RU2343121C1 - Electroflotator for sewage treatment - Google Patents

Abstract

FIELD: mechanics; chemistry.

SUBSTANCE: electroflotator contains the cylindrical chamber of flotation, the block of electrodes, the upholding chamber, the device for gathering and foam evacuation, the water switching centre and handlers and water drainage. The flotation chamber has in the average part the contraction chosen in it convergent tube and a diffuser, and the block of electrodes of alternating polarity established in it in the form of coaxial cylindrical envelopes. The water switching centre is organised with the convergent tube and the lower part of the chamber of flotation with an inclined bottom. The water handler is executed in the form of a branch pipe, is tangential interfaced to the lower part of the chamber and communicated through the adjusting valve with a pressure head branch pipe of the pump. The upholding chamber is organised by interface of the lower part of the chamber of flotation to its inclined bottom. The water drainage device consists of a by-pass branch pipe, coaxial to the chamber of the flotation, having above the drain funnel equipped with directing vanes, and communicated through the adjusting valve with a turnpike plum and, through the stop valve - with a soaking up branch pipe of the pump. The device of gathering and foam evacuation consists of an air collector with a ring nozzle and a conic deflector, the ventilator communicated with a pressure head branch pipe both adjusting by chimney valve, and the punched head communicated through a cyclone with the soaking up branch pipe of the ventilator.

EFFECT: an intensification of process of clearing, compactness of the electroflotator, simplicity of the device and an overall performance, possibility of its application in system of sewage treatment of the individual consumer.

2 cl, 2 dwg

Description

The invention relates to electrochemical methods of wastewater treatment and can be used in refineries, engineering, food industries, as well as in wastewater treatment plants of cottage villages.

Known electroflotator (AS No. 929584, 05/23/1982, C02F 1/46), comprising a housing, which is an anode, made in the form of a truncated cone with a bottom, an cathode equidistant to the housing, devices for introducing and discharging water and for removing foam, the cathode is provided with longitudinal teeth, and the inner surface of the casing is stepped.

A disadvantage of the known device is its significant hydraulic resistance to the flow of the processed fluid, the cause of which are the longitudinal teeth of the cathode and the steps of the housing.

A known apparatus for electroflotation wastewater treatment (patent No. 2051117 C1, 12.27.1995, C02F 1/465), containing a cylindrical flotation chamber with an electrode block located in its lower part, a settling chamber, a scraper device for evacuating foam in the form of a foam gutter, rotating a water distribution device, a device for supplying and discharging water, wherein the settling chamber is made in the form of a cylinder, inside which a flotation chamber is placed coaxially to it, the electrode block is made in the form of coaxial truncated cones alternately polarities facing upwards and installed at an angle of 10 ÷ 30 ° to the vertical axis, the water distribution device is made in the form of a Segner wheel equipped with water distribution pipes, in the upper part of which nozzles are placed at an angle of 10 ÷ 30 ° to the horizontal axis, and installed at block of electrodes.

The disadvantages of the known apparatus are:

- design complexity;

- the absence of a device that controls the water level that ensures the exact coincidence of the foam layer with the trajectory of the scraper foam in case of clogging of the nozzles of the water distribution device, leading to a decrease in the flow rate of the purified water and, as a result, to a decrease in the water level in the settling chamber within the thickness of the water flow through edge of the annular septum pocket pocket;

- the absence of suction of foam from the foam trough, which can lead to overflow of the latter in the event of substances that increase the stability of the foam, which can significantly reduce its natural outflow through the tube;

- significant hydraulic resistance to the flow of purified water provided by the electrode block, since the total movement of the entire mass of water is carried out along a path corresponding to a helical line that does not coincide with the direction of the walls of the truncated cones by 10–30 °. Only the stream of water from the nozzles coincides with the direction of the walls;

- destruction of part of the foam in contact with the solid surface of the scraper foam, which significantly reduces the efficiency of the apparatus.

The known apparatus is closest in technical results and essence to the claimed invention.

