CN216946279U - Treatment system for evaporative crystallization of wastewater of coking plant - Google Patents

Abstract

The utility model relates to a treatment system for evaporative crystallization of wastewater from a coking plant, which belongs to the technical field of coking wastewater treatment and comprises a first-effect concentration unit, a second-effect concentration unit and a third-effect concentration unit; the feed inlet of the first-effect concentration unit is connected with a preheating unit for preheating materials, and the discharge outlet of the first-effect concentration unit is connected with the feed inlet of the second-effect concentration unit; the discharge hole of the two-effect concentration unit is connected with the feed inlet of the three-effect concentration unit; the discharge port of the triple-effect concentration unit is connected with a solid-liquid separation unit; a steam inlet of the first-effect concentration unit is connected with the heating chamber, and a steam outlet of the first-effect concentration unit is connected with a steam inlet of the second-effect concentration unit; a steam outlet of the two-effect concentration unit is connected with a steam inlet of the three-effect concentration unit, and the heating chamber provides raw steam; and a steam outlet of the triple-effect concentration unit is connected with a final-effect condenser. Can separate solid salt and water in the wastewater of the coking plant, and reduce the pollution of the wastewater of the coking plant to the environment.

Description

Treatment system for evaporative crystallization of wastewater of coking plant

Technical Field

The utility model belongs to the technical field of coking wastewater treatment, and particularly relates to a treatment system for evaporative crystallization of wastewater of a coking plant.

Background

The coking wastewater is typical toxic refractory organic wastewater. Mainly comes from the process water and steam condensation waste water in the process of coke oven gas primary cooling and coking production. The coke-oven plant mainly produces chemical products such as coke, commercial gas, ammonium sulfate, light benzene and the like. The tar recovery system of the plant adopts an ammonium sulfate flow, the tar processing adopts two-tower continuous distillation of a tubular furnace, and the industrial naphthalene production process comprises two-furnace two-tower continuous distillation, washing and refining. In the processes of coke oven gas cooling, washing, crude benzene processing and tar processing, industrial wastewater containing phenol, cyanogen, oil, ammonia and a large amount of organic matters is generated.

In order to reduce the load of subsequent biochemical treatment, reduce the impact load of toxic substances and stabilize the subsequent biochemical treatment effect, and facilitate operation and management, pretreatment such as 'A1-A2-O' is often carried out before wastewater enters an evaporation system. The wastewater with COD, deamination and denitrification and oil content reduction after pretreatment still cannot meet the discharge requirement of national industrial production wastewater due to high TDS content of the water quality. When coking wastewater is treated, the evaporative crystallization technology is used to separate the wastewater from salt, and compared with other technologies, the wastewater treated by the evaporative crystallization technology can be recycled or discharged after reaching the standard, and finally zero discharge of the wastewater is realized.

SUMMERY OF THE UTILITY MODEL

In view of the above problems in the prior art, an object of the present invention is to provide a system for processing evaporative crystallization of wastewater from a coke-oven plant, which can separate solid salt and water in the wastewater from the coke-oven plant, thereby maximally reducing the loss of inorganic salt and recovering water in the wastewater, and reducing the pollution of the wastewater from the coke-oven plant to the environment.

In order to achieve the above object of the present invention, the present invention provides a technical solution as follows:

a treatment system for evaporative crystallization of wastewater from a coking plant comprises a first-effect concentration unit, a second-effect concentration unit and a third-effect concentration unit; the feed inlet of the first-effect concentration unit is connected with a preheating unit for preheating materials, and the discharge outlet of the first-effect concentration unit is connected with the feed inlet of the second-effect concentration unit; the discharge hole of the two-effect concentration unit is connected with the feed inlet of the three-effect concentration unit; the discharge hole of the triple-effect concentration unit is connected with a solid-liquid separation unit; a steam inlet of the first-effect concentration unit is connected with the heating chamber, and a steam outlet of the first-effect concentration unit is connected with a steam inlet of the second-effect concentration unit; a steam outlet of the two-effect concentration unit is connected with a steam inlet of the three-effect concentration unit, and the heating chamber provides raw steam; and a steam outlet of the triple-effect concentration unit is connected with a final-effect condenser.

Preferably, the single-effect concentration unit comprises a single-effect evaporator a, a single-effect separator a and a single-effect circulating pump a; the shell pass inlet of the first-effect evaporator is connected with the heating chamber through a steam air supply pipe; a first-effect circulating pipe a is connected between a material liquid outlet at the lower end of the first-effect evaporator a and a material inlet at the upper end of the first-effect evaporator a, the first-effect circulating pump a is arranged on the first-effect circulating pipe a, a feeding pipe a is communicated with a pipe section on the first-effect circulating pipe a, the pipe section is positioned between the material inlet of the first-effect evaporator a and the first-effect circulating pump a, and the feeding pipe a is connected with a discharge hole of the preheating unit; the non-condensable gas outlet of the first-effect evaporator a is connected with a first-effect non-condensable gas pipe, and the other end of the first-effect non-condensable gas pipe is connected with the steam inlet of the second-effect concentration unit; the material outlet of the first-effect evaporator a is connected with a first-effect outlet communicating pipe a, and the other end of the first-effect outlet communicating pipe is connected with the material inlet of the first-effect separator a; the steam outlet at the top of the first-effect separator a is connected with a first-effect steam exhaust pipe a, the other end of the first-effect steam exhaust pipe a is communicated with the first-effect noncondensable pipe, and the feed liquid outlet at the bottom of the first-effect separator a is communicated with the inlet of the first-effect circulating pump a; a condensed water outlet is formed in the first-effect evaporator a; the discharge port of the first-effect circulating pump a is also connected with a first-effect material output pipe, and the other end of the first-effect material output pipe is connected with the feed port of the second-effect concentration unit.

Preferably, the single-effect concentration unit comprises a single-effect evaporator b, a single-effect separator b and a single-effect circulating pump b; a material outlet at the upper end of the first-effect evaporator b is connected with a first-effect outlet communicating pipe b, the other end of the first-effect outlet communicating pipe b is communicated with a material inlet of the first-effect separator b, a material liquid outlet at the bottom end of the first-effect separator b is communicated with a first-effect circulating pipe b, the other end of the first-effect circulating pipe b is connected with a material inlet of the first-effect evaporator b, and the first-effect circulating pump b is arranged on the first-effect circulating pipe b; a discharge port of the preheating unit is connected with a feed pipe b, the other end of the feed pipe b is communicated with the single-effect circulating pipe b, and the communication position of the feed pipe b is located in a pipe section between the single-effect circulating pump b and a material inlet of the single-effect evaporator b; the shell pass inlet of the first-effect evaporator b is connected with the heating chamber through a steam air supply pipe; the non-condensable gas outlet of the first-effect evaporator b is connected with a first-effect non-condensable gas pipe, and the other end of the first-effect non-condensable gas pipe is connected with the steam inlet of the second-effect concentration unit; the steam outlet at the top end of the first-effect separator b is connected with a first-effect steam exhaust pipe b, and the other end of the first-effect steam exhaust pipe b is communicated with the first-effect noncondensable pipe; a condensate water outlet is formed in the first-effect evaporator b; the discharge gate of a imitate circulating pump b still is connected with an effect material output tube, the other end of an effect material output tube is connected the feed inlet of two effect concentration units.

