A process and apparatus for the thermal oxidation of mixed salts from coking wastewater

Abstract

The application discloses a kind of for coking sewage treatment's miscellaneous salt thermal oxidation equipment and method, belong to coking wastewater treatment technical field, including by upper and lower arrangement on fixed support and by pipeline sequentially communicated sewage pretreatment device, dewatering device, thermal oxidation equipment, the sewage pretreatment device has multiple, bottom is fixedly connected with connecting pipe, the top of the sewage pretreatment device is communicated to sewage main pipeline;The thermal oxidation equipment includes thermal oxidation shell, the bottom of the thermal oxidation shell is equipped with water tank, and the bottom of thermal oxidation shell is fixedly connected with heating device on the inner wall of front and back side surface, the upper portion of the heating device is equipped with heating tank, and the heating tank is fixedly connected with the inner wall of the thermal oxidation shell, the bottom of the heating tank is equipped with several drain holes, and the upper portion of the heating tank is rotatably connected with screw rod one;The application enters the moisture content of precipitate of thermal oxidation equipment, can effectively reduce the energy consumption required for thermal oxidation, achieve energy saving and environmental protection, reduce coking wastewater treatment cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coking wastewater treatment, in particular to a mixed salt thermal oxidation equipment and method for coking wastewater treatment. BACKGROUND

[0002] Coking wastewater is a typical toxic and refractory organic wastewater. It mainly comes from the production of coking wastewater and steam condensate wastewater in the process of coking production.

[0003] The concentration of pollutants in coking wastewater is high and difficult to degrade. Due to the presence of nitrogen in coking wastewater, the nitrogen source required for biological purification is excessive, which brings great difficulty to treatment standard.

[0004] The mixed salt contained in coking wastewater includes various inorganic salts and organic matter. These pollutants are often difficult to remove by traditional methods. Thermal oxidation technology is a kind of efficient wastewater treatment method, which promotes the oxidation and decomposition of pollutants by high temperature heating. The thermal oxidation process can be divided into two types: direct combustion and catalytic combustion. The pyrolysis process usually needs to be carried out in the temperature range of several hundred degrees, which helps to destroy the complex structure of organic matter, decompose large molecular organic pollutants into smaller molecules, and even completely mineralize into harmless gas.

[0005] The existing thermal oxidation equipment for thermal oxidation treatment of coking wastewater has the problems that the organic salt in coking wastewater is difficult to separate, which increases the difficulty of implementing thermal oxidation technology; the separated coking wastewater organic salt has high water content, and a large amount of heat is needed to pyrolyze the organic salt in the separated organic matter. Therefore, a mixed salt thermal oxidation equipment for coking wastewater treatment is needed to improve the separation and thermal oxidation efficiency of organic salt in coking wastewater, while reducing the energy consumption required for thermal oxidation and reducing the cost of coking wastewater thermal oxidation. SUMMARY

[0006] To solve the above technical problems, the present application provides a mixed salt thermal oxidation equipment and method for coking wastewater treatment.

[0007] The technical scheme of the present application is: a mixed salt thermal oxidation equipment for coking wastewater treatment, comprising a wastewater pretreatment device, a dehydration device and a thermal oxidation equipment arranged from top to bottom on a fixed support and sequentially connected by a pipeline, the wastewater pretreatment device has a plurality of bottom fixed communication connection pipes, and the top of the wastewater pretreatment device is connected to a wastewater main pipeline.

[0008] The thermal oxidation equipment includes a thermal oxidation shell, a water tank is arranged at the bottom of the thermal oxidation shell, heating devices are fixedly connected to the inner walls of the front and rear sides of the bottom of the thermal oxidation shell, a heating tank is arranged above the heating devices, the heating tank is fixedly connected to the inner wall of the thermal oxidation shell, a plurality of drain holes are arranged at the bottom of the heating tank, a screw rod one is rotatably connected above the heating tank, a rotating motor is fixedly connected to the left end of the thermal oxidation shell, the output shaft of the rotating motor is in transmission connection with the screw rod one, an exhaust pipe is fixedly connected to the top of the thermal oxidation shell, and the exhaust pipe is in communication with the inside of the thermal oxidation shell.

