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

Abstract

The invention provides a chemical high-concentration waste liquid resource utilization treatment device and a process thereof. The device comprises an evaporation concentration unit, a flash separation unit, a pyrolysis and waste heat circulation unit and a flue gas purification unit which are connected in sequence, according to the chemical high-concentration waste liquid resource utilization treatment device, through the combined action of the evaporation and concentration unit, the flash separation unit, the pyrolysis and waste heat circulation unit and the flue gas purification unit, multi-stage cyclic utilization of steam and pyrolysis gas is achieved, the energy utilization efficiency is optimized by dynamically adjusting the space between spiral channels and a steam distribution strategy, and the energy utilization efficiency is improved. The method has the advantages of reducing equipment investment cost, improving resource recovery rate and reducing harmful gas emission.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a device and process for the resource utilization and treatment of high-concentration chemical waste liquid. Background Technology

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

[0003] However, traditional processing lines often employ multi-effect evaporation in their evaporation and concentration units. While using the secondary steam generated in the previous effect as a heat source for the next effect is more energy-efficient than single-effect evaporation, its efficiency improvement is limited by the number of effects. As the number of effects increases, the thermal efficiency gain decreases. The concentrated waste liquid then enters the separation and conversion unit, i.e., the oxidation or pyrolysis unit. It is generally sent directly to a high-temperature incinerator for disposal. To ensure the complete decomposition of harmful substances, the furnace temperature needs to be maintained above 850°C, which requires a large amount of auxiliary fuel. Finally, in the purification unit, to treat the high-temperature flue gas generated from incineration, the processing line must be equipped with complex waste heat boilers and devices for quenching, scrubbing, and adsorption. Only a portion of the heat energy can be recovered, resulting in significant energy loss.

[0004] Traditional processing lines are essentially isolated units, with energy flowing in a single, open-loop manner, lacking proper integration and optimization. Therefore, traditional processing lines suffer from high energy consumption, low efficiency, and poor resource recovery rates. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems by providing a device and process for the resource utilization and treatment of high-concentration chemical waste liquid.

[0006] One technical solution of the present invention is a chemical high-concentration waste liquid resource utilization treatment device, characterized in that it includes an evaporation and concentration unit, a flash evaporation and separation unit, a pyrolysis and waste heat recycling unit and a flue gas purification unit connected in sequence. The evaporation and concentration unit includes a preheater, a spiral plate evaporator and a steam compressor connected in sequence. The evaporator has several concentric spiral channels inside, and the spacing between the spiral channels is adjusted according to the command signal. The outlet of the evaporator is equipped with a collector, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator through a first path via the steam compressor. The flash separation unit includes 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 flash tank includes several inner chambers connected from top to bottom with progressively decreasing gas pressure. The first inner chamber is equipped with a pressure sensor and a temperature sensor. The controller generates the command signal based on the detection values ​​of the pressure sensor and the temperature sensor. Several cyclone separators are correspondingly arranged on the top of several inner chambers. The concentrate of the collector is sent to the pyrolysis and waste heat circulation unit after passing through each inner chamber in sequence. The steam generated in each inner chamber is collected and sent to the preheater through a third path. The pyrolysis and waste heat recycling unit includes a rotary reactor and a waste heat boiler. The rotary reactor is used to pyrolyze the concentrate. The outlet of the rotary reactor is connected to a cyclone separator to separate the pyrolysis gas. The waste heat boiler causes the incoming pyrolysis gas to release heat to generate steam that is sent to the heating jacket of the evaporator through a fourth path and flue gas that is sent to the flue gas purification unit.

[0007] In one implementation, the spacing of the spiral channels can be adjusted from 10 to 50 mm.

[0008] In one embodiment, the spiral channel is made of stainless steel.

[0009] In one embodiment, the evaporator inlet is provided with a rotary distributor.

[0010] In one embodiment, the steam compressor is a centrifugal variable frequency compressor, a pressure transmitter is integrated on the top of the evaporator, and the inlet of the steam compressor is connected to the steam outlet of the evaporator via a flange. Specifically, when the pressure transmitter detects an increase in pressure inside the evaporator, the speed of the steam compressor increases.

