RU2743096C1 - Filter unit - Google Patents

Abstract

FIELD: mining industry.

SUBSTANCE: invention relates to the enrichment of raw materials in mining, chemical and other branches of industry where vacuum filters with a rotation drive are used, for example, in non-ferrous metallurgy for preparing raw materials in a process for producing alumina. The filter unit comprises a vacuum filter (1), a distributing device (16), a filtrate separation receiver (2, 3) and a residual droplet liquid trap (4) which are connected to each other by pipelines and a filtrate collector (7) which is connected to a trap (4) and a receiver with vertical hydrostatic discharge pipelines (12-14). The distributing device (16) is provided with a discharge pipeline (11), which is connected to the receiver body (3) and is formed at an angle relative to the horizontal axis of the distributing device (16) in such a way that the flow of the filtrate can be directed downwards from above, wherein a device for automatically adjusting the vacuum (17) is fixed on the pipeline (9) by means of a controlled shut-off element, said device being capable of maintaining a constant vacuum value in the distributing device (16) in the sediment formation zone.

EFFECT: use of the invention enables producing a product with a minimum moisture content in the sediment (cake) while simultaneously preventing the filtrate from being dropped together with air through a trap into a vacuum pump.

1 cl, 2 dwg

Description

Technology area

The invention relates to the field of enrichment of raw materials in the mining, chemical and other industries, where vacuum filters with a rotation drive are used, for example, in non-ferrous metallurgy in the preparation of raw materials in the process of producing alumina.

State of the art

Known distribution head of rotating vacuum filters (Nikolaev A.F., Blyakher I.G., Shindelevich L.L. and others. Distribution head of a rotating vacuum filter. AS No. 352661, 1968) with cavities for supply vacuum and reception of filtrate, as well as purge air, in which ground washers adjoin its body on both sides. On the inner side of the head, the stationary distribution washer is in contact with the rotating cell, on the outer side there is a movable or swivel washer, but it does not rotate with the filter journal due to the fit on the shaft with the bearing. A lever is attached to the movable washer for turning it through an angle within the filtration zone. In turn, in the vacuum cavity of this zone there is a rotary bridge in the form of a cylinder, which is attached at one end to a movable washer with a pressure spring, and at the other end it enters the hole of the distributor washer. When the movable washer is turned by means of a lever at a certain angle, the cylinder moves in the vacuum zone, cutting off part of the zone, which makes it possible to regulate the duration of the filtering surface of the filter under vacuum, i.e. affect performance. To prevent communication of the vacuum zone with the atmosphere, a sealing ring is placed in front of the bearing of the movable washer.

Known filter installation with a rotating drum vacuum filter, containing a container / trough for the suspension, connected by a centrifugal pump for feeding the suspension into the filter trough, the distributor of which is connected by a pipeline to the vacuum pump in series through the receiver and the trap. The filtrate and flushing liquid entering the receiver through the corresponding windows of the distribution device under the action of hydrostatic pressure through a vertical pipeline enter the collector, and the air entering the filter at the stage of washing and dewatering the sludge from the receiver through the pipeline, after separation from the dropping liquid in the trap, is removed a vacuum pump from the system (V.A.Zhuzhikov, "Filtration", Goskhimizdat, Moscow, 1961, pp. 198-199).

Known filtering installation for filtering suspensions, including a vacuum filter, receivers for taking the filtrate from the filtration zone and drying the sediment, pipelines connecting the filtering zone and the drying zone of the vacuum filter with receivers, a trap for capturing liquid droplets, a vacuum pump, a barometric box for collection of filtrate, connected by pipelines with receivers and a trap, characterized in that a chamber made in the form of a cylindrical shell with covers, the diameter of which is larger than the diameter of the pipeline, is built into the pipeline connecting the drying zone with the receiver through the distribution device of the vacuum filter, the chamber has a branch pipe embedded in the shell and connected to the receiver or trap (patent RU 2 346 723 C2, publ. 20.02.2009).

Known filter installation with a rotating drum vacuum filter, containing a container / trough for the suspension, connected by a centrifugal pump for feeding the suspension into the filter trough, the distributor of which is connected by a pipeline to the vacuum pump in series through the receiver and the trap. in a filtering installation with a drum or disk vacuum filter, containing a vacuum filter with a rotation drive and a suspension tank, the switchgear of which is connected in series with a pipeline with a vacuum pump through a receiver for filtrate separation and a trap of residual droplet liquid, and the receiver and the trap are connected by pipelines hydrostatic drain with a filtrate collector, the cavity of the zone for flushing and dewatering the sediment of the upper part of the switchgear housing is equipped with a device for continuous removal of air flow from the filtrate, made in the form of a pipeline connected to the cavity of the tank of the residual droplet liquid trap. At the same time, on the housing of the switchgear in the zone of washing and dewatering the sludge, a discharge branch pipe is installed for removing the air flow from the filtrate. (patent RU 2350374, publ. 03/20/2009). The known device is taken as a prototype.

