SU1390280A1 - Method and multichamber clarifier for clarifying fibrous suspension - Google Patents

Abstract

The invention relates to a slurry clarification technique and can be used primarily in the pulp and paper industry when regenerating cooking liquor. The purpose of the invention is to increase the productivity of the process by activating it in each of the chambers of the clarifier. The method of clarifying the suspension is carried out in a multi-chamber clarifier. The clarifier consists of a housing 1 with a conduit 2 for supplying a slurry stream and means for discharging the clarified slurry and a compacted sludge disposed in the housing of the diaphragm 5 for sedimentation of the sludge separating the internal cavity of the casing on s

Description

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Nizhmgo 6 and above the 7 cameras. A baffle 8 is installed in the diaphragm in the form of a closed vertical surface of rotation with open ends 9 and 10. The lower end 9 is located in chamber 6, and the upper 10 in chamber 7, with pipeline 2 communicating with a closed volume of vertical partition. 8. The clarifier may have an additional 11, covering the partition 8, npi-tchem the upper end of the additional partition is placed at the level of the diaphragm 5, the housing is equipped with a cap 12, and inside it on the drive shaft 13 are fixed scrapers 14 and 15, installed with a small clearance relative to the diameter fragments 5 and the bottom of the 16th case. The tool 3 is made in the form of perforated manifolds 17 and 18 fixed to the casing walls with nozzles 19 and 20. An additional partition 11, covering the main partition 8, forms with it an annular gap 21 that communicates chambers 6 and 7. 2c. i2z.p. , 1 Il.

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This invention relates to a slurry clarification technique and can be used primarily in the pulp and paper industry when registering cooking liquor.

The purpose of the invention is to increase the productivity of the process by activating it in each of the light cells.

In the drawing, an image of a multi-chamber clarifier for carrying out the method of clarifying a suspension.

The multi-chamber slurry clarifier consists of a housing 1 with a pipeline 2 for feeding the suspension stream and means for removing the clarified suspension 3 and compacted sludge 4 housed in the housing 1 of the diaphragm 5 for sedimentation of the sludge separating the inside of the housing 1 on the bottom 6 and 7 located in the chamber. In the diaphragm 5, a partition 8 is installed, having the form of a closed vertical rotational surface with open ends 9 and 10. The lower end 9 of the partition B is located in the lower chamber 6, and the upper 10 in the upper chamber 7, and the pipeline 2 for the flow of the suspension flow communicates with the closed volume of vertical partition 8.

The clarifier may have an additional partition 11, covering the closed partition 8, and the upper end of the additional partition is located at the level of the diaphragm 5. Corto

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The start 1 is fitted with a cap 12, and inside it on the drive shaft 13 there are fastened scrapers 14 and 15, installed with a small clearance relative to the diaphragm, we 5 and the bottom 16 of the housing 1. The means 3 for removing the clarified suspension is annular in the form of fixed on the walls of the housing 1 perforated collectors 17 and 18 with patches 19 and 20, Additional partition 11, covering the main partition 8, forms an annular gap 21 with it, communicating chambers 6 and 7,

The method is carried out as follows.

The initial suspension to be clarified is supplied via conduit 2 into a closed volume of a vertical partition 8, where solid particles of sludge contained in the suspension are deposited under the action of gravitational forces, resulting in an upward flow of suspension, which through its upper volume 10 is fed into the spaced chamber 7 has a lower concentration of solids (slurry depleted) than the initial suspension, while the downward flow of the suspension, through the lower open end 9 of the partition 8, supplies first into the lower chamber 6, sludge enriched in its concentration of solids higher than in the initial suspension. The slurry precipitated from the suspension in the upper chamber 7 on the surface of the diaphragm 5,

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rotating scrapers 14 through the annular gap 21 between the main 8 and additional 11 partitions, I feed into the lower chamber 6.

In the lower chamber 6, the sludge compaction process is carried out, as a result of which the liquid clarified suspension phase is displaced into the upper chamber hour and discharged through an annular manifold 18 and nozzle 20. The compacted sludge is scraped by scrapers 15 and removed by means of 4 for discharging the compacted sludge. From the above position of the chamber 7, the clarified suspension is removed through an annular manifold 17 and a pipe 19.

