High-viscosity sludge drying treatment method

Abstract

The invention discloses a drying treatment method for high-viscosity sludge. The drying treatment method comprises the following steps: physical gel breaking pretreatment, gradient thermal coupling drying, tail gas synergistic treatment and product regulation and control. According to the high-viscosity sludge drying treatment method provided by the invention, multiple technologies such as bio-enzyme pretreatment, physical fish hammer breaking, three-section gradient drying and tail gas heat energy recycling are coupled, so that the viscosity and the moisture content of sludge are remarkably reduced, wall sticking and blockage of equipment are effectively avoided, and the drying efficiency and the product fluidity are improved; the whole treatment method does not need to add a chemical conditioner during use, so that the secondary pollution is reduced, and the activity of organic matters in the sludge is retained; and meanwhile, tail gas latent heat is recycled for front-end pretreatment, energy recycling is achieved, and energy consumption is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sludge treatment, in particular to a high-viscosity sludge drying treatment method. BACKGROUND

[0002] Sludge treatment refers to the process of reducing, stabilizing, harmless and recycling of sludge generated in the sewage treatment process. The sludge contains a large amount of organic matter, pathogens, heavy metals and other harmful substances. If not properly treated, it will cause serious harm to the environment and human health. High-viscosity sludge usually refers to water content ≥80%, apparent viscosity >5000 mPa·s. Due to its strong colloidal stability, high water retention and plasticity, it faces three major problems in the existing drying process:

[0003] Low dewatering efficiency and high energy consumption: traditional hot air or steam drying relies on surface heat transfer, which is difficult to penetrate the dense colloidal structure, and the water evaporation rate is slow. The energy consumption per unit of dry sludge often exceeds 1000 kWh / t;

[0004] Easy to block and stick to the wall, unstable equipment operation: sludge is easily adhered to the surface of the equipment during transportation, stirring and drying cavity, resulting in heat transfer surface scaling, screw jamming and frequent shutdown for cleaning;

[0005] Excessive dependence on chemical conditioners causes secondary pollution: lime, FeCl3 or PAM and other chemical agents are commonly used to improve dewatering, which is effective in the short term, but introduces inorganic ash and residual harmful ions, reduces the heat value and organic matter activity of the sludge, and hinders subsequent incineration, composting or building material utilization.

[0006] Although existing technologies have tried to introduce microwaves, solar energy or mechanical extrusion, etc., but due to high cost or single process, the above-mentioned coupling problems have not been systematically solved. Therefore, we propose a high-viscosity sludge drying treatment method. SUMMARY

[0007] The purpose of the present application is to provide a high-viscosity sludge drying treatment method to solve the problems in the background art.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solution: a high-viscosity sludge drying treatment method, the high-viscosity sludge drying treatment method comprising the following steps:

[0009] Step 1: Physical gel breaking pretreatment: high-viscosity sludge is sent into a high-speed shearing mixer, and shearing treatment is carried out at a rotating speed of 1500-3000 rpm / min for 3-8 min to release internal bound water and reduce the apparent viscosity to more than 50%;

[0010] Step two: Gradient heat coupling drying: After the sludge treated by the gel breaking process is sent into the double-shaft paddle dryer, a partition temperature control system and a variable frequency stirring system are arranged inside the double-shaft paddle dryer, and the sludge treated by the gel breaking process is subjected to three-stage coupling drying treatment;

[0011] Step three: Tail gas treatment: After the drying tail gas in step two is subjected to condensation and dehumidification, the uncondensed gas is introduced into a photocatalytic oxidation unit for degrading volatile organic compounds;

[0012] Step four: Product regulation: After the sludge is sent out of the double-shaft paddle dryer, an annular steam injection ring is arranged at the middle section of the discharge position of the double-shaft paddle dryer, a plurality of steam inlet grooves are arranged outside the annular steam injection ring, low-pressure saturated steam is introduced into the steam inlet grooves to adjust the moisture of the output dried sludge, and the sludge treated by the low-pressure saturated steam is output and discharged by a double-screw conveyor.