Preferably, the two-effect concentration unit comprises a two-effect evaporator, a two-effect separator and a two-effect circulating pump, a material outlet at the upper end of the two-effect evaporator is connected with a two-effect outlet communicating pipe, the other end of the two-effect outlet communicating pipe is communicated with a material inlet of the two-effect separator, a material liquid outlet at the bottom end of the two-effect separator is communicated with a two-effect circulating pipe, the other end of the two-effect circulating pipe is connected with a material inlet of the two-effect evaporator, and the two-effect circulating pump is arranged on the two-effect circulating pipe; the discharge end of the first-effect material output pipe is communicated with the second-effect circulating pipe; the shell pass inlet of the secondary effect evaporator is connected with the primary effect noncondensable gas pipe, the noncondensable gas outlet of the secondary effect evaporator is connected with the secondary effect noncondensable gas pipe, and the other end of the secondary effect noncondensable gas pipe is connected with the steam inlet of the triple effect concentration unit; a steam outlet at the top end of the two-effect separator is connected with a two-effect steam exhaust pipe, and the other end of the two-effect steam exhaust pipe is communicated with the two-effect noncondensable pipe; the discharge gate of two effect circulating pump still is connected with two effect material output tubes, the feed inlet of triple effect concentration unit is connected to the other end of two effect material output tubes.

Preferably, the triple-effect concentration unit comprises a triple-effect evaporator, a triple-effect separator and a triple-effect circulating pump, a material outlet at the upper end of the triple-effect evaporator is connected with a triple-effect outlet communicating pipe, the other end of the triple-effect outlet communicating pipe is communicated with a material inlet of the triple-effect separator, a material liquid outlet at the bottom end of the triple-effect separator is communicated with a triple-effect circulating pipe, the other end of the triple-effect circulating pipe is connected with a material inlet of the triple-effect evaporator, and the triple-effect circulating pump is connected to the triple-effect circulating pipe; the secondary-effect material output pipe is communicated with the three-effect circulating pipe; a shell pass inlet of the triple-effect evaporator is connected with the double-effect non-condensing pipe, a non-condensing gas outlet of the triple-effect evaporator is connected with the triple-effect non-condensing pipe, the triple-effect non-condensing pipe is connected with an inlet of the last-effect condenser, and an outlet of the last-effect condenser is connected with a distilled water recovery pipe a; the exhaust port at the top end of the three-effect separator is connected with a three-effect exhaust pipe, and the other end of the three-effect exhaust pipe is communicated with the three-effect noncondensable pipe; the three-effect circulating pipe is also communicated with a three-effect material output pipe, and the other end of the three-effect material output pipe is connected with the solid-liquid separation unit.

Preferably, the preheating unit comprises a condensate water preheater and a steam preheater, a material inlet of the condensate water preheater is used for providing materials, a material outlet of the condensate water preheater is connected with a material inlet of the steam preheater, and a material outlet of the steam preheater is connected with a feed inlet of the primary concentrating unit; a distilled water inlet of the condensed water preheater is connected with a distilled water recovery unit, and the distilled water recovery unit is used for recovering distilled water drainage of the two-effect concentration unit and the three-effect concentration unit; a distilled water outlet of the condensed water preheater is connected with a distilled water recovery pipe b; a heat source inlet of the steam preheater is communicated with the heating chamber, and a heat source outlet of the steam preheater is connected with a steam condensate pipe; the condensed water outlet of the first effect concentration unit is connected with a condensed water recovery unit, and the steam condensed water pipe is connected with the condensed water recovery unit through the first effect concentration unit.

Preferably, the condensed water recovery unit comprises a condensed water tank and a condensed water pump, a water inlet end at the top of the condensed water tank is connected with an effective condensed water discharge pipe, and the other end of the effective condensed water discharge pipe is connected with a condensed water outlet of the effective concentration unit; the water outlet end of the lower end of the condensed water tank and the water inlet end of the condensed water pump are connected with a water inlet pipe of the water pump, and a water outlet pipe of the condensed water pump is connected with the boiler through a water outlet pipe of the water pump.

Preferably, the distilled water recovery unit comprises a distilled water tank and a distilled water pump, the water inlet end at the upper end of the distilled water tank is respectively communicated with a two-effect distilled water discharge pipe and a three-effect distilled water discharge pipe, the other end of the two-effect distilled water discharge pipe is communicated with a distilled water discharge port of the two-effect evaporator, and the other end of the three-effect distilled water discharge pipe is connected with a distilled water discharge port of the three-effect evaporator; the water outlet end at the lower end of the distilled water tank is communicated with the water inlet end of the distilled water pump through a distilled water inlet pipe; and a distilled water outlet pipe is connected between the water outlet of the distilled water pump and the distilled water inlet of the condensed water preheater.

Preferably, the solid-liquid separation unit comprises a discharge pump, a centrifuge, a mother liquor tank and a mother liquor reflux pump; the feed inlet of the discharge pump is connected with the triple-effect material output pipe, the discharge end of the discharge pump is connected with a mixed discharge pipe, the other end of the mixed discharge pipe is connected with the feed end of the centrifuge, the solid material discharge port of the centrifuge is connected with a solid discharge pipe, the mother liquid outlet of the centrifuge is connected with a mother liquid discharge pipe, and the other end of the mother liquid discharge pipe is connected with the mother liquid tank; a mother liquor outlet at the lower end of the mother liquor tank is connected with a mother liquor feeding pipe; the other end of the mother liquid feeding pipe is connected with a feeding hole of the mother liquid reflux pump, and a mother liquid reflux pipe is communicated between the mother liquid reflux pump and the triple-effect circulating pipe; the communication position of the mother liquid return pipe and the triple-effect circulating pipe is positioned on a pipe section between the triple-effect circulating pump and the triple-effect material output pipe.

The utility model provides a treatment system for evaporative crystallization of wastewater from a coking plant, which is characterized in that a preheating unit is arranged to enable materials to enter a concentration unit for evaporation in a boiling point state, so that the evaporation efficiency of a one-effect evaporator can be fully exerted, and the reduction of the evaporation efficiency of the one-effect evaporator caused by too low feeding temperature is avoided, and the heat exchange evaporation effect of the system is further influenced. The condensed water of the one-effect evaporator can be recovered through the arranged condensed water recovery unit, the condensed water is directly sent to the steam boiler and used as the make-up water of the steam boiler, the high-temperature condensed water directly enters the boiler, the temperature rising process of the make-up water of the boiler is omitted, the high-temperature condensed water is directly heated and converted into raw steam, the conversion efficiency of the boiler is improved, and the condensed water of the steam is used as the make-up water of the boiler due to few impurities in the condensed water of the steam, so that the service life of the boiler is effectively prolonged. Distilled water generated by the distilled water recovery unit is connected with the preheating unit for preheating, and energy generated by the evaporation system is fully recovered and applied, so that energy waste is reduced, and the effects of energy conservation and emission reduction are achieved.

