A high COD salt-containing wastewater incineration desalination cooling device and its application

Abstract

The present invention provides a desalination cooling device for incineration of high COD salt-containing wastewater, comprising a shell, a cooling component and a desalination component arranged inside the shell, a receiving component arranged below the shell, and a gas-liquid separator arranged on the top of the shell. The shell is provided with a flue gas inlet at one end and a flue gas outlet at the other end; the cooling component comprises a plurality of groups of heat exchange disks evenly arranged along the length direction of the shell, the gas-liquid outlet of the heat exchange disk is connected to the gas-liquid inlet of the gas-liquid separator, and its water inlet is connected to the liquid outlet of the gas-liquid separator through a pipeline; the desalination component comprises a scraper arranged on the front and rear end faces of the heat exchange disk, the scraper comprises three circumferentially evenly distributed blades, the bottom of the blade is connected to a scraper, and the scraper is in close contact with the disk surface of the heat exchange disk. The present invention has a simple structure and a reasonable design, solves the problem of molten salt precipitation blocking the heat exchanger tubes, realizes rapid cooling of high-temperature flue gas, and effectively recovers the heat of high-temperature flue gas, producing steam as a byproduct.

Description

Technical Field

[0001] The invention relates to a high-COD salt-containing wastewater incineration desalination cooling device and application thereof, belonging to the technical field of sewage treatment. Background Art

[0002] At present, in the production process of chemical, pharmaceutical, coking and other fields, a large amount of high COD salt-containing wastewater is usually generated. If these wastewaters are discharged directly, they will cause serious harm to water bodies and soil, leading to plant death and soil compaction, aggravating land desertification, and destroying regional ecosystems. Therefore, they must be treated to reduce harm. The traditional method of treating high COD salt-containing wastewater is to incinerate the wastewater to remove the organic matter in it, and the flue gas is cooled and desalted to meet the discharge standards.

[0003] The main components of salt in the high COD saline wastewater produced by our company are sodium sulfate and sodium chloride. In the actual wastewater treatment process, it was found that after the high COD saline wastewater was incinerated with kettle residue and natural gas at a temperature of 980℃, the incineration tail gas contained molten salt (sodium chloride melting point 801℃, sodium sulfate melting point 884℃). Such flue gas condensed into a solid state when it was cooled in the subsequent waste heat boiler and pipeline, and adhered to the inner wall of the pipeline; and the solid salt condensed from the molten state is different from the solid salt precipitated after evaporation and crystallization. The solid salt condensed from the molten state is easy to agglomerate, has no fixed crystal form and has a high hardness, which can easily cause blockage of waste heat boilers and pipelines, and is very difficult to clean, greatly increasing the equipment maintenance cost and the labor intensity of workers.

[0004] Therefore, how to solve the solidification problem of molten salt after cooling becomes the key to solving the problems that restrict the development of wastewater incineration treatment technology and expand the treatment capacity. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the purpose of the present invention is to provide a high COD salt-containing wastewater incineration desalination cooling device and its application.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A high COD salt-containing wastewater incineration desalination cooling device comprises a shell, a cooling component and a desalination component arranged inside the shell, a receiving component arranged below the shell, and a gas-liquid separator arranged on the top of the shell; a smoke inlet is arranged at one end of the shell, and a smoke outlet is arranged at the other end;

[0008] The cooling assembly includes a plurality of heat exchange disks evenly arranged along the length direction of the shell, the heat exchange disk is formed by two arc-shaped disk bodies buckled relative to each other, and the surface of the disk body is perpendicular to the flow direction of the high-temperature flue gas; the vapor-liquid outlet at the top of the heat exchange disk is connected to the vapor-liquid inlet of the vapor-liquid separator through a pipeline, and the water inlet at the bottom of the heat exchange disk is connected to the liquid outlet of the vapor-liquid separator through a pipeline, and the cooling medium flows in the cavity of the heat exchange disk; an axial hole that is not connected to the inner cavity of the heat exchange disk is also opened at the center of the heat exchange disk;

[0009] The desalination component includes a scraper and a driving system for driving the scraper to rotate; the scraper is arranged on the front and rear end surfaces of the heat exchange disk, and its center is mounted on the transmission shaft and fixed, and can rotate with the transmission shaft; the scraper includes three blades uniformly distributed circumferentially with the transmission shaft as the center, and a scraper is connected to the bottom of the blade. The scraper is in close contact with the disk surface of the heat exchange disk, and the lower edge of the scraper is an arc that matches the surface of the heat exchange disk, and the blade sharpening direction of the scraper is the same as the rotation direction of the transmission shaft.