[0011] In one embodiment, there are 3 to 5 inner chambers, and the air pressure in each inner chamber is gradually reduced by 0.1 to 0.05 MPa.

[0012] In one embodiment, the rotary reactor is a horizontal rotating cylinder, and the rotary reactor is divided into a preheating zone, a pyrolysis zone, and a cooling zone.

[0013] In one implementation, the first path, the second path, and the third path are converged by a gas collecting header with a pressure sensing element. The first path segment between the gas collecting header and the heating jacket of the evaporator, the second path segment between the gas collecting header and the heating jacket of the flash tank, the third path segment between the gas collecting header and the preheater, and the fourth path are each equipped with a pressure and temperature sensing element and a regulating valve. The controller is connected to each pressure and temperature sensing element and each regulating valve, and is configured to perform priority control of the opening and closing of each regulating valve to dynamically distribute steam. The first priority is to stabilize the pressure of the gas collecting header within the set pressure range by adjusting the speed of the steam compressor and the opening of the regulating valve in the first path segment. The second priority is to open the regulating valve of the second path segment according to the set opening ratio when the pressure of the gas collecting header exceeds the set pressure range. The third priority is to adjust the opening of the regulating valve in the third path segment according to the outlet temperature of the preheater; The fourth priority is to open the regulating valve of the fourth path and adjust the opening degree of the regulating valves of the first path segment and the second path segment when the feed concentration of the evaporator exceeds the set value.

[0014] In one implementation, a pressure stabilizing tank is provided downstream of the gas collecting header.

[0015] Another technical solution of the present invention is a process for the resource utilization and treatment of high-concentration chemical waste liquid, using the high-concentration chemical waste liquid resource utilization and treatment device described above, including... Evaporation and concentration steps: The pretreated waste liquid is evaporated and concentrated to generate concentrated liquid; Flash evaporation separation step: The concentrate is flash-evaporated at low temperature and low pressure to further concentrate it; Pyrolysis step: The concentrate is pyrolyzed to generate pyrolysis gas and residue; Purification steps: Purify the pyrolysis gas.

[0016] Compared with the prior art, the beneficial effects of this invention are that the chemical high-concentration waste liquid resource utilization treatment device achieves multi-stage recycling of steam and pyrolysis gas through the combined action of the evaporation and concentration unit, flash separation unit, pyrolysis and waste heat recycling unit and flue gas purification unit. By dynamically adjusting the spiral channel spacing and steam distribution strategy to optimize energy utilization efficiency, it has the advantages of reducing equipment investment costs, improving resource recovery rate and reducing harmful gas emissions. Attached Figure Description

[0017] Figure 1 A block diagram of a chemical high-concentration waste liquid resource utilization and treatment device provided for embodiments of the present invention; Figure 2 A flow chart of a high-concentration chemical waste liquid resource utilization treatment process provided for embodiments of the present invention.

[0018] In the diagram: 100, Evaporation and Concentration Unit; 200, Flash Separation Unit; 300, Pyrolysis and Waste Heat Circulation Unit; 400, Flue Gas Purification Unit. Detailed Implementation

[0019] The above and other embodiments and advantages of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] In one implementation, such as Figure 1 As shown.

[0021] This embodiment provides a chemical high-concentration waste liquid resource utilization treatment device, which includes an evaporation and concentration unit 100, a flash separation unit 200, a pyrolysis and waste heat circulation 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 several concentrically arranged spiral channels, the spacing of which is adjusted according to a command signal. A collector is provided at the outlet of the evaporator, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator via a first path through the steam compressor. The flash separation unit 200 includes a flash tank and several cyclone separators. The steam outlet of the evaporator is also connected to the heating jacket of the flash tank via a second path. The flash tank includes a... The system consists of several chambers connected sequentially from bottom to top, with the air pressure decreasing at each level. The first chamber is equipped with a pressure sensor and a temperature sensor. The controller generates a command signal based on the detection values ​​of the pressure sensor and the temperature sensor. Several cyclone separators are correspondingly installed on the top of the chambers. The concentrated liquid from the collector passes through each chamber sequentially and is then sent to the pyrolysis and waste heat circulation unit 300. The steam generated in each chamber is collected and sent to the preheater via a third path. The pyrolysis and waste heat circulation unit 300 includes a rotary reactor and a waste heat boiler. The rotary reactor is used to pyrolyze the concentrated liquid. The outlet of the rotary reactor is connected to a cyclone separator to separate the pyrolysis gas. The waste heat boiler causes the incoming pyrolysis gas to release heat to generate steam that is sent to the heating jacket of the evaporator via a fourth path and flue gas that is sent to the flue gas purification unit 400.