[0013] There are three major problems in the existing drying process: low dewatering efficiency and high energy consumption; traditional hot air or steam drying relies on surface heat transfer, which is difficult to penetrate the dense gel structure, the water evaporation rate is slow, and the energy consumption per unit of dry sludge often exceeds 1000 kWh / t; easy to block and stick to the wall, the equipment runs unstably; excessive dependence on chemical conditioning agents causes secondary pollution: lime, FeCl3 or PAM and other chemical agents are commonly used to improve dewatering, which is effective in the short term, but introduces inorganic ash and residual harmful ions, reduces the heat value and organic matter activity of the sludge, and hinders subsequent incineration, composting or building material utilization. Although existing technologies have tried to introduce microwaves, solar energy or mechanical extrusion, etc., they have not been able to systematically solve the above coupling problems due to high cost or single process. The present application uses a high-speed shear mixer to mechanically shear high-viscosity sludge, effectively destroying the gel structure of the sludge, releasing the internal bound water, and reducing the apparent viscosity by more than 50%, fundamentally improving the flowability and dewatering performance of the sludge, and creating good conditions for subsequent drying. Secondly, a double-shaft paddle dryer with partition temperature control and variable frequency stirring function is used to implement three-stage gradient heat coupling drying, avoiding the problem of surface hardening caused by sudden temperature rise in traditional drying, realizing efficient evaporation of water from the inside to the outside, and significantly improving the heat energy utilization efficiency and reducing the energy consumption per unit of dry sludge.

[0014] In addition, the tail gas generated during the drying process is dehumidified by condensation, and then the uncondensed gas is introduced into the photocatalytic oxidation unit, which can effectively degrade volatile organic compounds (VOCs) and prevent harmful gas emissions, achieving clean treatment of waste gas and meeting environmental protection requirements. In the product output stage, low-pressure saturated steam is precisely supplemented into the annular dried sludge through annular steam injection, and a double-screw conveyor is used to stabilize the discharge, which not only can flexibly regulate the moisture content of the final product, but also can improve the uniformity of the dried sludge and the subsequent resource utilization value.

[0015] As a further description of the above technical solution:

[0016] In step one, while using a high-speed shearing mixer for shearing treatment, saturated water vapor at a temperature of 60-80°C is introduced to heat and expand the high-viscosity sludge and tear it with mechanical force, releasing internal bound water and reducing the apparent viscosity by more than 50%.

[0017] As a further description of the above technical solution:

[0018] The three-stage coupled drying treatment of step two includes the following steps:

[0019] Step A1: Low-temperature loosening treatment: The low-temperature loosening treatment is used to avoid hardening of the sludge surface, the low-temperature loosening treatment temperature is 60-80°C, the stirring frequency is 10-15 Hz, and the stirring time is 10-15 min;

[0020] Step A2: Medium-temperature dewatering treatment: The medium-temperature dewatering treatment is used to strengthen the convection and conduction dewatering of the sludge, the medium-temperature dewatering treatment temperature is 100-130°C, the stirring frequency is 20-25 Hz, and the stirring time is 15-20 min;

[0021] Step A3: High-temperature shaping treatment: The high-temperature shaping treatment is used to form a hydrophobic shell layer on the surface of the sludge particles by micro-pyrolysis, the high-temperature shaping treatment temperature is 140-160°C, the stirring frequency is 15 Hz, and the stirring time is 5-10 min.

[0022] As a further description of the above technical solution:

[0023] The surface of the double-shaft paddle dryer is sprayed with a titanium dioxide and silicon carbide composite coating.

[0024] As a further description of the above technical solution:

[0025] In the product regulation of step four, a microwave moisture meter is arranged at the rear end of the discharge position of the double-shaft paddle dryer for real-time detection of the moisture content of the sludge.

[0026] As a further description of the above technical solution:

[0027] The outer wall of the high-speed shearing mixer in step one and the outer wall of the double-shaft paddle dryer in step two are provided with ultrasonic generators, and the ultrasonic frequency of the ultrasonic generator is 20-40 Hz.

[0028] As a further description of the above technical solution:

[0029] The biological enzyme pretreatment step is added at the front end of the physical gel breaking pretreatment in step one, the high-viscosity sludge is mixed with a composite enzyme preparation, the composite enzyme is a mixture of protease, polysaccharase and lipase, the mass addition amount of the protease, polysaccharase and lipase is 1:1:1, the action temperature of the composite enzyme is 35-45 DEG C, the pH value of the composite enzyme is 6.5-7.5, and the reaction time of the high-viscosity sludge and the composite enzyme is 30-60 min.