Drawings

FIG. 1 is a flow chart of a system for treating evaporative crystallization of wastewater from a coke-oven plant according to example 1 of the present invention;

FIG. 2 is a flow chart of a treatment system for evaporative crystallization of wastewater from a coke-oven plant according to example 2 of the present invention;

reference numbers in the figures:

100. a first effect concentration unit; 1a, a one-effect evaporator a; 1b, a one-effect separator a; 1c, a one-effect circulating pump a; 1d, a one-effect circulating pipe a; 1e, a first effect outlet communicating pipe a; 1f, a one-effect noncondensable gas pipe; 1g, a one-effect exhaust pipe a; 1h, a first-effect condensed water discharge pipe; 1j, a condensed water tank; 1k, a water inlet pipe of a water pump; 1m, a condensate pump; 1n, a water outlet pipe of the water pump; 1p, a first-effect material output pipe; 1r, a steam air supply pipe; 1s, a feeding pipe a;

200. a second effect concentration unit; 2a, a double-effect evaporator; 2b, a two-effect separator; 2c, a two-effect circulating pump; 2d, a two-effect circulating pipe; 2e, a two-effect outlet communicating pipe; 2f, a double-effect non-condensation pipe; 2g, a double-effect exhaust pipe; 2h, discharging a double-effect distilled water; 2j, a distilled water tank; 2k, a distilled water inlet pipe; 2m, a distilled water pump; 2n, a distilled water outlet pipe; 2p, a two-effect material output pipe;

300. a triple effect concentration unit; 3a, a triple-effect evaporator; 3b, a three-effect separator; 3c, a three-effect circulating pump; 3d, a three-effect circulating pipe; 3e, a triple-effect outlet communicating pipe; 3f, triple-effect non-condensation pipe; 3g, a triple-effect exhaust pipe; 3h, discharging a triple-effect distilled water; 4a, a final effect condenser; 4h, a distilled water recovery pipe a;

500. a solid-liquid separation unit; 5a, a centrifugal machine; 5b, a solid discharge pipe; 5c, a discharge pump; 5d, outputting a three-effect material pipe; 5e, a mixing discharge pipe; 5h, a mother liquor discharge pipe; 5j, a mother liquor tank; 5k, a mother liquor feeding pipe; 5m, a mother liquor reflux pump; 5n, a mother liquor return pipe;

600. a preheating unit; 6a, a condensate water preheater; 6b, a distilled water recovery pipe b; 6c, a steam preheater; 6d, a steam condensate pipe;

7a, a one-effect evaporator b; 7b, a first-effect separator b; 7c, a one-effect circulating pump b; 7d, a one-effect circulating pipe b; 7e, a first effect outlet communicating pipe b; 7g, a first-effect exhaust pipe b; 7s and a feeding pipe b.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the utility model and are not intended to limit the utility model. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The utility model provides a treatment system for evaporative crystallization of wastewater of a coke-oven plant, which is shown in figure 1 and comprises a first-effect concentration unit 100, a second-effect concentration unit 200 and a third-effect concentration unit 300; the feed inlet of the first-effect concentration unit 100 is connected with a preheating unit 600 for preheating materials, and the discharge outlet of the first-effect concentration unit 100 is connected with the feed inlet of the second-effect concentration unit 200; the discharge hole of the two-effect concentration unit 200 is connected with the feed inlet of the three-effect concentration unit 300; the discharge hole of the triple-effect concentration unit 300 is connected with a solid-liquid separation unit 500; the steam inlet of the first-effect concentration unit 100 is connected with the heating chamber, and the steam outlet is connected with the steam inlet of the second-effect concentration unit 200; a steam outlet of the two-effect concentration unit 200 is connected with a steam inlet of the three-effect concentration unit 300, and a heating chamber provides raw steam; the steam outlet of the triple-effect concentration unit 300 is connected with a final-effect condenser 4 a.

When the treatment system is used for treating wastewater, the coking wastewater containing sodium sulfate enters the preheating unit 600 through the material feeding pipe to be preheated and heated; after preheating, heating, evaporating and concentrating the coking wastewater containing sodium sulfate, the temperature of which reaches the first-effect evaporation temperature, in a first-effect concentration unit 100 to form a first-effect concentrated solution, wherein water in the raw material is heated and evaporated to generate first-effect secondary steam; after the first-effect concentration unit 100 is used for heating, evaporating and concentrating, the first-effect concentrated solution enters the second-effect concentration unit 200 for heating, evaporating and concentrating to form a second-effect concentrated solution, and moisture in the second-effect concentrated solution is heated and continuously evaporated to generate second-effect secondary steam. The double-effect concentration also enters the triple-effect concentration unit 300, the triple-effect concentration unit 300 is heated, evaporated and concentrated until crystals are generated, the crystals become triple-effect crystal slurry, finally, the solid-liquid separation unit 500 is used for carrying out solid-liquid separation, and the last-effect condenser 4a is used for condensing triple-effect secondary steam formed in the triple-effect concentration unit 300 to form condensed water.

One-effect concentration unit 100 includes one-effect evaporator a1a, one-effect separator a1b, and one-effect circulation pump a1 c. The shell pass inlet of the first-effect evaporator a1a is connected with the heating chamber through a steam air supply pipe 1 r; a first-effect circulating pipe a1d is connected between a material liquid outlet at the lower end of the first-effect evaporator a1a and a material inlet at the upper end of the first-effect evaporator a1a, a first-effect circulating pump a1c is arranged on the first-effect circulating pipe a1d, a feeding pipe a1s is communicated on a pipe section, located between the material inlet of the first-effect evaporator a1a and the first-effect circulating pump a1c, on the first-effect circulating pipe a1d, and the feeding pipe a1s is connected with a discharging port of the preheating unit 600; the non-condensable gas outlet of the first-effect evaporator a1a is connected with a first-effect non-condensable gas pipe 1f, and the other end of the first-effect non-condensable gas pipe 1f is connected with the steam inlet of the second-effect concentration unit 200; the material outlet of the first-effect evaporator a1a is connected with a first-effect outlet communicating pipe a1e, and the other end of the first-effect outlet communicating pipe a1e is connected with the material inlet of a first-effect separator a1 b; the steam outlet at the top of the first-effect separator a1b is connected with a first-effect steam exhaust pipe a1g, the other end of the first-effect steam exhaust pipe a1g is communicated with a first-effect non-condensing pipe 1f, and the feed liquid outlet at the bottom of the first-effect separator a1b is communicated with the inlet of a first-effect circulating pump a1 c; a condensate water outlet is arranged on the first-effect evaporator a1 a; the discharge hole of the one-effect circulating pump a1c is also connected with a one-effect material output pipe 1p, and the other end of the one-effect material output pipe 1p is connected with the feed hole of the two-effect concentration unit 200.

