DE2130501A1 - Device for changing sieves - Google Patents

Description

Cosham Engineering and Design Limited, 18, Aston Road, Waterlooville, Hampshire (ENGLAND)

"Device for changing sieves"

The invention is directed generally to removal screens of foreign matter from a flowable material that passes through the sieve Material and closer bezeicjb.net on a device for Replace a dirty or clogged sieve with a clean sieve. The invention is preferably applicable to the Removal of foreign matter from flowable plastic materials before they are fed to an extrusion machine leaving this machine in strand or sheet form.

According to the invention, a device for replacing a soiled screen with a clean screen is proposed which is characterized by a limb with a conduit extending through it for the material to be screened to flow through, wherein at least two screen blocks each having a number of associated with opposite faces of the block standing holes are provided and one of the .. blocks in a actuation position can be brought in the line during the

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ORIGINAL INSPECTED

other block is located in the vicinity of the conduit and within the body member, further valve means are ^{operable to 'draw material from the conduit into the interior of the other block H} kb- "when this is in the vicinity of the conduit to the block interior fill and thus keep air or air and foreign matter away, and finally drive means are provided for removing one block from the line and replacing it with the other block. ". '"""""".

Further features and details of the invention are set out below For example, explained in more detail with reference to the drawing. This shows in

Fig. 1 is a side view of a device according to the invention with four sieve blocks,

FIG. 2 shows a side view offset by 90 ° with respect to FIG. 1, partly reproduced in section and in

3 shows successive operating positions of the device according to FIGS. 1 and 2.

The device has a body 10 with a conduit 12 extending therethrough for the flow of the to be screened Material on, in the present case, plasticize or flowable Plastic material. A sliding path 14 extends transversely to the line 12, which is equipped with specially treated, removable storage

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plates 16 is designed. The length of the sliding path is such that three precisely machined screen blocks can be arranged in the body 10 in end to end position. In order to arrange the blocks in the slide path, a hydraulic piston and cylinder unit 20 is secured by spacers 22 at one end of the body with a fixed with the Koloen stamp 24, the betütigbar lst ₃ when a block of the space formed by inclined surfaces L4A Gleitwegeingang spent with the unit 20 actuated to put that block into the glide path; to force to a point adjacent to the line 12. By arranging a second block at the sliding path entrance and actuating the unit 20 again, the second block engages against the first block and moves it by a distance that corresponds to the length of the blocks into a position in which the first block is transverse to Line 12 is arranged, the second block being brought into the vicinity of the line.

Each block has a series of bores 13a which are in communication with opposite main surfaces of the block and are distributed over a main part thereof, one of the zxipt surfaces having a recess 18b for receiving one or more filter nets 30, all of which Do foreign matter from aem through the lei .-- Remove 12 flowing i'.material.

To keep all plastic materials in a flowable state, are electrical heating plates 32 on opposite side surfaces of the body. -

BATH ORIGINAL

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The body is also provided with a trigger system to allow all Keep air or air and foreign matter away from the aforementioned second or standby block when it is in the vicinity of the line 12 is arranged. The system has a first drain line 34, which connect in the flow direction in front of -cLen blocks with the line 12 and with one side of the sliding path in the region of the lower part of the second block and a second Ab ;; train line 36, which is connected to an opposite side of the Glide path in the area of the upper part of the second block in connection stands as well as with the exterior of the body, the line 3 ^ through a rotatable valve 38 with a handle 40 is controllable.

The normal sieving operation of the device is shown in Fig. 3a, which also shows a third block at the glideslope entrance. If a pressure sensor not shown upstream at one point 42 of the body reaches a predetermined height and thus a dirty or blocked filter network in the working position is an indicator or an alarm signal triggered to indicate the need to change the screen ...

The sieve replacement is carried out as follows:

The valve 38 is opened by the handle 40 (Fig. 3b) and the plastic material from the upstream side of the blocks into the interior of the standby block via its filter element deducted. This withdrawal continues until an in-

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aügenscheinnahme the outlet of the orifice 36 is apparent that no more air escapes from the interior of the second block * Valve 38 is then closed and the unit 20 is actuated (Fig. * _3c)} to force the third block in the slide path, whereby the dirty sieve is quickly replaced by the ready-to-use sieve, which is both preheated and filled with plastic material. During the change process, it can be seen that the flow of material through the line 12 is not significantly interrupted because, as a result of the selected block bore pattern, the effective number of bores 18a of the soiled and the standby blockj which are each in the line 12 ^ is not significantly reduced during the change process. In addition, inclined parts 12a of the line downstream of the blocks support a deformation of the plastic material flow if it should be interrupted.