[0030] As a further description of the above technical solution:

[0031] After the biological enzyme pretreatment in step one is completed, the high-viscosity sludge is sent into the high-speed shearing mixer, then the high-speed shearing mixer is sealed, the inside of the high-speed shearing mixer is heated to 90-100 DEG C at a speed of 5-8 DEG C / min and pressure is maintained for 2-5 min, and after the pressure maintaining is completed, the pressure inside the high-speed shearing mixer is instantaneously released to normal pressure.

[0032] As a further description of the above technical solution:

[0033] In the dry tail gas treatment in step three, the latent heat of the high-temperature section is recovered through the first-stage condenser first, and the latent heat of the high-temperature section is introduced into the high-speed shearing mixer in step one as saturated steam through a conveying pipe.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1、The present application introduces biological enzyme and physical gel breaking double means in the pretreatment stage, the key components in the sludge extracellular polymer are selectively degraded under mild conditions by the composite enzyme preparation of protease, polysaccharase and lipase, and the colloidal stability is effectively weakened, then the high-speed shearing and saturated steam are combined, and the ultrasonic vibration and transient pressure release flash evaporation technology are used, so that the combined water in the sludge is efficiently released, the apparent viscosity is reduced by more than 50%, and the subsequent drying performance is greatly improved.

[0036] 2、Secondly, the process is subdivided into low-temperature loosening treatment, medium-temperature dewatering treatment and high-temperature shaping treatment in the core drying link, the surface hardening problem caused by traditional one-time high temperature is avoided, the water is uniformly evaporated from the inside to the outside, and the heat and mass transfer efficiency is strengthened by frequency conversion stirring and partition temperature control.

[0037] 3、Furthermore, the high-temperature latent heat of the dried exhaust gas is recovered after condensation and dehumidification and is used to supply steam in the pretreatment stage, forming a closed loop of heat energy and effectively reducing overall energy consumption; the uncondensed gas is introduced into a photocatalytic oxidation unit to efficiently degrade volatile organic compounds, achieving harmless emission of the exhaust gas and avoiding environmental pollution;

[0038] 4、Finally, the annular steam injection ring is linked with the microwave moisture meter through the discharge port, which can monitor and accurately adjust the moisture content of the dried sludge in real time, ensuring the consistency of product quality and meeting the requirements of subsequent resource utilization for moisture and heat value. The entire process does not require the addition of chemical conditioners such as lime and PAM, avoiding the introduction of inorganic ash and the loss of organic matter activity, and improving the resource value of the sludge. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0040] Embodiment one:

[0041] The present application provides a technical solution: a high-viscosity sludge drying treatment method, which comprises the following steps:

[0042] Step one: physical gel breaking pretreatment: the high-viscosity sludge is sent into a high-speed shearing mixer, and shearing treatment is carried out at a rotational speed of 1500-3000 rpm / min for 3-8 min to release the internal bound water and reduce the apparent viscosity to more than 50%;

[0043] Step two: gradient heat coupling drying: the gel breaking treated sludge is sent into a double-shaft paddle dryer, which is provided with a partitioned temperature control system and a variable frequency stirring system, for three-stage coupled drying treatment of the gel breaking treated sludge;

[0044] Step three: exhaust gas cooperative treatment: after the drying exhaust gas in the step two gradient heat coupling drying is condensed and dehumidified, the uncondensed gas is introduced into a photocatalytic oxidation unit for degradation of volatile organic compounds;

[0045] Step four: product regulation: after the sludge is sent out of the double-shaft paddle dryer, an annular steam injection ring is arranged at the middle section of the discharge position of the double-shaft paddle dryer, a plurality of steam inlet grooves are formed on the outside of the annular steam injection ring, low-pressure saturated steam is introduced into the steam inlet grooves to adjust the moisture of the output dried sludge, and the sludge treated by the low-pressure saturated steam is output and discharged by a double-screw conveyor.

