 50 is no longer used * is used, the liquid from the mixture can from the center of the screw 6 through the outlet 26 and the drain 28 and along with the liquid from the liquid seal through the outlet 53 are discharged. However, if the two liquids are to be kept separate from each other, so the filtrate can be returned through the pipe 30 by suction at the shaft end 34. The firm one Part of the liquid-solid mixture passes through the filter device and is through the gap executed, which is achieved by lifting the flange 33 from the corresponding end 38 of the Back pressure ring 32 results.

Claims (1)

Patent claims: 1. Screw filter press, the outer fixed cylindrical shell and one with the screw rotating inner filter surface for dewatering a suspension with one each Drainage for the filtrates are provided, the solid residues through a closed at the end Channel progressively smaller cross-section promoted and against the discharge to be compressed, characterized in that a conically tapered screw (6) and a with the same inclination provided jacket (8) are provided, the helical, turbidity-guiding Channels (10, 12) and on both sides between them filter surfaces (18) having zones (14, .16) with filtrate outlets (20, 26; 24). 2. Screw filter press according to claim 1, characterized in that the cloud leading Channel (10, 12) in the screw (6) with that in the jacket (8) covers. where in the direction of passage seen the first channel (10) decreases in cross section, while the one arranged in the jacket (8) Channel (12) has an increasing cross section. , 3. Screw filter press according to claim 1 or 2, characterized in that the filter surfaces (18) having zones (14, 16) than themselves covering, helical grooves are formed. 4. screw filter press according to claim 1, 2 or 3, characterized by the axial displacement the screw (6) enabling adjusting device (48). 5. Screw filter press according to one of the preceding claims, characterized in that at least part of the screw (6) and / or of the jacket surrounding it (8) is subject to heating. Publications considered: German utility model No. 1793 690; French patent specification No. 1278 283, 1360559;
British Patent Specification No. 11163 (1911), 837780. 1 sheet of drawings