[0009] Further, the sewage pretreatment device includes a stirring barrel, a water inlet pipe is fixedly connected above the left side of the stirring barrel, the upper end of the water inlet pipe is in communication with the sewage main pipeline, a control valve is arranged at the connection position of the water inlet pipe and the stirring barrel, a clean water collecting device is fixedly connected to the right side of the stirring barrel, a drain pipe is fixedly connected to the upper end of the clean water collecting device, and a flocculant adding device is fixedly connected to the top of the stirring barrel.

[0010] Description: The organic salt in the coking wastewater is flocculated and precipitated through the sewage pretreatment device, the stirring blades above the stirring rod are used to stir the sewage, so that the flocculant is fully mixed with the coking wastewater, the supernatant is extracted through the clean water collecting device, and the lower turbid liquid is discharged into the conveying pipe.

[0011] Further, the clean water collecting device includes a clean water collecting pipe, the clean water collecting pipe is fixedly connected below the right side of the stirring barrel, a buoyant ball is arranged in the clean water collecting pipe, a water inlet is arranged at the bottom of the buoyant ball, a water suction pipe is fixedly connected above the buoyant ball, a water suction pump is connected to the upper end of the water suction pipe, the water suction pump is fixedly connected to the drain pipe, and the water outlet of the water suction pump is fixedly connected to the inside of the drain pipe.

[0012] Description: The buoyant ball can ensure that the supernatant is always extracted, and the supernatant and the lower turbid liquid can be efficiently separated.

[0013] Further, the sewage pretreatment device is connected to the dewatering device through a connecting pipe and a conveying pipe via a vertical passage one, the conveying pipe includes a pipe body, the upper end of the pipe body is fixedly connected to the lower end of the connecting pipe, a screw rod three is rotatably connected in the pipe body, and a conveying motor is fixedly connected to the left side outer wall of the pipe body.

[0014] Description: The mixture of the wastewater and the precipitate is conveyed to the dewatering device through the screw rod three, compared with the pump type conveying, a plurality of connecting pipes can be connected above the conveying mode, the conveying efficiency is high, and the failure rate is low.

[0015] Further, the dewatering device comprises a dewatering shell, a filter cylinder is fixedly connected in the dewatering shell, a filter cylinder is fixedly connected in the filter cylinder in the transverse direction, a spiral rod four is rotatably connected in the filter cylinder, a dewatering motor is fixedly connected to the right end of the dewatering shell, the output shaft of the dewatering motor is in transmission connection with the spiral rod four, a backwater pump is fixedly connected to the inner bottom of the dewatering shell, the water outlet of the backwater pump is fixedly communicated with a filter pipe, and the filter pipe is communicated with the main sewage pipeline.

[0016] Description: The spiral blade interval of the spiral rod four is sparse on the right side and dense on the left side. The mixture enters the dewatering device, is conveyed to the left by the spiral rod four, and the moisture in the mixture is squeezed out because the spiral blade interval of the spiral rod four is smaller than that on the right side. The moisture flows into the bottom of the dewatering shell through the filter cylinder and is conveyed to the main sewage pipeline through the backwater pump.

[0017] Further, the heating device comprises two gas collecting boxes, the two gas collecting boxes are fixedly connected to the inner walls of the front side and the rear side of the thermal oxidation shell respectively, a plurality of gas injection nozzles are fixedly connected to the inner walls of the two gas collecting boxes, and the outer walls of the two gas collecting boxes are fixedly communicated with gas pipelines.

[0018] Description: The fuel gas enters the gas collecting box and is ignited after being sprayed out through the nozzle, the heating tank is heated, the organic salt is subjected to thermal oxidation and decomposition after being heated, and inorganic substances are formed.

[0019] Further, the end of the exhaust pipe is further connected with a gas washing device, the gas washing device comprises a shower pipe, a water storage cylinder is fixedly connected to the bottom of the shower pipe, a shower pump is arranged at the bottom of the water storage cylinder, a spray head is fixedly connected to the upper inner wall of the shower pipe, the water outlet of the shower pump is fixedly communicated with a water supply pipe, and the end of the water supply pipe is communicated with the spray head.

[0020] Description: The smoke dust volatilized in the thermal oxidation process of the organic matter is subjected to gas washing treatment, the safety of tail gas emission is improved, and the pollution of the tail gas to the environment is reduced.

[0021] Further, the bottom of the water tank is further fixedly connected with a water pump, the water outlet of the water pump is fixedly connected with a backflow pipe, and the top of the backflow pipe is communicated with the main sewage pipeline.