An object of the invention is to increase the efficiency of the electroflotator for wastewater treatment by reducing the hydraulic resistance of the electroflotator, efficiently collecting and evacuating the foam, increasing the flotation ability of the electroflotator by reducing the size of electrolysis bubbles, maintaining the water level within specified limits, and preliminary purifying water from macroscopic pollution particles and recirculation of purified water.

The technical problem of the electroflotator for wastewater treatment, containing a cylindrical flotation chamber, an electrode block, a settling chamber, a device for collecting and evacuating foam, a water distribution device and water supply and discharge devices, is solved according to the invention in that the flotation chamber has a narrowing in its middle part allocated in it by a confuser and a diffuser, and a block of electrodes of alternating polarity installed in it in the form of coaxial cylindrical shells, a water distribution device is formed onfuser and the lower part of the chamber with an inclined bottom, the water supply device consists of a nozzle tangentially mating with the lower part of the flotation chamber communicated through the control valve with the pressure port of the pump, the settling chamber is formed by pairing the bottom of the flotation chamber with its inclined bottom, a device for draining water consists of a branch pipe, a coaxial flotation chamber, having a drain funnel equipped with guide vanes at the top and communicated through a control valve with a drain line and through a shut-off valve with a suction nozzle of the pump, the device for collecting and evacuating foam consists of an air manifold with an annular nozzle and a conical deflector in communication with the pressure nozzle of the fan and the regulating gate, and a perforated suction head communicated through a cyclone with the suction nozzle of the fan, and is also solved the fact that the electroflotator includes a water level regulator, consisting of a straight elbow tangentially mated to the inlet of the diffuser, on the vertical link of which it is planted with axial displacement of the drain valve, connected by a cable system with pulleys, including a balancer and a return pulley block, with an annular float, and a collection funnel, which together with an annular overflow pocket along the top of the flotation chamber are communicated through a float valve with a pump suction port.

The invention is illustrated by drawings: Figure 1 - diagram of a flotator; Figure 2 - View A; Figure 3 - section bB; Figure 4 - section bb.

An electroflotator for wastewater treatment consists of a cylindrical flotation chamber 1 with a constriction 2 in its middle part 3, separated in chamber 1 using a confuser 4 and a diffuser 5. In constriction 2, a block of 6 electrodes of alternating polarity from coaxial cylindrical shells 7 is installed. Confuser 4 together with the lower part 8 of the chamber 1 form a water distribution device 9. The lower part 8 has an inclined bottom, in conjunction with which it forms a settling chamber 10 with a valve 11 for discharge of contaminants. The water supply device 12 consists of a nozzle 13 tangentially interfaced with the lower part 8 of the chamber 1, communicated through the control valve 14 with the pressure port of the pump 15. The device 16 for water drainage includes a branch pipe 17, a coaxial chamber 1 having a drain funnel 18 s on top guide vanes 19. The outlet pipe 17 is communicated through the control valve 20 with the drain line 21 and the suction pipe of the pump 15. The pump 15 is in communication with the water supply pipe 22 for cleaning. The device 23 for collecting and evacuating foam consists of an air collector 24 with an annular nozzle 25 and a conical deflector 26. The collector 24 is in communication with the discharge pipe of the fan 27, the pressure of which is regulated by the gate 28. The device 23 also includes a perforated suction head 29 communicated through the cyclone for 30 s fan suction pipe 27. At the beginning of the diffuser 5, a straight elbow 31 of the water level controller 32 is tangentially coupled to the flotation chamber 1. On the vertical link 33 of the knee 31, a drain bolt 34 is fitted with axial movement and is equipped with a prefabricated funnel 35. The bolt 34 is connected by a system 36 of cables and pulleys, including a return sheave 37 and a balancer 38, connected to an annular float 39 fixed against rotation in a horizontal plane. An overflow pocket 40 is placed at the top of the flotation chamber 1, together with the collection funnel 35 communicated through the float valve 41 with the suction port of the pump 15. Through the shut-off valve 43, the drain line 21 is in communication with the suction port of the pump 15.