In the process, the sodium sulfate-containing coking wastewater enters a first-effect circulating pipe a1d through a feeding pipe a1s, enters a first-effect evaporator a1a through a first-effect circulating pipe a1d, raw steam enters a shell pass of the first-effect evaporator a1a through a steam air supply pipe 1r, and the sodium sulfate-containing coking wastewater is heated, evaporated and concentrated in a first-effect evaporator a1a, wherein the raw steam enters a second-effect concentration unit 200 through a first-effect non-condensing pipe 1f after passing through the shell pass of the first-effect evaporator a1 a. The feed liquid enters the first-effect separator a1b through the first-effect outlet communicating pipe a1e to realize the separation of the feed liquid and steam, and the separated feed liquid circulates through the first-effect circulating pipe a1d and the first-effect circulating pump a1 c. When the concentrated solution reaches the corresponding conditions, the concentrated solution is conveyed to the two-effect concentration unit 200 through the first-effect material output pipe 1p for secondary concentration.

The preheating unit 600 comprises a condensate water preheater 6a and a steam preheater 6c, wherein a material inlet of the condensate water preheater 6a is used for providing materials, a material outlet of the condensate water preheater 6a is connected with a material inlet of the steam preheater 6c, and a material outlet of the steam preheater 6c is connected with a feed inlet of the primary concentrating unit 100; a distilled water inlet of the condensed water preheater 6a is connected with a distilled water recovery unit, and the distilled water recovery unit is used for recovering distilled water drainage of the two-effect concentration unit 200 and the three-effect concentration unit 300; a distilled water outlet of the condensed water preheater 6a is connected with a distilled water recovery pipe b6 b; a heat source inlet of the steam preheater 6c is communicated with the heating chamber, and a heat source outlet of the steam preheater 6c is connected with a steam condensate pipe 6 d; the condensed water drain port of the one-effect concentration unit 100 is connected to a condensed water recovery unit, and the steam condensed water pipe 6d is connected to the condensed water recovery unit through the one-effect concentration unit 100. Through the heat exchange effect of the condensate water preheater 6a and the steam preheater 6c, the materials enter the one-effect evaporator to be evaporated under the boiling point state, the evaporation efficiency of the one-effect evaporator a1a can be fully exerted, and the reduction of the evaporation efficiency of the one-effect evaporator a1a caused by too low feeding temperature is avoided, so that the heat exchange evaporation effect of the system is influenced.

Specifically, the coking wastewater containing sodium sulfate passes through a condensate water preheater 6a and a steam preheater 6c, and is subjected to primary preheating and secondary preheating. The sodium sulfate-containing coking wastewater entering the one-effect evaporator a1a can be at a high temperature, so that heating, evaporation and concentration can be conveniently carried out in the one-effect evaporator a1a, and one-effect concentrated solution can be quickly formed. In this process, the heat source of the condensate preheater 6a is distilled water in the two-effect concentration unit 200 and the three-effect concentration unit 300, which is relatively high in temperature, for the distilled water recovery unit, and the heat in the distilled water in the two-effect concentration unit 200 and the three-effect concentration unit 300 is recovered and utilized by the distilled water recovery unit. In the steam preheater 6c, steam is supplied to the steam preheater 6c through the heating chamber, a certain amount of condensed water with a high temperature is formed after heat exchange with the material, and the condensed water in the steam preheater 6c and the one-effect evaporator a1a is recycled through a condensed water recycling unit.

The condensate water recovery unit comprises a condensate water tank 1j and a condensate water pump 1m, wherein the water inlet end at the top of the condensate water tank 1j is connected with an effective condensate water discharge pipe 1h, and the other end of the effective condensate water discharge pipe 1h is connected with a condensate water outlet of the effective concentration unit 100. The water outlet end at the lower end of the condensed water tank 1j and the water inlet end of the condensed water pump 1m are connected with a water inlet pipe 1k of the water pump, and the water outlet pipe of the condensed water pump 1m is connected with the boiler through a water outlet pipe 1n of the water pump. During operation, condensed water generated by the steam preheater 6c and the one-effect separator a1b enters the condensed water tank 1j through the one-effect condensed water discharge pipe 1h, and is then intensively pumped out through the condensed water pump 1m to supply water to the boiler, and the condensed water generated by the steam preheater 6c and the one-effect separator a1b can be used as boiler make-up water due to the relatively high temperature of the condensed water.

The two-effect concentration unit 200 includes a two-effect evaporator 2a, a two-effect separator 2b, and a two-effect circulation pump 2 c. The material outlet at the upper end of the second-effect evaporator 2a is connected with a second-effect outlet communicating pipe 2e, and the other end of the second-effect outlet communicating pipe 2e is communicated with the material inlet of the second-effect separator 2 b. The feed liquid outlet at the bottom end of the two-effect separator 2b is communicated with a two-effect circulating pipe 2d, the other end of the two-effect circulating pipe 2d is connected with the material inlet of the two-effect evaporator 2a, and a two-effect circulating pump 2c is arranged on the two-effect circulating pipe 2 d. The discharge end of the first-effect material output pipe 1p is communicated with a second-effect circulating pipe 2 d; a shell pass inlet of the second-effect evaporator 2a is connected with a first-effect non-condensing pipe 1f, a non-condensing gas outlet of the second-effect evaporator 2a is connected with a second-effect non-condensing pipe 2f, and the other end of the second-effect non-condensing pipe 2f is connected with a steam inlet of the third-effect concentration unit 300; a steam outlet at the top end of the two-effect separator 2b is connected with a two-effect steam exhaust pipe 2g, and the other end of the two-effect steam exhaust pipe 2g is communicated with a two-effect noncondensable gas pipe 2 f; the discharge gate of two-effect circulating pump 2c still is connected with two-effect material output tube 2p, and the feed inlet of triple effect concentration unit 300 is connected to the other end of two-effect material output tube 2 p.

In the process, the first-effect concentrated solution enters the second-effect circulating pipe 2d through the first-effect material output pipe 1p, enters the second-effect evaporator 2a under the action of the second-effect circulating pump 2c to be heated, evaporated and concentrated, the feed liquid enters the second-effect separator 2b to be subjected to vapor-liquid separation, after the vapor-liquid separation, the vapor enters the third-effect concentrating unit 300 along with the second-effect noncondensable gas pipe 2f, meanwhile, the feed liquid circulates through the second-effect circulating pipe 2d until the second-effect concentrated solution meeting the requirements is formed, and the second-effect concentrated solution enters the third-effect concentrating unit 300 through the second-effect material output pipe 2p to be heated, evaporated and concentrated. The distilled water formed in the double effect evaporator 2a is recovered by the distilled water recovery unit.

