A post-processing dehydration and drying method for SBS device

Abstract

The invention relates to a post-processing dehydration and drying method for an SBS device. The invention eliminates the process of excessive extrusion, adopts a stirring cutter to cut pellets, eliminates the process of cutting pellets, and has good product stability. The material is directly sheared and divided, and the moisture inside the material is directly evaporated by contact heating, thereby saving energy used for mixing and achieving the purpose of energy saving. The invention transmits the material to downstream equipment through a feeding screw conveyor and a discharging screw conveyor through a primary sieve plate, thereby eliminating an air flow conveying device. Due to the streamlined process, the equipment is compact, and an inlet of low-pressure steam is arranged in a centrifugal dehydration dryer. After the steam heats the material in the centrifugal dryer, the steam enters a long net to dry the long net material. The equipment has fewer external interfaces and is simpler in configuration. The prior art process and equipment are complex, thereby greatly reducing the land occupation and investment.

Description

Technical Field

[0001] The invention relates to a post-processing dehydration and drying method for an SBS device. Background Art

[0002] SBS is a thermoplastic butadiene-styrene block copolymer produced by an ABA-shaped lithium-based anionic polymerization process with butadiene and styrene as monomers, cyclohexane as solvent, butyl lithium as initiator, tetrahydrofuran as activator, and silicon tetrachloride as coupling agent. It is widely used in various industrial and civil fields such as asphalt modification and thermoplastic molding. The production process of SBS consists of monomer preparation, polymerization, flash evaporation to remove solvents, solvent recovery, and post-treatment.

[0003] At present, the above post-treatment process is generally carried out using the following two processes: (1) The SBS granules containing 96-98% water are vibrated and dehydrated through a vibrating dehydration screen, and then the granules enter the extrusion dehydrator to be dehydrated by extrusion, and then enter the expansion dryer to be further dehydrated by expansion flash evaporation. The granules then enter the vibrating hot box for further dehydration while adding anti-caking agents. At the outlet of the hot box, they are sent to the fluidized bed or long net dryer through a pneumatic conveying system to further dry the granules, and the finished product at the outlet contains 0.5% volatile matter. , and sent to the packaging system to complete the post-drying production of the rubber particles; (2) The SBS rubber particles containing 96~98% water pass through the inclined filter screen and are dehydrated by the extrusion expansion dehydrator. After the extrusion expansion flash dehydration, the rubber particles enter the vibrating hot box for further dehydration and anti-caking agent is added. At the outlet of the hot box, they are sent to the fluidized bed or long net dryer through the pneumatic conveying system for further drying. At the outlet, the finished product contains 0.5% volatility and is sent to the packaging system to complete the post-drying production of the rubber particles. Among them, the vibration dewatering screen is to feed the material with a solid content of about 3-5% from the upstream into a horizontally placed vibration dewatering screen to preliminarily screen out the water, and then the material is directly sent to the extrusion dewatering machine, and the screened water returns to the hot water circulation system; the extrusion dewatering machine refers to the material being squeezed and kneaded by the screw in the extruder to further remove the moisture; the expansion dryer refers to the material entering the expansion dryer after extrusion. Under the action of jacket heating and screw mixing of the material, the material temperature rises, and the pressure is suddenly released when it is extruded through the template under the high pressure formed by the extrusion, and the moisture in the material expands and vaporizes to achieve the purpose of drying, and the material is cut into the required size by the high-speed rotating cutter on the template.

[0004] That is, the material needs to be dehydrated by extrusion and expansion flash evaporation first, and then a pelletizing mechanism is set at the outlet of the expander to pelletize the extruded material. The above process has the following disadvantages:

[0005] (1) The process is complicated, requiring many equipment and occupying a large area; the extrusion dehydrator and expansion dryer are high-pressure equipment, which are difficult to manufacture and require high investment;

[0006] (2) Material extrusion consumes high energy and causes severe agglomeration;

[0007] (3) The mixing process has high energy consumption and difficult temperature control, which can easily cause excessive temperature rise and degradation of the material, seriously affecting product stability. Summary of the invention

[0008] The technical problem to be solved by the present invention is to provide a post-processing dehydration and drying method for an SBS device with simplified process, small footprint and investment, and good product stability in view of the current status of the prior art.