[0022] Description: The water pump conveys the water in the water tank to the main sewage pipeline for reprocessing, so as to avoid direct discharge of sewage in the water tank and cause water environment pollution.

[0023] Further, a method for thermal oxidation of miscellaneous salt by using the above-mentioned miscellaneous salt thermal oxidation equipment for coking sewage treatment comprises the following steps:

[0024] S1, after opening the control valve, the coking wastewater passes through the wastewater main pipeline and then enters the stirring barrel of the wastewater pretreatment device through the water inlet pipe, after the stirring barrel is filled with wastewater, the control valve is closed, the flocculating agent is added through the flocculating agent adding device, and then the stirring barrel is stirred, the organic salt and inorganic salt in the coking wastewater are flocculated, after the flocculation forms a precipitate, the clear water in the stirring barrel is pumped out of the wastewater pretreatment device through the clear water collecting device, the supernatant passes through the buoyancy ball and the water suction pipe and enters the drain pipe, the water suction power is provided by the water suction pump, and the precipitate formed after flocculation enters the dehydration device for dehydration treatment, and then the precipitate enters the thermal oxidation equipment;

[0025] S2, the dehydration motor drives the spiral rod four to rotate, the spiral rod four drives the precipitate to rotate in the filter cylinder, the moisture of the precipitate penetrates into the dehydration shell through the filter cylinder, and finally enters the wastewater main pipeline through the filter pipe under the action of the backwater pump;

[0026] S3, the moisture in the precipitate penetrates into the water tank through the heating tank, the precipitate with certain humidity is heated and oxidized by the heating device, the rotating motor drives the spiral rod one to rotate, the spiral rod one drives the precipitate to slowly move to the right end of the thermal oxidation equipment, and the organic matter in the precipitate is decomposed into inorganic salt by high-temperature oxidation.

[0027] The beneficial effects of the present application are:

[0028] (1) After the organic salt in the coking wastewater is flocculated and precipitated by the flocculating agent, the supernatant and the precipitate are separated, the water content of the precipitate is reduced by the dehydration device, and the thermal oxidation efficiency of the organic salt can be improved.

[0029] (2) The present application has obvious effect on coking wastewater treatment, the wastewater pretreatment device has high removal efficiency for the organic salt in coking wastewater, the organic salt is directly heated by gas, the calorific value of the gas is high, the water content of the precipitate entering the thermal oxidation equipment is low, the energy consumption required for thermal oxidation can be effectively reduced, energy saving and environmental protection are achieved, and the coking wastewater treatment cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic diagram of the present application.

[0031] Figure 2 is a structural schematic diagram of the wastewater pretreatment device of the present application.

[0032] Figure 3 is a sectional view of the thermal oxidation equipment of the present application.

[0033] Among them, 1-sewage pretreatment device, 2-dehydration device, 3-thermal oxidation equipment, 4-sewage main pipeline, 5-fixed support, 6-connecting pipe, 7-feeding pipe, 8-vertical channel one, 9-vertical channel two, 31-thermal oxidation shell, 32-water tank, 33-heating device, 34-heating tank, 35-spiral rod one, 36-rotary motor, 37-exhaust pipe, 11-mixing drum, 12-mixing motor, 13-mixing rod, 131-mixing blade, 132-spiral blade, 14-inlet pipe, 141-control valve, 15-clean water collection device, 16-drainage pipe, 17-flocculator addition device, 151-clean water collection Pipe, 152-Buoyancy ball, 153-Suction pipe, 154-Suction pump, 171-Flocculant bin, 172-Connecting rod, 173-Feeding motor, 174-Screw rod II, 71-Pipe body, 72-Screw rod III, 73-Feeding motor, 21-Dehydration shell, 22-Filter cylinder, 23-Screw rod IV, 24-Dehydration motor, 25-Return pump, 26-Filter pipe, 331-Air collection box, 332-Air nozzle, 333-Air conveying pipe, 38-Air washing device, 381-Scrubber pipe, 382-Water storage cylinder, 383-Scrubber pump, 384-Sprayer, 385-Water supply pipe, 321-Water pump, 322-Return pipe. Detailed Implementation

[0034] Example 1:

[0035] like Figure 1 As shown, a thermal oxidation device for treating coking wastewater includes a wastewater pretreatment device 1, a dewatering device 2, and a thermal oxidation device 3, which are arranged from top to bottom on a fixed support 5 and connected in sequence by pipes. There are three wastewater pretreatment devices 1, each with a connecting pipe 6 fixedly connected to its bottom. The top of the wastewater pretreatment device 1 is connected to the main wastewater pipe 4. The side wall of the wastewater pretreatment device 1 is fixedly connected to the fixed support 5. The lower ends of the multiple connecting pipes 6 are connected to a conveying pipe 7. The bottom of the conveying pipe 7 is fixedly connected to the fixed support 5. The right end of the conveying pipe 7 is fixedly connected to a vertical channel 1 8. The lower end of the vertical channel 1 8 is fixedly connected to the upper right end of the dewatering device 2. The bottom of the dewatering device 2 is fixedly connected to the fixed support 5. The lower left side of the dewatering device 2 is fixedly connected to a vertical channel 2 9. The lower end of the vertical channel 2 9 is fixedly connected to the upper left side of the thermal oxidation device 3. The bottom of the thermal oxidation device 3 is fixedly connected to the fixed support 5.

[0036] The thermal oxidation equipment 3 comprises a thermal oxidation shell 31, a water tank 32 is arranged at the bottom of the thermal oxidation shell 31, heating devices 33 are fixedly connected to the inner walls of the front and rear sides of the bottom of the thermal oxidation shell 31, heating tanks 34 are arranged above the heating devices 33 and are fixedly connected to the inner walls of the thermal oxidation shell 31, a plurality of drain holes 341 are arranged at the bottom of the heating tank 34, a screw rod one 35 is rotatably connected above the heating tank 34, a rotating motor 36 is fixedly connected to the left end of the thermal oxidation shell 31, the output shaft of the rotating motor 36 is in transmission connection with the screw rod one 35, an exhaust pipe 37 is fixedly connected to the top of the thermal oxidation shell 31 and is in communication with the inside of the thermal oxidation shell 31.

[0037] As shown in Figure 2 The sewage pretreatment device 1 comprises a stirring cylinder 11, a stirring motor 12 is fixedly connected to the top of the stirring cylinder 11, a stirring rod 13 is rotatably connected in the stirring cylinder 11, stirring blades 131 are fixedly connected above the stirring rod 13, spiral blades 132 are fixedly connected below the stirring rod 13, the top of the stirring rod 13 is in transmission connection with the output shaft of the stirring motor 12, a water inlet pipe 14 is fixedly connected above the left side of the stirring cylinder 11, the upper end of the water inlet pipe 14 is in communication with the sewage main pipe 4, a control valve 141 is arranged at the connection position of the water inlet pipe 14 and the stirring cylinder 11, a clean water collecting device 15 is fixedly connected to the right side of the stirring cylinder 11, a water outlet pipe 16 is fixedly connected to the upper end of the clean water collecting device 15, and a flocculant adding device 17 is fixedly connected to the top of the stirring cylinder 11.

[0038] The clean water collecting device 15 comprises a clean water collecting pipe 151, the clean water collecting pipe 151 is fixedly connected below the right side of the stirring cylinder 11, a buoyancy ball 152 is arranged in the clean water collecting pipe 151, a water inlet is arranged at the bottom of the buoyancy ball 152, a water suction pipe 153 is fixedly connected above the buoyancy ball 152, the upper end of the water suction pipe 153 is connected with a water suction pump 154, the water suction pump 154 is fixedly connected with the water outlet pipe 16, and the water outlet of the water suction pump 154 is fixedly connected with the inside of the water outlet pipe 16.

[0039] The flocculant adding device 17 comprises a flocculant bin 171, connecting rods 172 are fixedly connected to the outer walls of the two sides of the flocculant bin 171, the lower ends of the connecting rods 172 are fixedly connected with the top of the stirring cylinder 11, a discharging motor 173 is fixedly connected to the top of the flocculant bin 171, a screw rod two 174 is rotatably connected in the flocculant bin 171, and the output shaft of the discharging motor 173 is in transmission connection with the screw rod two 174.