The triple-effect concentration unit 300 comprises a triple-effect evaporator 3a, a triple-effect separator 3b and a triple-effect circulating pump 3c, a material outlet at the upper end of the triple-effect evaporator 3a is connected with a triple-effect outlet communicating pipe 3e, the other end of the triple-effect outlet communicating pipe 3e is communicated with a material inlet of the triple-effect separator 3b, a material liquid outlet at the bottom end of the triple-effect separator 3b is communicated with a triple-effect circulating pipe 3d, the other end of the triple-effect circulating pipe 3d is connected with a material inlet of the triple-effect evaporator 3a, and the triple-effect circulating pump 3c is connected to the triple-effect circulating pipe 3 d; the two-effect material output pipe 2p is communicated with a three-effect circulating pipe 3 d; the shell pass inlet of the triple-effect evaporator 3a is connected with the double-effect non-condensing pipe 2f, the non-condensing outlet of the triple-effect evaporator 3a is connected with the triple-effect non-condensing pipe 3f, the triple-effect non-condensing pipe 3f is connected with the inlet of the last-effect condenser 4a, and the outlet of the last-effect condenser 4a is connected with a distilled water recovery pipe a4 h; the exhaust port at the top end of the three-effect separator 3b is connected with a three-effect exhaust pipe 3g, and the other end of the three-effect exhaust pipe 3g is communicated with a three-effect noncondensable gas pipe 3 f; the three-effect circulating pipe 3d is also communicated with a three-effect material output pipe 5d, and the other end of the three-effect material output pipe 5d is connected with the solid-liquid separation unit 500.

In the process, the two-effect concentrated solution enters the three-effect evaporator 3a through the two-effect material output pipe 2p and the three-effect circulating pipe 3d for heating, evaporation and concentration, then enters the three-effect separator 3b through the three-effect outlet communicating pipe 3e for vapor-liquid separation, and the vapor is converged with the vapor discharged from the non-condensable gas port in the three-effect evaporator 3a and finally condensed by the final-effect condenser 4a to form distilled water for recovery. The feed liquid enters the solid-liquid separation unit 500 for treatment, and finally crystals are formed.

The distilled water recovery unit comprises a distilled water tank 2j and a distilled water pump 2m, the water inlet end of the upper end of the distilled water tank 2j is respectively communicated with a double-effect distilled water discharge pipe 2h and a triple-effect distilled water discharge pipe 3h, the other end of the double-effect distilled water discharge pipe 2h is communicated with a distilled water discharge port of a double-effect evaporator 2a, and the other end of the triple-effect distilled water discharge pipe 3h is connected with a distilled water discharge port of a triple-effect evaporator 3 a; a distilled water outlet pipe 2n is connected between the outlet port at the lower end of the distilled water tank 2j and the distilled water inlet of the condensed water preheater 6 a. Distilled water produced in the two-effect evaporator 2a and the three-effect evaporator 3a can be fully carried to the condensate water preheater 6a for heat exchange through the set distilled water recovery unit, wastewater in a coking plant can be preheated through the heat exchange effect, and meanwhile, heat produced by an evaporation system is fully recycled, so that energy waste is reduced, and the effects of energy conservation and emission reduction are achieved.

The solid-liquid separation unit 500 comprises a discharge pump 5c, a centrifuge 5a, a mother liquor tank 5j and a mother liquor reflux pump 5 m; a feed inlet of a discharge pump 5c is connected with a triple-effect material output pipe 5d, a discharge end of the discharge pump 5c is connected with a mixed discharge pipe 5e, the other end of the mixed discharge pipe 5e is connected with a feed end of a centrifuge 5a, a solid material discharge port of the centrifuge 5a is connected with a solid discharge pipe 5b, a mother liquor outlet of the centrifuge 5a is connected with a mother liquor discharge pipe 5h, and the other end of the mother liquor discharge pipe 5h is connected with a mother liquor tank 5 j; a mother liquor outlet at the lower end of the mother liquor tank 5j is connected with a mother liquor feeding pipe 5 k; the other end of the mother liquid feeding pipe 5k is connected with a feed inlet of a mother liquid reflux pump 5m, and a mother liquid reflux pipe 5n is communicated between the mother liquid reflux pump 5m and the triple-effect circulating pipe 3 d; the communicating position of the mother liquor return pipe 5n and the triple-effect circulating pipe 3d is positioned on the pipe section between the triple-effect circulating pump 3c and the triple-effect material output pipe 5 d. After the triple-effect concentration unit 300 is processed, under the action of the discharge pump 5c, the crystal slurry enters the centrifuge 5a through the triple-effect material output pipe 5d, solid-liquid separation is carried out in the centrifuge 5a to form crystals and mother liquor, the crystals are discharged from the solid discharge pipe 5b, and the mother liquor enters the triple-effect circulation pipe 3d through the mother liquor return pipe 5n to continue circulation.

The specific treatment process is as follows: conveying the coking wastewater containing 12.8 percent of sodium sulfate into a condensate water preheater 6a for primary preheating, then conveying the coking wastewater into a steam preheater 6c for secondary preheating, conveying the coking wastewater into a first-effect circulating pipe a1d through a feeding pipe a1s after secondary preheating, and then conveying the coking wastewater into a first-effect concentrating unit 100 through a first-effect circulating pipe a1d for heating, evaporating and concentrating.

Wherein the temperature of steam in the shell pass of the first-effect evaporator a1a is about 110 +/-2 ℃, and the temperature of a non-condensable gas outlet of the first-effect evaporator a1a is 110 +/-2 ℃; the temperature in the condensed water outlet of the first-effect evaporator a1a is about 110 +/-2 ℃. The temperature of the material in the first-effect circulation pipe a1d is about 100 +/-2 ℃, and the temperature of the steam in the first-effect exhaust pipe a1g at the upper end of the first-effect separator a1b is about 90 +/-2 ℃. Finally, a first-effect concentrated solution which contains 18 +/-2% of sodium sulfate at the outlet of the first-effect circulating pump a1c and has the temperature of about 100 +/-2 ℃ is discharged through a first-effect material output pipe 1 p. The concentration of the wastewater of the coke-oven plant is improved by the concentration of the first-effect evaporator a1a, thereby providing conditions for the subsequent further concentration and separation of sodium sulfate.

The primary effect concentrated solution is conveyed to enter a secondary effect concentration unit 200 through a primary effect material output pipe 1p for heating, evaporating and concentrating, in the secondary effect concentration unit 200, the temperature of steam at a shell pass inlet of a secondary effect evaporator 2a is about 90 +/-2 ℃, and the temperature of a non-condensable gas outlet of the secondary effect evaporator 2a is about 90 +/-2 ℃; the outlet temperature of the distilled water of the double effect evaporator 2a is about 90 +/-2 ℃. The temperature of a material outlet of the double-effect evaporator 2a is about 80 +/-2 ℃, the temperature of steam in a double-effect steam exhaust pipe 2g at the top of the double-effect separator 2b is about 70 +/-2 ℃, and the temperature of a material liquid outlet at the bottom end of the double-effect separator 2b is about 80 +/-2 ℃. The two-way concentrated solution with 30 + -2% sodium sulfate and temperature of 80 + -2 deg.C is finally formed in the two-way concentration unit 200. The secondary evaporator 2a further concentrates the primary effect concentrated solution by using secondary steam generated by the primary effect separator a1b, thereby not only recovering the heat of the secondary steam generated by the primary effect concentration unit 100, but also further improving the concentration of the sodium sulfate coking wastewater.