[0009] The technical solution adopted by the present invention to solve the above technical problems is:

[0010] A post-processing dehydration and drying method for an SBS device comprises the following steps:

[0011] (1) The mixed liquid of rubber particles and hot water from the upstream process overflows from the feed port of the dehydration screen and enters the dehydration screen. The water is initially screened out through the inclined first-level screen plate and the screened water is discharged into the liquid collecting tank. Under the action of the induced draft fan, the hot air in the centrifugal dehydration dryer and the evaporated water of the rubber particles is discharged through the exhaust port. The entrained rubber particles are separated by the cyclone separator. The separated gas phase uses the waste heat of the gas in the heat exchanger to heat and dry the air entering the centrifugal dehydration dryer to recover heat, thereby reducing energy consumption. The gas after heat exchange is discharged to the tail gas treatment system.

[0012] (2) After being dehydrated by the dehydration inclined screen, the material enters the centrifugal dehydration dryer, and the water is further screened out by the secondary screen plate inside the centrifugal dehydration dryer. The screened water is discharged to the liquid collecting tank through the drain port. The material is pushed into the cylinder of the centrifugal dehydration dryer by the screw conveyor installed at the bottom of the secondary screen plate. It is stirred, crushed and granulated by the high-speed rotating cutter. The material is heated by contact with the cylinder under the action of high-speed centrifugal force. The water and volatiles in the material are evaporated by heat. The gas entering from the dry gas inlet is carried out of the centrifugal separator through the exhaust port. Under the action of the inclined cutter, the material is gradually transported to the discharge end of the centrifugal dehydration dryer, and is sent to the discharge port through the screw conveyor installed at the end, completing the first step of the dehydration process;

[0013] (3) A low-pressure steam coil is passed through the centrifuge cylinder jacket to heat the heat transfer oil, and the heat transfer oil heats the inner wall of the cylinder to make the heating more uniform; an anti-caking agent injection port is set above the discharge port, and the anti-caking agent is injected to prevent the material from caking; the fire steam nozzle set at the end of the centrifuge sprays fire steam to prevent the material from burning and causing a fire; the air in the atmosphere is purified by the fan inlet filter, and then heated by the blower through the outlet air heat exchange, and then passed into the centrifugal dehydration dryer, forming a counter-flow with the material, taking away the water and volatiles evaporated from the material;

[0014] (4) The material at the discharge port passes through the discharge three-way valve to the material distributor, and is evenly distributed on the fourdryer chain plate through the material distributor; the discharge three-way valve is used to discharge the material when the material is blocked; the low-pressure steam tail gas of the centrifugal dehydration dryer jacket enters the heater in the fourdryer, and a number of fans are arranged at the bottom of the fourdryer to heat and dry the material distributed on the chain plate in the fourdryer. The exhaust fan outside the fourdryer discharges the gas rich in steam and volatiles to the tail gas treatment unit; the steam condensate of the fourdryer heater is discharged into the liquid collecting tank;

[0015] (5) The dehydrated and dried materials are sent to the long net cooling zone. Under the action of the cooling circulation fan, the gas in the cooling zone enters the bag filter to remove the powdery materials, and then forms cold air through the heat exchanger. After the condensate is separated in the separator, it returns to the long net cooling zone to cool the materials.

[0016] (6) After the cooling, the material completes the dehydration and drying process, and is discharged by the spiral discharger at the end of the long net and sent to the packaging unit system.

[0017] Preferably, in step (4), fire-fighting steam is introduced into the fourdrinier net to prevent the powdered material from catching fire.