[0046] This invention utilizes a high-speed shear mixer to mechanically shear high-viscosity sludge, effectively disrupting the sludge's colloidal structure and releasing bound water, thereby reducing the apparent viscosity by more than 50%. This fundamentally improves the sludge's fluidity and dewatering performance, creating favorable conditions for subsequent drying. Furthermore, a twin-shaft paddle dryer with zoned temperature control and variable frequency stirring functions is employed to implement three-stage gradient thermo-coupling drying. This avoids the surface hardening problem caused by sudden temperature increases in traditional drying processes, achieving efficient evaporation of moisture from the inside out, significantly improving thermal energy utilization efficiency and reducing energy consumption per unit of dried sludge.

[0047] Example 2:

[0048] In step one, saturated steam at a temperature of 60℃-80℃ is simultaneously introduced during the shearing process using a high-speed shear mixer. This causes the high-viscosity sludge to expand under heat and be mechanically torn apart, releasing internal bound water and reducing apparent viscosity by more than 50%. Both the high-speed shear mixer in step one and the biaxial paddle dryer in step two are equipped with ultrasonic generators on their outer walls. The ultrasonic frequency of these generators is 20-40Hz. A biological enzyme pretreatment step is added before the physical debinding pretreatment in step one. This biological enzyme pretreatment step mixes the high-viscosity sludge with a compound enzyme preparation. The compound enzyme is a mixture of protease, polysaccharide enzyme, and lipase, with a mass ratio of 1:1:1. The reaction temperature of the compound enzyme is 35℃-45℃, the pH value is 6.5-7.5, and the reaction time between the high-viscosity sludge and the compound enzyme is 30-60 minutes.

[0049] First, a compound enzyme preparation composed of protease, polysaccharide enzyme and lipase in a 1:1:1 ratio is introduced. Under mild conditions, it acts for 30-60 minutes and can selectively degrade key colloidal stabilizing components such as proteins, polysaccharides and lipids in the extracellular polymers of sludge. This weakens the colloidal network structure of sludge at the molecular level and reduces its water holding capacity and viscoelasticity.

[0050] Secondly, saturated water vapor at 60℃-80℃ is simultaneously introduced during the high-speed shearing process, causing the sludge to expand due to heat and increase its porosity. At the same time, it is strongly torn apart under the action of high shear force, effectively releasing the internal bound water that was originally difficult to remove. This can form a synergistic effect of heat and shear force with the high-speed shear mixer, which to a certain extent enhances the physical breaking effect, reduces the apparent viscosity by more than 50%, significantly improves fluidity, and avoids clogging problems during the conveying and drying process.

[0051] Furthermore, an ultrasonic generator with an ultrasonic frequency of 20-40Hz is added to the outer wall of the high-speed shear mixer and the twin-shaft paddle dryer. The cavitation effect and micro-disturbance generated by low-frequency ultrasound further destroy the micro-agglomeration structure of sludge, promote water migration, and prevent adhesion to the inner wall of the equipment, thereby improving heat transfer efficiency and operational stability. This setup abandons the traditional method of relying on chemical conditioners, which not only avoids the introduction of inorganic ash and secondary pollution, but also preserves the organic activity of sludge, which is conducive to subsequent resource utilization.

[0052] After the bio-enzyme pretreatment in step one is completed, the high-viscosity sludge is fed into the high-speed shear mixer. The high-speed shear mixer is then sealed, and the temperature inside the high-speed shear mixer is raised to 90℃-100℃ at a rate of 5℃-8℃ / min and held at pressure for 2-5 minutes. After the pressure holding is completed, the air pressure inside the high-speed shear mixer is instantly released to atmospheric pressure.

[0053] The process involves feeding sludge into a high-speed shear mixer and sealing it under pressure. This allows the internal moisture of the sludge to be fully heated and vaporized without escaping, creating a high-temperature, high-pressure saturated steam environment. This setup not only softens the sludge particles but also promotes thermal expansion and micro-cracks in the cell walls and colloidal networks. Subsequently, by instantly depressurizing to atmospheric pressure, the internal superheated steam rapidly flashes, generating a "micro-explosion effect." This exerts strong internal stress on the sludge particles, causing their microstructure to rupture completely and releasing a large amount of bound water and interstitial water trapped within the cells or colloidal networks. This significantly improves the dewatering performance and fluidity of the sludge. This setup can significantly enhance the degelatinization efficiency, compensating for the shortcomings of simple enzymatic hydrolysis or mechanical shearing. Secondly, it avoids the use of chemical conditioning agents, maintaining the integrity of the sludge's organic matter, which is beneficial for subsequent resource recovery. Finally, it is highly synergistic with the preceding enzymatic hydrolysis, shearing, and subsequent drying stages, forming a multi-stage coupled pretreatment system. This reduces overall drying energy consumption, improves system stability, and reduces the risk of equipment clogging.