The disadvantage of the device is that the outlet branch pipe of the residual droplet liquid removal pipeline has a tangential outlet from the distribution vacuum head directed vertically upward. With this design, the end wall of the distribution vacuum head performs the function of a baffle plate, thereby sharply reducing the rate of removal of residual droplet liquid from the zone of washing and sludge dewatering. The next disadvantage of the applied design is the connection of the pipeline from the distribution vacuum head to the trap. Unstable pressure in the vacuum system increases the risk of the filtrate being thrown with air through the trap into the vacuum pump.

The next disadvantage of the applied design is manual regulation of the vacuum value in the zone of sludge formation by opening or closing valves on the pipeline. An unstable value of vacuum in the zone of sediment formation during filtration of the suspension leads to irregularities and significant differences in the thickness of the sediment layer (cake).

These shortcomings stimulated the search for new technical solutions.

Disclosure of invention

The technical objective of the claimed invention is to obtain products with a minimum moisture content in the sludge (cake) while eliminating the throwing of the filtrate together with air through the trap into the vacuum pump.

The technical task is achieved due to the fact that in a filtering installation containing a vacuum filter, a distribution device, a receiver for separating the filtrate and a trap of residual droplet liquid, connected by pipelines, a collection of filtrate connected to the trap and the receiver by vertical pipelines of the hydrostatic drain, according to the claimed According to the invention, the distribution device is equipped with a discharge pipeline connected to the receiver body and made at an angle relative to the horizontal axis of the distribution device with the possibility of directing the filtrate flow from top to bottom, while an automatic vacuum control device is fixed on the pipeline by means of a locking-adjustable element, made with the ability to maintain a constant value vacuum in the switchgear in the deposit formation zone.

The following dependent features of the claimed invention contribute to the achievement of the technical problem. The angle of inclination of the discharge pipeline can be 50-70 degrees relative to the horizontal axis.

The proposed technical solution is aimed at the effective use of the filter unit, by increasing the speed of movement of the residual dropping liquid from the drying zone of the filter suspension, as well as stabilizing the thickness and uniform distribution of the sediment on the surface of the filter cloth.

The first distinguishing feature of the proposed device is the installation of an additional pipeline for removing residual droplet liquid from the working zone of deep drying and sludge dewatering.

The design of the housing of the distribution vacuum device is equipped with an element for continuous removal of residual dropping liquid (filtrate), made in the form of a pipeline connected to the cavity of the receiver tank. In this case, on the housing of the distribution vacuum device in the zone of deep drying and sludge dewatering, a discharge branch pipe is installed for the removal of residual droplet liquid (filtrate). The pipeline branch pipe is installed in the end wall of the vacuum switchgear horizontally relative to the plane. The pipeline relative to the branch pipe is directed downward relative to the distribution head to the lower part of the drying receiver and is connected to the receiver. The angle of inclination of the pipeline can be within 50-70 degrees relative to the horizontal axis. This design of connecting the pipeline to the distribution vacuum device, due to the elimination of right geometric angles, and gravitational force (flow direction from top to bottom), provides a high rate of removal of the liquid flow from the working area of deep drying and dehydration.

The second distinguishing feature of the proposed device is a device for automatic regulation of the amount of vacuum in the zone of sediment formation.

The housing of the distribution vacuum device for continuous removal of residual dropping liquid (filtrate) is equipped with a branch pipe for removing the filtrate from the zone of sediment (cake) formation. Shut-off and control valves with a gearbox and an electric drive are installed on the branch pipe. A constant value of the vacuum value is maintained by an automatic vacuum control device, which in the zone of sediment (cake) formation ensures the stabilization of the thickness and uniform distribution of the sediment on the surface of the filter cloth. The operation of the filter unit in this mode allows you to obtain products with a minimum moisture content in the cake (cake) and increase productivity.

The analysis of the known technical solutions concerning the rotating drum or disk vacuum filters, as well as the analysis of the set of essential features of the proposed invention allow us to conclude that it meets the criteria of "novelty".

