RU194980U1 - SCREW CONVEYOR-DEHYDRATER DRAINAGE FROM LIQUID Sump - Google Patents

Abstract

The utility model relates to devices used to clean liquids from mechanical particles. The screw conveyor-dehydrator is used to remove sludge deposited at the bottom of the sump and shifted into the storage pit, as well as to dewater the sludge. The conveyor is used for vertical installation or with a small angle of deviation of its axis from the vertical. Sludge dewatering is ensured by draining through the holes in the tubular shaft of the rotating screw of the liquid, which is separated from the mechanical particles by the action of centrifugal force, as well as by a slotted filter. The movable filter plates do not contact the screw and are shifted by centrifugal forces acting on the mechanical particles of the sediment. Periodic cleaning of the entire working surface of the filter is carried out by a reverse fluid flow. The intake part of the screw conveyor contains two helically curved blades and an impeller in the form of a propeller to prevent clogging of the tubular shaft of the screw. The screw has two sections with different pitch screw blades and a space for the formation of a plug from the sediment, providing compression of the sediment in the filter. The result is a combination of the functions of transportation and dewatering of sludge without complicating the design of the conveyor-dehydrator. 5 cp f-ly, 3 ill.

Description

The utility model relates to devices used in the industry for cleaning liquids from contamination by mechanical particles, as well as soluble pollutants when using adsorbents mixed with liquid in the cleaning process. Sedimentation is the simplest and most often used in practice method of separating dispersed impurities from liquids that, under the influence of gravitational force, settle to the bottom of the sump.

The proposed utility model is used to remove sludge deposited on the bottom of the sump and in one way or another shifted into the sump - sediment accumulator, as well as dewatering (thickening) the sludge by removing excess liquid from it during transportation.

There are known cases of the use of a screw conveyor for the removal of sediment from the pits of liquid purifiers (RF patent No. 2156641). The auger conveyor comprises a shaft with a screw blade (auger), a pipe-shaped housing, a screw rotation drive installed in the upper part of the conveyor, an unloading tray and an intake part located in the pit where dirt is deposited. In this patent, to expand the area of sediment intake, additional precipitation surfaces are used in the form of plates with slots through which scrapers rotating behind the plates pass, the ends of which move towards the intake part of the screw conveyor.

Such a technical solution can be used to clean the water flow supplied to the settling plates and the screw conveyor, which carries pollution in the form of plant sediments or fibers, films, etc. pollution of technological origin.

Removing from the pit of mechanical particles of adsorbent, sand and similar contaminants according to this patent is not effective, which requires the use of other options for the intake part of the screw conveyor.

Commercially available auger conveyors of bulk materials work, usually at an angle of inclination of 0-45 ° from the vertical. The vertical conveyors (conveyors) of the VVK-VK-B, ADRF and others series are known, which are additionally equipped with horizontal screw feeders, which allow forcing the conveyed material to be fed to the main screw. This is due to the fact that the rotating auger in the intake part (outside the housing pipe) has the ability to discard the load from itself. The effect of forced feeding of the transported material is also achieved in the case when there is a high and narrowed receiving hopper, from which, under the pressure of the weight of the column of bulk material in it, it is possible to introduce it into the pipe of the auger body.

In patent No. 2452677, the intake conveyor of the screw conveyor has a housing with an expanding initial part and a screw located in it with a shaft in the form of a hollow expanding to the initial part of the pipe, equipped with windows made along a helical line and curved blades. Inside the hollow expanding initial part of the shaft along its axis is an insert in the form of a cone, on which a smaller screw is also placed. Bulk material comes from the hopper into the hollow part, is taken by the blades of the conical insert and fed from the inside to the blades of the expanding part of the screw.

This design reduces the effect of discarding the transported material by the main blades of the screw, however, it does not provide adequate conditions for the fence with a vertical or steeply located screw conveyor. This is due to the fact that the expanding part of the conveyor body, like a screen located close to the bottom of the hopper, contributes to the formation of bulk material, which impedes normal operation of the conveyor and sufficiently complete emptying of the hopper.

In SU patent No. 456404, a screw conveyor intake device is proposed in the form of two inclined blades enclosing the housing rigidly mounted on a disk mounted on the screw shaft, during rotation of which the blades press the bulk material under the blades mounted on the conveyor body and feed it through the provided slots to auger blade.