The two-effect concentrated solution enters the three-effect concentration unit 300 through the effect of the two-effect circulating pump 2 c. In the three-effect concentration unit 300, the temperature of steam at the shell pass inlet of the three-effect evaporator 3a is about 70 +/-2 ℃, the temperature of the non-condensable gas outlet of the three-effect evaporator 3a is about 70 +/-2 ℃, and the temperature of the distilled water outlet of the three-effect evaporator 3a is 70 +/-2 ℃. The material outlet temperature of the triple-effect evaporator 3a is about 60 +/-2 ℃, the steam temperature in a triple-effect steam exhaust pipe 3g at the top end of the triple-effect separator 3b is about 50 +/-2 ℃, and the temperature in a triple-effect circulating pipe 3d at the lower end of the triple-effect separator 3b is about 60 +/-2 ℃. After heating, evaporating and concentrating in the triple-effect concentration unit 300, a triple-effect concentrated solution containing 40 +/-5% of sodium sulfate and having a temperature of about 60 +/-2 ℃ is finally formed. Through the evaporation and crystallization of the triple-effect evaporator 3a, the wastewater of the coking plant is concentrated into a crystal slurry mixture from a nearly saturated state, and then is sent out of the triple-effect evaporator 3a by the discharge pump 5c, so that initial conditions are provided for the next stage of solid-liquid separation.

The steam discharged by the triple-effect concentration unit 300 enters the final-effect condenser 4a for condensation, at the moment, the steam temperature is about 50 +/-2 ℃, the steam enters the final-effect condenser 4a to be converted into distilled water at the temperature of 50 +/-2 ℃, and the distilled water is recycled through the triple-effect distilled water discharge pipe 3h on the lower side.

The triple-effect concentrated solution discharged by the triple-effect concentration unit 300 enters a centrifuge 5a through a discharge pump 5c for solid-liquid separation, after the solid-liquid separation by the centrifuge, the water content of sodium sulfate crystals is less than 4 wt%, the sodium sulfate crystals are connected with a solid product conveying pipeline through a solid discharge port of the centrifuge 5a, and the sodium sulfate salt after the centrifugal treatment enters a production workshop for continuous recycling, so that the resource recycling of inorganic salt products is realized.

Centrifuge 5a exhaust mother liquor enters into mother liquor tank 5j and keeps in, pumps the mother liquor into triple effect circulating pipe 3d again through mother liquor backwash pump 5m in, sends back triple effect evaporimeter 3a, continues to carry out the evaporation crystallization, separates the solid salt and the moisture in the centrifugal mother liquor, and the loss of the maximize reduction inorganic salt and the moisture of retrieving the waste water reduce the pollution of coking plant waste water to the environment.

The utility model provides a treatment system for increasing hair and crystallizing wastewater of a coking plant, which can gradually concentrate the wastewater of the coking plant through a primary concentration unit, a secondary concentration unit and a tertiary concentration unit to provide initial conditions for final solid-liquid separation, and the solid-liquid separation unit realizes the recycling of inorganic salt products of the coking wastewater.

The preheating unit enables materials to enter the concentration unit for evaporation in a boiling point state, evaporation efficiency of the one-effect evaporator can be fully exerted, and reduction of evaporation efficiency of the one-effect evaporator caused by too low feeding temperature is avoided, so that heat exchange evaporation effect of the system is influenced. The condensed water of the one-effect evaporator can be recovered through the arranged condensed water recovery unit, the condensed water is directly sent to the steam boiler and used as the make-up water of the steam boiler, the high-temperature condensed water directly enters the boiler, the temperature rising process of the make-up water of the boiler is omitted, the high-temperature condensed water is directly heated and converted into raw steam, the conversion efficiency of the boiler is improved, and the condensed water of the steam is used as the make-up water of the boiler due to few impurities in the condensed water of the steam, so that the service life of the boiler is effectively prolonged. Distilled water generated by the distilled water recovery unit is connected with the preheating unit for preheating, and energy generated by the evaporation system is fully recovered and applied mechanically, so that energy waste is reduced, and the effects of energy conservation and emission reduction are achieved.

Example 2

Referring to fig. 2, the difference from embodiment 1 lies in a one-effect concentrating unit 100, specifically, the one-effect concentrating unit 100 includes a one-effect evaporator b7a, a one-effect separator b7b, and a one-effect circulating pump b7 c; a material outlet at the upper end of the first-effect evaporator b7a is connected with a first-effect outlet communicating pipe b7e, the other end of the first-effect outlet communicating pipe b7e is communicated with a material inlet of the first-effect separator b7b, a material liquid outlet at the bottom end of the first-effect separator b7b is communicated with a first-effect circulating pipe b7d, the other end of the first-effect circulating pipe b7d is connected with a material inlet of the first-effect evaporator b7a, and the first-effect circulating pump b7c is arranged on the first-effect circulating pipe b7 d; a material outlet of the preheating unit 600 is connected with a material inlet pipe b7s, the other end of the material inlet pipe b7s is communicated with the single-effect circulating pipe b7d, and the communication position is a pipe section between the single-effect circulating pump b7c and a material inlet of the single-effect evaporator b7 a; the shell side inlet of the first-effect evaporator b7a is connected with the heating chamber through a steam air supply pipe 1 r; the non-condensable gas outlet of the first-effect evaporator b7a is connected with a first-effect non-condensable gas pipe 1f, and the other end of the first-effect non-condensable gas pipe 1f is connected with the steam inlet of the second-effect concentration unit 200; the steam outlet at the top end of the first-effect separator b7b is connected with a first-effect steam exhaust pipe b7g, and the other end of the first-effect steam exhaust pipe b7g is communicated with a first-effect noncondensable pipe 1 f; a condensate water outlet is arranged on the first-effect evaporator b7 a; the discharge gate of a imitate circulating pump b7c still is connected with an effect material output tube 1p, and the feed inlet of two effect concentration unit 200 is connected to the other end of an effect material output tube 1 p.

Specifically, during treatment, about 8.57% of coking wastewater containing sodium chloride enters a first-effect circulating pipe b7d of a first-effect evaporator b7a after being preheated for the second time, enters a first-effect evaporator b7a under the action of a first-effect circulating pump b7c for heating, evaporating and concentrating, feed liquid enters a first-effect separator b7b for gas-liquid separation, and steam after gas-liquid separation enters a first-effect noncondensable gas pipe 1f through a first-effect exhaust pipe b7g and finally enters a second-effect concentrating unit 200. The separated feed liquid is circulated through a first-effect circulating pipe b7d until a first-effect concentrated solution meeting the requirement is formed, and the first-effect concentrated solution enters a second-effect concentrating unit 200 through a first-effect material output pipe 1p for further heating, evaporating and concentrating.

