Chemical high-concentration waste liquid resource utilization treatment device and process thereof

Abstract

The application provides a chemical high-concentration waste liquid resource utilization treatment device and a process thereof. The device comprises an evaporation and concentration unit, a flash separation unit, a pyrolysis and waste heat recycling unit and a flue gas purification unit connected in sequence. The chemical high-concentration waste liquid resource utilization treatment device realizes multi-stage recycling of steam and pyrolysis gas through the joint action of the evaporation and concentration unit, the flash separation unit, the pyrolysis and waste heat recycling unit and the flue gas purification unit, optimizes energy utilization efficiency through dynamic adjustment of the spiral channel spacing and steam distribution strategy, and has the advantages of reducing equipment investment cost, improving resource recovery rate and reducing harmful gas emission.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a chemical high-concentration waste liquid resource utilization treatment device and process thereof. BACKGROUND

[0002] The resource utilization of chemical high-concentration waste liquid is a great challenge in the field of industrial environmental protection. The core technical route usually includes four main units of pretreatment, evaporation and concentration, oxidation or pyrolysis, and purification.

[0003] However, the traditional treatment line usually adopts multi-effect evaporation in the evaporation and concentration unit. By using the secondary steam generated in the previous effect as the heating source of the next effect, although it is more energy-saving than single-effect evaporation, the efficiency improvement is limited by the number of effects. With the increase of the number of effects, the heat efficiency gain decreases. The concentrated waste liquid enters the separation and conversion unit, i.e. the oxidation or pyrolysis unit. Generally, it is directly sent to a high-temperature incinerator for disposal. In order to ensure the complete decomposition of harmful substances, the furnace temperature needs to be maintained at 850℃ or above, which requires a large amount of auxiliary fuel. Finally, in the purification unit, in order to treat the high-temperature flue gas generated by incineration, the treatment line must be equipped with complex waste heat boilers and devices for quenching, washing, adsorption, etc. Among them, only part of the heat energy can be recovered, resulting in a huge energy loss.

[0004] The traditional treatment line is essentially in an island mode between units, with single energy flow and open loop state, lacking reasonable integration and optimization. Therefore, the traditional treatment line has defects such as high energy consumption, low efficiency, and poor resource recovery rate. SUMMARY

[0005] The present application solves the above technical problems and provides a chemical high-concentration waste liquid resource utilization treatment device and process thereof.

[0006] One technical solution of the present application is a chemical high-concentration waste liquid resource utilization treatment device, characterized in that it comprises an evaporation and concentration unit, a flash separation unit, a pyrolysis and waste heat recycling unit, and a flue gas purification unit connected in sequence.

[0007] The evaporation and concentration unit comprises a preheater, a spiral plate evaporator, and a steam compressor connected in sequence, the evaporator comprises a plurality of spiral channels arranged concentrically, the spacing of each spiral channel is adjusted according to an instruction signal, the outlet of the evaporator is provided with a collector, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator through a first path of the steam compressor.

[0008] The flash separation unit comprises a flash tank and several cyclone separators, the steam outlet of the evaporator is also connected to the heating jacket of the flash tank through a second path, the inside of the flash tank comprises several inner chambers connected in sequence from top to bottom and with gradually reduced air pressure, the first inner chamber is provided with a pressure sensor and a temperature sensor, the controller generates the instruction signal according to the detection values of the pressure sensor and the temperature sensor, the several cyclone separators are correspondingly arranged at the top of the several inner chambers, the concentrated liquid of the collector is sent to the pyrolysis and waste heat recycling unit after sequentially passing through each inner chamber, and the steam generated by each inner chamber is collected and then sent to the preheater through a third path.

[0009] The pyrolysis and waste heat recycling unit comprises a rotary reactor and a waste heat boiler, the rotary reactor is used for pyrolyzing the concentrated liquid, the outlet of the rotary reactor is connected to a cyclone separator to separate out pyrolysis gas, the waste heat boiler releases heat from the entering pyrolysis gas to generate steam sent to the heating jacket of the evaporator through a fourth path and flue gas sent to the flue gas purification unit.

[0010] As an implementation form, the spacing of the spiral channel is adjusted to be 10-50 mm.

[0011] As an implementation form, the material of the spiral channel is stainless steel.

[0012] As an implementation form, the inlet of the evaporator is provided with a rotary distributor.

[0013] As an implementation form, the steam compressor is a centrifugal variable frequency compressor, the top of the evaporator is integrated with a pressure transmitter, and the inlet of the steam compressor is connected to the steam outlet of the evaporator through a flange;

[0014] When the pressure transmitter detects that the pressure in the evaporator is increased, the rotating speed of the steam compressor is increased.