The disadvantages of this device include the presence of a solid disk of large diameter, eliminating the possibility of taking bulk material from the end of the auger housing, which creates a “dead” zone in the hopper. The helical surface of relatively narrow blades does not create direct pressure on the bulk material directly in the direction of the screw rotating in the housing, which does not ensure its high filling and conveyor productivity.

Known methods and devices for separation during the transportation of the suspension into two parts - solid and liquid (for example, RF patent No. 2355578). The device contains, with separate drives, a screw press with a permeable cylinder wall and a screw conveyor, and between them a sealing device in the form of a curved pipe in which a tube of transported material is formed. At the same time, the suspension flow is delayed and the liquid phase is displaced under the pressure that arises. The solution to the obvious problem - clogging the cylinder wall openings with mechanical particles and the possibility of cleaning them, is not considered in this patent.

To separate the solid and liquid phases of the sludge removed from the liquid sump, devices are widely used that contain a liquid-permeable packet of plates with a central hole through which the screw passes and peripheral holes used to fasten the plates with threaded rods into a single slot filter unit. To compress the sludge passing through the slit filter, the screw pitch is made to decrease in the direction from the intake part to the discharge outlet of the dehydrated sludge, for example, in commercially available units KIT OSh 300/2 et al. [SMZ.su].

To reduce the likelihood of clogging of the filter slots by particles falling into them, the package of plates includes alternately mounted fixed (fastened with studs) and movable plates that can be displaced relative to the fixed plates within specified limits. Examples of such devices - dehydrators, are described in RF patents No. 241056 (Japan), No. 2526638 (Japan).

The displacement of the moving plates can occur when their central hole is smaller than the diameter of the screw and its rotating blade moves the plate in the direction of their contact point. With such a scheme, increased wear on the inner surface of the plate and the outer surface of the screw should be expected. Other more complex circuits using eccentric drives can be used.

The dehydrator according to the patent of the Russian Federation No. 152716 provides for the rotation of the body formed by a packet of plate rings fastened by three studs and movable rings installed between them with a diameter of the central hole less than the diameter of a screw having a variable pitch of a helix. The rotation of the package of plates as a slotted filter with a horizontal axis of the auger and dripping of the allocated liquid down allows you to increase the total working area of the slotted filter. This is the advantage of this design, and the disadvantage is the absence of distance inserts between the plates, which can lead to a shift of the plates until they are adjacent to each other and the formation of wide gaps through which large particles of the processed suspension can pass. In addition, wear of the rings and auger over their contact surface is possible, the rotation of the plate package significantly complicates the design.

Given the positive qualities of the considered analogues, a utility model is proposed whose technical tasks are to combine the functions of transporting sediment from a sedimentation tank and separating its liquid and solid fractions without significantly complicating the design of a vertical or steeply installed screw conveyor, thereby saving production space.

The set of essential features set forth in the formula of the utility model, allows to achieve the desired technical result.

The utility model is illustrated by the figures:

FIG. 1. - General view of the screw conveyor-dehydrator and its remote element, showing the location of the holes for draining fluid from the auger blades;

FIG. 2. - slot filter device;

FIG. 3. - design of the intake part of the screw conveyor. The screw conveyor-dehydrator 1 (Fig. 1) is in working condition in an inclined channel in the end wall of the sump, and its intake part 2 is located above the bottom of the pit, into which the sediment moves from the bottom of the sump. At the top of the tubular conveyor housing there is a screw drive 3 of rotation of the screw 4 and a tray 5 for unloading the dehydrated sludge.

Between the intake part and the gear motor, above the upper liquid level in the sump, the tubular body has a section for separating solid and liquid sediment fractions in the form of a slit filter located in the housing 6, in the lower part of which there is a nozzle with a valve 7 for draining the leak from the rotating screw through slots of liquid. In the upper part of the housing there is a pipe 8 for supplying washing liquid to the filter.

The slit filter (Fig. 2) consists of a package of fixed metal plates 10 fastened with pins 9 with a central hole for the diameter of the screw, and spacer sleeves 11 and movable plates 12 alternating with them.