[0018] Preferably, in step (5), in order to quickly cool down and reduce the heat exchange area, the heat exchanger used uses chilled water for heat exchange.

[0019] In the present invention, the centrifugal dehydration dryer comprises:

[0020] A drying cylinder is arranged transversely and is hollow inside to form a drying chamber, wherein a material inlet is provided at the first end of the drying cylinder and a material outlet is provided at the second end;

[0021] A transmission shaft is rotatably arranged through the central axis of the drying cylinder;

[0022] A driving member is arranged outside the drying cylinder and connected to the end of the transmission shaft, and is used to drive the transmission shaft to rotate; the driving member is a motor, and the motor is connected to the end of the transmission shaft through a speed reduction mechanism;

[0023] The scraper is used to stir, crush and pelletize the material in the drying cylinder. The scraper is in multiple groups and the first end is connected to the transmission shaft and the second end extends to the inner wall of the drying cylinder. The multiple groups of scrapers are arranged in an axially spaced manner along the transmission shaft, thereby enclosing a feeding channel for axially conveying the material with the inner wall of the drying cylinder.

[0024] A heating coil is arranged around the outer circumference of the drying cylinder and is used to heat the drying cylinder;

[0025] The dewatering screen is arranged at the inlet end of the drying cylinder and is used for dewatering the material.

[0026] Preferably, the first end of the scraper is connected to the transmission shaft, and the second end is a rotating free end arranged close to the inner wall of the drying cylinder. The scraper is adjustably tilted from the first end to the second end along the feeding direction. Correspondingly, the feeding channel is a spiral channel tilted along the feeding direction.

[0027] Preferably, the dewatering screen includes an upper part and a lower part, the upper part is provided with a primary sieve plate arranged vertically and obliquely, and the lower part is provided with a horizontally arranged secondary sieve plate, and the area under the secondary sieve plate corresponding to the transmission shaft is connected to the drying cylinder to constitute the material inlet of the drying cylinder.

[0028] Preferably, a feed port for feeding by overflow is provided at the bottom of the upper part of the dewatering screen, and an exhaust port is opened at the top; the primary sieve plate is arranged downstream of the feed port; a drain port is provided at the bottom of the corresponding primary sieve plate on the upper part of the dewatering screen; a baffle plate is provided at the junction of the upper and lower parts of the primary sieve plate so that the material can be transported downward directly toward the secondary sieve plate.

[0029] Preferably, a feeding screw conveyor is provided at the material inlet of the drying cylinder, and a discharging screw conveyor is provided at the material outlet of the drying cylinder.

[0030] Preferably, the drying cylinder is provided with a steam inlet and a heat transfer oil inlet at the bottom near the second end, the drying cylinder is provided with a steam and condensate outlet at the bottom near the first end, and a gas outlet at the top.

[0031] Preferably, the drying cylinder is provided with a fire-fighting steam nozzle on the inner wall surface of the second end thereof, and the drying cylinder is provided with an anti-caking agent nozzle on the inner top wall near the second end.

[0032] Compared with the prior art, the advantages of the present invention are as follows: the prior art directly extrudes materials through mechanical transmission, which may cause excessive extrusion of materials and affect the properties of rubber particles. The present invention eliminates the process of excessive extrusion and adopts a stirring cutter to cut particles, thereby eliminating the process of cutting particles and achieving good product stability; the prior art forms high pressure on materials through mixing, and then suddenly reduces pressure through a template to expand and gasify and dry the water. The present invention directly shears and divides the materials, and directly evaporates the water inside the materials through contact heating, thereby saving energy used for mixing and achieving the purpose of energy saving; the present invention transmits materials through a feeding screw conveyor and a discharging screw conveyor through a primary sieve plate and to downstream equipment, thereby eliminating the need for an air flow conveying device; the prior art low-pressure steam enters the extruder, expander and long net respectively, and each device is provided with a low-pressure steam inlet. The present invention simplifies the process and has compact equipment. The low-pressure steam is provided with an inlet in the centrifugal dehydration dryer. After the steam heats the materials in the centrifugal dryer, it enters the long net to dry the long net materials. The equipment has fewer external interfaces and is simpler in configuration. The present invention eliminates extrusion, expansion and pelletizing, and only has one centrifugal dehydration dryer, thereby greatly reducing land occupation and investment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a flow chart of an embodiment of the present invention;

[0034] Figure 2 for Figure 1 Schematic diagram of the structure of the centrifugal dehydration dryer. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below with reference to the accompanying drawings.