Due to the redistribution of the solid concentration - in the suspension coming in for clarification, the slurry with a slurry concentration lower than in the initial suspension enters the upstream chamber 7, which leads to a significant increase in the sedimentation rate of the slurry in it and, accordingly, an increase in the process of the clarified suspension. Due to the redistribution of the concentration of the sludge, the slurry enters the lower chamber 6 with the concentration of the solid phase slightly higher than the initial one.

Example. The initial suspension of white liquor with a solids concentration of 92.5 g / l with a flow rate of 980 l / h is fed into a multi-chamber clarifier having the following design parameters: diameter 1.6 m, total height 5.0 m, height of the spaced chamber 1 , 5 m height of the lower chamber 3.5 m, diameter of the closed partition 300 mm, height 2,0 m (0.5 m above the diaphragm, 1.5 m under the diaphragm), additional partition diameter 600 mm, height 0.75 m. as a result of the redistribution of the concentration, an suspension with a concentration of solid matter enters the upstream chamber 75 g / l, the deposition rate of the sludge in the upper chamber is I 1 mm / m ascending flow rate 10 mm / m Suspension comes to the lower chamber with a solid phase concentration of 120.1 g through the gap between the main and additional closed partitions From the pulverized chamber, a precipitate is fed from the bottom of the chamber, which is 238.6 g / l.

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The clarified suspension is sampled from the above chamber at a rate of 600 l / h and a solids concentration of less than 0.1 g / l. A clarified suspension is taken from the lower chamber at a flow rate of 200 l / h and a concentration of less than 0.1 g / l. The compacted sludge is discharged with a flow rate of 180 l / h and a solids concentration of 500 g / l.

When using the known clarification scheme with feeding the initial suspension to the upper chamber (the design parameters of the clarifier and the concentration of the initial suspension are the same as in the implementation of the proposed method), the flow rate of the supplied suspension is 736 l / h. The clarified fraction with a concentration of solids less than 0 g / l is taken at a flow rate of 400 l / h from an upstream chamber, and 200 l / h from a lower chamber. The removal of sludge wastes is 5 with a flow rate of 136 l / h at a concentration of 500 g / l. Attempts to increase the consumption of liquor from the upper or lower chamber lead to a sharp decrease in the quality of clarification, the concentration of the solid phase in the exhaust clarified suspension increases unacceptably.

Thus, the use of the invention will allow a 33% increase in the productivity of the process in the clarified suspension by increasing the Bbmie productivity of the located chamber (the performance of the lower chamber does not change).

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Claims (3)

1. A method of clarifying a suspension in a multi-chamber brightener, including flow in the lower and upper compartments, sedimentation of the sludge in the upper chamber, compaction of the sludge in the lower chamber, removal of the compacted sludge from the lower chamber and removal of the dried suspension from the chambers that, in order to increase the productivity of the process by activating it in each of the chambers, before supplying the stream to the chambers it is confined in a confined space, a part of the stream is squeezed, and a slurry-rich seal is supplied to the lower chamber (M111u current with monomer. tagging and: cameras „ a portion of the clarified slurry, which is combined with the unconsolidated portion of the stream in a closed volume, and serves a combined stream into the upper chamber. 2. Method POP1, characterized in that a part of the stream is compacted by gravitational sedimentation of sludge in a closed volume, 3. A multi-chamber slurry clarifier comprising a housing with a conduit for supplying flow and means for removing the clarified slurry and compacted sludge, a diaphragm for sludge deposition placed in the housing dividing the cavity of the housing into the lower and upstream chambers. characterized in that it has a closed vertical septum with open ends installed in the diaphragm, the lower of which is located in the lower chamber and the upper one in the superposed chamber, with the pipeline for supplying flow communicating with the closed volume of the vertical septum. 4, Poplar clarifier pop. 3, characterized in that it has an additional partition covering a closed vertical partition, with the upper end of the additional partition placed at the level of the diaphragm.