[0040] The bottom of the sewage pretreatment device 1 is connected to the dewatering device 2 through the connecting pipes 6 and the feed pipe 7 via the vertical passage one 8, the feed pipe 7 comprises a pipe body 71, the upper portion of the pipe body 71 is fixedly communicated with the lower ends of the three connecting pipes 6, the screw rod three 72 is rotatably connected in the pipe body 71, the feed motor 73 is fixedly connected to the left outer wall of the pipe body 71, and the output shaft of the feed motor 73 is in transmission connection with the screw rod three 72.

[0041] The dewatering device 2 comprises a dewatering shell 21, the dewatering shell 21 is fixedly connected with a filter cylinder 22, the filter cylinder 22 is fixedly connected with a filter cylinder 22 in the transverse direction, the screw rod four 23 is rotatably connected in the filter cylinder 22, the dewatering motor 24 is fixedly connected to the right end of the dewatering shell 21, the output shaft of the dewatering motor 24 is in transmission connection with the screw rod four 23, the backwater pump 25 is fixedly connected to the inner bottom of the dewatering shell 21, the water outlet of the backwater pump 25 is fixedly communicated with the filter pipe 26, and the filter pipe 26 is communicated with the sewage main pipeline 4.

[0042] As shown in Figure 3 The heating device 33 comprises two gas collecting boxes 331, the two gas collecting boxes 331 are fixedly connected to the front inner wall and the rear inner wall of the thermal oxidation shell 31 respectively, the inner wall of the gas collecting box 331 is fixedly communicated with a plurality of gas injection nozzles 332, and the outer walls of the two gas collecting boxes 331 are fixedly communicated with gas pipelines 333.

[0043] Example 2

[0044] On the basis of example 1, the difference between example 2 and example 1 is that the number of the sewage pretreatment device 1 in the embodiment is two, and the number of the corresponding connecting pipes 6 is two.

[0045] Example 3

[0046] On the basis of example 1, the difference between example 3 and example 1 is that the number of the sewage pretreatment device 1 in the embodiment is one, and the number of the corresponding connecting pipes 6 is one.

[0047] Comparing example 1 to example 3, the flocculation efficiency is improved in example 1 because the number of the sewage pretreatment device 1 is three, and the efficiency of the entire device in treating coking sewage is the highest, so example 1 is the best.

[0048] Example 4

[0049] On the basis of embodiment 1, embodiment 4 is different from embodiment 1 in that the end of the exhaust pipe 37 in embodiment 4 is also connected with a gas washing device 38, the gas washing device 38 comprises a shower pipe 381, the bottom of the shower pipe 381 is fixedly connected with a water storage cylinder 382, the bottom of the water storage cylinder 382 is provided with a shower pump 383, the inner wall above the shower pipe 381 is fixedly connected with a spray head 384, the water outlet of the shower pump 383 is fixedly communicated with a water supply pipe 385, and the end of the water supply pipe 385 is communicated with the spray head 384.

[0050] Compared with embodiment 1, embodiment 4 can perform gas washing treatment on the smoke dust volatilized in the thermal oxidation process of the organic matter, improve the safety of the tail gas emission, and reduce the pollution of the tail gas to the environment.

[0051] Embodiment 5:

[0052] On the basis of embodiment 4, embodiment 5 is different from embodiment 4 in that the bottom of the water tank 32 in embodiment 5 is also fixedly connected with a water suction pump 321, the water outlet of the water suction pump 321 is fixedly connected with a backflow pipe 322, and the top of the backflow pipe 322 is communicated with the main sewage pipe 4.

[0053] Compared with embodiment 4, the water in the water tank 32 in embodiment 5 is transported to the main sewage pipe 4 by the water suction pump 321 for reprocessing, so as to avoid direct discharge of the sewage in the water tank and cause water environment pollution.

[0054] Embodiment 6:

[0055] On the basis of embodiment 5, embodiment 6 provides a method for performing thermal oxidation of miscellaneous salts by using the miscellaneous salt thermal oxidation equipment for coking sewage treatment, comprising the following steps:

[0056] S1, after the control valve 141 is opened, the coking sewage passes through the water inlet pipe 14 and enters the stirring barrel 11 of the sewage pretreatment device 1, after the stirring barrel 11 is filled with the sewage, the control valve 141 is closed, the flocculating agent is added through the flocculating agent adding device 17, and then the stirring barrel 11 is stirred to flocculate the organic salt and inorganic salt in the coking wastewater, after the flocculation forms a precipitate, the clear water in the stirring barrel 11 is pumped out of the sewage pretreatment device through the clear water collecting device 15, the supernatant enters the drain pipe 16 through the buoyancy ball 152 and the water suction pipe 153, the water suction power is provided by the water suction pump 154, and the precipitate formed after the flocculation enters the thermal oxidation equipment 3 after dehydration treatment by the dehydration device 2;