The electroflotator for wastewater treatment works as follows: along the line 22, the wastewater is supplied to the pump 15, from where the water enters the water distribution device 9 through the tangential nozzle 13 of the supply device 12, specifically into the lower part 8 of the chamber 1, is twisted and forms a rotational-axial the upward flow, from which the macroscopic particles of contamination (particles visible to the naked eye) are discarded to the wall of the lower part 8 by centrifugal forces, slide down it into the settling chamber 10, settle in it and through the crane 11, as they accumulate, are discharged into the sewer. Thus, a preliminary treatment of wastewater is carried out. The flow is accelerated in confuser 4 and passes with great speed in the gaps between the shells 7 of the block 6 of the electrodes, which reduces the size of the gas bubbles released during the electrolysis of wastewater on the surface of the shells 7, due to the preventive separation of gas bubbles from the surface of their formation by the high-speed water flow, before they, having grown in size, come off under the influence of their lifting force. This increases the number of electrolysis gas bubbles, their total contact surface and, therefore, the floating ability of the electroflotator, as well as the stability of the foam layer formed on the water surface, which ultimately contributes to an increase in the performance of the electroflotator. The water flow slows down in the diffuser 5, finely dispersed electrolysis gas bubbles, evenly distributed in the treated wastewater stream, move upward, having a higher lifting force, collide with pollution particles, adhere to them and then float them on the water surface, forming a stable foam layer. Other electrolysis products disinfect water and purify it from organic contaminants. The flow of purified water rises to the top of the outlet pipe 17, while the flow is further untwisted, since the bore of the chamber 1 is clamped by an annular float 39 and a drain funnel 18. The guide vanes 19 wind the flow through an angle α between the blade 19 and the flow motion vector R, which is the sum of the vectors : N is the radial component and P is the circumferential component of the movement of the water flow. The flow begins to spin long before the zone of direct impact on the flow of the blades 19. The rotation of the water flow increases the curvature (rise) of the surface from the center to the periphery of the vortex funnel 42, formed during rotation of the flow (see Figure 4) due to centrifugal forces. The flow overflows over the edge of the drain funnel 18 and through the branch pipe 17 the water goes to the drain line 21 and then by gravity to the storage tank (not shown conditionally).

The surface of the vortex funnel 42 extends from the point of contact with the float 39 and to the point of contact with the top of the vanes 19. Thus, the height of the vanes 19 is equal to the thickness of the flow overflowing the edge of the drain funnel 18. To achieve this position, regulate the ratio of water supply and drain with adjusting valves 14, 20. By valve 43, it is possible to control the power of water recirculation through the electroflotator with significant wastewater contamination if the floatability of the electroflotator is not sufficient for complete cleaning of sludge necessary to increase the degree of waste water purification. When draining purified water by gravity, fluctuations in the throughput of the discharge line 21 are likely, especially if the drain is carried out under the surface of the volume of water in the storage tank. These fluctuations are reflected at the water level in chamber 1 and, therefore, at the position of the vortex funnel 42 relative to the drain funnel 18 of the branch pipe 17. To prevent this, the water level controller 32 is used. When the water level in the chamber 1 fluctuates, the vertical movements of the float 39 are transmitted by the system 36 to the drain gate 34 in a 2-fold larger value. The shutter 34 lowers when the water level in chamber 1 rises, and since the link 33 is a communicating vessel with chamber 1, the excess discharge of the excess water supply to chamber 1 into the collection funnel 35 increases. When the water level in chamber 1 drops, the shutter 34 rises and decreases discharge of excess water supply to chamber 1. Since the water level in chamber 1, i.e. the position of the float 39 and the vortex funnel 42 relative to the funnel 18 is determined not only by the static position of the water, i.e. the ratio of the supply and removal of water from the chamber 1, but also the speed of the water jet from the pipe 13, which depends on the amount of water supply to the chamber 1 and determines the speed of rotation of the water in the chamber 1, the elbow 31 mates with the diffuser 5 tangentially, towards the direction of rotation of the water. This is done in order to take into account the dynamic component of the flow pressure, and not just the static. The controller 32 maintains the position of the vortex funnel 42 relative to the drain funnel 18 within the specified limits as follows: at a nominal level of water in the chamber 1 through the shutter 34 into the funnel 35, the water flow constantly merges with a given minimum flow rate. When the shutter 34 is displaced, the flow rate changes in one direction or another. When changing the ratio of water supply and drain, the regulator 32 manages to adequately respond to changes in the water level (funnel position 18), since the rate of this change is insignificant due to the inertia of the entire system, including the supply and discharge of water, the volume of the chamber 1. When changing the speed of the jet from the nozzle 13, the level changes rapidly, and the design of the controller 32 provides for accelerating its reaction to a change in the level by decreasing or increasing the dynamic pressure of the water flow in the link 33 along with raising or lowering the shutter 34, respectively of course. This is achieved by the fact that the nozzle 13 mates with the diffuser 5 tangentially, towards the direction of rotation of the water in the chamber 1. A decrease or increase in the dynamic pressure of the water flow in the link 33 causes a decrease or increase in the dynamic water level in it, which, at the same time, increases or decreases the shutter 34 causes a rapid corresponding change in the amount of water draining from the gate 34 to the funnel 35. When the water level in the chamber 1 fluctuates, it can overflow over the edge where water is collected in the overflow pocket 40 and through the pop avkovy valve 41 is directed to the inlet of the pump 15. In the same manner utilized water from the collection hopper 35.

