FI72359C - Cylindrical horizontal mass separation device. - Google Patents

Description

rBl nn ADVERTISEMENT πλ ,, 0 Β 11 UTLÄGGNINGSSKRIFT / Ζόθ9 ^ (45) p ^,. . ^. _. c ^ ^ (51) Kv.lk. * / lnt.CI.4 D 21 D 5/20 (21) Patent application - Patenttnsökning 800 ^ 67 (22) Application date - Ansökningsdag 1 5 · 0 2.8 0 (FI) (23) Start date - Giltlghetsdag 1 5 · 0 2.8 0 (41) Become public - Blivit offentllg 1 7.08.80

Patent * and National Board of Registration Date of issue and date of publication— 3O.OI.87

Patent * och registerstyrelsen '' Ansökan utlagd och utl.skriften publicerad (86) Kv. application - Int. ansökan (32) (33) (31) Privilege requested - Begärd priority 16.02.79 England-England (GB) 7905558 (71) Beloit Walmsley Limited, Atlas Works, Bury, Lancashire, England-Eng1 and (GB) (72) Roderic Field, Bury, Lancashire, England-England (GB) (7 * 0 Leitzinger Oy (5 * 0 Cylindrical horizontal pulp separator -

Cylindrical risk, horizon with mass1jningsanordning

The invention relates to a cylindrical, horizontal pulp separation device with a rotor at one end wall. More specifically, the invention relates to devices constructed to receive pulp containing various impurities and to separate it into two or more fractions, wherein the quality of the pulp leaving the "approved" end of the device is better than the quality of the input pulp and the impurities are discharged by one or more "rejected" discharges. through the opening.

In one such device, the pulp is fed into a cylindrical horizontal container and made to rotate therein by a rotor or propeller attached to the other end wall of the container. As a result of the movement of the pulp, its heavier fraction is ejected outwards and passes out of the outlet possibly containing the fastening device for transfer to the rubbish. The lighter contaminants tend to settle in the center of the tank around the vortex or in the vortex itself, which extends through the surrounding mass and pass out of the wreck opening arranged in the center of the end wall of the tank opposite the rotor or propeller support wall. After the heavy and light scrap products have been separated and discharged, the remaining mass forms an approved product and passes through a filter in the wall supporting the rotor or propeller for use or post-treatment. In such devices, the feed mass containing impurities is generally fed in from the circumferential region of the container, often tangentially, whereby the vortex movement of the main part of the mass inside the container is improved or increased.

At this stage, it has been found that if the mass to be fed is pushed into the tank in its lower pressure zone, the whole unit can be operated at a lower pressure than was previously the case. Typical pressures on the tank shell of 22 and 55 cm in diameter during operation are 26.6 and 483 kPa, respectively, while the pressure in the center of the unit is atmospheric pressure. Therefore, by feeding the pulp to the center of the cylindrical tank or very close to it, there is no need to pressurize the feed channel, and operating costs are reduced. The centrifugal motion in the tank is mainly due to the operation of the rotor or propeller, and therefore the movement of the mass feed channel from the circumference of the jacket to the center of the unit does not greatly affect the motion that causes the mass to separate into fractions. Nevertheless, a certain shape of the feed channel can affect the mass movement.

According to the present invention, the pulp separation device comprises a pulp feed channel in the form of a trough located in the center of an end wall substantially opposite the rotor away from the rotor, the trough surrounding a waste product discharge channel arranged to operate countercurrent to the feed channel.

In the following, the invention will be explained in more detail in the form of an example with reference to the accompanying drawings, in which:

Figure 1 is a schematic side elevational view of a pulp separation apparatus according to the present invention.

Figure 2 is a corresponding view seen from above.

Figure 3 is an end view taken from the left side of Figure 1.

3 72359

Figures 4 and 5 are side and end views, respectively, of a combined feed and discharge channel casting including a chute as schematically shown in Figures 1-3.

Looking first at Figures 1-3, it can be seen that the horizontal cylindrical container 10 has end plates 12 and 14 which, together with the cylindrical shell, form a processing space for separating the pulp. In the middle of the end wall 12 there is a combined feed and discharge device, generally indicated by reference numeral 16, which is arranged to allow the pulp to be fed through the feed channel S and to discharge light waste products through the discharge channel LR. The cylindrical shell of the tank 10 has a heavy waste product discharge channel 18 from which larger contaminants can be discharged.

The end wall 14 has a propeller or rotor 20 including a drive mechanism 22 for moving the pulp in the tank 10 and further end filter 14 includes a filter or screen 24 through which the pulp separated from heavy and light waste products passes into a small chamber 26 from which the pulp can be discharged. the discharge channel 28 through the arrow A direction.

In previous constructions, the mass containing impurities is generally conducted from the circumference of the shell 10 of the container 10, often in a tangential direction, with the incoming mass joining the rotating contents of the container 10 in the outer regions where the pressure is greatest due to centrifugal forces. In the present invention, the inlet mass is fed through the end wall 12 and substantially in the middle thereof from the point where the internal pressure of the device is substantially atmospheric. The pulp is fed in the direction of the arrow S through the combined device also acts so as to emit light away from the broke-products of the arrow LR direction.

The combined member 16 is shown in more detail in Figures 4 and 5, where it can be seen that although the inlet and outlet passages are connected to the same casting, they are formed by different passages within the jacket. The feed channel has a chute 30 because, when the mass enters the chamber 10, it already has a component of the vortex movement in the container 10. This chute 30 surrounds the outlet channel 32 but 72359 4 is spaced apart from it by the outlet channel being a straight bore extending through the jacket and freely releasing light waste products as they enter the vortex or core that tends to form in the device as the rotor 20 operates.

For this reason, it can be clearly seen that the pulp feed channel consists of a trough in the form of a helically or helically twisted tube and opens into an annular space and surrounds a central outlet pipe arranged for light scrap products.

Claims (3)

5 72359 A cylindrical, horizontal pulp separator having a rotor at one end wall, characterized in that it comprises a pulp feed channel in the form of a trough (30) located substantially in the middle of the end wall (12) opposite the rotor (20) away from the rotor. a waste product discharge channel (32) arranged to operate upstream of the supply channel, Device according to Claim 1, characterized in that the trough (30) has a helical shape and opens into the annular space. Device according to Claim 1 or 2, characterized in that the chute (30) and the outlet channel (32) for light waste products are a uniform casting (16).