[0015] As an implementation form, the number of the inner chambers is 3-5, and the air pressure of each inner chamber is gradually reduced by 0.1-0.05 MPa.

[0016] As an implementation form, the rotary reactor is a horizontal rotary cylinder, and the rotary reactor is divided into a preheating zone, a pyrolysis zone and a cooling zone.

[0017] As an implementation form, the first path, the second path and the third path are collected through a gas collecting main pipe provided with a pressure detection element, the first path segment between the gas collecting main pipe and the heating jacket of the evaporator, the second path segment between the gas collecting main pipe and the heating jacket of the flash tank, the third path segment between the gas collecting main pipe and the preheater and the fourth path are each provided with a pressure temperature detection element and an adjusting valve.

[0018] The controller is connected with each pressure temperature detection element and each regulating valve, and is configured to execute priority control to open and close each regulating valve to dynamically distribute steam.

[0019] The first priority is to stabilize the pressure of the gas collecting main pipe in a set pressure range by adjusting the rotating speed of the steam compressor and the opening degree of the regulating valve of the first path section;

[0020] The second priority is to open the regulating valve of the second path section at a set opening degree ratio when the pressure of the gas collecting main pipe exceeds the set pressure range;

[0021] The third priority is to adjust the opening degree of the regulating valve of the third path section according to the outlet temperature of the preheater;

[0022] The fourth priority is to open the regulating valve of the fourth path and adjust the opening degrees of the regulating valves of the first path section and the second path section when the feed concentration of the evaporator exceeds a set value.

[0023] As an embodiment, a pressure stabilizing tank is arranged downstream of the gas collecting main pipe.

[0024] Another technical solution of the present application is a chemical high-concentration waste liquid resource utilization treatment process using the chemical high-concentration waste liquid resource utilization treatment device as described above, comprising

[0025] Evaporation and concentration step: the pretreated waste liquid is evaporated and concentrated to generate concentrated liquid;

[0026] Flash separation step: the concentrated liquid is flashed at low temperature and low pressure for further concentration;

[0027] Pyrolysis step: the concentrated liquid is pyrolyzed to generate pyrolysis gas and residue;

[0028] Purification step: the pyrolysis gas is purified.

[0029] The beneficial effects of the present application compared with the prior art are that the chemical high-concentration waste liquid resource utilization treatment device realizes multi-stage recycling of steam and pyrolysis gas through the joint action of the evaporation and concentration unit, the flash separation unit, the pyrolysis and waste heat recycling unit, and the flue gas purification unit, optimizes energy utilization efficiency through dynamic adjustment of the spiral channel spacing and steam distribution strategy, and has the advantages of reducing equipment investment cost, improving resource recovery rate, and reducing harmful gas emission. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The chemical high-concentration waste liquid resource utilization treatment device block diagram provided for the embodiments of the present application;

[0031] Figure 2A chemical high-concentration waste liquid resource utilization treatment process diagram is provided for the embodiments of the present application.

[0032] In the figure: 100, evaporation and concentration unit; 200, flash separation unit; 300, pyrolysis and waste heat recycling unit; 400, flue gas purification unit. DETAILED DESCRIPTION

[0033] The above and other embodiments and advantages of the present application are more fully described in conjunction with the attached drawings, in which the described embodiments are merely part of the present application and not all embodiments.

[0034] In one embodiment, as shown in Figure 1 .

[0035] The chemical high-concentration waste liquid resource utilization treatment device provided by the embodiment includes an evaporation and concentration unit 100, a flash separation unit 200, a pyrolysis and waste heat recycling unit 300, and a flue gas purification unit 400 connected in sequence; the evaporation and concentration unit 100 includes a preheater, a spiral plate evaporator, and a steam compressor connected in sequence, the evaporator includes a plurality of spiral channels arranged concentrically inside, the spacing of each spiral channel is adjusted according to the instruction signal, the outlet of the evaporator is provided with a collector, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator through a first path of the steam compressor; the flash separation unit 200 includes a flash tank and a plurality of cyclone separators, the steam outlet of the evaporator is also connected to the heating jacket of the flash tank through a second path, the flash tank includes a plurality of inner chambers connected in sequence from top to bottom and with gradually decreasing air pressure inside, the first inner chamber is provided with a pressure sensor and a temperature sensor, and a controller generates an instruction signal according to the detection values of the pressure sensor and the temperature sensor, the plurality of cyclone separators are correspondingly arranged at the top of the plurality of inner chambers, the concentrated liquid of the collector is sent to the pyrolysis and waste heat recycling unit 300 after passing through each inner chamber in sequence, and the steam generated by the inner chambers is collected and sent to the preheater through a third path; the pyrolysis and waste heat recycling unit 300 includes a rotary reactor and a waste heat boiler, the rotary reactor is used for pyrolyzing the concentrated liquid, the outlet of the rotary reactor is connected to a cyclone separator to separate out pyrolysis gas, and the waste heat boiler makes the entering pyrolysis gas release heat to generate steam sent to the heating jacket of the evaporator through a fourth path and flue gas sent to the flue gas purification unit 400.