The valve 41 prevents air from entering the inlet of the pump 15, which could result in failure of its operation.

A layer of foam with impurities on the surface of the vortex funnel 42 along the slope of its surface under its own weight and under the influence of an air stream from the annular nozzle 25 flows to the drain funnel 18, where it is sucked into the cyclone 30 through the perforated suction head 29 under the influence of the fan 27 and separated in it pollution, water and electrolysis gas. Pollution with water is discharged into the sewer.

By the fan 27, air, in a quantity dosed by the gate 28, is supplied to the air collector 24, and from it to the nozzle 25. The hydraulic resistance of the electroflotator is insignificant, since the main cause of the high resistance is the block of 6 electrodes, but unlike the prototype, where the electrodes are conical in shape , the electroflotator electrodes are made in the form of shells of a cylindrical shape and therefore do not exert significant resistance to the flow flowing along the axis of the shells.

The design of the electroflotator allows you to intensify the cleaning process, which makes it possible to make it compact. This, along with the simplicity of its structure and operational efficiency, makes it possible to use it in the wastewater treatment system of an individual consumer.

The simplicity of the design of the electroflotator and its efficiency will ensure widespread use of the invention in practice.

Claims (2)

1. Electroflotator for wastewater treatment, containing a cylindrical flotation chamber, an electrode block, a settling chamber, a device for collecting and evacuating foam, a water distribution device and water supply and drainage devices, characterized in that the flotation chamber has in its middle part a constriction allocated to it with a confuser and a diffuser, and a block of electrodes of alternating polarity installed in it in the form of coaxial cylindrical shells, a water distribution device is formed by a confuser and the lower part of the flotation chamber and with an inclined bottom, the water supply device is made in the form of a nozzle tangentially interfaced with the lower part of the chamber and communicated through the control valve with the pressure port of the pump, the settling chamber is formed by interfacing the bottom of the flotation chamber with its inclined bottom, the water drainage device consists of a branch pipe, coaxial flotation chamber having a drain funnel at the top, equipped with guide vanes, and communicated through the control valve with the drain line and through the shut-off valve - with suction the pump nozzle, the device for collecting and evacuating foam consists of an air manifold with an annular nozzle and a conical deflector in communication with the pressure pipe of the fan and the regulating gate, and a perforated head communicated through the cyclone with the suction pipe of the fan. 2. The electroflotator for wastewater treatment according to claim 1, characterized in that it includes a water level regulator consisting of a straight elbow tangentially mated to the inlet of the diffuser, on the vertical link of which a drain valve is connected with the possibility of axial movement, connected by a cable system with pulleys, comprising a balancer and a reverse chain hoist, with an annular float, and a collection funnel, which together with an annular overflow pocket along the top of the flotation chamber are communicated through a float valve with a pump suction pipe.

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