[0036] like Figure 1 , 2 As shown, the post-treatment dehydration and drying method of the SBS device in this embodiment includes the following steps:

[0037] (1) The mixed liquid of rubber particles and hot water from the upstream process overflows from the feed port of the dehydration screen and enters the dehydration screen. The water is initially screened out through the inclined first-level screen plate and the screened water is discharged into the liquid collecting tank. Under the action of the induced draft fan, the hot air in the centrifugal dehydration dryer and the evaporated water of the rubber particles is discharged through the exhaust port. The entrained rubber particles are separated by the cyclone separator. The separated gas phase uses the waste heat of the gas in the heat exchanger to heat and dry the air entering the centrifugal dehydration dryer to recover heat, thereby reducing energy consumption. The gas after heat exchange is discharged to the tail gas treatment system.

[0038] (2) After being dehydrated by the dehydration inclined screen, the material enters the centrifugal dehydration dryer, and the water is further screened out by the secondary screen plate inside the centrifugal dehydration dryer. The screened water is discharged to the liquid collecting tank through the drain port. The material is pushed into the cylinder of the centrifugal dehydration dryer by the screw conveyor installed at the bottom of the secondary screen plate. It is stirred, crushed and granulated by the high-speed rotating cutter. The material is heated by contact with the cylinder under the action of high-speed centrifugal force. The water and volatiles in the material are evaporated by heat. The gas entering from the dry gas inlet is carried out of the centrifugal separator through the exhaust port. Under the action of the inclined cutter, the material is gradually transported to the discharge end of the centrifugal dehydration dryer, and is sent to the discharge port through the screw conveyor installed at the end, completing the first step of the dehydration process;

[0039] (3) A low-pressure steam coil is passed through the centrifuge cylinder jacket to heat the heat transfer oil, and the heat transfer oil heats the inner wall of the cylinder to make the heating more uniform; an anti-caking agent injection port is set above the discharge port, and the anti-caking agent is injected to prevent the material from caking; the fire steam nozzle set at the end of the centrifuge sprays fire steam to prevent the material from burning and causing a fire; the air in the atmosphere is purified by the fan inlet filter, and then heated by the blower through the outlet air heat exchange, and then passed into the centrifugal dehydration dryer, forming a counter-flow with the material, taking away the water and volatiles evaporated from the material;

[0040] (4) The material at the discharge port passes through the three-way discharge valve to the material distributor, and is evenly distributed on the fourdryer chain plate through the material distributor; the three-way discharge valve is used to discharge the material when the material is blocked; the low-pressure steam tail gas of the centrifugal dehydration dryer jacket enters the heater in the fourdryer, and a number of fans are arranged at the bottom of the fourdryer to heat and dry the material distributed on the chain plate in the fourdryer. The exhaust fan outside the fourdryer discharges the gas rich in steam and volatiles to the tail gas treatment unit; the steam condensate of the fourdryer heater is discharged into the liquid collecting tank; in order to prevent the powdered material from catching fire, fire steam is introduced into the fourdryer at the same time;

[0041] (5) The dehydrated and dried materials are sent to the long net cold zone. Under the action of the cooling circulation fan, the gas in the cold zone enters the bag filter to remove the powdered materials, and then forms cold air through the heat exchanger. After the condensate is separated in the separator, it returns to the long net cold zone to cool the materials. In order to quickly cool down and reduce the heat exchange area, the heat exchanger uses chilled water for heat exchange.