[0054] Example 3:

[0055] The three-stage coupling drying process in step two includes the following steps:

[0056] Step A1: Low-temperature loosening treatment: The low-temperature loosening treatment is used to prevent the sludge surface from hardening. The temperature of the low-temperature loosening treatment is 60℃-80℃, the stirring frequency is 10Hz-15Hz, and the stirring time is 10-15min.

[0057] Step A2: Medium-temperature dewatering treatment: The medium-temperature dewatering treatment is used for enhanced convection and conduction dewatering of sludge. The temperature of the medium-temperature dewatering treatment is 100℃-130℃, the stirring frequency is 20Hz-25Hz, and the stirring time is 15-20min.

[0058] Step A3: High-temperature setting treatment: The high-temperature setting treatment is used to micro-coke the surface of sludge particles to form a hydrophobic shell layer, thereby improving fluidity. The high-temperature setting treatment temperature is 140℃-160℃, the stirring frequency is 15Hz, and the stirring time is 5-10min.

[0059] In the low-temperature loosening treatment stage of step A1, a lower temperature and gentle stirring are used to effectively avoid the hard shell phenomenon caused by rapid evaporation of surface moisture in the early stage of traditional high-temperature drying.

[0060] Secondly, in the medium-temperature dehydration stage of step A2, the temperature is increased to enhance heat conduction and convective heat transfer. At the same time, the stirring frequency is increased to enhance the material agitation and renewal of the heat transfer surface, which greatly accelerates the evaporation rate of free water and some bound water. This setting achieves rapid and uniform removal of moisture without densification, significantly improving drying efficiency and reducing unit energy consumption.

[0061] Finally, in the high-temperature shaping stage of step A3, the moderate high temperature causes slight coking of the surface of the sludge particles, forming a dense but hydrophobic hard shell layer. The formation of the hard shell layer not only inhibits the particles from absorbing moisture and becoming damp during subsequent transportation or storage, but also significantly improves the flowability and dispersibility of the dried product, avoids clumping and adhesion, and facilitates automated discharge and resource utilization.

[0062] The blades of the biaxial blade dryer are coated with a composite coating of titanium dioxide and silicon carbide. The titanium dioxide and silicon carbide composite coating has superhydrophobic and photocatalytic self-cleaning properties, which can prevent sludge adhesion to a certain extent.

[0063] In step four, the product control process, a microwave moisture meter is installed at the rear end of the discharge position of the biaxial blade dryer to detect the sludge moisture content in real time. The microwave moisture meter can detect the moisture content of the discharged sludge in real time, and this setting can adjust the injection steam content of the annular steam injection ring in a timely manner.

[0064] In the third step of the exhaust gas co-treatment, the latent heat of the high-temperature section is first recovered through the first-stage condenser during the drying of the exhaust gas. The latent heat of the high-temperature section is then introduced into the high-speed shear mixer in the first step as saturated water vapor through the conveying pipe. The exhaust gas generated during the drying process contains a large amount of high-temperature water vapor. By setting up the first-stage condenser to efficiently recover the heat of the high-temperature section exhaust gas, the heat released by condensation is converted into saturated water vapor at 60℃–80℃, which is precisely recycled to the front-end physical debinding pretreatment stage as the heat source required for the thermal expansion and mechanical tearing of sludge, greatly reducing the energy consumption requirement of external steam or electric heating.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for drying high-viscosity sludge, characterized in that: The method for drying high-viscosity sludge includes the following steps: Step 1: Physical debinding pretreatment: The high-viscosity sludge is fed into a high-speed shear mixer and sheared for 3-8 minutes at a speed of 1500-3000 rpm / min to release the internal bound water and reduce the apparent viscosity to more than 50%. Step 2: Gradient thermo-coupling drying: The sludge after degumming is fed into a biaxial blade dryer, which is equipped with a zoned temperature control system and a variable frequency stirring system to perform three-stage coupled drying treatment on the sludge after degumming. Step 3: Co-treatment of exhaust gas: After the exhaust gas dried in step 2 is condensed and dehumidified, the uncondensed gas is introduced into the photocatalytic oxidation unit, which is used to degrade volatile organic compounds. Step 4: Product Control: After the sludge is discharged from the twin-screw dryer, an annular steam injection ring is set in the middle of the discharge position of the twin-screw dryer. Multiple steam inlet troughs are opened on the outside of the annular steam injection ring. Low-pressure saturated steam is introduced into the steam inlet troughs to adjust the moisture content of the output dried sludge. The sludge treated by the low-pressure saturated steam is discharged through a twin-screw conveyor.