[0022] In this embodiment, the chemical high-concentration waste liquid resource utilization treatment device 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 uses mechanical vapor recompression technology to efficiently evaporate water from the waste liquid, achieving concentration. The evaporation and concentration unit 100 includes a preheater, a spiral plate evaporator, and a steam compressor. The evaporator has adjustable-pitch spiral channels, and the steam outlet is split into two paths, connected to its own heating jacket and the flash tank heating jacket, respectively. The flash separation unit 200 flashes the concentrate at low temperature and low pressure, separating water vapor and volatile organic compounds for further concentration. The flash separation unit 200 includes a multi-stage pressure-reducing chamber and a cyclone separator, generating channel adjustment commands by detecting the parameters of the first-stage chamber. The pyrolysis and waste heat recycling unit 300 pyrolyzes the concentrate, generating pyrolysis gas and stable residue, and utilizes waste heat to improve energy efficiency. The pyrolysis and waste heat recycling unit 300 converts the waste heat from pyrolysis gas into steam for reuse in the evaporation process via a waste heat boiler. The spiral channel spacing adjustment refers to changing the gap between adjacent spiral plates via an electric actuator, specifically achieved using a servo motor-driven screw mechanism. This feature allows the evaporator to adapt to the treatment needs of waste liquids with different properties. The multi-stage pressure-reducing inner chamber of the flash tank refers to multiple vertically arranged independent chambers, which can be separated by partitions to form a stepped pressure distribution. This structural design enables the gradual flash separation of the concentrated liquid. The steam energy management system integrates three steam delivery paths through a gas collection header, specifically employing a pressure-temperature interlocking control strategy. This configuration achieves dynamic balance of steam energy across the entire system.

[0023] Specifically, the waste liquid, after being heated by a preheater, enters a spiral plate evaporator. The spiral channel spacing is automatically adjusted based on the real-time operating conditions of the first inner chamber of the flash tank. The operating conditions of the first inner chamber of the flash tank, such as temperature and pressure, directly reflect the current state of the concentrate 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 stages of concentration can be predicted, allowing for advance adjustments. Therefore, the temperature and pressure signals of the first inner chamber of the flash tank are used as feedforward control signals for adjusting the spiral channel spacing of the evaporator. This forms a closed-loop control system. The adjustment of the spiral channel spacing directly responds to the current state of the concentrate in the flash tank. The adjustment of the spiral channel spacing is based on the boiling point and fluidity of the waste liquid. When viscosity increases, the controller sends a command to appropriately increase the spiral channel spacing to reserve space for handling liquids with higher viscosity, thus maintaining evaporation efficiency. If the viscosity stabilizes at a low level, the controller commands to decrease the spiral channel spacing to increase the heat exchange area and improve evaporation efficiency. The secondary steam generated by evaporation is pressurized by a compressor and then divided into two paths, supplying the evaporator jacket itself and the flash tank jacket respectively. The concentrate is flash-evaporated stage by stage in a multi-stage depressurization environment in a flash tank, and the separated steam is returned to the preheater as a heat source. The concentrate after flash evaporation enters a rotary reactor for pyrolysis, and the generated pyrolysis gas is heated in a waste heat boiler to generate steam for reuse in the evaporation stage. Each steam loop is pressure-interlocked through a gas collection header to prioritize the heat energy supply to the evaporation unit.

[0024] Compared to existing technologies, traditional multi-effect evaporation systems only utilize steam in series. This solution, however, uses a steam compressor and multi-path distribution design to allow steam generated by a single evaporator to simultaneously meet its own reboiling and flash heating needs. Existing flash evaporation devices are mostly single-stage structures; this solution employs a multi-stage pressure-reducing chamber combined with a cyclone separator, achieving higher concentration efficiency within the same equipment volume. While waste heat from traditional pyrolysis units is only used for power generation or heating, this solution uses a waste heat boiler to generate steam that is directly recycled to the evaporation stage, forming a closed-loop energy system across units.