[0036] In the present embodiment, the chemical high-concentration waste liquid resource utilization treatment device comprises an evaporation and concentration unit 100, a flash separation unit 200, a pyrolysis and waste heat recycling unit 300, and a flue gas purification unit 400 connected in sequence. The evaporation and concentration unit 100 is used to evaporate the water in the waste liquid efficiently through mechanical vapor recompression technology to achieve concentration. The evaporation and concentration unit 100 comprises a preheater, a spiral plate evaporator, and a steam compressor. The evaporator is internally provided with an adjustable pitch spiral channel, and the steam outlet is connected to the self-heating jacket and the flash tank heating jacket in two ways. The flash separation unit 200 is used to flash the concentrated liquid at low temperature and low pressure to separate water vapor and volatile organic compounds for further concentration. The flash separation unit 200 comprises a multi-stage pressure reduction inner chamber and a cyclone separator, and the channel adjustment instruction is generated by detecting the parameters of the first-stage inner chamber. The pyrolysis and waste heat recycling unit 300 is used to pyrolyze the concentrated liquid to generate pyrolysis gas and stable residue, and to improve energy efficiency by using waste heat. The pyrolysis and waste heat recycling unit 300 converts the pyrolysis gas waste heat into steam through a waste heat boiler and recycles it to the evaporation link. The spiral channel pitch adjustment refers to changing the gap between adjacent spiral plates through an electric actuator, which can be realized by a servo motor driving screw mechanism. This feature enables the evaporator to adapt to the processing needs of waste liquids with different physical properties. The flash tank multi-stage pressure reduction inner chamber refers to a plurality of vertically arranged independent cavities, which can be formed by a stepped pressure distribution through a partition. This structure design realizes the step-by-step flash separation of the concentrated liquid. The steam energy management system refers to integrating three steam delivery paths through a gas collection main pipe, which can be realized by a pressure-temperature interlocking control strategy. This configuration realizes the dynamic balance of steam energy in the whole system.

[0037] Specifically, the waste liquid is heated by a preheater and then enters a spiral plate evaporator. The spacing of the spiral channels is automatically adjusted according to the real-time working condition of the first inner chamber of the flash tank. The working condition, such as the temperature and pressure, of the first inner chamber of the flash tank directly reflects the current state of the concentrated liquid from the evaporator. By monitoring this state, the ideal channel spacing required for the next batch of waste liquid entering the evaporator in the later stage of concentration can be predicted, so that the adjustment can be made in advance. Therefore, the temperature and pressure signals of the first inner chamber of the flash tank are used as the feedforward control signals for adjusting the spacing of the spiral channels of the evaporator. The two parts form a closed-loop control, and the spacing of the spiral channels of the evaporator is directly responsive to the current state of the concentrated liquid in the flash tank. The adjustment of the spacing of the spiral channels is based on the boiling point and flowability of the waste liquid. The viscosity is calculated by temperature and pressure data, the controller sends instructions to appropriately increase the spacing of the spiral channels to reserve space for handling higher viscosity liquid to maintain evaporation efficiency. If the viscosity is stable at a low level, the controller instructs to reduce the spacing of the spiral channels to increase the heat exchange area and improve the evaporation efficiency. The secondary steam generated by evaporation is pressurized by a compressor and then divided into two paths, which are respectively supplied to the evaporator jacket and the flash tank jacket. The concentrated liquid is flash evaporated in the multi-stage pressure reduction environment of the flash tank, and the separated steam returns to the preheater as a heat source. The concentrated liquid after flash evaporation enters the rotary reactor for pyrolysis, and the pyrolysis gas generates steam in the waste heat boiler, which is reused to the evaporation link. The steam circuits are interconnected through a gas collection main pipe to realize pressure interlocking control, and the heat energy supply of the evaporation unit is preferentially guaranteed.

