Powder drying device and method for pea starch production

Abstract

The invention discloses a powder drying device and method for pea starch production, and relates to the technical field of powder drying. The device comprises a hot-blast stove and a cyclone separator, an air outlet pipe is arranged at an outlet of the hot-blast stove, a connecting pipe is arranged at the air inlet end of the cyclone separator, a drying pipe is rotationally installed between the air outlet pipe and the connecting pipe, a spiral filter disc is arranged on the outer side of the drying pipe, and multiple sets of sliding openings are formed in the outer side of the drying pipe. And the outer side of the drying pipe is sleeved with a pre-drying cylinder. Through filtration of the spiral filter disc, water is left at the lower part, starch is conveyed upwards, the starch is conveyed into the starch cavity from the upper part to be secondarily dried, the water content of the starch can be controlled to be 35%-40%, and then the starch is sprayed into the air outlet pipe by high-pressure gas and enters the drying pipe along with hot air to be dried; dehydration equipment, spiral conveying equipment and scattering equipment do not need to be additionally used, the equipment integration degree is high, and the structure is compact.

Description

Technical Field

[0001] The invention relates to the technical field of powder drying, and in particular to a powder drying device and method for producing pea starch. Background Art

[0002] In the production process of pea starch, dehydration and drying is one of the key links. Traditional pea starch drying methods mainly include natural sun drying, spray drying, drum drying, etc. Among them, airflow drying is widely used due to its high efficiency. Airflow drying mainly uses hot air flow to quickly dry pea starch slurry.

[0003] In a Chinese patent (publication number: CN219103619U), an airflow powder drying and collecting device is disclosed, including a spiral feeder, a hot air furnace, a feed pipe, a collecting pipe, a cyclone separator, a distribution pipe, an electric valve, a drying pipe and a controller. The feed pipe is a three-way pipe and the two feed ports are respectively connected to the discharge port of the spiral feeder and the air outlet of the hot air furnace, and the discharge port is connected to the feed port of the collecting pipe. The discharge port of the collecting pipe is connected to the feed port of the spiral feeder through a wavy drying pipe. The distribution pipe is a three-way pipe and the feed port is connected to the discharge port of the spiral feeder, and electric valves are respectively installed at the two air outlets. One of the discharge ports of the distribution pipe is connected to the return port of the collecting pipe through an extension pipe. The spiral feeder, hot air furnace, cyclone separator and electric valve are respectively electrically connected to the controller. The following technical problems exist in the actual use of this patent and the prior art: 1. This patent and the existing powder airflow drying equipment both need to dehydrate the starch slurry when drying starch. A vacuum dehydrator is mainly used to control the moisture content of the starch at 35%-40% before the powder airflow drying equipment can be used for drying. The dehydrated starch needs to be transported to the drying equipment by a spiral conveyor and a breaking device. The process is complicated and the equipment integration is low.

[0004] 2. After the cyclone separator separates the starch from the hot air, the hot air is directly discharged, which not only wastes energy, but also brings out some starch with the hot air. Additional dust treatment equipment is required to recover the dust from the discharged hot air, which has low energy utilization and wastes starch. Summary of the invention

[0005] The object of the present invention is to: in order to solve the above problems, the present invention provides a pea starch production powder drying device and method.

[0006] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: A powder drying device for pea starch production, comprising a hot blast furnace and a cyclone separator, wherein an outlet of the hot blast furnace is provided with an air outlet pipe, an air inlet end of the cyclone separator is provided with a connecting pipe, a drying pipe is rotatably installed between the air outlet pipe and the connecting pipe, a spiral filter is provided on the outside of the drying pipe, a plurality of sliding ports are provided on the outside of the drying pipe, a sealing sliding plate is slidably connected inside the sliding port, and a scattering wheel is rotatably installed on the outside of the sealing sliding plate; A pre-drying cylinder is sleeved on the outer side of the drying tube, and a dewatering chamber and a starch chamber are provided inside the pre-drying cylinder from the inside to the outside. The dewatering chamber is connected to the top of the starch chamber, a drain pipe is provided at the bottom of the dewatering chamber, the starch chamber is connected to the air outlet pipe through the starch pipe, a slurry inlet pipe is provided on the outer side of the dewatering chamber, and a compressor is installed at the air outlet end of the cyclone separator, and the compressor is connected to the pre-drying cylinder through a high-pressure air pipe.

[0007] Furthermore, the bottom end of the pre-drying cylinder is designed to be inclined.

[0008] Furthermore, the inner wall of the starch cavity is provided with a dispersion ring, and the dispersion ring is designed to be obliquely downward.

[0009] Furthermore, an upper baffle is provided at the top of the spiral filter, and the upper baffle extends into the starch cavity.

[0010] Furthermore, a reset elastic rope is arranged between the sealing slide and the inner wall of the sliding port, a driving sprocket and a driven sprocket are rotatably installed inside the drying tube, an impeller is fixedly installed on the outer side of the driving sprocket, the driving sprocket and the driven sprocket are connected by a transmission chain, a shifting rod is fixedly installed on the outer side of the transmission chain, a shifting shaft is fixedly installed on the side of the breaking wheel close to the inside of the drying tube, and the axes of the driving sprocket and the driven sprocket are on the same horizontal plane.

[0011] Furthermore, a gear rod is provided on the inner wall of the drying tube, and a transmission gear is fixedly installed on the outer side of the shifting shaft, and the transmission gear is meshed with the gear rod.