The thickness of the movable plates is less than the height of the spacer sleeves by the value of the required limit size of the mechanical particles transmitted by the slit filter. The diameter of the central hole of the movable plates is equal to the diameter of the holes of the fixed plates fastened by four threaded rods, and on the peripheral surface of the movable plates there are four arcuate grooves 13 curved in the direction of the center of the plates by a radius greater than the radius of the distance bushings by 2-3 mm. The axis of the arcs coincides with the axes of the studs, while parallel sections of the groove adjacent to the arc have a length of 6-9 mm.

The package of plates at the top and bottom is limited by thick mounting plates 14, which are compressed by stud nuts. The filter is inserted into the housing and worn on the protruding edge of the tubular housing of the screw conveyor, and the upper part of the tubular housing is mounted on top in the same way and attached with its flange 15 to the flange of the filter housing.

The screw is divided into two sections, the first section has a length from the bottom end of the screw blade to the exit of the blade from the slotted filter. The beginning of the screw blade of the second section of the screw is spaced from the upper end of the blade of the first section at a distance of 0.8-1.0 steps of the helix, and ends near the upper end of the tubular body of the screw in the area of the discharge opening with a tray for unloading the transported sediment from the tubular body of the screw. The pitch of the helix of the first section refers to the step of the second section, as 1: 0.8.

The screw shaft is made of pipe 16, in the wall of which there are holes 17 (Fig. 1) with a diameter of 3-5 mm drilled on the interface line between the upper plane of the screw blade and the pipe wall at an angle of 30-45 ° to the plane of the blade. The number of holes 4-6 on one revolution of the screw blade, while the first hole is 3-4 steps from the bottom of the blade, and the last hole is 1-2 steps from the start of the slotted filter at a distance of 1-2 steps of the helix. The same holes are made in the wall of the screw shaft pipe in its second section.

The intake part of the screw conveyor is equipped with a device for feeding sediment to the screw blade of the screw, made in the form of two spirally curved blades 18 (Fig. 3), fixed with their lower ends through two plates 19 and two plates 20 to the disk 21. The disk is rigidly connected to the cylindrical sleeve 22, which is an element of the bearing assembly 23 and connected with the end of the pipe 16 by a bolt 24. In this case, the beginning of the spiral-developing blades are in the same diametrical plane from different sides of the axis of rotation of the screw at a small distance from four racks 25 attached to the tubular housing of the screw and holding the disk 26 of the mounting of the bearing assembly of the screw, located at a distance from the end of the tubular housing equal to 1.2-1.3 of its diameter. The ends of the blades are on the other hand in the same diametrical plane at a greater distance from the axis. Moreover, the upper ends of the blades are 5-10 mm higher than the lower end of the tubular auger body.

The plates 20, fastening the ends of the beginning and end of the blades with the disk below, are L-shaped, while the protruding part of the plates is bent outward at an angle of 30 °, and rectangular plates 27 are also bent, fastening the ends of the spiral blades to each other from above, thereby forming scrapers shifting the sediment from the ends into the intake part of the screw conveyor during rotation of the screw.

The lower part of the cylindrical sleeve 22, protruding beyond the disk to which the spiral blades of the intake device are mounted, has symmetrical longitudinal grooves 28 on both sides so that the width of the remaining two protrusions is equal to the inner diameter of the screw shaft pipe. The protrusions have transverse sections 29 at an angle of 20-30 ° to the diametrical plane of the sleeve opposite to each other, to which the impeller blades 30 are attached in the form of a propeller, the direction of which, when the screw rotates, ensures that the sediment surrounding the intake part is pulled down and the fluid is sucked out of the shaft pipe auger.

The intake part is enclosed by a protective cage containing a ring 31 connected to the pipe of the screw housing by four racks 32 and cross members 33 welded to the wall of the tubular screw housing and racks 25.

Screw conveyor dehydrator is used as follows. After pumping out the settled water from the sump and shifting the sludge into the pit with the open valve 7, the drive 3 is turned on. Rotating blades 18 capture the sludge and feed it to the blade of the rotating screw 4. The rotational movement of the sludge is braked by the struts 25, the screw blade picks up the sludge and lifts it into the tubular body , in which the sediment unwinds, a centrifugal force arises, pressing the sediment against the pipe wall. The rotational movement of the sediment is braked and there is a further shift of the sediment with the auger blade up. It is known that for vertical and steeply installed conveyors, the screw rotation speed is taken equal to 200-1000 rpm, for liquid suspensions the speed can be even greater.

