DISTRIBUTING DEVICE FOR PAPER PULP

Abstract: A device for distribution of pulp at the supply of the pulp to a container (19) for pulp flow. The device comprises an inlet (11, 22) for central connection to one end of the container (10) and a distribution chamber (14, 24) located after the inlet (11, 22), which chamber communicate with the interior of the container (10). The distribution chamber (14, 24) is defined in lateral direction by a cylindric wall (15, 25) and directly opposite the inlet (11, 22) by a surface element (16, 26). An adjustable overall gap is located between the cylindric wall (15, 25) and surface element (16, 26).

Description: DISTRIBUTING DEVICEFOR PAPER PULP This invention relates to a device for distributing pulp at the supply of pulp to a container for storage and/or treatment of the pulp. In a container for pulp flow it is often essential that the staytime of the pulp in the container is substant¬ ially the same for all parts of the pulp flowing through. This applies especially to treatment of the pulp by an agent, for example bleaching of the pulp. It is, thus, essential to avoid channelization in the container. At the treatment of pulp with an agent, which is supplied prior to the supply of the pulp to the container, it is also important that the agent is distributed uni¬ formly in the pulp at the inlet to the container, in order thereby to achieve homogenous treatment. It was found that the way in which the pulp is supplied to the container is of decisive importance for the sol¬ ution of the aforesaid problems. At the supply of pulp, different types of distributor are used. For example, mechanical distributors with an inlet housing and an axial rotor, the shaft of which is supported in bearings and sealed by a packing box. A gear and a motor are required for driving the rotor. Mechanical distributors are also used, at which a rotor is formed with two or more outlet channels. These mechanical distributors have a complicated design, because they comprise a rotor with accessory drive and bearings and sealing. These distributors are not adapted, either, to varying pulp flows and production levels. According to a somewhat simplified construction, a distr¬ ibutor is used which comprises a pump-like housing out¬ side the container bottom where at least four outlets are arranged symmetrically about the circumference of the container. Such a device requires a control valve in each outlet and separate pipe lines for connection to the container. This device, too, is very complicated, its distribution effect is limited, and its flow direct¬ ion is wrong . There exist in addition to the mechanical distributors also static ones with conical surfaces for dispersing the pulp in the container. These distributors cannot be controlled, and the ditribύtion achieved often is in¬ sufficient . The present invention has the object to solve the afore¬ said problems. It is directed to a distributing device of a simple design, which allows control of the pulp flow and at the same time also can be used for closing the container. The distribution takes place from a central position outward to the circumference of the container uniformly across its cross-section. The characterizing features of the invention are apparent from the attached claims . The invention is described in greater detail in the following, with reference to the accompanying drawings illustrating two embodiments of the device according to the invention. Figs. 1 and, respectively, 2 are cross-sections of two different embodiments of the device. The device shown in Fig. 1 is located centrally at one end of a container 10 for pulp flow, preferably at the bottom of an upstream container. It is, however, possible alternatively to connect the device at the top of a down¬ stream container. The device comprises an inlet 11 de¬ fined by an inlet flange 12, to which a supply line 13 for pulp is connected. After the inlet 11, a distribution chamber 1A is located, which in lateral direction is defined by a substantially cylindric wall 15 and directly opposite the inlet 11 by a surface element 16. This surface element preferably shall have a substantially plane surface, but also diff¬ erent rotation symmetrical forms can be imagined, for example a conical surface or a surface curved in some other way. The distribution chamber 14 communicates with the interior of the container 10 through an adjustable overall gap 17, which is defined between the wall 15 and surface element 16. The gap is adjustable in that a ' portion 18 of the wall 15 is axially movable and co- -operates with the surface element 16, which is stationary The cross-sectional area of the distribution chamber 14 exceeds the cross-sectional area of the inlet 11. Accord¬ ing to the embodiment shown, the surface element 16 is attached to a number of guide plates 19 arranged rad¬ ially in the cham.ber 14. The movable wall portion 18 is coupled to set screws 20, by which the wall portion 18, and thereby the gap 17, can be controlled. The set screws can be locked by nuts 21. The wall portion 18 can be formed so that the gap 17 can be closed completely. The device shown in Fig. 2 also is located centrally at one end of a container 10. It can be connected at the bottom of an upstream container or at the top of a down¬ stream container. The device comprises an inlet 22 with a throttle ring 23. After the throttle ring 23 a distrib¬ ution chamber 24 is located, which is defined in lateral direction by a substantially cylindric wall 25 and directly opposite to the inlet 22 by a surface element 26. This surface element preferably shall have a substanti¬ ally plane surface, but also other forms can be imagined, as stated above with reference to the first embodiment. The distribution chamber 24 communicates with the inter¬ ior of the container 10 through an adjustable overall gap 27, which is defined between the wall 25 and surface element 26. The gap 27 is adjustable in that the surface element 26 is axially movable and co-operates with the stationary wall 25. The cross-sectional area of the distribution chamber 24 exceeds the area of the inlet 21, i.e. the area at the opening in the throttle ring 23. The surface element 26 is attached to a central shaft 28, which is axially movable by means of a set cylinder 29 The inlet 11 can be connected to a supply line 30 for pulp obliquely from the side. The size of the gap 27 is controlled by the surface element 26 so that it is poss¬ ible to close the gap completely. Supply lines 31 for treatment agent are connected to the distribution chamber 24. It is, however, also possible to add treatment agents to the pulp before the inlet 21. A channel 32 for the evacuation of gas from the pulp is located in the shaft 28. This channel 32 opens on the rear side of the surface element 26. The pulp supplied through the supply lines 13,30 passes through the inlet 11,21 and, respectively, throttling 23. From the distribution chambers 14,24 the pulp flows through the adjustable gaps 17,27, which effect throttling and distribution as well as dispersion of the pulp from a central position at the inlet end of the container 10 uniformly and smoothly outward across the cross-section of the container. The gaps 17,27 are adjusted to the pulp flow in question. Due to the fact that the gaps 17,27 can be closed, it is possible to prevent return flow from the container 10. The lines 31 for the supply of treatment agent allow the addition of the agent in question, such as steam, gas nd chemicals,in a place favourable, for admixture^ " which . promotes the treatment of the pulp in the container. Gas, for example, air, can be evacuated from the pulp through the channel 32 in cases when the pulp has an undesired gas content. Thf invention, of course, is not restricted to the em¬ bodiments shown, but can be varied within the scope of the invention idea.