[0057] S2, the dehydration motor 24 drives the fourth screw rod 23 to rotate, the fourth screw rod 24 drives the precipitate to rotate in the filter cylinder 22, the water of the precipitate penetrates into the dehydration shell through the filter cylinder 22, and finally enters the main sewage pipe 4 through the filter pipe 26 under the action of the backwater pump 25;

[0058] S3, water in the precipitate permeates into the water tank 32 through the heating tank 34, the precipitate with certain humidity is heated and oxidized by the heating device 33, the rotating motor 36 drives the screw rod 35 to rotate, the screw rod 35 drives the precipitate to move slowly to the right end of the hot oxidation equipment 3, and the organic matter in the precipitate is decomposed into inorganic salt through high-temperature oxidation;

[0059] S4, the gas enters the gas collecting box 331 through the gas pipeline 333 and is sprayed out through the gas nozzle 332, the sprayed gas is ignited below the heating tank 34, the heat generated by the gas combustion heats the heating tank 34, the tail gas generated by the heating is introduced into the gas washing device 38, the water in the water storage cylinder 382 is pumped out through the water supply pipe 385 and enters the spray head 384, the tail gas is washed by the spray head 384, and the washed water falls into the water storage cylinder 382.

[0060] The stirring motor 12, the control valve 141, the water suction pump 154, the rotating motor 36, the discharging motor 173, the feeding motor 73, the dehydration motor 24, the washing pump 383 and the water pump 321 used in the above embodiments are all commercially available products, as long as they can realize the functions of the present application, and those skilled in the art can select and use them according to conventional common sense, which is not specially limited here.

Claims

1. A hot oxidation plant for the treatment of coking waste waters, characterized in that, The sewage pretreatment device (1), the dehydration device (2) and the thermal oxidation equipment (3) are sequentially arranged on the fixed support (5) from top to bottom and are sequentially communicated through pipelines, the sewage pretreatment device (1) has a plurality of sewage pretreatment devices, the bottom of each sewage pretreatment device is fixedly connected with a connecting pipe (6), and the top of each sewage pretreatment device is communicated with a sewage main pipeline (4); The thermal oxidation equipment (3) comprises a thermal oxidation shell (31), the bottom of the thermal oxidation shell (31) is provided with a water tank (32), the front and rear inner walls of the bottom of the thermal oxidation shell (31) are fixedly connected with a heating device (33), the upper side of the heating device (33) is provided with a heating tank (34), the heating tank (34) is fixedly connected with the inner wall of the thermal oxidation shell (31), the bottom of the heating tank (34) is provided with a plurality of drainage holes (341), the upper side of the heating tank (34) is rotatably connected with a screw rod (35), the left end of the thermal oxidation shell (31) is fixedly connected with a rotating motor (36), the output shaft of the rotating motor (36) is in transmission connection with the screw rod (35), the top of the thermal oxidation shell (31) is fixedly connected with an exhaust pipe (37), and the exhaust pipe (37) is in communication with the inside of the thermal oxidation shell (31); The sewage pretreatment device (1) comprises a stirring cylinder (11), the upper side of the left side of the stirring cylinder (11) is fixedly connected with a water inlet pipe (14), the upper end of the water inlet pipe (14) is communicated with the sewage main pipeline (4), a control valve (141) is arranged at the connection position of the water inlet pipe (14) and the stirring cylinder (11), the right side of the stirring cylinder (11) is fixedly connected with a clean water collecting device (15), the upper end of the clean water collecting device (15) is fixedly connected with a drain pipe (16), and the top of the stirring cylinder (11) is fixedly connected with a flocculant adding device (17); The clean water collecting device (15) comprises a clean water collecting pipe (151), the clean water collecting pipe (151) is fixedly connected with the lower side of the right side of the stirring cylinder (11), a buoyancy ball (152) is arranged in the clean water collecting pipe (151), the bottom of the buoyancy ball (152) is provided with a water inlet, the upper side of the buoyancy ball (152) is fixedly connected with a water suction pipe (153), the upper end of the water suction pipe (153) is connected with a water suction pump (154), the water suction pump (154) is fixedly connected with the drain pipe (16), and the water outlet of the water suction pump (154) is fixedly connected with the inside of the drain pipe (16); The bottom of the sewage pretreatment device (1) is connected to the dehydration device (2) through the connecting pipe (6) and a material conveying pipe (7) and a vertical passage (8), the material conveying pipe (7) comprises a pipe body (71), the upper side of the pipe body (71) is fixedly connected with the lower end of the connecting pipe (6), a screw rod (72) is rotatably connected in the pipe body (71), a material conveying motor (73) is fixedly connected with the left side outer wall of the pipe body (71), and the output shaft of the material conveying motor (73) is in transmission connection with the screw rod (72). The dewatering device (2) comprises a dewatering shell (21), a filter cylinder (22) is fixedly connected in the dewatering shell (21), a spiral rod four (23) is transversely and fixedly connected in the filter cylinder (22), a dewatering motor (24) is fixedly connected to the right end of the dewatering shell (21), the output shaft of the dewatering motor (24) is in transmission connection with the spiral rod four (23), a backwater pump (25) is fixedly connected to the inner bottom of the dewatering shell (21), the water outlet of the backwater pump (25) is fixedly communicated with a filter pipe (26), and the filter pipe (26) is communicated with the sewage main pipeline (4).