The precipitate in the form of a suspension of liquid and denser mechanical particles under the action of centrifugal force exfoliates. Dense mechanical particles fall onto the wall of the housing, and fluid remains around the screw shaft. In this case, the liquid can flow downward along the inclined helical surface under the action of gravity, and also flow from the blade through the holes 17 in the wall of the pipe 16 into it.

In the initial lower portion of the screw, drilling of holes in the pipe wall is not provided, since the precipitation of mechanical particles under the action of centrifugal force does not occur instantly, i.e. it takes some time to unwind the sediment.

An impeller in the form of a propeller 30 at the lower end of the shaft of the rotating auger prevents clogging of the auger shaft pipe with sediment and facilitates the drainage of fluid flowing through the holes into the shaft pipe from the sediment transported by the auger, ensuring its more complete dehydration.

The shift of the slit filter plates 12 occurs under the action of centrifugal force acting on the particles raked by the blade in the area where the peripheral part of the screw blade adjoins the inner surface of the plates. Each plate is statically unbalanced, since the mass of the platen being rolled from mechanical particles in the zone of contact of the blade to the plate is always greater than the mass of particles currently deposited from the suspension on the diametrically opposite surface of the plate. This leads to a "dip" of the movable plate with respect to adjacent fixed plates. The absence of direct contact of the screw with the movable plate eliminates the associated wear of the screw and plates during their mutual friction.

When the screw rotates, the area of such a fit shifts around the circumference and height of the slit filter, which leads to wave-like movements of the moving plates. This eliminates the clogging of the cracks between the plates penetrating them with mechanical particles. The fluid flowing from the rotating auger through the slit filter through the nozzle and the open valve 7 is directed back to the sump.

In the gap between the screw blade of the first section of the screw and the beginning of the blade of the second section of the screw, a plug is formed from it as the sediment is transported. This leads to an increase in the total pressure of the sludge in the area of the slit filter, contributing to a better extraction of the liquid from the transported sludge. In the slot filter section, holes in the screw shaft pipe are not provided.

The compressed sediment from the cork is taken by the screw blade of the second section of the screw, having a step smaller than the step of the first section and the holes on the shaft pipe, the same as in the first section of the screw. Through these openings, the liquid separated by centrifugal force from mechanical particles also flows down the auger shaft pipe into the sump. Passing through the whole auger and substantially dehydrated sludge is discharged through tray 5, for example, to a platform or a conveyor belt, with subsequent delivery to the place of use for its intended purpose.

The slotted filter is washed with a certain frequency with the tap 7 closed and the washing liquid supplied to the filter housing through the nozzle 8. In this case, mechanical particles are washed out of the slots between the plates along the entire surface of the slotted filter inside and merged into the sump.

Thus, the positive qualities of the proposed design that solve the technical problems are:

sludge dewatering occurs during its transportation from the sump due to separation of the suspension under the action of centrifugal forces into mechanical particles and liquid, which is removed through the screw shaft pipe, as well as through a slotted filter;

the entire surface of the slit filter is equally involved in the filtering of the sludge, and not only its lower part, as is the case in most horizontal dehydrators or those tilted at a small angle;

simple design and manufacturing technology of a screw with two sections of screw blades with different constant pitch compared to a screw with a variable pitch;

simple technological support due to the height of the spacers of any desired size of the filter slots, ensuring the mobility of the slit filter plates without contact with the screw, which contributes to the filter without clogging and reduces wear on the screw and plates;

reliable washing of filter slots over its entire working surface with a static pressure of the backflow of washing liquid;

screw conveyor-dehydrator due to the proposed design of the intake part can work effectively with vertical installation or with a slight deviation from the vertical, which reduces the need for production space.

Thus, the proposed utility model solves the technical problems.