[0025] Through the above technical solutions, this application effectively solves the problem of low energy utilization in traditional processing devices. The steam mutual supply design between the evaporation unit and the flash evaporation unit reduces the demand for external heat sources, and the steam recovery from pyrolysis waste heat reduces fuel consumption. The dynamic adjustment of the spiral channel spacing ensures evaporation efficiency under different operating conditions, and the multi-stage flash evaporation structure improves the treatment effect of the concentrate. The energy coupling of each unit reduces the overall energy consumption of the system, and the cascade utilization of steam energy significantly improves the resource recovery rate.

[0026] In one embodiment, the spacing of the spiral channel of the chemical high-concentration waste liquid resource utilization treatment device is adjustable from 10 to 50 mm.

[0027] In this embodiment, the adjustable range of the spiral channel spacing refers to the adjustable width of the fluid channel formed between the concentrically arranged spiral plates inside the evaporator. Specifically, this can be achieved using adjustable baffles or a hydraulic drive device, by changing the relative position of adjacent spiral plates to adjust the channel width. This adjustment range is limited to 10–50 mm, which can be achieved by using shims of different thicknesses or by controlling the stroke of an electric actuator, ensuring that the channel width can cover the flow requirements of waste liquids ranging from low to high viscosity.

[0028] When processing low-viscosity waste liquid, the channel spacing is adjusted to a smaller value, such as 10mm. In this case, the waste liquid forms a thin liquid film within the narrow channels, increasing the heat transfer area and enhancing turbulence, thereby increasing the evaporation rate. When processing high-viscosity waste liquid, the channel spacing is adjusted to a larger value, such as 50mm. This reduces the flow resistance of the waste liquid, preventing channel blockage due to excessive viscosity. By real-time monitoring of the waste liquid concentration or viscosity parameters, the actuator adjusts the spiral plate spacing to ensure the evaporator is always in optimal heat transfer condition. For example, if an increase in viscosity is detected during the waste liquid pretreatment stage, the controller can automatically expand the spacing from 20mm to 40mm to ensure that the high-viscosity waste liquid passes smoothly through the evaporator.

[0029] Compared to existing technologies, traditional evaporators employ a fixed-gap spiral channel design, which cannot be dynamically adjusted according to the characteristics of the waste liquid. For example, when treating waste liquids with large viscosity fluctuations, a fixed gap may result in insufficient heat transfer efficiency under low viscosity conditions or excessive flow resistance under high viscosity conditions. This solution, however, uses an adjustable gap design, enabling the evaporator to adapt to changes in the physical properties of waste liquids with different concentrations and viscosities, ensuring heat transfer efficiency while preventing channel blockage.

[0030] Through the above technical solution, this chemical high-concentration waste liquid resource utilization and treatment device solves the problems of low heat transfer efficiency and poor concentration effect caused by the fixed channel spacing of traditional evaporators. By dynamically adjusting the spiral channel spacing, the evaporator can automatically optimize the channel width according to the viscosity of the waste liquid, enhance heat transfer under low viscosity conditions, and reduce flow resistance under high viscosity conditions, thereby improving evaporation efficiency and extending the continuous operation cycle of the equipment.

[0031] In one embodiment, the spiral channel of the chemical high-concentration waste liquid resource utilization treatment device is made of stainless steel.

[0032] In this embodiment, the spiral channel can be made of austenitic stainless steel or duplex stainless steel. During the treatment of high-concentration chemical waste, this material resists chemical corrosion from acidic, alkaline, or saline components through its passivation properties. When the spiral channel is in continuous contact with high-concentration corrosive waste in the evaporation and concentration unit 100, the stainless steel material maintains its structural integrity through the self-healing ability of its 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 reforms a protective layer, preventing continuous loss of the base metal. Thus, the geometry of the spiral channel remains stable, avoiding a decrease in heat transfer efficiency or leakage risk due to localized corrosion, while also reducing downtime maintenance requirements caused by material failure.

[0033] In one embodiment, the inlet of the evaporator of the chemical high-concentration waste liquid resource utilization treatment device is equipped with a rotary distributor.

