SU808781A1 - Plant for evaporation of industrial sewage - Google Patents

Description

one

The invention relates to a plant for the neutralization by evaporation of wastewater with a low concentration of dissolved organic impurities, in particular, wastewater from the impregnation production, containing vapor-volatile phenols, resins and other organic compounds, and can be used to concentrate process solutions, absorption and cooling of gases.

Methods are known for the disposal of wastewater by evaporation by flue gases with direct contact of heat-transfer agent and wastewater.

Spray scrubbers, Venturi scrubbers, and other devices will be used to implement these methods.

Significant drawbacks of the known devices are increased entrainment of liquid with steam due to the lack of separable elements, as well as the large size and complexity of the devices used, the need to supply liquid or gases under high pressure and frequent clogging of spray nozzles with deposits.

The closest to the proposed technical essence and the achieved effect is an installation for evaporation, containing a closed tank with gas inlet and gas outlet nozzles and a water sprayer made of horizontally arranged A-shaped boxes with slots on the ridge 2.

The drawbacks of the installation when used as an evaporator when evaporating wastewater is the difficulty of removing sediment formed during evaporation of effluent from the walls, and the removal of liquid from the vapor-gas medium due to the absence of separating elements.

The purpose of the invention is to reduce the entrainment of liquid and simplify the design.

The goal is achieved by

In the installation for evaporation of industrial wastewater containing a closed tank with a gas inlet and gas outlet pipe and a water sprayer made of horizontally arranged A-shaped boxes with slots on the ridge, the water sprayer is mounted in the gas inlet pipe, and the gas outlet pipe is fitted with a braid sponge. with

Claims (2)

0 side water sprayer. Such a design provides for spraying a liquid by a gas stream without using nozzles and creating a developed contact surface and relative velocity of the gas and liquid phases, as well as their subsequent separation. All this makes it possible to use the device both for evaporation of wastewater and for condensation of the resulting vapors. FIG. 1 is a flow chart of a wastewater treatment plant; in fig. 2 shows the design of an installation for evaporation of industrial wastewater. The installation includes a vaporizer 1, a recirculation pump 2, a condenser 3, a fan 4, a gas duct 5 for supplying off-gases, a pipe 6 for discharging them into the atmosphere, a pipeline for recirculating evaporated water, steam B and 9 for supplying and discharging oro water and a pipe 10 for discharging residue from the evaporation of waste water. The installations for evaporation of wastewater and vapor condensation are of the same design and consist of a closed tank 11 with gas inlet 12 and gas outlet 13. In the gas inlet pipe a water-sprayer is mounted from horizontal A-about different ducts 14 with slots 15 on the side walls forming wedge-shaped slots between them. The gas outlet nozzle 13 is equipped with a vertical visor 16 on the side of the movement of the gases. The nozzles 17, 18 and 19 are intended for supplying and discharging water and starting the residue. The installation works as follows. The waste water to be evaporated is poured into the closed tank 11 of the evaporators 1 and the recirculation pump 2 through the pipeline 7 is continuously fed to the A-shaped boxes 14 of the water spray gun. Water exits through the slot 15 on their side walls and flows down over them in the form of a film. The flow of exhaust gases with a temperature of 200-300 ° C, forcibly supplied by fan 4 to evaporator 1, the passage at increasing speed through the gaps between the A-shaped boxes breaks the waste water film into small droplets and evaporates moisture from their surface. . The large contact surface and the relative velocity of the gas and liquid phases intensify the evaporation process, and the presence of a water film on the surface of the ducts prevents them from overheating and corrosion by flue gases. In the tank 11, the gas flow makes a turn around the vertical visor 16 in the horizontal and vertical planes, in which the liquid is separated from the gas and is again pumped to the water sprayer. From the vaporizer 1, a stream of gases saturated with water vapor is directed to the condenser 3, and low-concentrated waste water with a temperature below the dew point of the incoming gases is fed to the water sprayer. As a consequence, upon contact of gases with water droplets, vapor condenses on their surface, together with which volatile organic impurities are trapped. The sprayed water in the same manner as in the evaporator is separated from the gas stream and sent for purification by known methods, and the cooled gases are vented by the fan 4 to the atmosphere. The presence of heat transfer surfaces and nozzles susceptible to corrosion and contamination by deposits, greatly simplifies the operation of the evaporator. For its operation, a gas head is required 30-50% less than for Venturi scrubbers. The concentration of harmful impurities in the exhaust gases does not exceed the NIR in the air of the working area. In addition, the waste gases, when contacted with sprayed water, are partially cleaned from ash and other combustion products. To condense vapors, it is possible to use wastewater sent to conventional treatment plants, which eliminates additional water consumption. The invention The apparatus for evaporation of industrial wastewater, containing a closed tank with gas inlet and gas outlet pipes and a water sprayer made of horizontal A-shaped boxes with slots on the crest, characterized in that, in order to reduce the entrainment of liquid and simplify the design, mounted in the gas outlet pipe, and the gas outlet pipe is made with a visor placed on the water spray side. Sources of information taken into account during the examination 1. Gaubman EI, Bilder Z.P. Thermal neutralization of saline industrial wastewater. L., Himi, 1975, p. 64-65. 2 .. USSR Author's Certificate No. 484381, cl. F 28 f 3/06, 1973.