[0042] (6) After the cooling, the material completes the dehydration and drying process, and is discharged by the spiral discharger at the end of the long net and sent to the packaging unit system.

[0043] In this embodiment, the centrifugal dehydration dryer comprises:

[0044] The drying cylinder 11 is arranged horizontally and is hollow inside to form a drying chamber. A material inlet 111 is provided at the first end of the drying cylinder 11, and a material outlet 112 is provided at the second end.

[0045] The transmission shaft 8 is rotatably arranged to pass through the central axis of the drying cylinder 11;

[0046] The driving member 29 is arranged outside the drying cylinder 11 and connected to the end of the transmission shaft 8, and is used to drive the transmission shaft 8 to rotate; the driving member 29 is a motor, and the motor is connected to the end of the transmission shaft 8 through a speed reduction mechanism;

[0047] The scraper 7 is used to stir, crush and pelletize the material in the drying cylinder 11. The scraper 7 is composed of multiple groups, and the first end of the scraper 7 is connected to the transmission shaft 8, and the second end extends to the inner wall of the drying cylinder 11. The multiple groups of scrapers 7 are arranged in an axially spaced manner along the transmission shaft 8, thereby enclosing a feeding channel for axially conveying the material with the inner wall of the drying cylinder 11;

[0048] The heating coil 21 is arranged around the outer circumference of the drying cylinder 11 and is used to heat the drying cylinder 11;

[0049] The dewatering screen 1 is arranged at the inlet end of the drying cylinder 11 and is used for dewatering the material.

[0050] The first end of the scraper 7 is connected to the transmission shaft 8, and the second end is a rotating free end arranged close to the inner wall of the drying cylinder 11. The scraper 7 is adjustably tilted from the first end to the second end along the feeding direction. Correspondingly, the feeding channel is a spiral channel tilted along the feeding direction.

[0051] The above-mentioned dewatering screen 1 includes an upper part 1a and a lower part 1b. The upper part 1a is provided with a primary sieve plate 3 arranged vertically and tiltedly, and the lower part 1b is provided with a horizontally arranged secondary sieve plate 25. The secondary sieve plate 25 is connected to the drying cylinder 11 corresponding to the area under the transmission shaft 8, forming the material inlet of the drying cylinder 11.

[0052] The bottom of the upper part 1a of the above-mentioned dewatering screen 1 is provided with a feed port 30 for feeding by overflow, and the top is provided with an exhaust port 2. The first-level sieve plate 3 is arranged downstream of the feed port 30. The upper part 1a of the dewatering screen 1 is provided with a drain port 31 at the bottom corresponding to the first-level sieve plate 3. The lower end of the first-level sieve plate 3 is provided with a flow-blocking baffle 34 at the connection between the upper part 1a and the lower part 1b, which can enable the material to be transported downward directly toward the second-level sieve plate 25.

[0053] A feeding screw conveyor 27 is provided at the material inlet of the drying cylinder 11 , and a discharging screw conveyor 15 is provided at the material outlet of the drying cylinder 11 .

[0054] The drying cylinder 11 is provided with a steam inlet 18 and a heat transfer oil inlet 19 at the bottom near the second end, and a steam and condensate outlet 22 at the bottom near the first end and a gas outlet 6 at the top.

[0055] The drying cylinder 11 is provided with a fire steam nozzle 35 on the inner wall surface of the second end, and an anti-caking agent nozzle 36 is provided on the inner top wall of the drying cylinder 11 near the second end. The drying cylinder 1 is provided with a steam outlet or a drying gas inlet 9 at the top near the second end.