[0010] A further improvement of the present invention is that: a water inlet and three vapor-liquid outlets are arranged on the heat exchange disk; the water inlet is connected to the medium delivery pipe through a water inlet branch pipe, and the other end of the medium delivery pipe is connected to the liquid outlet of the vapor-liquid separator; the three vapor-liquid outlets are respectively connected to a vapor-liquid discharge branch pipe, the vapor-liquid branch pipes are connected to the vapor-liquid discharge main pipe, and the other end of the vapor-liquid discharge main pipe is connected to the vapor-liquid inlet of the vapor-liquid separator.

[0011] A further improvement of the present invention is that a flow regulating valve is arranged on the water inlet branch of each heat exchange disk, a pressure interlock and a temperature interlock are arranged on the steam-liquid discharge branch of the heat exchange disk, and the water flow entering the heat exchange disk is interlocked with the pressure and temperature of the steam pipeline.

[0012] A further improvement of the present invention is that the plurality of groups of heat exchange disks are arranged alternately along the height direction of the shell, and two adjacent groups of heat exchange disks are respectively located at the upper part and the lower part of the shell.

[0013] A further improvement of the present invention is that each group of heat exchange plates is composed of two heat exchange plates arranged side by side, and the sum of the widths of the two heat exchange plates is slightly smaller than the width of the shell.

[0014] A further improvement of the present invention is that a water replenishment port is also provided at the bottom of the vapor-liquid separator, the water replenishment port is connected to the softened water delivery pipeline through a water replenishment pipe, and a water replenishment pump is provided on the water replenishment pipe.

[0015] A further improvement of the present invention is that: a liquid level interlock is also provided on the vapor-liquid separator, and the liquid level interlock is interlocked and controlled with the water supply pump.

[0016] A further improvement of the present invention is that the receiving component includes a conical bucket and a screw conveyor; the top of the conical bucket is connected to the inner cavity of the shell, and the bottom is provided with an openable and closable discharge port, the discharge port is connected to the feed port of the screw conveyor, and a cart for transporting solid salt is provided under the discharge port of the screw conveyor.

[0017] A further improvement of the present invention is that it is applied to a high COD salt-containing wastewater incineration treatment system.

[0018] A further improvement of the present invention is that the high COD salt-containing wastewater incineration treatment system comprises an incinerator, an incineration desalination cooling device, a bag filter and a chimney which are connected in sequence, and an induced draft fan is arranged between the bag filter and the chimney.

[0019] Due to the adoption of the above technical solution, the technical progress achieved by the present invention is:

[0020] The present invention provides a high-COD salt-containing wastewater incineration and desalination device with a simple structure and reasonable design. It solves the problem of molten salt precipitation in high-temperature flue gas clogging the tubes of the heat exchanger, realizes rapid cooling of the high-temperature flue gas, and effectively recovers the heat of the high-temperature flue gas. While effectively cooling the flue gas, it produces about 1.5t / h of 0.4MPa steam as a by-product.

[0021] When the original treatment device exchanges heat through a vertical circulating water heat exchanger during use, there is no energy recovery, and a lot of heat is wasted. The present invention uses an arc-shaped heat exchange plate with a large heat exchange area and high heat exchange efficiency; the arc-shaped heat exchange plate is equipped with a sharp scraper to immediately remove the attached solid salt, which does not accumulate on the surface of the heat exchange plate and does not affect the heat exchange effect, thereby reducing the loss of flue gas heat and allowing it to be fully recovered. Since the heat exchange effect of the device of the present invention is significantly better than that of the original treatment device, it can replace the four cooling and heat exchange devices of the settling chamber, waste heat boiler, air heat exchanger and semi-dry quenching tower device in the original treatment device, greatly reducing the number and floor space of equipment and pipelines, and saving equipment investment.

[0022] During the operation of the original treatment device, it is necessary to continuously use manual heavy hammer desalination (high-temperature flue gas passes through the vertical circulating water heat exchanger tube, the heat exchange tube diameter is DN50, and there are 57 heat exchange tubes in total. After being raised by a heavy hammer, these 57 tubes are cleaned regularly by gravity to remove the salt attached to the tube wall and extend the operation time) in the circulating water heat exchanger for desalination, which is very labor-intensive. The device of the present invention significantly reduces the labor intensity of workers. On the one hand, the device adopts automatic control by the central control host, and has a high degree of automation; on the other hand, the device automatically desalinates during the heat exchange process, and is not easy to condense on the outer wall of the heat exchange plate. There is no need for regular manual cleaning and desalination, which reduces inspection and maintenance.