[0034] In this embodiment, a rotary distributor refers to a device that disperses liquid to a target area through rotational motion. Specifically, it can be implemented using a rotating shaft structure with helical blades, driven by a motor and rotating at a set speed. The centrifugal force of the rotary distributor breaks the natural flow of the waste liquid, causing the high-concentration waste liquid to form a uniformly distributed liquid film before entering the evaporator. Specifically, after entering the rotary distributor, the waste liquid is forcibly dispersed into the circumferential area of ​​the helical channel under the centrifugal force generated by the rotating blades. The waste liquid forms a uniform liquid film coverage under the combined action of centrifugal force and rotational motion, avoiding localized excessive concentrations or flow dead zones caused by differences in static pressure distribution. The uniformly distributed liquid film maintains a laminar flow state after entering the helical channel, providing stable initial conditions for the subsequent evaporation process. Therefore, the heat transfer efficiency of each area within the evaporator tends to be consistent, avoiding coking problems caused by localized overheating.

[0035] In one embodiment, the steam compressor of the chemical high-concentration waste liquid resource utilization treatment device is a centrifugal variable frequency compressor, and a pressure transmitter is integrated on the top of the evaporator. The inlet of the steam compressor is connected to the steam outlet of the evaporator through a flange. When the pressure transmitter detects an increase in pressure inside the evaporator, the speed of the steam compressor increases.

[0036] In this embodiment, the centrifugal variable frequency compressor refers to a centrifugal gas compression device that adjusts its speed by changing the motor input frequency. Specifically, it can be implemented by using a frequency converter to drive a three-phase asynchronous motor, used to adjust the compressor's output power in real time according to changes in the steam pressure inside the evaporator. The pressure transmitter is a sensor used to measure the gas pressure inside the sealed container and convert it into an electrical signal. It can be implemented using piezoresistive or capacitive sensing elements, and is positioned at the top of the evaporator to avoid droplet interference, used to monitor fluctuations in the steam pressure inside the evaporator in real time. Specifically, when the evaporation and concentration unit 100 is running, the steam generated inside the evaporator enters the steam compressor through the top outlet. The pressure transmitter continuously monitors the steam pressure inside the evaporator. When it detects an increase in pressure, such as due to a sudden increase in waste liquid evaporation leading to an increase in steam 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 a preset pressure-speed correspondence, for example, increasing the speed from 3000 rpm to 4000 rpm, thereby increasing the suction capacity of the steam compressor and restoring the pressure inside the evaporator to the set range. Conversely, when the pressure inside 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 changes in compressor speed and prevent steam leakage.

[0037] The above technical solution achieves real-time stable control of the steam pressure inside the evaporator, avoids ineffective energy consumption of the compressor under low load conditions, and ensures precise matching between steam supply and evaporation demand.

[0038] In one embodiment, the chemical high-concentration waste liquid resource utilization treatment device has 3 to 5 internal chambers, and the air pressure in each internal chamber is gradually reduced by 0.1 to 0.05 MPa.

[0039] In this embodiment, the inner chamber refers to the independent cavity formed inside the flash tank by partitions. Specifically, it can be implemented using an annular partition structure with sealing flanges. Each inner chamber has an independent steam outlet at the top to create a pressure gradient. The progressively decreasing pressure refers to the decreasing pressure difference between adjacent inner chambers created by pressure regulating valves. This can be achieved by using a proportional-integral-derivative (PID) controller linked to a pressure sensor and regulating valve, maintaining the set pressure difference value through real-time feedback adjustment. After the concentrate enters the first-stage inner chamber through the collector, it undergoes staged flash evaporation in a progressively decreasing pressure environment. When the number of inner chambers is set to 3 to 5, it satisfies the phase change space required for multi-stage separation while avoiding excessive equipment size due to too many cavities. The pressure difference range of 0.1 to 0.05 MPa between adjacent inner chambers is achieved through closed-loop control of the pressure sensor and regulating valve, matching the steam release rate with the concentrate flow rate. This pressure difference range prevents incomplete flash evaporation due to excessive pressure drop, while also avoiding steam backflow caused by excessive pressure drop.

[0040] The above technical solutions can effectively improve the phase change stability of the concentrate during the flash evaporation separation process, reduce the probability of solid particles being entrained by steam, and reduce equipment vibration caused by pressure fluctuations.