[0038] Compared with the prior art, the traditional multi-effect evaporation system only realizes the series utilization of steam, while the present scheme realizes the simultaneous satisfaction of the self-reboiling and flash heating requirements of the single evaporator through the steam compressor and multi-path distribution design. The existing flash evaporation device is mostly single-stage structure, and the present scheme adopts a multi-stage pressure reduction inner chamber cooperating with a cyclone separator to realize higher concentration efficiency under the same equipment volume. The waste heat of the traditional pyrolysis unit is only used for power generation or heating, and the present scheme generates steam through a waste heat boiler and directly reuses it to the evaporation link to form an energy closed loop across the units.

[0039] Through the above technical scheme, the present application effectively solves the problem of low energy utilization rate of the traditional treatment device. The steam mutual supply design of the evaporation unit and the flash evaporation unit reduces the external heat source requirement, and the steam reuse of the pyrolysis waste heat reduces fuel consumption. The dynamic adjustment of the spacing of the spiral channels ensures the evaporation efficiency under different working conditions, and the multi-stage flash evaporation structure improves the treatment effect of the concentrated liquid. The energy coupling of each unit reduces the overall energy consumption of the system, and the step-by-step utilization of steam energy significantly improves the resource recovery rate.

[0040] In one embodiment, the spacing adjustment range of the spiral channels of the chemical high-concentration waste liquid resource utilization treatment device is 10-50 mm.

[0041] In the embodiment, the pitch adjustment range of the spiral channel refers to the adjustable width of the fluid channel formed between the concentrically arranged spiral plates inside the evaporator. Specifically, an adjustable baffle or a hydraulic drive device can be used to achieve the adjustment of the channel width by changing the relative position of adjacent spiral plates. The adjustment range is limited to 10-50mm, and the channel width can cover the flow requirements of low-viscosity to high-viscosity waste liquid by setting different thickness of gaskets or using the stroke control of electric push rods.

[0042] When processing low-viscosity waste liquid, the channel pitch is adjusted to a small value, for example 10mm, at this time the waste liquid forms a thin liquid film in the narrow channel, increases the heat transfer area and strengthens the turbulent flow effect, thereby improving the evaporation rate; when processing high-viscosity waste liquid, the channel pitch is adjusted to a large value, for example 50mm, at this time the flow resistance of the waste liquid is reduced, avoiding the blockage of the channel due to too high viscosity. By real-time detection of waste liquid concentration or viscosity parameters, the actuator is driven to adjust the pitch of the spiral plates, so that the evaporator is always in the best heat transfer state. For example, when the viscosity is detected to increase during the pretreatment stage of the waste liquid, the controller can automatically expand the pitch from 20mm to 40mm to ensure that the high-viscosity waste liquid can smoothly pass through the evaporator.

[0043] Compared with the prior art, the traditional evaporator adopts a spiral channel design with a fixed pitch, which cannot be dynamically adjusted according to the characteristics of the waste liquid. For example, when processing waste liquid with large viscosity fluctuations, a fixed pitch may result in insufficient heat transfer efficiency at low viscosity or excessive flow resistance at high viscosity. The present scheme adjusts the pitch to adapt to the changes in the physical properties of waste liquid of different concentrations and viscosities, ensuring heat transfer efficiency while avoiding channel blockage.

[0044] Through the above technical scheme, the chemical high-concentration waste liquid resource utilization treatment device solves the problem of low heat transfer efficiency and poor concentration effect of traditional evaporators caused by fixed channel pitch. By dynamically adjusting the pitch of the spiral channel, the evaporator can automatically optimize the channel width according to the viscosity of the waste liquid, strengthening heat transfer at low viscosity and reducing flow resistance at high viscosity, thereby improving evaporation efficiency and prolonging the continuous operation cycle of the equipment.

[0045] In one embodiment, the material of the spiral channel of the chemical high-concentration waste liquid resource utilization treatment device is stainless steel.

[0046] In the present embodiment, the material of the spiral channel can be austenitic stainless steel or duplex stainless steel. In the treatment of high-concentration chemical waste liquid, the material resists chemical corrosion of the spiral channel by acidic, alkaline or salt components through its passivation characteristics. When the spiral channel continuously contacts high-concentration corrosive waste liquid in the evaporation and concentration unit 100, the stainless steel material maintains structural integrity through the self-repairing ability of the surface oxide film. When hydrogen ions, chloride ions or other active substances in the corrosive medium react with the stainless steel surface, the oxide film preferentially dissolves and re-forms a protective layer, preventing continuous loss of the base metal. In this way, the geometry of the spiral channel is kept stable, avoiding the risk of reduced heat transfer efficiency or leakage due to localized corrosion, while reducing the need for downtime maintenance due to material failure.

[0047] In one embodiment, the inlet of the evaporator of the chemical high-concentration waste liquid resource utilization treatment device is provided with a rotating distributor.