[0056] The centrifugal dehydration dryer of the present embodiment is equipped with a secondary sieve plate 25 and a feeding screw conveyor 27 installed in the body. The feeding screw conveyor 27 is installed above the secondary sieve plate 25 in the separator, and the secondary sieve plate 25 serves as a material receiving mechanism at the bottom of the screw conveyor; the high-speed rotating transmission shaft 8 drives the staggered stirring scrapers 7 to rotate, and the inclined scrapers 7 push the materials to move the materials from left to right; the materials are heated by contacting the hot cylinder under the action of the rotating centrifugal force, and the heat transfer oil is heated by a steam coil. The heat transfer oil is isolated and transferred to the cylinder by the secondary structure so that the heating is uniform and the temperature control is accurate; the inclined sieve plate realizes self-cleaning ability by flushing; the cylinder of the present embodiment can also be arranged with a mechanical seal to prevent the leakage of materials, moisture, steam, etc.; the cylinder is equipped with a steam outlet or a dry gas inlet, and exhaust or introduction of dry gas can be realized as needed to enhance the drying effect; the centrifugal dehydration dryer outlet is provided with an anti-caking nozzle, and the anti-caking agent prevents the materials from sticking and caking; the cylinder is provided with a fire steam nozzle for extinguishing the flame to prevent the spread and expansion of the fire.

[0057] The existing extruder forms a high-pressure area at the discharge end, making the machine body and the screw difficult to manufacture. The axial force of the screw is too large, the processing is difficult and the cost is high. The present invention only has a transmission shaft that only bears a very small axial force, and the material is driven to rotate by the scraper, which greatly reduces the manufacturing cost and difficulty. The existing technology directly extrudes the material through mechanical transmission, which will cause the material to be over-extruded, affecting the properties of the rubber particles. The present invention eliminates the process of over-extrusion and uses a stirring cutter to cut the particles, eliminating the process of cutting the particles. The existing technology forms a high pressure on the material through mixing, and then suddenly reduces the pressure through the template to expand the water and gasify it for drying. The present invention directly shears and divides the material, and directly evaporates the water inside the material through contact heating, saving the energy used for mixing and achieving the purpose of energy saving. The existing technology transmits the material through a feeding screw conveyor and a discharging screw conveyor through a primary screen plate and to the downstream equipment. The present invention omits the airflow conveying device. The existing technology has a complicated process. The present invention omits extrusion, expansion, and pelletizing, and only has one centrifugal dehydration dryer, which greatly reduces the land occupation and investment.

[0058] When the centrifugal dehydration dryer of this embodiment is in operation, the colloid-hot water mixture from the upstream process overflows from the feed port 30 of the dehydration screen 1 into the dehydration screen 1, and 40-60% of the water is screened out through the primary screen plate 3 to the dehydration screen outlet 4. The steam in the colloid liquid is discharged through the exhaust port 2, and the water in the colloid liquid is discharged through the drain port 31. The primary dehydration screen is arranged obliquely, and the inclination angle is set according to the material characteristics. The baffle 34 has a diversion function, and the diverted material enters the secondary screen plate 25 installed in the barrel for further sieving the water. The screened water is discharged through the drain port 26. The feeding screw conveyor 27 driven by the motor pushes the material into the centrifugal dehydration dryer barrel 11. The high-speed stirring scrapers 7 arranged in an interlaced manner on the transmission shaft 8 rotate together with the transmission shaft 8, driving the material to rotate at a high speed, stirring, crushing and pelletizing. The high-speed stirring scrapers 7 are arranged obliquely to push the material from the feed port to the discharge port. The moving speed and material distribution are achieved by adjusting the rotation speed and the inclination angle as needed. High-temperature steam is introduced from the steam inlet 18 to the steam heating coil 21, and heat transfer oil is introduced from the heat transfer oil inlet 19. The cylinder is heated by secondary conduction, and the inner wall of the high-temperature cylinder is heated and dehydrated by high-temperature heating. Excess steam or condensate is discharged through the steam and condensate outlet 22. The material is discharged from the discharge port of the centrifugal dehydration dryer under the push of the discharge screw conveyor, and the moisture content of the discharged material can reach 3-15%. The discharge screw conveyor is driven by the motor 15. The steam outlet or dry gas inlet 9 can discharge the steam in the material as needed, or dry gas can be passed into the cylinder. The motor drives the centrifugal dehydration dryer through the reduction gear box 28, and the transmission shaft 8 is supported by radial bearings at both ends, a thrust bearing at one end, and an intermediate bearing and a bracket 20 in the middle. The radial bearing and the thrust bearing are placed in the bearing box. The mechanical seal 33 prevents the material, gas and steam from leaking into the atmosphere. The cylinder is equipped with an anti-caking agent nozzle 35 for spraying anti-caking agent, and a fire steam nozzle 36 for extinguishing fire in the cylinder.