[0041] In one embodiment, the rotary reactor of the chemical high-concentration waste liquid resource utilization treatment device is a horizontal rotating cylinder, and the rotary reactor is divided into a preheating zone, a pyrolysis zone and a cooling zone.

[0042] In this embodiment, the preheating zone refers to the area where the material receives initial heating after entering the reactor, the pyrolysis zone refers to the area where the material undergoes a pyrolysis reaction under high-temperature conditions, and the cooling zone refers to the area where the pyrolysis residue is cooled before being discharged. Specifically, when the material moves axially within the rotating cylinder, it first absorbs the residual heat discharged from the pyrolysis zone in the preheating zone to achieve initial heating, reducing the demand for external heat sources. Subsequently, it enters the pyrolysis zone, where it continuously contacts the high-temperature wall surface under the action of rotation, promoting the decomposition of organic matter into gaseous products. Finally, the residue enters the cooling zone, where it is cooled by exchanging heat with the cooling medium. The recovered heat can be recycled for use in the preheating zone or other parts of the system. The combined action of the three zones forms a closed-loop heat exchange path, realizing the cascade utilization of thermal energy.

[0043] In one embodiment, the first, second, and third paths of the chemical high-concentration waste liquid resource utilization treatment device converge through a gas collecting header equipped with a pressure detection element. Each of the following paths—the first path section between the gas collecting header and the heating jacket of the evaporator, the second path section between the gas collecting header and the heating jacket of the flash tank, the third path section between the gas collecting header and the preheater, and the fourth path—is equipped with a pressure and temperature detection element and a regulating valve. A controller is signal-connected to each pressure and temperature detection element and each regulating valve and is configured to dynamically distribute steam by controlling the opening and closing of each regulating valve according to priority. The first priority is to stabilize the pressure of the gas collecting header within a set pressure range by adjusting the speed of the steam compressor and the opening degree of the regulating valve in the first path section. The second priority is to open the regulating valve in the second path section according to a set opening ratio when the pressure of the gas collecting header exceeds the set pressure range. The third priority is to adjust the opening degree of the regulating valve in the third path section according to the outlet temperature of the preheater. The fourth priority is to open the regulating valve in the fourth path and adjust the opening degrees of the regulating valves in the first and second path sections when the feed concentration of the evaporator exceeds a set value.

[0044] In this embodiment, the gas collecting header refers to a pipeline structure used to collect steam from multiple paths. Specifically, it can be implemented using a ring-shaped header with pressure detection function. Its function is to integrate steam from different sources and form a pressure balance node. The pressure and temperature detection element refers to a sensor used to monitor steam state parameters in real time. Specifically, it can be implemented using a combination of an integrated pressure transmitter and a thermocouple. Its function is to provide the controller with input signals for dynamic regulation. The regulating valve refers to an actuator used to control steam flow. Specifically, it can be implemented using an electric proportional regulating valve. Its function is to adjust the steam distribution ratio of different paths according to a priority strategy. The first path segment, second path segment, and third path segment refer to a segment of the first, second, and third paths. The priority control strategy refers to a hierarchical control logic based on operating parameters. Specifically, it can be implemented using a multivariable feedback control algorithm. Its function is to ensure an optimal balance between system pressure stability and energy distribution efficiency. In detail, after steam is collected through the gas collecting header to form a pressure balance node, the controller prioritizes adjusting the steam compressor speed and the opening of the regulating valve in the first path segment based on the header pressure data to maintain header pressure stability. When the main pipe pressure exceeds the threshold, the regulating valve in the second path section opens according to a preset ratio, diverting excess steam to the flash tank heating jacket while simultaneously reducing system pressure. The preheater outlet temperature triggers the third priority control, optimizing the preheating steam supply by adjusting the valve opening in the third path section. When excessively high evaporator feed concentration is detected, the regulating valve in the fourth path opens to introduce waste heat steam from pyrolysis gas, while simultaneously coordinating the valve openings in the first and second path sections to ensure a combined improvement in evaporation efficiency and energy utilization.