[0023] As the operation time goes by, the original treatment device needs to be shut down at least once a month to clean the sedimentation chamber, waste heat boiler and its connecting pipes to continue to ensure the heat exchange and cooling effect, which is very troublesome; and frequent shutdowns will damage the incinerator and reduce the service life of the incinerator. The device of the present invention is easy to operate, and the heat exchange and desalination processes are carried out in parallel. There is no need to shut down the furnace for cleaning, and the continuous treatment of saline wastewater in the factory can be achieved, which is more suitable for large-scale industrial use.

[0024] The present invention also provides an application of the cooling and desalination device. When it is used for the incineration treatment of high-COD salt-containing wastewater, it can replace the cooling and heat exchange effects of four devices. On the basis of ensuring the flue gas cooling and dust removal effects, it greatly reduces the processing time and energy consumption, and can realize continuous treatment of wastewater, which is suitable for industrial promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the instrument control of water inlet and outlet of the heat exchange disk of the present invention;

[0027] Figure 3 It is a left side schematic diagram of the shell part;

[0028] Figure 4 is a right side schematic diagram of the shell part;

[0029] Figure 5 It is a left side schematic diagram of the interior of the shell;

[0030] Figure 6 is a schematic diagram of the right side view of the interior of the shell;

[0031] Figure 7 It is a schematic diagram of the structure of a straight scraper;

[0032] Figure 8 It is a structural schematic diagram of an arc-shaped scraper;

[0033] Fig. 9 It is a structural schematic diagram of a curved scraper;

[0034] The solid lines in the figure are pipeline connections, and the double-dotted lines are signal transmission connections;

[0035] In the figure, 1-shell, 11-smoke inlet, 12-smoke outlet, 2-heat exchange plate, 21-water inlet branch, 22-gas-liquid discharge branch, 23-pressure interlock, 24-flow regulating valve, 25-temperature interlock, 31-drive motor, 32-reducer, 33-first transmission shaft group, 34-second transmission shaft group, 35-scraper, 4-gas-liquid separator, 41-gas-liquid discharge main pipe, 42-medium conveying pipe, 43-medium circulation pump, 44-liquid level interlock, 45-water supply pipe, 46-water supply pump, 51-conical bucket, 52-observation window, 53-screw conveyor, 54-trolley. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below with reference to the accompanying drawings.

[0037] A high COD salt-containing wastewater incineration desalination cooling device comprises a shell 1, a cooling component, a desalination component, a receiving component and a vapor-liquid separator 4. The cooling component and the desalination component are arranged inside the shell 1, the cooling component is used to cool the high-temperature flue gas and solidify the molten salt, and the desalination component is used to scrape off the solid salt condensed on the cooling component; the receiving component is arranged below the shell 1, and is used to receive the scraped and dropped solid salt; the vapor-liquid separator 4 is arranged above the shell 1, and is used to provide circulating cooling water for the cooling component and separate and generate steam.

[0038] The specific structure of the high COD salt-containing wastewater incineration desalination and cooling device is described in detail below with reference to the accompanying drawings.

[0039] About Shell 1:

[0040] The housing 1 is a rectangular housing 1, with a smoke inlet 11 at one end and a smoke outlet 12 at the other end. The smoke inlet 11 is connected to the high-temperature smoke pipe, and the smoke outlet 12 is connected to the low-temperature smoke pipe to form a continuous smoke flow path. The high-temperature smoke generated by the incineration of high-COD salt-containing wastewater enters the desalination device housing 1 through the high-temperature smoke pipe to cool down, and then is discharged through the low-temperature smoke pipe and sent to a further post-processing section.

[0041] The inner side of the shell 1 is covered with a heat insulation layer to reduce the heat loss of flue gas heat in the desalination device and reduce safety hazards in production. The heat insulation material is selected from high-temperature heat insulation materials with a use temperature of more than 1000°C, such as ceramics, asbestos and other inorganic heat insulation materials, which can not deform or melt under long-term use. Due to the presence of the heat insulation material, the shell 1 material can be selected from low-grade materials, and ordinary carbon steel materials can be selected to reduce equipment investment.

[0042] About cooling components:

[0043] The cooling assembly includes a plurality of heat exchange discs 2 evenly arranged along the length direction of the shell 1. The heat exchange disc 2 is formed by two arc-shaped disc bodies buckled relative to each other, and the surface of the disc body is perpendicular to the flow direction of the high-temperature flue gas. The interior of the heat exchange disc 2 is a cavity structure, and the cooling medium flows in the cavity, and heat is exchanged with the high-temperature flue gas flowing in the shell 1 through the disc wall.