[0048] In the present embodiment, the rotating distributor refers to a device that disperses liquid to the target area through rotational motion, which can be realized by a rotating shaft structure with spiral blades. The rotating shaft is driven by a motor and rotates at a set speed. The centrifugal force of the rotating distributor can break the natural flow state of the waste liquid, so that the high-concentration waste liquid forms a uniformly distributed liquid film before entering the evaporator. Specifically, after the waste liquid enters the rotating distributor, it is forced to disperse to the circumferential area of the spiral channel under the action of the centrifugal force generated by the rotating blades. The waste liquid forms a uniform liquid film under the combined action of centrifugal force and rotational motion, avoiding local over-concentration or flow dead zones caused by differences in static pressure distribution. The uniformly distributed liquid film maintains a laminar flow state after entering the spiral channel, providing stable initial conditions for the subsequent evaporation process. In this way, the heat transfer efficiency of each region in the evaporator tends to be consistent, avoiding coking problems caused by local overheating.

[0049] In one embodiment, the steam compressor of the chemical high-concentration waste liquid resource utilization treatment device is a centrifugal variable frequency compressor, the top of the evaporator is integrated with a pressure transmitter, and the inlet of the steam compressor is connected to the steam outlet of the evaporator through a flange; wherein when the pressure transmitter detects an increase in pressure in the evaporator, the rotational speed of the steam compressor increases.

[0050] In the present embodiment, the centrifugal variable frequency compressor refers to a centrifugal gas compression device that adjusts the rotational speed by changing the input frequency of the motor. Specifically, it can be achieved by using a frequency converter to drive a three-phase asynchronous motor. It is used to adjust the output power of the compressor in real time according to the change of the vapor pressure in the evaporator. The pressure transmitter refers to a sensor that measures the gas pressure in a closed container and converts it into an electrical signal. It can be achieved by using a piezoresistive or capacitive sensing element. It is arranged at the top of the evaporator to avoid interference from liquid droplets and is used to monitor the fluctuation of the vapor pressure in the evaporator in real time. Specifically, when the evaporation and concentration unit 100 is running, the vapor generated inside the evaporator enters the vapor compressor through the top outlet. The pressure transmitter continuously monitors the vapor pressure in the evaporator. When an increase in pressure is detected, for example due to a sudden increase in the evaporation rate of the waste liquid causing an increase in vapor production, the pressure transmitter transmits an electrical signal to the control system of the centrifugal variable frequency compressor. The control system increases the compressor speed according to the pre-set pressure-speed correspondence, for example from 3000 rpm to 4000 rpm, thereby increasing the suction capacity of the vapor compressor and restoring the pressure in the evaporator to the set range. Conversely, when the pressure in the evaporator decreases, the compressor speed decreases accordingly to avoid energy waste. The rigid sealing structure formed by the flange connection can withstand the vibration caused by the change in compressor speed and prevent vapor leakage.

[0051] Through the above technical solution, real-time stable control of the vapor pressure inside the evaporator is achieved, avoiding the invalid energy consumption of the compressor under low load conditions, while ensuring accurate matching of the vapor supply and evaporation demand.

[0052] In one embodiment, the inner chamber of the chemical high-concentration waste liquid resource utilization treatment device is provided with 3-5 inner chambers, and the air pressure of each inner chamber is gradually reduced by 0.1-0.05 MPa.

[0053] In the present embodiment, the inner chamber refers to an independent cavity formed by a partition in the flash tank. It can be achieved by using a ring-shaped partition with a sealing flange. Each inner chamber is provided with an independent vapor outlet at the top to form a pressure gradient. The gradual reduction of air pressure refers to the formation of a decreasing pressure difference between adjacent inner chambers through a pressure regulating valve. It can be achieved by using a proportional-integral-derivative controller to link a pressure sensor and a regulating valve, and the set pressure difference value is maintained through real-time feedback adjustment. The concentrated liquid enters the first inner chamber through the collector and is flash evaporated in stages in the gradually reduced air pressure environment. When the number of inner chambers is set to 3-5, the required phase change space for multi-stage separation is met, and the device size is not excessively large due to too many cavities. The pressure difference between adjacent inner chambers is 0.1-0.05 MPa, which is realized through closed-loop control of the pressure sensor and the regulating valve, so that the vapor release speed matches the flow rate of the concentrated liquid. This pressure difference range can prevent insufficient flash evaporation due to too small pressure drop, and also prevent vapor backflow due to too large pressure drop.

