SU747498A1 - Apparatus for clarifying suspensions - Google Patents

Description

(54) APPARATUS FOR LIGHTING SUSPENSIONS

one

The invention relates to the clarification of less concentrated suspensions and can be used in chemical technology and hydrometallurgy.

A clarifier with a suspended sediment layer is known, which is used for pre-clarification of turbulent water before the final clarification operation in contact filters 1.

The operations of preliminary and final clarification of water containing suspensions can be combined in one apparatus. Such an apparatus is a device for clarifying water, consisting of a vertical sump and a clarifier-diffuser with a conical bottom 2.

On the outer side of the unit case, an annular two-layer filter is installed. Since the device operates according to a pressure scheme, its body is equipped with a lid. Overflowing over the edge of the sump, water passes under pressure through the first layer of the filter, and then through the second. The filters are regenerated by a reverse flow of water.

A disadvantage of the known apparatus is that it operates under pressure, and therefore there is a need for a cap to seal it. This creates certain difficulties in the operation of the device. In the case of the clarification of suspensions with a significant solid content in an apparatus of this type, there is a need for frequent filter regeneration, which is associated with a significant consumption of a clean circulating leaching solution.

The closest in technical essence and the achieved result is an apparatus that includes a cylindrical 10 body, in which sections of blasted filter sludge and control volume filtering load 3 are placed one above the other.

A disadvantage of the known apparatus is its low reliability and low efficiency of clarification.

The purpose of the invention is to increase the efficiency of clarification and reliability of the structure by preventing overshoot and overflow from the overflow.

The goal is achieved by the fact that the apparatus is equipped with perforated pipes for supplying compressed air and circulating washing solution, once

between the sections of the weighted filter sludge and the control volumetric filter, it is loaded, which is placed in a removable perforated basket with a movable lid and a cylindrical shell attached to it from below.

FIG. 1 shows an apparatus for clarifying suspensions, a general view; in fig. 2 shows section A-A in FIG. one; in fig. 3 - a general view of the control volumetric filter loading section; in fig. 4 - node B in FIG. 3

The apparatus consists of a housing 1 made of two shells connected by a conical junction 2. A collector 3 is installed in the lower part of the apparatus for supplying the initial suspension. In the middle part there is a slat-removal device 4, connected to the zone of the weighted filtering slit: a 5. A support ring 6 is installed in the upper part of the apparatus, on which a removable perforated basket 7 with volumetric filtering load 8 is placed. 10 and can be raised to the upper position with the help of the handle 11. In the upper position, the lid is fixed with the help of pins 12. A cylindrical shell 13 is attached to the underside of the movable lid, which, when raised to cover the upper stop is a fixed part of the basket and kryschkoy closed loop. A perforated tube 14 for supplying compressed air and a perforated tube 15 for flushing working solution from the pressure tank 16 to the protective section of the clarified solution 17 are installed under the basket.

The device works as follows.

The initial flocculated slurry enters the collector 3. After a certain period of time in the apparatus, a blasted flocculated sediment layer is formed, which has a clear phase boundary with a clarified zone. Excess sediment is discharged through the sludge removal device 4 into the zone of suspended filter sludge 5. The clarified solution containing a small amount of suspensions passes through the protective section of the clarified solution 17 and enters the bulk filter charge, in which the thinnest suspensions occur.

During the long-term operation of the apparatus, a filtering charge is being poured in and a suspension overshoot is observed with the overflow, the content of which is recorded by the automatic control device. In the case of suspension in the discharge above the allowable amount, the cover 9 is lifted. After that, the washing solution is supplied to the apparatus simultaneously through pipe 15 and compressed air through pipe 14. During regeneration, some upward expansion occurs

bulk filter loading and removal of sediment from the layer. During regeneration, the overflow, containing a significant amount of suspended matter, is mixed with the initial suspension. When the cover is raised, the cylindrical shell 13 constitutes a closed loop with a fixed part of the basket, preventing the removal of particles of the filtering load from the bed. After the regeneration is complete, the basket lid is lowered to its original position, and the lightening cycle begins again.

Installing a perforated basket in the upper part of the clarifier ensures the operation of the apparatus without a pressure; the location under the basket of the perforated compressed air supply pipe reduces the total amount of leaching solution needed to regenerate the bulk filter load, compared to the case if only the leaching solution.

. ,,

As the basket lid is made movable relative to the guide axes and can be lowered to the initial position after flushing, this circumstance provides the necessary optimum density of the filter charge when the suspension is brightened. The presence of a cylindrical shell in the lid of the basket prevents the removal of the bulk filter load when the lid is raised.

Below are the results of experimental studies of a device with a diameter of 200 mm, height 4, O m in the operation of clarifying a mineral suspension formed in the technology of rare metals. The total height of the volumetric filtering charge, consisting of individual lavsan filaments, is 0.6 m. The solid content in the initial suspension varies between 1.0 - + -1.5 g / l.

With the performance of the original suspension for 38 days, the following technological parameters were obtained: the content of suspended solids in the apparatus before the bulk loading was 0.020 g / l;

suspended matter content

5 overflow; 0.003 g / l;

density of the bulk filtration charge; 0, the flow rate of the washing solution during the regeneration operation with simultaneous supply of compressed air 2.1% of the initial supply; air consumption for regeneration operations, day consumption of a 0.1% solution of polyacrylide J (in terms of the active substance of suspensions of Zr / m, ratio W: T of pulp discharged from the apparatus 10: 1

ratio W: T pulp in

slurry seal 3: 1

the amount of liquid phase

coming for operation

regeneration referred to

the consumption of the original suspension,

without compressed air supply 5%

The presence in the apparatus of a perforated basket with a volumetric filter loading allows, in one stage, to obtain a clarified solution with an almost complete absence of suspension. At the same time, during the regeneration stage, the flow rate of the recycled washing solution, for example, the filtrate containing valuable components, is significantly reduced. Since the apparatus operates without pressure, the need for sealing is eliminated.

The annual economic effect from the introduction of the device on one operation of clarification with a capacity of up to 100-200 / day will be 20-30 thousand rubles.

Claims (3)

1. USSR Author's Certificate No. 255930, cl. C 02 B 1/00, 1963. 2. Authors certificate of the USSR 68867, cl. From 02 to 1/00, 1947. 3. USSR author's certificate number 391837, cl. On 01 D 21/00, 1971. H X -eight - " LA 15 I I I And I I n if AFigM A