[0044] In this embodiment, water is selected as the cooling medium. Water has a large specific heat capacity and can not only cool the flue gas but also produce steam for factory use.

[0045] Specifically, each heat exchange plate 2 is provided with a water inlet at the bottom and a vapor-liquid outlet at the top. There is one water inlet, which is provided at the bottom of the heat exchange plate 2 where it is fastened. There are three vapor-liquid outlets, which are arranged at intervals along the fastening line of the heat exchange plate 2, and the vapor-liquid outlet in the middle is provided at the top of the heat exchange plate 2. Since the heat exchange area of ​​the heat exchange plate 2 is large, the water in the inner cavity absorbs heat and turns into steam, and the volume of the steam expands. If it is not transported out in time, the pressure in the inner cavity of the heat exchange plate 2 will increase; therefore, three vapor-liquid outlets are provided at the top of the heat exchange plate 2 to facilitate the timely output of steam.

[0046] The water inlet and outlet of each heat exchanger 2 are connected to a water inlet branch pipe 21, and all water inlet branches 21 are connected to the output end of the medium delivery pipe 42. The input end of the medium delivery pipe 42 is connected to the liquid outlet of the vapor-liquid separator 4; the three vapor-liquid outlets of each heat exchanger 2 are respectively connected to a vapor-liquid discharge branch pipe 22, and all vapor-liquid discharge branch pipes 22 are connected to the vapor-liquid discharge main pipe 41, and the other end of the vapor-liquid discharge main pipe 41 is connected to the vapor-liquid inlet of the vapor-liquid separator 4. Generally speaking, the specifications of the vapor-liquid discharge main pipe 41 are two models larger than the vapor-liquid discharge branch pipe 22. For example, the vapor-liquid discharge branch pipe 22 adopts DN50, and the vapor-liquid discharge main pipe 41 adopts DN100, so as to ensure the smooth discharge of steam in the heat exchanger.

[0047] In order to prevent the heat exchanger from lacking water, a flow control valve 24 is set on the water inlet branch 21 of each heat exchanger, and a pressure interlock 23 and a temperature interlock 25 are set on the steam-liquid discharge branch 22 of the heat exchanger to interlock the water flow entering the heat exchanger with the pressure and temperature of the steam pipeline. The signal is transmitted to the central control host and controlled by the central control host. When the pressure and temperature of the steam-liquid discharge branch 22 increase, it proves that the amount of steam generated is large, and the central control host sends a signal to the flow control valve 24 to increase the water inlet flow; if the pressure and temperature display is lower than the set value, it means that the amount of steam generated is small, and the amount of cooling water required for the heat exchanger and the following heat exchangers can be reduced, and the opening of the flow control valve 24 is automatically reduced through the central control host to reduce the amount of water inlet. As the flue gas flows, its temperature gradually decreases. The heat exchange plates at different positions require different amounts of hot water. The water inlet flow rate is adjusted in time through the pressure interlock 23 and the temperature interlock 25 to ensure the actual heat exchange demand and avoid waste. At the same time, the processing pressure of the vapor-liquid separator 4 is minimized to ensure the stable by-product of steam.

[0048] The pressure interlock 23 can be installed on any vapor-liquid discharge branch pipe 22, preferably installed on the vapor-liquid discharge branch pipe 22 connected to the top vapor-liquid outlet.

[0049] The flow control valve 24 can be a pneumatic control valve or an electric control valve, which is determined according to the pipeline configuration and explosion-proof level of the plant. Generally speaking, a pneumatic control valve is preferred, which has a fast response speed and is sensitive, but requires an instrument air source.

[0050] When the device is in operation, cooling water flows in the cavity of the heat exchange disk 2, and the high-temperature flue gas enters the shell 1 and contacts the outer surface of the heat exchange disk 2, and heat exchange is generated through the disk wall. After the step-by-step heat exchange, the temperature of the high-temperature flue gas drops and is discharged. The cooling water flowing in the heat exchange disk 2 is heated and heated to generate steam. After separation by the vapor-liquid separator 4, the steam is sent to the steam network of the factory for use. The separated hot water is driven by the medium circulation pump 43 and returns to the water inlet at the bottom of the heat exchange disk 2 through the medium delivery pipe 42 for circulating heat exchange.

[0051] Preferably, the plurality of groups of heat exchange disks 2 are arranged alternately along the height direction of the shell 1, and two adjacent groups of heat exchange disks 2 are respectively located at the upper part and the lower part of the shell 1. Such an arrangement can ensure that the high-temperature flue gas fully contacts and exchanges heat with the heat exchange disks 2 to the maximum extent, and can also avoid generating high flow resistance.