[0054] By the technical scheme, the phase change stability of the concentrated liquid in the flash separation process can be effectively improved, the probability of steam entraining solid particles can be reduced, and the equipment vibration caused by pressure fluctuation can be reduced.

[0055] In an embodiment, the rotating reactor of the chemical high-concentration waste liquid resource utilization treatment device is a horizontal rotating cylinder, and the rotating reactor is divided into a preheating zone, a pyrolysis zone, and a cooling zone.

[0056] In the embodiment, the preheating zone refers to a region where the material is subjected to preliminary heating after entering the reactor, the pyrolysis zone refers to a region where the material is subjected to pyrolysis under high-temperature conditions, and the cooling zone refers to a region where the pyrolysis residue is subjected to cooling treatment before being discharged. Specifically, when the material moves in the rotating cylinder along the axial direction, it first absorbs the residual heat discharged from the pyrolysis zone in the preheating zone to complete preliminary heating, thereby reducing the demand for external heat sources; then enters the pyrolysis zone, and continuously contacts the high-temperature wall surface under the action of rotation to promote the decomposition of organic matter into gaseous products; finally, the residue enters the cooling zone, and is cooled by heat exchange with the cooling medium, and the recovered heat can be recycled for the preheating zone or other links of the system. The combined action of the three zones forms a closed-loop heat exchange path, and realizes the cascade utilization of heat energy.

[0057] In an embodiment, the first path, the second path, and the third path of the chemical high-concentration waste liquid resource utilization treatment device are collected through a gas collection main pipe provided with a pressure detection element, each of a first path segment between the gas collection main pipe and the heating jacket of the evaporator, a second path segment between the gas collection main pipe and the heating jacket of the flash tank, a third path segment between the gas collection main pipe and the preheater, and a fourth path is provided with a pressure and temperature detection element and an adjusting valve; the controller is signal-connected with each pressure and temperature detection element and each adjusting valve, and is configured to execute the opening and closing of each adjusting valve according to the priority to dynamically distribute the steam; the first priority is to stabilize the pressure of the gas collection main pipe in the set pressure range by adjusting the rotating speed of the steam compressor and the opening degree of the adjusting valve of the first path segment; the second priority is to open the adjusting valve of the second path segment at a set opening degree ratio when the pressure of the gas collection main pipe exceeds the set pressure range; the third priority is to adjust the opening degree of the adjusting valve of the third path segment according to the outlet temperature of the preheater; and the fourth priority is to open the adjusting valve of the fourth path and adjust the opening degrees of the adjusting valves of the first path segment and the second path segment when the feed concentration of the evaporator exceeds the set value.

[0058] In this embodiment, the gas collecting main pipe refers to a pipeline structure for collecting multi-path steam, which can be implemented by a ring main pipe with pressure detection function. Its role is to integrate steam from different sources and form a pressure balance node. The pressure and temperature detection element refers to a sensor for real-time monitoring of steam state parameters, which can be implemented by a combination of integrated pressure transmitter and thermocouple. Its role is to provide input signals for dynamic control of the controller. The regulating valve refers to an actuator for controlling steam flow, which can be implemented by an electric proportional regulating valve. Its role is to adjust the steam distribution ratio of different paths according to the priority strategy. The first path segment, the second path segment and the third path segment refer to a segment of the first path, the second path and the third path. The priority control strategy refers to a hierarchical control logic based on working condition parameters, which can be implemented by a multivariable feedback control algorithm. Its role is to ensure the optimal balance between system pressure stability and energy distribution efficiency. Specifically, steam is collected through the gas collecting main pipe to form a pressure balance node. The controller adjusts the steam compressor speed and the regulating valve opening of the first path segment according to the main pipe pressure data to maintain stable main pipe pressure. When the main pipe pressure exceeds the threshold, the regulating valve of the second path segment opens at a preset ratio to divert excess steam to the flash tank heating jacket, while reducing the system pressure. The third priority control is triggered by the preheater outlet temperature to optimize the preheating steam supply by adjusting the valve opening of the third path segment. When the evaporator feed concentration is detected to be too high, the regulating valve of the fourth path is opened to introduce pyrolysis gas waste heat steam, while coordinating the valve openings of the first path segment and the second path segment to ensure the simultaneous improvement of evaporation efficiency and energy utilization rate.

[0059] Compared with the prior art, in the traditional processing line, steam only flows to fixed equipment in one direction, which cannot be dynamically distributed according to real-time working conditions, resulting in energy waste and system pressure fluctuation. The present scheme realizes closed-loop regulation and control of steam resources by constructing a steam network through a gas collecting main pipe and combining a multi-level priority control strategy. For example, the traditional system needs manual intervention to adjust when the main pipe pressure is abnormal, while the present scheme quickly stabilizes the pressure through an automatic hierarchical response mechanism, and significantly improves the waste heat utilization rate by using excess steam to heat the flash tank and the preheater.