A fourth screen block is used to change another screen brought to the glide slope entrance and the prescribed actuation repeated. The dirty first screen block is pushed out of the sliding path (Fig. 3d) «

If desired, the change process can be carried out automatically, in the awake case, an actuator not shown influences the valve as a function of the material flow pressure influenced by the aforementioned Sensor would operate. Furthermore, a time delay mechanism (not shown) could control the actuation of the unit 20.

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The main advantages of the present device are as follows

1. All air and foreign matter are removed from the standby block kept away and the change process can take a few seconds be terminated * '.,.

2 * The blocks' are formed so that the _s Materialdurchflüßieitüng gii no time is closed during Weöhselvörganges *:

3. The working surfaces of the glide path are easily exchangeable.

4. The blocks can easily be removed from the fixture body for cleaning purposes removed d

5. The device is easy to use, effective in the field bit by bit and not very expensive. '

Patent claims:

Claims (1)

Patent claims: Γ
1.1 Device for replacing a dirty or blocked \ J Sieve through a clean sieve, characterized by a body member (10) with a conduit (12) extending through this for the flow of the material to be sieved with at least two sieve blocks (18), each of which has a number of bores (18a) which are in communication with opposite surfaces of the block, one of the blocks being able to be brought into a working position in the line, while the other block is in the vicinity of the line and within the body. Per member is arranged, such actuatable valve means (38, 40) to material from the line in the interior of the other block while placing it near the pipe to fill the inside of the block and thus air or air and foreign matter and finally by drive means (20) for removing the one block from the conduit and replacing it the same through the other block. 2. Apparatus according to claim 1, characterized in that the M body member (10) is formed with a sliding path (14) in which the screen blocks (18) are guided during the changing process. 3. Apparatus according to claim 2, characterized in that the body member (10) has a first exhaust line (34) which communicates with the line (12) and with one side of the sliding path (14) and that a second drain line (36) with 209842/0 5 73 an opposite side of the sliding path and communicating with the exterior of the limb, one of the conduits (34,%) being controlled by the valve means (38, 40). 4. Apparatus according to claim 3 »characterized in that the a line is formed by the first line (3 ^). 5. Apparatus according to claim 2, 3 or 4 with a third screen block, characterized in that the sliding path (14) is sufficiently long to allow three sieve blocks (18) against one another to be arranged abutting and is arranged such that if a _ Block (18) is in line (12.), the other two Blocks within the limb (10) are located on opposite sides of the conduit (12). 6. Apparatus according to claim 5, characterized by a fourth Sieve block (18). ^ 7. Apparatus according to claim 2 or one of the following, characterized by a punch (24) which, when actuated, moves each sieve block (18) in the sliding path (14) by one of the length the blocks corresponding piece moves in the glide path. 3. Apparatus according to claim 7, characterized in that the Stamp (24) can be actuated to counteract a at the entrance of the Slideway (14) arranged sieve block (l8) to grab and 209842/0573 '* 213050T Forcing this into the glide path, causing the others in the screen blocks located on the sliding path are moved. 9. Apparatus according to claim 7 or 8, characterized in that the punch (24) has a fluid-operated cylinder, which is attached to one end of the limb (10) by means of spacers (22). 10. The device according to claim 1 or one of the following, characterized characterized in that each sieve block (18) 'is provided with a filter mesh (20) on one of the outer surfaces of the same is attachable. 11. The device according to claim 1 or one of the following, characterized by means of automatic block replacement depending on the pressure of the material flowing through. 12. Procedure for replacing a dirty or blocked Sieve through a clean sieve using a device ■ according to claims 1-11, characterized in that the Inside a ready-to-use block is filled with flow material and then this block is moved to a soiled one Eject block from line and replace. 13.- The method according to claim 12, characterized in that the material flowing through is withdrawn upstream of the in working position uiebblockes. 2 0 ff84 7 '0S 1 3 14. The method according to claim 12, characterized in that the Material through the filter mesh of the stand-by screen block flows before it enters its interior. 15 · Method according to claim 12 or one of the following, characterized characterized in that the pressure in the material flowing through is measured upstream of the limb and when it is reached Chen a predetermined value the pull and exchange processes are automatically effected. -