[0052] Preferably, each group of heat exchange disks 2 is composed of two heat exchange disks 2 arranged side by side, and the sum of the widths of the two heat exchange disks 2 is slightly smaller than the width of the shell 1, which greatly increases the heat exchange area; it is necessary to try to avoid using a heat exchange disk 2 with too large specifications for heat exchange. If the heat exchange disk 2 is too large, a large cooling water flow rate is required, which has higher requirements for the water pipe type and the circulating pump model, increasing the equipment cost. Moreover, a heat exchange disk 2 with too large specifications is not conducive to maintenance.

[0053] Preferably, the heat exchange plate 2 is made of stainless steel with good heat transfer effect and low rust resistance, and its inner and outer surfaces are polished to facilitate the scraping of solidified salt and the cleaning of scale inside the plate.

[0054] In addition, an axial hole is provided in the center of the heat exchange disk 2, and the axial hole passes through the disk body of the heat exchange disk 2, and the axial hole is not connected to the inner cavity of the heat exchange disk 2, so no mass transfer occurs.

[0055] About desalination components:

[0056] The desalination assembly includes a scraper 35 and a driving system for driving the scraper 35 to rotate.

[0057] The driving system includes a driving motor 31, a reducer 32 and a transmission shaft. The driving motor 31 and the reducer 32 are located outside the shell 1. The power output shaft of the driving motor 31 is connected to the reducer 32, and the power output end of the reducer 32 is connected to the transmission shaft through a sprocket transmission mechanism. After the driving motor 31 is turned on, the driving power is transmitted step by step to the transmission shaft to drive the transmission shaft to rotate.

[0058] The transmission shaft includes a first transmission shaft group 33 and a second transmission shaft group 34 arranged in parallel, and the first transmission shaft group 33 and the second transmission shaft group 34 rotate synchronously under the drive of the driving system. The first transmission shaft group 33 and the second transmission shaft group 34 each include two transmission shafts arranged side by side. Among them, the first transmission shaft group 33 is located at the upper part of the shell 1, and the two transmission shafts pass through the axial holes in the centers of the two rows of heat exchange disks 2 located at the upper part of the shell 1; the second transmission shaft group 34 is located at the lower part of the shell 1, and the two transmission shafts pass through the axial holes in the centers of the two rows of heat exchange disks 2 located at the lower part of the shell 1, thereby realizing the synchronous desalination of all heat exchange disks 2 in the shell 1.

[0059] The scraper 35 is arranged on the front and rear end surfaces of the heat exchange disk 2, and its center is mounted on the transmission shaft and fixed, and can rotate with the rotation of the transmission shaft. The scraper 35 includes three blades uniformly distributed circumferentially with the transmission shaft as the center, and a scraper is connected to the bottom of the blade. The scraper is in close contact with the disk surface of the heat exchange disk 2. The lower edge of the scraper is an arc that matches the surface of the heat exchange disk 2. The blade direction of the scraper is the same as the rotation direction of the transmission shaft; when the transmission shaft rotates, the scraper 35 drives the scraper to rotate along the disk surface of the heat exchange disk 2, scraping off the solid salt condensed on the surface of the heat exchange disk 2 when it is cold, so as to keep the surface of the heat exchange disk 2 clean and the heat transfer effect. The scraper is connected to the blade by bolts. After a certain period of use, the blade is blunted and a new scraper can be replaced.

[0060] The shape of the scraper can be Figure 6 The straight line shown can also be Figure 7 The arc shape and Figure 8 The curve type shown can be selected according to the state of the solid salt. Generally speaking, for scraping solid salt with high viscosity, arc-shaped and curved scrapers are better, and for scraping solid salt with low viscosity, straight scrapers are better. On different groups of heat exchange plates 2 of the same desalination device, scrapers of different shapes can also be selected according to actual needs to maximize the scraping efficiency of solid salt.

[0061] About vapor-liquid separator 4:

[0062] The vapor-liquid separator 4 is arranged above the shell 1 . The vapor-liquid separator 4 is provided with a vapor-liquid inlet, a liquid outlet, a steam outlet and a waste liquid outlet. A liquid level interlock 44 is also arranged on the vapor-liquid separator 4 .

[0063] The vapor-liquid inlet is arranged in the middle of the vapor-liquid separator 4 , and is connected to the vapor-liquid discharge main pipe 41 . The vapor-liquid mixture generated by the heat exchange disk 2 is collected through the vapor-liquid discharge main pipe 41 and then enters the vapor-liquid separator 4 from the middle.