Wherein, the one-effect evaporator b7a is a falling-film evaporator which has the advantages of good heat transfer effect, low energy consumption of a circulating pump and the like, and is particularly suitable for low-concentration materials such as coking wastewater containing sodium chloride.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "rear", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly and may include, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a direct connection, an indirect connection via an intermediate medium, and a communication between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art. The embodiments and features of the embodiments of the present invention may be combined with each other without conflict.

The above-mentioned embodiments only express the implementation manner of the present invention, and the description thereof is specific and detailed, but not to be understood as the limitation of the patent scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (9)

1. A treatment system for evaporative crystallization of wastewater from a coke-oven plant is characterized by comprising a first-effect concentration unit (100), a second-effect concentration unit (200) and a third-effect concentration unit (300);

a feed inlet of the first-effect concentration unit (100) is connected with a preheating unit (600) for preheating materials, and a discharge outlet of the first-effect concentration unit (100) is connected with a feed inlet of the second-effect concentration unit (200); the discharge hole of the two-effect concentration unit (200) is connected with the feed inlet of the three-effect concentration unit (300); a discharge hole of the triple-effect concentration unit (300) is connected with a solid-liquid separation unit (500);

a steam inlet of the first-effect concentration unit (100) is connected with the heating chamber, and a steam outlet is connected with a steam inlet of the second-effect concentration unit (200); a steam outlet of the two-effect concentration unit (200) is connected with a steam inlet of the three-effect concentration unit (300), and the heating chamber provides raw steam;

the steam outlet of the triple-effect concentration unit (300) is connected with a final-effect condenser (4 a).

2. The system for treating evaporative crystallization of wastewater from a coke-oven plant as recited in claim 1, characterized in that the single-effect concentration unit (100) comprises a single-effect evaporator a (1 a), a single-effect separator a (1 b), and a single-effect circulation pump a (1 c);

the shell side inlet of the first-effect evaporator a (1 a) is connected with the heating chamber through a steam air supply pipe (1 r);

a first-effect circulating pipe a (1 d) is connected between a material liquid outlet at the lower end of the first-effect evaporator a (1 a) and a material inlet at the upper end of the first-effect evaporator a (1 a), the first-effect circulating pump a (1 c) is arranged on the first-effect circulating pipe a (1 d), a feeding pipe a (1 s) is communicated with the first-effect circulating pipe a (1 d) and a pipe section between the material inlet of the first-effect evaporator a (1 a) and the first-effect circulating pump a (1 c), and the feeding pipe a (1 s) is connected with a discharge hole of the preheating unit (600);

the non-condensable gas outlet of the first-effect evaporator a (1 a) is connected with a first-effect non-condensable gas pipe (1 f), and the other end of the first-effect non-condensable gas pipe (1 f) is connected with the steam inlet of the second-effect concentration unit (200);

the material outlet of the first-effect evaporator a (1 a) is connected with a first-effect outlet communicating pipe a (1 e), and the other end of the first-effect outlet communicating pipe is connected with the material inlet of the first-effect separator a (1 b);

the steam outlet at the top of the primary-effect separator a (1 b) is connected with a primary-effect steam exhaust pipe a (1 g), the other end of the primary-effect steam exhaust pipe a (1 g) is communicated with the primary-effect noncondensable gas pipe (1 f), and the feed liquid outlet at the bottom of the primary-effect separator a (1 b) is communicated with the inlet of the primary-effect circulating pump a (1 c);

a condensed water outlet is formed in the first-effect evaporator a (1 a);

the discharge gate of a imitate circulating pump a (1 c) still is connected with an effect material output tube (1 p), the other end of an effect material output tube (1 p) is connected the feed inlet of two effect concentration unit (200).

3. The system for treating evaporative crystallization of wastewater from a coke-oven plant as recited in claim 1, wherein the single-effect concentration unit (100) comprises a single-effect evaporator b (7 a), a single-effect separator b (7 b), and a single-effect circulation pump b (7 c);

a material outlet at the upper end of the first-effect evaporator b (7 a) is connected with a first-effect outlet communicating pipe b (7 e), the other end of the first-effect outlet communicating pipe b (7 e) is communicated with a material inlet of the first-effect separator b (7 b), a material liquid outlet at the bottom end of the first-effect separator b (7 b) is communicated with a first-effect circulating pipe b (7 d), the other end of the first-effect circulating pipe b (7 d) is connected with a material inlet of the first-effect evaporator b (7 a), and the first-effect circulating pump b (7 c) is arranged on the first-effect circulating pipe b (7 d);

a discharge port of the preheating unit (600) is connected with a feed pipe b (7 s), the other end of the feed pipe b (7 s) is communicated with the single-effect circulating pipe b (7 d), and the communication position of the feed pipe b (7 s) is located in a pipe section between the single-effect circulating pump b (7 c) and a material inlet of the single-effect evaporator b (7 a);

the shell side inlet of the first-effect evaporator b (7 a) is connected with the heating chamber through a steam air supply pipe (1 r); the non-condensable gas outlet of the first-effect evaporator b (7 a) is connected with a first-effect non-condensable gas pipe (1 f), and the other end of the first-effect non-condensable gas pipe (1 f) is connected with the steam inlet of the second-effect concentration unit (200); the steam outlet at the top end of the first-effect separator b (7 b) is connected with a first-effect steam exhaust pipe b (7 g), and the other end of the first-effect steam exhaust pipe b (7 g) is communicated with the first-effect noncondensable pipe (1 f);

a condensed water outlet is arranged on the first-effect evaporator b (7 a);

the discharge gate of an effect circulating pump b (7 c) still is connected with an effect material output tube (1 p), the other end of an effect material output tube (1 p) is connected the feed inlet of two effect concentration units (200).

4. The system for processing evaporative crystallization of wastewater from a coke-oven plant according to claim 2 or 3, characterized in that the two-effect concentration unit (200) comprises a two-effect evaporator (2 a), a two-effect separator (2 b) and a two-effect circulation pump (2 c),

a material outlet at the upper end of the secondary evaporator (2 a) is connected with a secondary effect outlet communicating pipe (2 e), the other end of the secondary effect outlet communicating pipe (2 e) is communicated with a material inlet of the secondary effect separator (2 b), a material liquid outlet at the bottom end of the secondary effect separator (2 b) is communicated with a secondary effect circulating pipe (2 d), the other end of the secondary effect circulating pipe (2 d) is connected with a material inlet of the secondary effect evaporator (2 a), and the secondary effect circulating pipe (2 d) is provided with a secondary effect circulating pump (2 c);

the discharge end of the first-effect material output pipe (1 p) is communicated with the second-effect circulating pipe (2 d);

a shell pass inlet of the secondary evaporator (2 a) is connected with the primary effect noncondensable gas pipe (1 f), a noncondensable gas outlet of the secondary evaporator (2 a) is connected with the secondary effect noncondensable gas pipe (2 f), and the other end of the secondary effect noncondensable gas pipe (2 f) is connected with a steam inlet of the triple effect concentration unit (300); a steam outlet at the top end of the secondary effect separator (2 b) is connected with a secondary effect steam exhaust pipe (2 g), and the other end of the secondary effect steam exhaust pipe (2 g) is communicated with the secondary effect noncondensable pipe (2 f);

the discharge gate of two effect circulating pump (2 c) still is connected with two effect material output tube (2 p), the feed inlet of triple effect concentration unit (300) is connected to the other end of two effect material output tube (2 p).

