RU2102328C1 - Water treatment system - Google Patents

Abstract

FIELD: water treatment. SUBSTANCE: water treatment plant containing in-series connected water chemical- treatment unit, chemically treated water heater, deaerator, pump, multistep evaporation installation with secondary steam manifold having branches to deaerator and chemically treated water heater, is additionally provided with distillation sweetening installation with horizontal tubular apparatuses, which has heating steam manifold at its first inlet and blow pipeline at its first outlet. Secondary steam manifold in multistep evaporation installation is connected to plant manifold, blow pipeline in distillation sweetening installation to inlet of water chemical-treatment unit, and end condenser to second outlet and second inlet of distillation sweetening installation. EFFECT: reduced heat loss and reduced investment and operational cost of water chemical-treatment unit.

Description

 The invention relates to the field of water treatment and can be used at thermal power plants (TPPs).

 Known water treatment plants [1] based on the use of distillation desalination plants with a horizontal-tube film apparatus operating on water that has undergone simplified processing.

 The source water is purified from mechanical impurities on mechanical filters and fed to a distillation plant. Heating steam comes from low potential turbine power take-offs. The resulting distillate is used to make up for the loss of working heat at thermal power plants. Purge in an amount of approximately 30 to 35% of the capacity is discharged into the industrial sewage system.

 The disadvantages of such plants include the high cost and large volume of wastewater from the plant, which leads to low environmental efficiency and the presence of heat loss from such plants. In addition, such installations are characterized by relatively low reliability. The fact is that a scale layer forms on the surface of the heat exchange pipes of such plants, which necessitates a periodic (approximately twice a year) shutdown for chemical washing.

 Also known is a water treatment plant with multiple use of the once introduced regeneration solution, based on the use of adhesive type evaporators (type “I”) [2] The source water enters the chemical water treatment unit, where its coagulation and / or liming processes in clarifiers and two-stage sodium cation are carried out . Sodium-cationized water from the chemical water treatment unit is supplied with power to a multi-stage evaporator installation, consisting of a series of boiling-type evaporators connected in series (“I” type). Heating steam to a multi-stage evaporation plant is supplied from a selection of turbines of thermal power plants. The distillate formed in the process of thermal desalination is fed to make up for the loss of the working fluid in the TPP cycle; purging in the amount of 1 2% of the capacity is sent to the sludge dump. The excess secondary steam of such plants by evaporation of 0.15 0.25 MPa (steam that cannot be condensed inside the thermal circuit of the water treatment plant) is usually condensed at the general plant consumers of low-grade steam or, if this is not possible, they are sent to the terminal condenser of the installation, cooled by circulating water.

 The disadvantages of these plants include: the need to use imported reagents (lime, table salt, coagulant) to ensure chemical treatment of water, high capital costs for the construction of equipment for pre-treatment of the source water (chemical water treatment unit), the need for condensation of excess secondary steam of a multi-stage evaporative installation, which often leads to heat loss.

 The technical problem solved by the invention, reducing heat loss from a water treatment plant, reducing operating costs and the construction of a chemical water treatment unit while maintaining high environmental performance.

 The stated technical problem is solved by the fact that the known water treatment plant, comprising a chemical water treatment unit connected in series, a chemically purified water heater, a deaerator, a pump, a multi-stage evaporator installation with a secondary steam collector, having a branch to the aerator and chemically purified water heater, an end condenser, is additionally equipped with a distillation-desalination unit installation with horizontal-tube film apparatus having a heating steam collector at the first inlet and at the first outlet de purge pipe, wherein the secondary steam manifold of the multi-stage evaporation unit is connected to the collector of the heating steam of the distillation-desalination plant, the purge pipeline of the distillation-desalination plant is connected to the input of the chemical water treatment unit, and the end condenser is connected to the second input of the distillation-desalination plant and has a communication with the second input distillation and desalination plants.

 The proposed device is presented in the drawing. The installation consists of a multi-stage evaporation unit 1, a deaerator 2, a chemically purified water heater 3, a chemical water treatment unit 4, a distillation-desalination plant with horizontal pipe film devices 5, an end condenser 6, the secondary steam collector 7 of the multi-stage evaporative installation being connected to a collector of a heating steam distillation - desalination plant, and the purge pipe 8 of the distillation-desalination plant is connected to the input of the chemical water treatment unit.

 The installation works as follows. The entire flow of the source water is swayed and fed to the distillation-desalination plant, preheated in the end condenser by the secondary steam of the distillation-desalination plant. Purge of the distillation-desalination plant is sent to the chemical water treatment unit, where it is calcified and coagulated in clarifiers and sodium cation in ion-exchange filters. Sodium-cationized water is fed to a multi-stage evaporator, made on the basis of series-connected evaporators of the "I" type. Heating steam is supplied to a multi-stage evaporative installation from the turbine sampling of a TPP. Excessive secondary steam of a multi-stage evaporation plant is fed to a distillation-desalination plant with horizontal pipe film units as a heating device. The distillate of the distillation-desalination plant is mixed with the distillate of a multi-stage evaporation plant and is used to compensate for the loss of working heat of the TPP. The purge of the multi-stage evaporator is discharged into the sludge dump.

 Thus, the use of purging of a distillation-desalination plant with horizontal pipe film apparatuses as the source water for supplying a multi-stage evaporation plant allows, on the one hand, to exclude heat loss by purging a distillation-desalination plant with horizontal pipe film apparatuses and, on the other hand , significantly reduce the required performance of the unit for pre-treatment of the source water of a multi-stage evaporative installation (unit chemical water treatment s), which results in lower costs for its construction and operation. The use of excess secondary steam of a multistage evaporative installation as heating steam of a distillation-desalination plant with horizontal pipe film apparatuses eliminates heat loss with excess secondary steam of a multistage evaporative installation.

 In addition, the use of purge of a distillation-desalination plant with horizontal pipe film apparatuses as feed water for a multi-stage evaporation plant allows to reduce the concentration of source water in a distillation-desalination plant with horizontal pipe film apparatuses without heat loss, which will lead to a decrease in the intensity of scale formation in her and, as a result, to increase reliability.

Literature
1. Slesarenko V.N. Distillation desalination plants. M. Energy, 1980.

 2. Sedlov A.S. Ilyina I.P. Shishchenko V.V. Sidorova S.V. Egorov S.L. Thermal water and wastewater treatment for production with high environmental performance. Industrial Energy, 1993, N 7 (prototype).

Claims (1)

 A water treatment plant, comprising a chemical water treatment unit connected in series, a chemically purified water heater, a deaerator, a pump, a multi-stage evaporator installation with a secondary steam collector having taps on a deaerator and a chemically purified water heater, an end condenser, characterized in that it is additionally equipped with a horizontal distillation and desalination plant -pipe film apparatus having a heating steam collector at the first inlet and a purge conduit at the first outlet, and the secondary steam manifold of the multi-stage evaporation unit is connected to the collector of the heating steam of the distillation-desalination plant, the purge pipe of the distillation-desalination plant is connected to the input of the chemical water treatment unit, and the end condenser is connected to the second output of the distillation-desalination plant and is in communication with the second input of the distillation-desalination plant.