[0064] The liquid outlet is arranged at the bottom of the vapor-liquid separator 4, and the liquid outlet is connected to the medium delivery pipe 42, and the medium delivery pipe 42 is connected to the water inlet of each heat exchange disk 2 through each water inlet branch pipe 21; a medium circulation pump 43 is arranged on the medium delivery pipe 42 to provide circulation power. The liquid obtained after the vapor-liquid mixture is separated is discharged from the liquid outlet and then pumped into each heat exchange disk 2 to circulate heat as cooling water.

[0065] The steam outlet is arranged at the top of the vapor-liquid separator 4, and the steam outlet is connected to the steam network of the factory through a pipeline.

[0066] The bottom of the vapor-liquid separator 4 is also provided with a water replenishment port and a waste liquid outlet. The water replenishment port is connected to the softened water delivery pipeline through a water replenishment pipe 45, and a water replenishment pump 46 is provided on the water replenishment pipe 45. The water replenishment pump 46 is connected to the liquid level interlock 44 of the vapor-liquid separator 4. When the liquid level interlock 44 detects that the water volume in the vapor-liquid separator 4 is insufficient, it transmits a signal to the central control host. After receiving the signal, the central control host drives the water replenishment pump 46 to adjust the flow rate and replenish cold water into the vapor-liquid separator 4 to ensure sufficient cooling of the high-temperature flue gas. The concentrated waste liquid generated by the repeated operation of the vapor-liquid separator 4 is discharged through the waste liquid outlet.

[0067] Preferably, there are two medium circulation pumps 43 and two water replenishment pumps 46, which are arranged in parallel, with one in operation and the other in standby.

[0068] About the receiving component:

[0069] A receiving assembly for receiving the scraped solid salt and completing the transportation is arranged below the shell 1. The receiving assembly includes a conical bucket 51 and a screw conveyor 53; the top of the conical bucket 51 is connected to the inner cavity of the shell 1, and the bottom thereof is provided with an openable and closable discharge port, which is connected to the feed port of the screw conveyor 53, and a cart 54 for transporting solid salt is arranged below the discharge port of the screw conveyor 53. The solid salt scraped by the scraper 35 falls into the conical bucket 51 for storage under the action of gravity; when the salt storage reaches a certain level, the screw conveyor 53 and the discharge port are opened, and the solid salt is transferred to the cart 54 by the screw conveyor 53, and then transferred to other storage places by the cart 54.

[0070] The top of the conical bucket 51 is fixedly connected to the bottom of the housing 1 by bolts. When the device is stopped for cleaning, the conical bucket 51 can be removed to thoroughly clean the inside of the bucket. An observation window 52 and an operation window are also provided on the side wall of the housing 1. The observation window 52 is used for workers to observe the amount of solid salt and discharge it in time. The operation window is used to clean and dredge when the solid salt is not discharged smoothly or the discharge port is blocked.

[0071] The number of receiving components can be adjusted according to actual conditions. When the high-temperature flue gas flow is large, the number of cooling plates is large, and the shell is long, multiple groups of receiving components can be set under the shell, for example, two groups are set in this embodiment. Multiple groups of receiving components can avoid solid salt backlog and improve the smoothness of solid salt discharge.

[0072] The central control host used in the present invention is a PLC controller that can write programs, and the operation of each component is controlled by the program. For example, the STC89C52 single-chip microcomputer is selected, and its specific control method is not the main body of the present invention. The technicians in this field can choose it according to their needs, and it will not be described in detail here.

[0073] The equipment of the present invention should be high temperature resistant and corrosion resistant. For example, the heat exchange plate and scraper can be made of Hastelloy or tungsten cobalt hard alloy, preferably Hastelloy C-276, which still has good hardness and corrosion resistance at high temperature.

[0074] The working principle of the high COD salt-containing wastewater incineration desalination cooling device is:

[0075] The high-temperature flue gas generated by the incineration of high-COD salt-containing wastewater enters the shell through the flue gas inlet. At the same time, hot water as a cooling medium enters the inner cavity of the heat exchange disk under the drive of the medium delivery pump, and the flue gas contacts and exchanges heat with the heat exchange disk; after the flue gas is cooled, part of the molten salt contained in it condenses and solidifies on the surface of the heat exchange disk, is scraped off by the high-speed rotating scraper, and naturally falls into the conical bucket for temporary storage; the flue gas after step-by-step cooling is discharged from the flue gas outlet and enters the next treatment section;

[0076] The hot water in the inner cavity of the heat exchanger absorbs heat, heats up and generates steam; the vapor-liquid mixture enters the vapor-liquid separator for separation, the separated steam is incorporated into the steam network, and the separated hot water is pumped back to the heat exchanger for circulation.