[0060] Through the above technical scheme, the problem of energy waste caused by unreasonable steam distribution is solved, and dynamic regulation and control of multi-path steam is realized. The specific effects include: maintaining stable main pipe pressure through pressure balance node and priority control to avoid evaporator operation fluctuation; automatically adjusting steam supply according to preheating temperature to reduce preheating energy consumption; coordinating external heat source and internal steam distribution under high concentration feed working conditions to improve system processing efficiency; reducing the need for manual intervention through hierarchical response mechanism to enhance the adaptability of the system under all working conditions.

[0061] In an embodiment, a pressure stabilizing tank is arranged downstream of the gas collection main of the chemical high-concentration waste liquid resource utilization treatment device.

[0062] In the present embodiment, the pressure stabilizing tank refers to a pressure buffer container connected downstream of the gas collection main, which can be implemented by a closed container with a pressure regulating valve. The pressure stabilizing tank absorbs transient fluctuations in steam pressure to maintain the dynamic balance of steam pressure in the gas collection main, thereby avoiding frequent adjustment of the opening degree of the regulating valve or the rotating speed of the steam compressor due to sudden pressure changes. When the amount of steam generated by the evaporation and concentration unit 100 or the flash separation unit 200 fluctuates, the pressure stabilizing tank absorbs or releases steam through internal volume changes. For example, when the steam pressure transiently increases, the excess steam enters the pressure stabilizing tank for storage; when the pressure decreases, the pressure stabilizing tank releases the stored steam to supplement the gas collection main. This process enables the controller to stably distribute steam based on a priority strategy, avoiding frequent opening and closing of the regulating valve or sudden changes in the rotating speed of the steam compressor due to severe pressure fluctuations. As a result, the steam supply pressure of the evaporator heating jacket, the flash tank heating jacket, and the preheater remains stable, and the overall system operation stability is improved.

[0063] In an embodiment, as shown in Figure 2 .

[0064] The chemical high-concentration waste liquid resource utilization treatment process provided in the present embodiment uses the above chemical high-concentration waste liquid resource utilization treatment device, which includes an evaporation and concentration step of evaporating and concentrating the pretreated waste liquid to generate a concentrated liquid; a flash separation step of flashing the concentrated liquid at low temperature and low pressure for further concentration; a pyrolysis step of pyrolyzing the concentrated liquid to generate pyrolysis gas and residue; and a purification step of purifying the pyrolysis gas.

[0065] In the present embodiment, the evaporation and concentration step refers to the evaporation treatment of the waste liquid by combining a spiral plate evaporator with a steam compressor, which can be implemented by adjusting the spacing of the spiral channels to optimize the dynamic heat transfer efficiency. This step recovers secondary steam waste heat from the steam compressor to supply the heating jacket, reducing external energy consumption.

[0066] The flash separation step refers to the multi-stage flashing of the concentrated liquid in an inner chamber with a stepwise pressure drop, which can be implemented by using a pressure sensor and a temperature sensor to control the pressure gradient of the inner chamber. This step reduces the energy consumption required for the pre-treatment of the concentrated liquid before pyrolysis under low temperature and low pressure conditions. The pyrolysis step refers to the regional control of the pyrolysis process using a rotary reactor, which can be implemented by setting the temperature gradient of the preheating zone, the pyrolysis zone, and the cooling zone. This step recovers sensible heat from the pyrolysis gas using a waste heat boiler to generate steam, forming an energy cycle to supply the evaporation unit. The purification step refers to the multi-stage treatment of the pyrolysis gas, which can be implemented by combining a quenching device, a washing device, and an adsorption device. This step achieves common control of pollutants through energy cascade utilization.

[0067] Through the technical scheme, the waste heat waste problem caused by the one-way flow of energy in the traditional process is solved, the energy consumption of the evaporation unit is reduced through steam recycling, the limitation of high-temperature incineration depending on auxiliary fuel is broken, the pyrolysis temperature is reduced through multi-stage flash evaporation to reduce fuel consumption, and the unit island operation defect is overcome, and the waste liquid treatment efficiency is improved through energy coupling.

