SU742394A1 - Unit for dehydrating precipitates - Google Patents

Description

This invention relates to a wastewater treatment technique and can be used in water supply and sewage.

A device for sludge dewatering is known, comprising two conveyors with filter belts of electrically conductive material / one above the other on drums with a conductive surface connected to a constant voltage source.

The purpose of the invention is to improve the performance of the device in operation by improving the regeneration of the filter belts.

This is achieved by the fact that the device (Equipped with treads with through-cutouts installed on the conductive surface of the drums under the ribbons, and water-sprayers installed inside the conveyors and directed to the treads.

FIG. 1 shows a diagram of the device; in fig. 2 - conveyor drum; in fig. 3 shows section A-A in FIG.

The proposed device consists of two (upper and lower) drive belt conveyors. Each conveyor includes drums 1 (one of

drive drums), filter belt 2 and rollers 3 tension filter belts. Tape 2 is made of permeable electrically conductive material, for example, carbon fiber-based carbon fiber. This material has high strength and elasticity, resistance in aggressive environments, good electrical conductivity and porosity. The device includes a dispenser 4 for supplying initial sludge 5, wash water sprayers 6, additional wash water sprayers 7, dehydrated sludge collecting bin 8 15, filtrate and washing water collections 9, waterproof case 10, scrapers 11 and control valves 12-14.

One of the drums of each conveyor is made in the form of a dielectric cylinder 15 with shoulder 16, pressed on the upper part 17.

Claims (1)

The outer surface of cylinder 15 is covered with a grid 18 of electrolytic insoluble material, for example, from titanium platinized wire. The grids are connected to a constant voltage source and serve as electrodes. The surface of the grid 18 is protected by a dielectric protector 19 in which through-cut chevron-shaped cuts 20 are provided that act as collectors of contaminations tapes. the nature of the particles and the degree of dehydration required. The thickness of the tread is selected within 3 10 mm. The proposed device works as follows. With the aid of the drums 1, the filter belt of the conveyor belt 2 is set in motion. The valves 12-14 open. Through valve 12 and the metering device 4, the initial sediment 5 is fed to the filtering belt 2 of the upper conveyor, on which hydrostatic removal of moisture occurs under the action of the force of the draft gravity. The separated moisture accumulates in the filtrate collector 9, from which it is discharged through the overflow pipe to the bottom conveyor collector, then into the body pan 10 and drains through the valve 14 into the waste system. Through the filter belt 2 of the upper conveyor, the partially dewatered sediment enters the lower conveyor belt and then into the narrowing space between the upper and lower belts, where under the effect of the pressure created between them, a deeper sludge dewaters. Simultaneously with the pressure dewatering process, due to the connection of 2 conveyors to one of the poles of a constant voltage source with water filtering belts, additional electroosmotic displacement of the liquid phase of the sediment occurs between the belts. The dewatering process proceeds more intensively, the degree of drying of the sludge increases, its volume decreases. G using wash water supplied through valve 13 to the spray guns 6 and 7, performs continuous preventive regeneration of the upper and lower filter belts, as well as cleaning the drums 1; Cutouts 20 of the tread 19 in the overlap zone with their tape 2 are filled with wash water. Water enters the cutouts either directly from the nozzles or from the surface of the tapes. Each of the notches 20 in the overlap zone serves as an electrophoretic cell. As the degree of residual contamination of the drive filter belts 2 increases, the grid 18 is connected to a constant voltage source, to a pole opposite to the pole of the tape. Under the action of the electric field, the electrophoretic movement of the dispersed phase (polluter) from the thickness of the filter tapes 2 to their surface and further to the grid 18 occurs. The contaminants accumulating around the grid 18 in the cells 20 as the drums turn, are washed off installed at an angle to the free surface of the reels 1, are discharged together with the washing water into collectors 9 and discharged from the device. The chevron shape of the cutouts 20 facilitates the cleaning of the nets 18. It is also these cutouts in the tread 19 that contribute to the stabilization of the tape on the drum and prevent it from slipping to the left or right from the middle of the drum. The dehydrated sludge enters the hopper 8. The bacterial phase, contained in most of the sludge being treated, is a colloidal structure with a charge that is predominantly of a negative sign. Under the action of the electric field created between the driving filter tapes 2, their electrophoretic movement will occur in the direction opposite to the direction of movement of the dispersion medium, i.e. the filtrate and flush water will be disinfected, which will remove them from the device without additional treatment. The regulation of the speed of the sludge dewatering process, and consequently the productivity of the entire device, is preliminarily carried out by loading the conveyor shafts, and more precisely, by changing the magnitude of the electrical voltage on the driving filter belts. Regulation of the speed and quality of the process of recording drive filter tapes can also be made by varying the voltage on the drive belts 2 and grids 18. Claims The device for dewatering sediments includes two conveyors with filter belts made of electrically conductive material, one above the other on drums a surface connected to a constant voltage source, characterized in that, in order to increase device performance by improving regeneration and filtering belts, the device is provided with protectors with through cuts mounted on the conductive surface of the drums under the belts, and water mist nozzles installed inside the conveyors and directed to the protectors.