Claims (6)

1. Screw conveyor-dehydrator sludge from the liquid sump, containing a shaft with a screw blade fixed thereon, forming a screw, which is installed in a tubular body, at the top of which there is a screw rotation drive and a tray for unloading the dehydrated sludge from the tubular body, and at the bottom there is an intake part made with the possibility of location in the pit of the sump, in which sediment accumulates, while the tubular body has a section of separation of solid and liquid fractions in the form of a slit filter consisting of fastened ogo pins of a package of fixed metal plates with a central hole for the diameter of the screw and alternating with them movable plates with a hole, characterized in that the slotted filter, configured to be located above the liquid level in the sump, contains a housing fastened with a tubular housing, while in the lower part of the slotted filter housing there is a pipe with a tap for draining the fluid flowing from the rotating screw through the slots of the slotted filter, and in the upper part there is a pipe for feeding washing fluid, and the intake part of the tubular housing is equipped with a device for feeding sludge to the screw blade of the screw, made in the form of two spirally curved blades, fastened by plates to each other and fastened by their lower ends by means of plates to the disk, rigidly connected to the cylindrical sleeve, which is an element of the bearing of the screw assembly and the screw connected to the end of the screw shaft, while the beginnings of two spirally curved blades are located in the same diametrical plane from different sides from the axis the auger at a distance from four posts attached to the tubular body and holding the disk at a distance from the end of the tubular body equal to 1.2-1.3 of its diameter, and the ends of two spiral curved blades are located on the other side in the same diametrical plane on a larger the distance from the axis of rotation of the screw, while the upper end of the blades is 5-10 mm higher than the lower end of the tubular body, the intake part of which is made with the possibility of enclosing it with a protective stand. 2. The screw conveyor-dehydrator according to claim 1, characterized in that the spirally curved blades are attached to the disk by means of two plates fastening the ends of the beginning and end of the blades to the disk and having a L-shaped shape with a protruding part bent outward at an angle of 30 °, and two flat rectangular-shaped plates located in the perpendicular-diametrical plane and connecting the lower ends of the blades with the disk, while the blades are fastened together by two curved rectangular plates that fasten the ends of the blades between on top with the formation of scrapers to shift the sediment from the ends into the intake part of the screw conveyor-dehydrator. 3. The screw conveyor-dehydrator according to claim 1, characterized in that the slotted filter is made with spacer sleeves and four studs on which the spacer sleeves are worn, while the thickness of the movable plates is less than the height of the spacer sleeves by the size of the size limit of the mechanical particles passed through the slotted filter, and the diameter of the Central hole of the fixed plates is equal to the diameter of the holes of the movable plates, and on the peripheral surface of the movable plates are four arcuate grooves, curved in the direction of the center of the plates along a radius greater than the radius of the spacer sleeves by 2-3 mm, while the axis of the arcs coincide with the axes of the studs, and parallel sections of the groove adjacent to the arc have a length of 6-9 mm. 4. The screw conveyor-dehydrator according to claim 1, characterized in that the screw is made with two sections, the first of which has a length from the bottom end of the screw blade to the exit of the blade from the slot filter, and the beginning of the screw blade of the second section of the screw is separated from the upper end of the blade the first section at a distance of 0.8-1.0 steps of the helix, and ends at the upper end of the tubular body in the area of the discharge hole and the tray for unloading the dehydrated sludge made in the tubular body, while the helix pitch the first section refers to the helix pitch of the second section, as 1: 0.8. 5. The screw conveyor-dewatering sludge according to claim 4, characterized in that the screw shaft is made in the form of a pipe with holes with a diameter of 3-5 mm in its wall drilled on the interface line of the upper plane of the screw blade with the pipe wall at an angle of 30-45 ° to the plane of the blade, the number of holes 4-6 on one revolution of the screw blade, while the first hole is separated from the lower end of the blade by a distance of 3-4 steps of the helix, and the last hole is separated from the beginning of the slot filter by a distance of 1-2 pitch screw l NII. 6. The screw conveyor-dehydrator according to claim 5, characterized in that the lower part of the cylindrical sleeve is made with impeller blades in the form of a propeller, protrudes beyond the disk and has symmetrical longitudinal grooves on both sides, forming two protrusions with a width equal to the inner diameter of the screw shaft pipe while the protrusions have transverse sections at an angle of 20-30 ° to the diametrical plane of the sleeve, opposite in direction to each other, to which the aforementioned impeller blades are attached, the direction of which is ensured by rotation of the screw Repulsion of the sediment surrounding the intake part downward and liquid suction from the screw shaft pipe.

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