[0059] The equipment of the present invention adopts two main equipments, namely centrifugal dehydration dryer and long net, to complete the drying process, eliminating the extruder, expansion pelletizer, hot box and pelletizer, thus solving the problem of multiple equipments and long process. The centrifugal drying equipment of the present invention does not need to extrude and mix the materials, which not only has a significant energy-saving effect, but also better guarantees the stability of the product. In addition, the drying method adopted by the centrifugal dehydration dryer of the present invention can adapt to products of various types and brands.

Claims

1. A post-treatment dehydration and drying method for an SBS device, characterized in that The following steps are involved: (1) The mixed liquid of rubber particles and hot water from the upstream process overflows from the feed port of the dehydration screen and enters the dehydration screen. The water is initially screened out through the inclined first-level screen plate and the screened water is discharged into the liquid collecting tank. Under the action of the induced draft fan, the hot air in the centrifugal dehydration dryer and the evaporated water of the rubber particles is discharged through the exhaust port. The entrained rubber particles are separated by the cyclone separator. The separated gas phase uses the waste heat of the gas in the heat exchanger to heat and dry the air entering the centrifugal dehydration dryer to recover heat, thereby reducing energy consumption. The gas after heat exchange is discharged to the tail gas treatment system. (2) After being dehydrated by the dehydration inclined screen, the material enters the centrifugal dehydration dryer, and the water is further screened out by the secondary screen plate inside the centrifugal dehydration dryer. The screened water is discharged to the liquid collecting tank through the drain port. The material is pushed into the cylinder of the centrifugal dehydration dryer by the screw conveyor installed at the bottom of the secondary screen plate. It is stirred, crushed and granulated by the high-speed rotating cutter. The material is heated by contact with the cylinder under the action of high-speed centrifugal force. The water and volatiles in the material are evaporated by heat. The gas entering from the dry gas inlet is carried out of the centrifugal separator through the exhaust port. Under the action of the inclined cutter, the material is gradually transported to the discharge end of the centrifugal dehydration dryer, and is sent to the discharge port through the screw conveyor installed at the end, completing the first step of the dehydration process; (3) A low-pressure steam coil is passed through the centrifuge cylinder jacket to heat the heat transfer oil, and the heat transfer oil heats the inner wall of the cylinder to make the heating more uniform; an anti-caking agent injection port is set above the discharge port, and the anti-caking agent is injected to prevent the material from caking; the fire steam nozzle set at the end of the centrifuge sprays fire steam to prevent the material from burning and causing a fire; the air in the atmosphere is purified by the fan inlet filter, and then heated by the blower through the outlet air heat exchange, and then passed into the centrifugal dehydration dryer, forming a counter-flow with the material, taking away the water and volatiles evaporated from the material; (4) The material at the discharge port passes through the discharge three-way valve to the material distributor, and is evenly distributed on the fourdryer chain plate through the material distributor; the discharge three-way valve is used to discharge the material when the material is blocked; the low-pressure steam tail gas of the centrifugal dehydration dryer jacket enters the heater in the fourdryer, and a number of fans are arranged at the bottom of the fourdryer to heat and dry the material distributed on the chain plate in the fourdryer. The exhaust fan outside the fourdryer discharges the gas rich in steam and volatiles to the tail gas treatment unit; the steam condensate of the fourdryer heater is discharged into the liquid collecting tank; (5) The dehydrated and dried materials are sent to the long net cooling zone. Under the action of the cooling circulation fan, the gas in the cooling zone enters the bag filter to remove the powdery materials, and then forms cold air through the heat exchanger. After the condensate is separated in the separator, it returns to the long net cooling zone to cool the materials. (6) The material after cooling completes the dehydration and drying process, and is discharged by the spiral discharger at the end of the long net and sent to the packaging unit system; The centrifugal dehydration dryer comprises: A drying cylinder is arranged transversely and is hollow inside to form a drying chamber, wherein a material inlet is provided at the first end of the drying cylinder and a material outlet is provided at the second end; A transmission shaft is rotatably arranged through the central axis of the drying cylinder; A driving member, which is arranged outside the drying cylinder and connected to the end of the transmission shaft, and is used to drive the transmission shaft to rotate; The scraper is used to stir, crush and pelletize the material in the drying cylinder. The scraper is in multiple groups and the first end is connected to the transmission shaft and the second end extends to the inner wall of the drying cylinder. The multiple groups of scrapers are arranged in an axially spaced manner along the transmission shaft, thereby enclosing a feeding channel for axially conveying the material with the inner wall of the drying cylinder. A heating coil is arranged around the outer circumference of the drying cylinder and is used to heat the drying cylinder; A dehydration screen, arranged at the inlet end of the drying cylinder, for dehydrating the material; The dewatering screen comprises an upper part and a lower part, wherein the upper part is provided with a primary sieve plate which is arranged inclined up and down, and the lower part is provided with a secondary sieve plate which is arranged transversely, and the area under the secondary sieve plate corresponding to the transmission shaft is communicated with the drying cylinder and constitutes the material inlet of the drying cylinder; the bottom of the upper part of the dewatering screen is provided with a feed port for feeding by overflow, and the top is provided with an exhaust port, the primary sieve plate is arranged downstream of the feed port, and the upper part of the dewatering screen is provided with a drain port at the bottom corresponding to the primary sieve plate, and the lower end of the primary sieve plate is provided with a flow-blocking baffle at the junction of the upper part and the lower part so that the material can be transported downward directly to the secondary sieve plate.