2. The method for drying high-viscosity sludge according to claim 1, characterized in that: In step one, saturated steam at a temperature of 60℃-80℃ is simultaneously introduced during the shearing process using a high-speed shear mixer. This causes the high-viscosity sludge to expand due to heat and be torn apart by mechanical force, releasing the internal bound water and reducing the apparent viscosity by more than 50%.

3. The method for drying high-viscosity sludge according to claim 2, characterized in that: The three-stage coupling drying process in step two includes the following steps: Step A1: Low-temperature loosening treatment: The low-temperature loosening treatment is used to prevent the sludge surface from hardening. The temperature of the low-temperature loosening treatment is 60℃-80℃, the stirring frequency is 10Hz-15Hz, and the stirring time is 10-15min. Step A2: Medium-temperature dewatering treatment: The medium-temperature dewatering treatment is used for enhanced convection and conduction dewatering of sludge. The temperature of the medium-temperature dewatering treatment is 100℃-130℃, the stirring frequency is 20Hz-25Hz, and the stirring time is 15-20min. Step A3: High-temperature setting treatment: The high-temperature setting treatment is used to micro-coke the surface of sludge particles to form a hydrophobic shell layer. The high-temperature setting treatment temperature is 140℃-160℃, the stirring frequency is 15Hz, and the stirring time is 5-10min.

4. The method for drying high-viscosity sludge according to claim 3, characterized in that: The blades of the biaxial blade dryer are coated with a composite coating of titanium dioxide and silicon carbide.

5. The method for drying high-viscosity sludge according to claim 4, characterized in that: In step four, product control, a microwave moisture meter is installed at the rear end of the discharge position of the biaxial blade dryer for real-time detection of sludge moisture content.

6. The method for drying high-viscosity sludge according to claim 5, characterized in that: Both the high-speed shear mixer in step one and the biaxial paddle dryer in step two are equipped with ultrasonic generators on their outer walls, and the ultrasonic frequency of the ultrasonic generators is 20-40Hz.

7. The method for drying high-viscosity sludge according to claim 6, characterized in that: The physical depolymerization pretreatment step in step one is supplemented with a biological enzyme pretreatment step. In this biological enzyme pretreatment step, high-viscosity sludge is mixed with a compound enzyme preparation. The compound enzyme is a mixture of protease, polysaccharide enzyme, and lipase. The mass ratio of the protease, polysaccharide enzyme, and lipase added is 1:1:

1. The reaction temperature of the compound enzyme is 35℃-45℃, the pH value of the compound enzyme is 6.5-7.5, and the reaction time of the high-viscosity sludge with the compound enzyme is 30-60 min.

8. The method for drying high-viscosity sludge according to claim 7, characterized in that: After the bio-enzyme pretreatment in step one is completed, the high-viscosity sludge is fed into the high-speed shear mixer. The high-speed shear mixer is then sealed, and the temperature inside the high-speed shear mixer is raised to 90℃-100℃ at a rate of 5℃-8℃ / min and held at pressure for 2-5 minutes. After the pressure holding is completed, the air pressure inside the high-speed shear mixer is instantly released to atmospheric pressure.

9. The method for drying high-viscosity sludge according to claim 8, characterized in that: In the third step of the exhaust gas co-treatment, the latent heat of the high-temperature section is first recovered through the first-stage condenser during the drying of the exhaust gas, and the latent heat of the high-temperature section is introduced into the high-speed shear mixer in the first step as saturated water vapor through the conveying pipe.