[0045] Compared to existing technologies, traditional steam processing lines only allow unidirectional steam flow to fixed equipment, failing to dynamically allocate steam based on real-time operating conditions, leading to energy waste and system pressure fluctuations. This solution constructs a steam network through a main steam collection pipe, combined with a multi-level priority control strategy to achieve closed-loop regulation of steam resources. For example, traditional systems require manual intervention to adjust when the main pipe pressure is abnormal, while this solution quickly stabilizes the pressure through an automatic graded response mechanism, while simultaneously using excess steam for heating in flash tanks and preheaters, significantly improving waste heat utilization.

[0046] The above technical solution solves the problem of energy waste caused by unreasonable steam distribution and achieves dynamic control of multi-path steam. Specific effects include: maintaining stable main pipe pressure through pressure balance nodes and priority control to avoid evaporator operation fluctuations; automatically adjusting steam supply based on preheating temperature to reduce preheating energy consumption; coordinating external heat sources and internal steam distribution under high-concentration feed conditions to improve system processing efficiency; and reducing the need for manual intervention through a graded response mechanism to enhance the system's adaptability to all operating conditions.

[0047] In one embodiment, a pressure stabilizing tank is provided downstream of the gas collection header of the chemical high-concentration waste liquid resource utilization and treatment device.

[0048] In this embodiment, the pressure stabilizing tank refers to a pressure buffer container connected downstream of the gas collecting header, specifically a sealed container with a pressure regulating valve. The pressure stabilizing tank absorbs instantaneous fluctuations in steam pressure, maintaining a dynamic balance of steam pressure within the gas collecting header, thereby preventing frequent adjustments to the regulating valve opening or steam compressor speed by the controller 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 changes in its internal volume. For example, when the steam pressure increases instantaneously, excess steam enters the pressure stabilizing tank for storage; when the pressure decreases, the pressure stabilizing tank releases the stored steam to replenish the gas collecting header. This process allows the controller to stably distribute steam based on a priority strategy, avoiding frequent opening and closing of the regulating valve or sudden changes in steam compressor speed due to drastic pressure fluctuations. As a result, the steam supply pressure of the evaporator heating jacket, flash tank heating jacket, and preheater remains stable, improving the overall operational stability of the system.

[0049] In one implementation, such as Figure 2 As shown.

[0050] The chemical high-concentration waste liquid resource utilization treatment process provided in this embodiment uses the above-mentioned chemical high-concentration waste liquid resource utilization treatment device, including an evaporation and concentration step: evaporating and concentrating the pretreated waste liquid to generate a concentrated liquid; a flash separation step: flashing the concentrated liquid at low temperature and low pressure to further concentrate it; a pyrolysis step: pyrolyzing the concentrated liquid to generate pyrolysis gas and residue; and a purification step: purifying the pyrolysis gas.

[0051] In this embodiment, the evaporation and concentration step refers to the evaporation treatment of waste liquid by combining a spiral plate evaporator with a steam compressor. Specifically, the dynamic heat transfer efficiency can be optimized by adjusting the spacing of the spiral channels. This step recovers the waste heat of secondary steam through the steam compressor to supply the heating jacket, thereby reducing external energy consumption.

[0052] The flash evaporation separation step involves multi-stage flash evaporation of the concentrate in a progressively depressurized chamber. Specifically, pressure and temperature sensors are linked to control the pressure gradient within the chamber. This step reduces the energy consumption required for the pre-pyrolysis treatment of the concentrate by using low-temperature, low-pressure conditions. The pyrolysis step utilizes a rotary reactor with zoned pyrolysis control. This can be achieved by setting temperature gradients in the preheating, pyrolysis, and cooling zones. This step combines this with a waste heat boiler to recover the sensible heat of the pyrolysis gas to generate steam, forming an energy cycle that supplies the evaporation unit. The purification step involves multi-stage treatment of the pyrolysis gas, typically using a combination of quenching, washing, and adsorption devices. This step achieves comprehensive control of pollutants through tiered energy utilization.

[0053] The above technical solutions solve the problem of waste heat caused by the unidirectional flow of energy in traditional processes, reduce the energy consumption of the evaporation unit by recycling steam, overcome the limitation of high-temperature incineration relying on auxiliary fuel, reduce fuel consumption by using multi-stage flash evaporation to lower the pyrolysis temperature, and overcome the defects of isolated unit operation by improving the efficiency of waste liquid treatment through energy coupling.