2. The post-treatment dehydration and drying method of the SBS device according to claim 1, characterized in that: In step (4), in order to prevent the powdered material from catching fire, fire-fighting steam is introduced into the fourdrinier at the same time.

3. The post-treatment dehydration and drying method of the SBS device according to claim 1, characterized in that: In step (5), in order to quickly cool down and reduce the heat exchange area, the heat exchanger used uses chilled water for heat exchange.

4. The post-treatment dehydration and drying method of the SBS device according to claim 1, characterized in that: The first end of the scraper is connected to the transmission shaft, and the second end is a rotating free end arranged close to the inner wall of the drying cylinder. The scraper is adjustably tilted from the first end to the second end along the feeding direction. Correspondingly, the feeding channel is a spiral channel tilted along the feeding direction.

5. The post-treatment dehydration and drying method of the SBS device according to any one of claims 1 to 4, characterized in that: A feeding screw conveyor is arranged at the material inlet of the drying cylinder, and a discharging screw conveyor is arranged at the material outlet of the drying cylinder.

6. The post-treatment dehydration and drying method of the SBS device according to any one of claims 1 to 4, characterized in that: The drying cylinder is provided with a steam inlet and a heat transfer oil inlet at the bottom near the second end, and the drying cylinder is provided with a steam and condensate outlet at the bottom near the first end and a gas outlet at the top.

7. The post-treatment dehydration and drying method of the SBS device according to any one of claims 1 to 4, characterized in that: The drying cylinder is provided with a fire-fighting steam nozzle on the inner wall surface of the second end thereof, and the drying cylinder is provided with an anti-caking agent nozzle on the inner top wall near the second end.

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