[0077] By incinerating and desalting the high-COD salt-containing wastewater according to the present invention, the temperature of the high-temperature flue gas can be reduced from 980°C to below 200°C, and about 1.5 t / h of steam can be produced as a by-product.

[0078] 2. Application

[0079] The application of the high COD salt-containing wastewater incineration desalination cooling device is to be used in a high COD salt-containing wastewater incineration treatment system, and its position is set after the incinerator and before the bag filter to achieve rapid cooling of flue gas and effective recovery of waste heat.

[0080] The salt-containing wastewater incineration treatment system using the desalination device comprises: an incinerator, a desalination device, a bag dust collector and a chimney connected in sequence, and an induced draft fan is arranged between the bag dust collector and the chimney to provide flue gas flow power.

[0081] The incineration treatment process of saline wastewater using this desalination device is:

[0082] S1. High COD salt-containing wastewater enters the incinerator in atomized form through a pump and is mixed with natural gas for combustion at a temperature of about 980°C.

[0083] S2. The high-temperature flue gas discharged from the incinerator enters the desalination device and is cooled step by step through multiple sets of heat exchange plates, and the flue gas temperature drops from about 1000℃ to below 200℃;

[0084] S3. Low-temperature flue gas with a temperature below 200°C enters the bag filter for dust removal and is then discharged from the chimney.

[0085] The factory's original high-COD salt-containing wastewater treatment system included: an incinerator, a settling chamber, a waste heat boiler, a circulating water heat exchanger, a semi-dry quenching tower, a bag dust collector, a spray washing tower, a mist water separator and a chimney connected in sequence, with an induced draft fan installed between the mist water separator and the chimney.

[0086] The treatment process of the original saline wastewater is:

[0087] A. High COD salt-containing wastewater enters the incinerator in atomized form through a pump and is mixed with natural gas for combustion at a temperature of about 980°C;

[0088] B. High-temperature flue gas enters the settling chamber, and some salts are deposited in the settling chamber by gravity;

[0089] C. Flue gas enters the waste heat boiler, and steam is produced as a by-product using high-temperature flue gas. At the same time, the flue gas temperature is reduced to about 650°C;

[0090] D. The flue gas enters the semi-dry quenching tower, where the flue gas exchanges heat with the blast air, and the flue gas temperature after heat exchange is reduced to about 550°C;

[0091] E. The flue gas enters the quenching spray tower and is sprayed with primary water to cool down the flue gas. The flue gas temperature drops to ≤200℃ within 2s. The spraying water volume is 1.8~2.5m 3 / h;

[0092] F. The flue gas enters the bag filter for dust removal, then passes through the mist-water separator and enters the chimney for discharge into the air.

[0093] By comparing the two processes, it can be seen that in the original process, the flue gas needs to be treated by seven treatment devices before it can be discharged, while in this process, the flue gas only needs two treatment devices to be discharged. The number of equipment is greatly reduced, the difficulty of pipeline layout and equipment selection is significantly reduced, and the footprint is small; in addition, due to the significant reduction in the number of equipment and pipeline length, the time spent on wastewater treatment is shortened and the energy consumption is significantly reduced.

[0094] The high COD salt-containing wastewater incineration treatment system of the present invention is used for flue gas treatment. The organic matter content and other parameters of the exhaust flue gas are monitored for three consecutive days, and the average value is calculated. The average flue gas treatment energy consumption and hourly steam production are also calculated and compared with the annual average values ​​of the relevant parameters of the original treatment process last year. The results are shown in the table below.

[0095]

[0096]

[0097] The above data show that after the use of the incineration and desalination device of the present invention, the emissions of flue gas particulate matter, nitrogen oxides and sulfur dioxide are the same as the original process, far lower than the emission limits given in the "Hazardous Waste Incineration Pollutant Control Standard" (GB18484-2001), and meet the clean emission requirements; at the same time, the amount of steam generated is 7 to 8.5 times the amount of steam generated in the original process, and the increase is significant, proving that the waste heat of the flue gas is effectively recovered.

[0098] Confirmed through actual operation, the device can replace the four equipment in the original process, namely the settling chamber, waste heat boiler, circulating water heat exchanger and semi-dry quenching tower. Moreover, since no spray cooling is used and no mist water separator needs to be installed, the incineration treatment process is greatly simplified. The optimized high COD salt-containing wastewater incineration treatment process is simple and easy to control, with short batch processing time and low processing energy consumption. It can fully recover the waste heat of flue gas and stabilize the by-product steam.