[0054] The above detailed embodiments further illustrate the inventive purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, or improvements made by those skilled in the art within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A device for the resource utilization and treatment of high-concentration chemical waste liquid, characterized in that, It includes 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 evaporation and concentration unit includes a preheater, a spiral plate evaporator and a steam compressor connected in sequence. The evaporator has several concentric spiral channels inside, and the spacing between the spiral channels is adjusted according to the command signal. The outlet of the evaporator is equipped with a collector, and the steam outlet of the evaporator is connected to the heating jacket of the evaporator through a first path via the steam compressor. The flash separation unit includes 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 flash tank includes several inner chambers connected from top to bottom with progressively decreasing gas pressure. The first inner chamber is equipped with a pressure sensor and a temperature sensor. The controller generates the command signal based on the detection values ​​of the pressure sensor and the temperature sensor. Several cyclone separators are correspondingly arranged on the top of several inner chambers. The concentrate of the collector is sent to the pyrolysis and waste heat circulation unit after passing through each inner chamber in sequence. The steam generated in each inner chamber is collected and sent to the preheater through a third path. The pyrolysis and waste heat recycling unit includes a rotary reactor and a waste heat boiler. The rotary reactor is used to pyrolyze the concentrate. The outlet of the rotary reactor is connected to a cyclone separator to separate the pyrolysis gas. The waste heat boiler causes the incoming pyrolysis gas to release heat to generate steam that is sent to the heating jacket of the evaporator through a fourth path and flue gas that is sent to the flue gas purification unit.

2. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The spacing of the spiral channels can be adjusted from 10 to 50 mm.

3. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The spiral channel is made of stainless steel.

4. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The evaporator is equipped with a rotary distributor at its inlet.

5. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The steam compressor is a centrifugal variable frequency compressor, and the top of the evaporator integrates a pressure transmitter. The inlet of the steam compressor is connected to the steam outlet of the evaporator via a flange. Specifically, when the pressure transmitter detects an increase in pressure inside the evaporator, the speed of the steam compressor increases.

6. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The inner chambers are configured as 3 to 5, and the air pressure in each inner chamber is gradually reduced by 0.1 to 0.05 MPa.

7. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The rotary reactor is a horizontal rotating cylinder, and the rotary reactor is divided into a preheating zone, a pyrolysis zone, and a cooling zone.

8. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 1, characterized in that, The first path, the second path, and the third path converge through a gas collecting header with a pressure detection element. The first path segment between the gas collecting header and the heating jacket of the evaporator, the second path segment between the gas collecting header and the heating jacket of the flash tank, the third path segment between the gas collecting header and the preheater, and the fourth path are each equipped with a pressure and temperature detection element and a regulating valve. The controller is connected to each pressure and temperature sensing element and each regulating valve, and is configured to perform priority control of the opening and closing of each regulating valve to dynamically distribute steam. The first priority is to stabilize the pressure of the gas collecting header within the set pressure range by adjusting the speed of the steam compressor and the opening of the regulating valve in the first path segment. The second priority is to open the regulating valve of the second path segment according to the set opening ratio when the pressure of the gas collecting header exceeds the set pressure range. The third priority is to adjust the opening of the regulating valve in the third path segment according to the outlet temperature of the preheater; The fourth priority is to open the regulating valve of the fourth path and adjust the opening degree of the regulating valves of the first path segment and the second path segment when the feed concentration of the evaporator exceeds the set value.

9. The chemical high-concentration waste liquid resource utilization and treatment device according to claim 8, characterized in that, A pressure stabilizing tank is located downstream of the gas collecting header.

10. A process for the resource utilization and treatment of high-concentration chemical waste liquid, characterized in that, Using the chemical high-concentration waste liquid resource utilization treatment device as described in any one of claims 1 to 9, including Evaporation and concentration steps: The pretreated waste liquid is evaporated and concentrated to generate concentrated liquid; Flash evaporation separation step: The concentrate is flash-evaporated at low temperature and low pressure to further concentrate it; Pyrolysis step: The concentrate is pyrolyzed to generate pyrolysis gas and residue; Purification steps: Purify the pyrolysis gas.

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