5. The system for treating evaporative crystallization of wastewater from a coke-oven plant according to claim 4, wherein the triple-effect concentration unit (300) comprises a triple-effect evaporator (3 a), a triple-effect separator (3 b) and a triple-effect circulation pump (3 c);

a material outlet at the upper end of the triple-effect evaporator (3 a) is connected with a triple-effect outlet communicating pipe (3 e), the other end of the triple-effect outlet communicating pipe (3 e) is communicated with a material inlet of the triple-effect separator (3 b), a material liquid outlet at the bottom end of the triple-effect separator (3 b) is communicated with a triple-effect circulating pipe (3 d), the other end of the triple-effect circulating pipe (3 d) is connected with a material inlet of the triple-effect evaporator (3 a), and the triple-effect circulating pump (3 c) is connected to the triple-effect circulating pipe (3 d);

the secondary-effect material output pipe (2 p) is communicated with the three-effect circulating pipe (3 d);

a shell pass inlet of the triple-effect evaporator (3 a) is connected with the double-effect non-condensing pipe (2 f), a non-condensing outlet of the triple-effect evaporator (3 a) is connected with the triple-effect non-condensing pipe (3 f), the triple-effect non-condensing pipe (3 f) is connected with an inlet of the final-effect condenser (4 a), and an outlet of the final-effect condenser (4 a) is connected with a distilled water recovery pipe a (4 h);

an exhaust port at the top end of the three-effect separator (3 b) is connected with a three-effect exhaust pipe (3 g), and the other end of the three-effect exhaust pipe (3 g) is communicated with the three-effect noncondensable gas pipe (3 f);

the triple-effect circulating pipe (3 d) is also communicated with a triple-effect material output pipe (5 d), and the other end of the triple-effect material output pipe (5 d) is connected with the solid-liquid separation unit (500).

6. The system for treating evaporative crystallization of wastewater from a coke plant according to claim 5, characterized in that the preheating unit (600) comprises a condensate water preheater (6 a) and a steam preheater (6 c),

the material inlet of the condensed water preheater (6 a) is used for providing materials, the material outlet of the condensed water preheater (6 a) is connected with the material inlet of the steam preheater (6 c), and the material outlet of the steam preheater (6 c) is connected with the feed inlet of the primary concentrating unit (100);

a distilled water inlet of the condensed water preheater (6 a) is connected with a distilled water recovery unit, and the distilled water recovery unit is used for recovering distilled water drainage of the two-effect concentration unit (200) and the three-effect concentration unit (300); a distilled water outlet of the condensed water preheater (6 a) is connected with a distilled water recovery pipe b (6 b);

a heat source inlet of the steam preheater (6 c) is communicated with the heating chamber, and a heat source outlet of the steam preheater (6 c) is connected with a steam condensate pipe (6 d);

a condensed water drainage port of the one-effect concentration unit (100) is connected with a condensed water recovery unit, and the steam condensed water pipe (6 d) is connected with the condensed water recovery unit through the one-effect concentration unit (100).

7. The system for treating evaporative crystallization of wastewater from a coke-oven plant according to claim 6, wherein the condensate recovery unit comprises a condensate tank (1 j) and a condensate pump (1 m), the water inlet end of the top of the condensate tank (1 j) is connected with a first-effect condensate discharge pipe (1 h), and the other end of the first-effect condensate discharge pipe (1 h) is connected with the condensate outlet of the first-effect concentration unit (100);

the water outlet end of the lower end of the condensed water tank (1 j) and the water inlet end of the condensed water pump (1 m) are connected with a water pump water inlet pipe (1 k), and the water outlet pipe of the condensed water pump (1 m) is connected with a boiler through a water pump water outlet pipe (1 n).

8. The evaporative crystallization treatment system for wastewater from a coke-oven plant according to claim 6, wherein said distilled water recovery unit comprises a distilled water tank (2 j) and a distilled water pump (2 m),

the water inlet end at the upper end of the distilled water tank (2 j) is respectively communicated with a double-effect distilled water discharge pipe (2 h) and a triple-effect distilled water discharge pipe (3 h), the other end of the double-effect distilled water discharge pipe (2 h) is communicated with a distilled water discharge port of the double-effect evaporator (2 a), and the other end of the triple-effect distilled water discharge pipe (3 h) is connected with a distilled water discharge port of the triple-effect evaporator (3 a);

the water outlet end at the lower end of the distilled water tank (2 j) is communicated with the water inlet end of the distilled water pump (2 m) through a distilled water inlet pipe (2 k);

and a distilled water outlet pipe (2 n) is connected between the water outlet of the distilled water pump (2 m) and the distilled water inlet of the condensed water preheater (6 a).

9. The system for treating evaporative crystallization of wastewater from a coke-oven plant according to claim 5, characterized in that the solid-liquid separation unit (500) comprises a discharge pump (5 c), a centrifuge (5 a), a mother liquor tank (5 j), and a mother liquor reflux pump (5 m);

the feed inlet of the discharge pump (5 c) is connected with the triple-effect material output pipe (5 d), the discharge end of the discharge pump (5 c) is connected with a mixed discharge pipe (5 e), the other end of the mixed discharge pipe (5 e) is connected with the feed end of the centrifuge (5 a), and the solid material discharge outlet of the centrifuge (5 a) is connected with a solid discharge pipe (5 b);

a mother liquor outlet of the centrifuge (5 a) is connected with a mother liquor discharging pipe (5 h), and the other end of the mother liquor discharging pipe (5 h) is connected with the mother liquor tank (5 j); a mother liquor outlet at the lower end of the mother liquor tank (5 j) is connected with a mother liquor feeding pipe (5 k);

the other end of the mother liquor feeding pipe (5 k) is connected with a feeding hole of the mother liquor reflux pump (5 m), and a mother liquor reflux pipe (5 n) is communicated between the mother liquor reflux pump (5 m) and the triple-effect circulating pipe (3 d);

the communication position of the mother liquor return pipe (5 n) and the triple-effect circulating pipe (3 d) is positioned on a pipe section between the triple-effect circulating pump (3 c) and the triple-effect material output pipe (5 d).

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