[0099] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the present invention.

Claims

1. A high COD salt-containing wastewater incineration desalination cooling device, characterized by: It comprises a shell, a cooling component and a desalting component arranged inside the shell, a receiving component arranged below the shell, and a gas-liquid separator arranged on the top of the shell; a smoke inlet is arranged at one end of the shell, and a smoke outlet is arranged at the other end opposite to the shell; The cooling assembly includes a plurality of heat exchange disks evenly arranged along the length direction of the shell, the heat exchange disk is formed by two arc-shaped disk bodies buckled relative to each other, and the surface of the disk body is perpendicular to the flow direction of the high-temperature flue gas; the vapor-liquid outlet at the top of the heat exchange disk is connected to the vapor-liquid inlet of the vapor-liquid separator through a pipeline, and the water inlet at the bottom of the heat exchange disk is connected to the liquid outlet of the vapor-liquid separator through a pipeline, and the cooling medium flows in the cavity of the heat exchange disk; an axial hole that is not connected to the inner cavity of the heat exchange disk is also opened at the center of the heat exchange disk; The desalination assembly includes a scraper and a driving system for driving the scraper to rotate; the scraper is arranged on the front and rear end surfaces of the heat exchange disk, and the center thereof is sleeved on the transmission shaft and fixed, and can rotate with the transmission shaft; the scraper includes three blades uniformly distributed circumferentially with the transmission shaft as the center, and a scraper is connected to the bottom of the blade, and the scraper is in close contact with the disk surface of the heat exchange disk, and the lower edge of the scraper is an arc shape that matches the surface of the heat exchange disk, and the blade opening direction of the scraper is the same as the rotation direction of the transmission shaft; A water inlet is arranged at the bottom of the heat exchange plate, and three vapor-liquid outlets are arranged at the top; the water inlet is connected to the medium delivery pipe through a water inlet branch pipe, and the other end of the medium delivery pipe is connected to the liquid outlet of the vapor-liquid separator; each vapor-liquid outlet is respectively connected to a vapor-liquid discharge branch pipe, and the three vapor-liquid branch pipes are connected to the vapor-liquid discharge main pipe at the other end of which is connected to the vapor-liquid inlet of the vapor-liquid separator; The plurality of groups of heat exchange plates are arranged alternately along the height direction of the shell, and two adjacent groups of heat exchange plates are respectively located at the upper part and the lower part of the shell.

2. The high COD salt-containing wastewater incineration desalination cooling device according to claim 1 is characterized in that: A flow regulating valve is arranged on the water inlet branch of each heat exchange disk, and a pressure interlock and a temperature interlock are arranged on the steam-liquid discharge branch of the heat exchange disk. The water flow entering the heat exchange disk is interlocked with the pressure and temperature of the steam pipeline for control.

3. The high COD salt-containing wastewater incineration desalination cooling device according to claim 1 is characterized by: Each group of heat exchange plates consists of two heat exchange plates arranged side by side, and the sum of the widths of the two heat exchange plates is slightly smaller than the width of the shell.

4. The high COD salt-containing wastewater incineration desalination cooling device according to claim 1 is characterized in that: A water replenishment port is also provided at the bottom of the vapor-liquid separator, and the water replenishment port is connected to the softened water delivery pipeline through a water replenishment pipe, and a water replenishment pump is arranged on the water replenishment pipe.

5. The high COD salt-containing wastewater incineration desalination cooling device according to claim 4 is characterized in that: The vapor-liquid separator is also provided with a liquid level interlock, which is interlocked and controlled with the water supply pump.

6. The high COD salt-containing wastewater incineration desalination cooling device according to claim 1 is characterized by: The receiving assembly includes a conical bucket and a screw conveyor; the top of the conical bucket is connected to the inner cavity of the shell, and the bottom is provided with an openable and closable discharge port, which is connected to the feed port of the screw conveyor, and a cart for transporting solid salt is provided under the discharge port of the screw conveyor.

7. Application of the high COD salt-containing wastewater incineration desalination cooling device as claimed in claim 1, characterized in that: It is applied to the high COD salt-containing wastewater incineration treatment system.

8. Application of the high COD salt-containing wastewater incineration desalination cooling device as claimed in claim 7, characterized in that: The high COD salt-containing wastewater incineration treatment system comprises an incinerator, an incineration desalination cooling device, a bag dust collector and a chimney which are connected in sequence, and an induced draft fan is arranged between the bag dust collector and the chimney.

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