2. A hot oxidation plant for the treatment of sludges from coking plants as claimed in claim 1, characterized in that, The heating device (33) comprises gas collecting boxes (331), the two gas collecting boxes (331) are fixedly connected to the inner walls of the front side and the rear side of the thermal oxidation shell (31) respectively, a plurality of gas injection nozzles (332) are fixedly communicated with the inner walls of the gas collecting boxes (331), and the outer walls of the two gas collecting boxes (331) are fixedly communicated with gas conveying pipelines (333).

3. A hot oxidation plant for the treatment of sludges from coking processes, according to claim 1, characterized in that, The end of the exhaust pipe (37) is further connected with a gas washing device (38), the gas washing device (38) comprises a shower pipe (381), the bottom of the shower pipe (381) is fixedly connected with a water storage cylinder (382), the bottom of the water storage cylinder (382) is provided with a shower pump (383), the upper inner wall of the shower pipe (381) is fixedly connected with a spray head (384), the water outlet of the shower pump (383) is fixedly communicated with a water supply pipe (385), and the end of the water supply pipe (385) is communicated with the spray head (384).

4. A method for performing thermal oxidation of the mixed salt using the mixed salt thermal oxidation apparatus for coking wastewater treatment according to claim 1, characterized in that, The method comprises the following steps: S1, after the control valve (141) is opened, the coking sewage passes through the sewage main pipeline (4) and then enters the stirring cylinder (11) of the sewage pretreatment device (1) through the water inlet pipe (14), after the stirring cylinder (11) is filled with sewage, the control valve (141) is closed, the flocculating agent is added through the flocculating agent adding device (17), and then the stirring cylinder (11) is stirred, so that the organic salt and the inorganic salt in the coking wastewater are flocculated, after the flocculation, the supernatant passes through the water collection device (15) and is pumped out of the sewage pretreatment device, the supernatant passes through the buoyancy ball (152) and the water suction pipe (153) and enters the drain pipe (16), the water suction power is provided by the water suction pump (154), and the precipitate formed after the flocculation enters the thermal oxidation equipment (3) after being dewatered by the dewatering device (2); S2, the dewatering motor (24) drives the spiral rod four (23) to rotate, the spiral rod four (23) drives the precipitate to rotate in the filter cylinder (22), the water of the precipitate penetrates into the dewatering shell through the filter cylinder (22), and finally the water enters the sewage main pipeline (4) through the filter pipe (26) under the action of the backwater pump (25). S3, the water in the precipitate permeates into the water tank (32) through the heating tank (34), the precipitate with certain humidity is heated and oxidized by the heating device (33), the rotating motor (36) drives the screw rod I (35) to rotate, the screw rod I (35) drives the precipitate to move slowly to the right end of the thermal oxidation device (3), and the organic matter in the precipitate is decomposed into inorganic salt through high-temperature oxidation.

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