[0068] The above specific embodiments further specifically explain the inventive purpose, technical scheme and beneficial effects of the present application. It should be understood that the above is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A chemical high-concentration waste liquid resource utilization treatment device, characterized in that, The unit comprises, in sequence, an evaporation and concentration unit, a flash separation unit, a pyrolysis and waste heat recycling unit, and a flue gas purification unit. The evaporation and concentration unit comprises, in sequence, a preheater, a spiral-plate evaporator, and a steam compressor, the evaporator comprises a plurality of spiral channels arranged concentrically, the spacing of each spiral channel is adjusted according to an instruction signal, the outlet of the evaporator is provided with a collector, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator through a first path of the steam compressor. The flash separation unit comprises a flash tank and a plurality of cyclone separators, the steam outlet of the evaporator is also connected to the heating jacket of the flash tank through a second path, the flash tank comprises a plurality of inner chambers arranged in sequence from top to bottom and having gradually decreasing air pressure, the first inner chamber is provided with a pressure sensor and a temperature sensor, and a controller generates the instruction signal according to the detection values of the pressure sensor and the temperature sensor, the plurality of cyclone separators are arranged at the top of the plurality of inner chambers in a corresponding manner, and the concentrated liquid of the collector is sent to the pyrolysis and waste heat recycling unit after passing through each inner chamber in sequence. The pyrolysis and waste heat recycling unit comprises a rotary reactor and a waste heat boiler, the rotary reactor is used for pyrolyzing the concentrated liquid, the outlet of the rotary reactor is connected to a cyclone separator to separate out pyrolysis gas, the waste heat boiler releases heat from the entering pyrolysis gas to generate steam sent to the heating jacket of the evaporator through a fourth path and flue gas sent to the flue gas purification unit.

2. The device according to claim 1, characterized in that, The spacing adjustment range of the spiral channels is 10-50 mm. 3.The chemical industry high-concentration waste liquid resource utilization treatment device according to claim 1, characterized in that, The material of the spiral channels is stainless steel.

4. The chemical industry high-concentration waste liquid resource utilization treatment device according to claim 1, characterized in that, The inlet of the evaporator is provided with a rotary distributor.

5. The device according to claim 1, characterized in that, The steam compressor is a centrifugal variable frequency compressor, the top of the evaporator is integrated with a pressure transmitter, and the inlet of the steam compressor is connected to the steam outlet of the evaporator through a flange; When the pressure transmitter detects that the pressure in the evaporator increases, the rotating speed of the steam compressor increases. 6.The device for resource utilization of chemical high-concentration waste liquid according to claim 1, characterized in that, The number of the inner chambers is 3-5, and the air pressure of each inner chamber decreases by 0.1-0.05 MPa.

7. The device according to claim 1, characterized in that, The rotary reactor is a horizontal rotary cylinder, and the rotary reactor is divided into a preheating zone, a pyrolysis zone, and a cooling zone. 8.The device for resource utilization of chemical high-concentration waste liquid according to claim 1, characterized in that, The first path, the second path, and the third path are collected through a gas collecting main pipe provided with a pressure detection element, each of the first path segment between the gas collecting main pipe and the heating jacket of the evaporator, the second path segment between the gas collecting main pipe and the heating jacket of the flash tank, the third path segment between the gas collecting main pipe and the preheater, and the fourth path is provided with a pressure and temperature detection element and an adjusting valve; The controller is signal-connected with each pressure and temperature detection element and each adjusting valve, and is configured to control the opening and closing of each adjusting valve according to the priority to dynamically distribute steam; The first priority is to stabilize the pressure of the gas collecting main pipe in a set pressure range by adjusting the rotating speed of the steam compressor and the opening degree of the adjusting valve of the first path segment; The second priority is to open the adjusting valve of the second path segment at a set opening degree ratio when the pressure of the gas collecting main pipe exceeds the set pressure range. The third priority is to adjust the opening degree of the adjusting valve of the third path segment according to the outlet temperature of the preheater; The fourth priority is to open the adjusting valve of the fourth path and adjust the opening degree of the adjusting valves of the first path segment and the second path segment when the feed concentration of the evaporator exceeds a set value. 9.The device for chemical industry high-concentration waste liquid resource utilization treatment according to claim 8, characterized in that, A pressure stabilizing tank is arranged downstream of the gas collecting main pipe.

10. A chemical high-concentration waste liquid resource utilization treatment process, characterized in that, The chemical high-concentration waste liquid resource utilization treatment device according to any one of claims 1 to 9 is used, comprising An evaporation and concentration step: the pretreated waste liquid is evaporated and concentrated to generate a concentrated liquid; A flash separation step: the concentrated liquid is flashed at low temperature and low pressure for further concentration; A pyrolysis step: the concentrated liquid is pyrolyzed to generate pyrolysis gas and residue; A purification step: the pyrolysis gas is purified.

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