The possibility of realizing the set technical problem with the proposed set of essential features is confirmed by the following example of a specific embodiment of the invention with a drum design of a vacuum filter and is illustrated by the drawings.

Brief Description of Drawings

Figure 1 shows a diagram of the proposed filter installation with a drum vacuum filter, figure 2 - the housing of the distribution vacuum device.

The installation contains a drum vacuum filter 1 with an outer filtering surface. The drum of the vacuum filter is mounted on trunnions and is connected with the filtrate outlet pipelines (not shown in the drawing) to the housing of the vacuum filter switchgear. The zones of the cavity of the switchgear housing, organized by a distributor washer, responsible for filtering the suspension, washing and dewatering the sludge (not shown in the drawing), through the filtrate outlet pipes are connected in series with pipelines 9 (filtrate) with the cavity of the receiver tank. 2, drying pipeline 10) by the tank cavity receiver 3 and through the outlet pipeline 11 (deep drying and dehydration) with the receiver tank 3. The reservoirs of receivers 2 and 3 and traps 4 are connected by vertical pipelines 12, 13, 14 with a filtrate collector 7. On pipeline 9, shut-off and control valves with an electric drive 17 , the regulation of the magnitude of the vacuum in the zone of sediment formation is carried out by an automatic vacuum control device by means of a control and measuring regulator. The vacuum in the filtering unit is maintained due to the operation of the vacuum pump 6, the barometric condenser 5 and the hydraulic seal 8. To blow off the sludge (cake) obtained in the filtration process, a compressed air pipeline 15 is used.

Implementation of the invention

The installation works as follows.

The suspension is fed into the tank / trough of the vacuum filter 1 from the apparatus by a centrifugal pump (not shown in the drawing). In the process of sedimentation, washing and dewatering of the sludge on the drum of the vacuum filter 1, the filtrate under the action of vacuum in the form of an air-liquid mixture is directed through the outlet pipelines 9, 10 through the distribution vacuum head 16 (the design of which consists of successive zones of filtration, washing, dehydration and blowing off the sludge connected by a washer) into receivers 2 and 3, as well as the flow of residual dropping liquid enters into receiver 3 through pipeline 11. The vacuum value in the sludge formation zone is controlled by an automatic control device 17. The vacuum value is regulated in the drying, deep drying and dehydration zones carried out in manual mode. The filtrate from the reservoirs of receivers 2 and 3 through vertical pipelines 12, 13, 14, with a height that provides hydrostatic drainage, enters the filtrate collector 7. Air from receivers 2 and 3 is sent to trap 4, where it is separated from the residual liquid droplets, and then enters barometric condenser 5, and then by vacuum pump 6 is removed from the system. The filtrate from the trap 4 through the pipeline 4 flows by gravity into the filtrate collector 7. The constant vacuum in the system is provided by the barometric condenser 5 and the hydraulic seal 8.

The solid precipitate (cake) obtained in the filtration process is separated from the drum surface under the action of impulse blowing. The air under excess pressure for stripping the sludge (cake) is supplied from the compressors through the pipeline 15, which is hermetically connected to the vacuum distribution device of the drum vacuum filter.

The filter unit equipped with a disk vacuum filter operates in exactly the same mode.

As a result of two-stage separation (the first separation stage (main) provides a drying zone, to which the receiver tank 2 is connected through the branch pipe, the second separation stage (additional) provides a deep drying zone, to which the receiver tank 3 (Fig. 2) is connected through the branch pipe. liquid flow in the housing of the switchgear increases the degree of separation of the air fraction of the filtrate, as well as the reliability and efficiency of the device as a whole, due to the possibility of increasing the pressure drop in the filtering unit system, which allows to increase the degree of dehydration of the filter cake (cake).

Claims (2)

1. A filtering installation containing a vacuum filter (1), a distributor (16), a receiver for separating the filtrate (2, 3) and a trap of residual droplet liquid (4), connected by pipelines, a collection of filtrate (7) connected to a trap (4) and a receiver with vertical hydrostatic drain pipelines (12-14), characterized in that the distribution device (16) is equipped with a discharge pipeline (11) connected to the receiver body (3) and made at an angle relative to the horizontal axis of the distribution device (16 ) with the possibility of directing the flow of filtrate from top to bottom, while on the pipeline (9) by means of a shut-off-adjustable element, an automatic vacuum control device (17) is fixed, made with the ability to maintain a constant vacuum value in the distributor (16) in the zone of sediment formation. 2. Installation according to claim 1, characterized in that the angle of inclination of the discharge pipeline is 50-70 °.

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