SU644892A1 - Apparatus for flushing and dehydrating fibrous mass - Google Patents

Description

one

The invention relates to the pulp and paper industry and is used for washing and dewatering pulp.

A device for washing and dewatering a pulp containing a drum with a perforated surface and fixed blades installed in the trunnions, an airtight casing gradually tapering in the direction of the mass movement and forming a spill-out and rinsed mass with the drum surface, and a system for feeding and draining the pulp. mass, washing liquid and filtrate, 1.

However, an increase in the total amount of filtrate to be taken causes the filtrate and the liquid squeezed out of the layer to be thrown on the inner surface of the drum as it rotates and spreads over it in the form of a film. This leads to the fact that the fluid is reabsorbed by the fibrous layer coming out from under the casing with a certain degree of compression and expanding due to the elastic forces acquired during compression. Absorption by a layer of freshly pressed liquid leads to a slight decrease in efficiency and

the quality of the washing of the layer and the degree of its dehydration.

The aim of the invention is to improve the efficiency and quality of washing and dewatering the pulp.

This is achieved by the fact that the device has a liquid reflector with a cutting edge located under the mass outlet slot mounted inside the drum on an axis passing through its trunnion.

The drawing shows the proposed device.

Claims (2)

The device contains a hermetic casing 1 and a perforated drum 2 with blades 3 rigidly fixed on its surface. The free surface of the drum 2 is not covered by the casing 1 and the mass layer, facing downwards. Casing 1 covers the drum 2 from the sides and top. The casing 1 is made with distances to the surface of the drum 2 gradually decreasing in the direction of mass movement. The blades 3 are made in the form of rectangular or comb-shaped plates, and the vanes and hollows of the comb-shaped plate can be made in the form of semi-woolens, semicircles, triangles, rectangles, trapezoids; 3, etc. The base of the blades is attached directly to the surface of the drum, without gaps between the drum and the plates. The casing has grooves 4 located along the circumscribed blades of a circle longer than the distance between adjacent blades and a sectional profile corresponding to the profile of the blades with a minimum gap between the edges of the blades and the surface of the grooves. A squeegee roller 5 is installed near the free surface of the drum, rotating in the same direction as the drum 2. The scoop roller 5 is installed below the axis of the drum 2 within the central angle a formed by two planes intersecting along the axis of the drum the axis of the scraper roller 5, and the other horizontal, and equal to from 5 to 60 °. The distance from the surface of the roller 5 to the surface of the drum 2 is chosen taking into account that the blades 3 do not hit the surfaces of the roller 5 when the drum 2 rotates, i.e. this distance is equal to the height of the blade 3 plus the minimum gap between the roller 5 and the rectangular blade . If the blades 3 have the shape of a comb plate, the sorber roller 5 is made with a surface profile corresponding to the profile of the blades combs. Since the protrusions of the comb blade 3 can enter the grooves of the scraper roller 5, the squeegee roller 5 approaches, either partially or completely, both the surface of the drum 2 and the level of the axis of the drum. A nozzle 6 is provided for mass entry. A washing chamber 7 is installed on the casing. The nozzle 8 serves to drain the filtrate. The outlet slit 9 is designed to drain the washed mass from under the casing 1. Inside the drum 2 is installed a liquid reflector 10, made in the form of plates. The edge of the reflector 10 is located opposite the opening slit 9 with a minimum clearance to the inner surface of the drum 2. The reflector 10 is installed at the required angle to the horizontal surface and fixed on the axis 11. The And axis is placed in the hollow pins of the drum 2 and partially protrudes beyond the drum. The axis can be rotated to install the reflector 10 in the desired position. Inclined nloskosti 12 for the descent of the washed mass, removed with a needle roller 5 from the surface of the drum. The device works as follows. The fibrous mass is supplied under pressure through the pipe 6 and enters the space between the casing 1 and the surface of the drum 2. Due to the pressure difference on both sides of the perforation of the drum, the liquid 4 passes bone inside the drum 2, and a layer of sediment forms on its surface, which intersects the cross section between the casing 1 and the drum 2 at some distance from the entrance. Under the action of the blades 3, the mass layer moves in the direction of rotation of the drum 2, intensively dehydrating due to the reduction of the distance between the surfaces of the drum 2 and the casing 1. Preliminary, the pressed mass layer is washed with a liquid supplied through the washing chamber 7. The filtrate and the washing liquid fall inside the drum 2, effectively washing its perforation from the fibers. The excess fluid, not passed through the perforation, is drained through the open end of the drum 2 and is removed through the pipe 8. The washed and finally pressed mass exits the casing through the discharge slot 9, is removed by the scraper roller 5 and is dropped on the inclined plane 12. The filtrate thrown at rotating the drum 2 onto its inner surface, the reflector 10 is thrown towards the center of the drum. The perforated partition, thoroughly rinsed with liquid backflow, passes further through the grooves 4. Since the profile of the cross section of the grooves 4 corresponds to the profile of the blades 3, and the length of the grooves along the circumference described by the blades exceeds the distance between two adjacent loiast 3, 4, in combination with the passage The blades 3 through them are a reliable sealing device that prevents the mass from leaking when it enters. After passing through the vents, the perforated surface of the drum 2 with its fixed blades 3 is inserted into a coactant with the incoming mass, and the work cycle is repeated. Installing the reflector 10 inside the drum 2 prevents the filtrate from spreading on the inner surface of the drum 2, which prevents undesirable absorption of this lacquer layer before removing it from the surface of the drum 2 and improves the efficiency and quality of work). The invention of the device for washing and dewatering pulp containing drum mounted with perforated surface and fixed blades, hermetic casing, gradually narrowing in the direction of mass movement and forming with the surface of the drum a slit for the exit of the pressed and washed mass and the system of supply and removal of fibrous mass, washing liquid and filter, characterized in that, in order to increase the efficiency and quality of washing and dewatering the pulp, it has A fluid with a cutting edge, located under the slit for mass exit, mounted inside the drum on the axis passing through its trunnions. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 511402, cl. D 21C 9/18, 1973. ten