Claims: Claims 1. A device for distribution of pulp at the supply of the pulp to a container (10) for pulp flow, which device comprises an inlet (11,22) for central connection to one end of the container (10), and a distribution chamber (14,24) located after said inlet (11,22) , which chamber communicates with the interior of the container (10), c h a r a c t e r i z e d i n that the distribution chamber (14,24) is defined in lateral direction by a cylindric wall (15,25) and directly opposite the inlet (11,22) by a surface element (16,26), and an adjustable overall gap is located between the cylindric wall (15,25) and surface element (16,26). 2. A device as defined in claim 1, c h a r a c t e r ¬ i z e d i n that the surface element (16,26) has a substantially plane surface. 3. A device as defined in claim l or 2, c h a r a c t ¬ e r i z e d i n that the surface element (16) is stationary, and the gap (17) is defined between an axi¬ ally movable portion (18) of the cylindric wall (15) and surface element (16). 4. A device as defined in claim l or 2, c h a r a c t ¬ e r i z e d i n that the surface element (26) is axially movable, and the gap (27) is defined between the cylindric wall (25), which is stationary, and the movable surface element (26). 5. A device as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that the cross- sectional area of the distribution chamber (14,24) exceeds the cross-sectional area of the inlet (11,22). 6. A device as defined in claim 3, c h a r a c t e r - i z e d i n that the surface element (16) is attached to a number of guide plates (19) arranged radially in the distribution chamber (14). 7. A device as defined in claim 4, c h a r a c t e r - i z e d i n that the surface element (26) is attached to a central axially movable shaft (28). 8. A device as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that means (31) for supply of treatment agent are connected to the distribut¬ ion chamber (24). 9. A device as defined in any one of the preceding claims, c h a r a c t e r i z e d i n that a channel (32) for evacuation of gas from the pulp communicates with the rear side of the surface element (26).

Inventors: BERGDAHL ANDERS, FORSLUND KJELL, KRISTROEM KLAS, LINDSTROEM ALF, BERGDAHL, ANDERS, FORSLUND, KJELL, KRISTROEM, KLAS, LINDSTROEM, ALF
Applicants: BERGDAHL ANDERS, FORSLUND KJELL, KRISTROEM KLAS, LINDSTROEM ALF, SUNDS DEFIBRATOR IND AB, BERGDAHL, ANDERS, FORSLUND, KJELL, KRISTROEM, KLAS, LINDSTROEM, ALF, SUNDS DEFIBRATOR INDUSTRIES AB
Application year: 1997
Main classification: D21C9
IPC codes: D21C7, D21C9