[0012] Furthermore, a partition is provided inside the drying tube, a sealed cavity is formed between the partition and the inner wall of the drying tube, the driving sprocket, the driven sprocket and the shifting shaft are all located in the sealed cavity, and the impeller is located outside the partition.

[0013] Furthermore, a guide vane is arranged on the outer side of the partition, and the guide vane is arranged corresponding to the impeller.

[0014] Furthermore, a driving motor is fixedly installed on the outside of the air outlet pipe, a driving wheel is fixedly installed on the output end of the driving motor, a transmission gear ring is fixedly installed on the outside of the bottom end of the drying pipe, the transmission gear ring is meshed with the driving wheel, the radius of the driving wheel is smaller than the maximum radius of the transmission gear ring, a pressure sensor is arranged on the top of the pre-drying cylinder, solenoid valves are installed on the starch tube and the drain pipe, and the pressure sensor is electrically connected to the solenoid valve through a controller.

[0015] A method for drying powder for producing pea starch, comprising the following steps: S1. Dehydration: Starch slurry is injected into the dehydration chamber through the slurry inlet pipe, and the hot air is sent into the drying tube by the hot air furnace. Then, it enters the pre-drying cylinder through the cyclone separator and the compressor at high pressure. At the same time, the drying tube transports the slurry upward along the dehydration chamber through the spiral filter. Under the conditions of temperature of 100℃-120℃ and pressure of 100-110kPa, the starch slurry is pre-dried to make the starch moisture content at 35%-40%; S2. Drying: The high pressure air inside the pre-drying cylinder sprays the pre-treated starch into the air outlet pipe. The starch is sent into the drying pipe along with the hot air cup to be dried, and then collected by the cyclone separator.

[0016] The beneficial effects of the present invention are as follows: The present invention transports starch upward under a high temperature and high pressure environment by setting a pre-drying cylinder and a spiral filter disc. Water is retained at the bottom through filtering by the spiral filter disc, and the starch is transported upward. The starch is transported from the top to the starch cavity for secondary drying, so that the water content of the starch can be controlled at 35%-40%. Then, the starch is sprayed into the air outlet pipe by high-pressure gas, and is dried in the drying pipe along with the hot air. There is no need to use additional dehydration equipment, spiral conveying equipment and disintegrating equipment. The equipment has a high degree of integration and a compact structure.

[0017] The present invention arranges a pre-drying cylinder outside a drying tube to absorb excess heat from the drying tube. Then, a compressor compresses the hot air separated by a cyclone separator into the pre-drying cylinder, so that the heat in the hot air dries and dehydrates the starch. The starch powder in the hot air is filtered into the starch, thereby making full use of the waste heat of the equipment and preventing starch waste.

[0018] The invention can break up the starch agglomerated on the spiral filter disc by arranging multiple groups of breaking wheels, thereby improving the starch dehydration efficiency and ensuring that the starch can be stably transported upward, thereby achieving a good dehydration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the pre-drying cylinder of the present invention; Figure 3It is a schematic diagram of the drying tube structure of the present invention; Figure 4 It is a schematic diagram of the cross-sectional structure of the drying tube of the present invention; Figure 5 This is a schematic diagram of the driving structure of the sealing slide and the breaking wheel of the present invention; Figure 6 It is a schematic diagram of the sliding structure of the drying tube of the present invention.

[0020] Figure numerals: 1, hot air furnace; 2, air outlet pipe; 21, driving motor; 22, driving wheel; 3, drying tube; 31, spiral filter; 32, upper baffle; 33, transmission gear ring; 34, slide; 35, sealing slide; 36, reset elastic rope; 37, scattering wheel; 38, pull shaft; 39, transmission gear; 310, gear rod; 311, impeller; 312, driving sprocket; 313, driven sprocket; 314, transmission chain; 315, pull rod; 316, partition; 317, guide vane; 4, connecting pipe; 5, cyclone separator; 6, compressor; 7, high-pressure air pipe; 8, pre-drying cylinder; 81, dewatering chamber; 82, starch chamber; 83, dispersion ring; 84, slurry inlet pipe; 9, starch pipe; 10, drainage pipe; 11, solenoid valve. DETAILED DESCRIPTION

[0021] To make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0022] Embodiment 1, as Figure 1-Figure 6 As shown, a powder drying device for pea starch production comprises a hot air furnace 1 and a cyclone separator 5, wherein an outlet of the hot air furnace 1 is provided with an air outlet pipe 2, an air inlet end of the cyclone separator 5 is provided with a connecting pipe 4, a drying pipe 3 is rotatably installed between the air outlet pipe 2 and the connecting pipe 4, a spiral filter disc 31 is arranged on the outer side of the drying pipe 3, a plurality of groups of sliding ports 34 are provided on the outer side of the drying pipe 3, a sealing sliding disc 35 is slidably connected inside the sliding ports 34, a dispersing wheel 37 is rotatably installed on the outer side of the sealing sliding disc 35, the sliding ports 34 and the sealing sliding disc 35 are both spirally designed, and the spiral pitch is the same as that of the spiral filter disc 31, so that the dispersing wheel 37 can roll up and down along the upper surface of the spiral filter disc 31 to disperse the starch; A pre-drying cylinder 8 is sleeved on the outer side of the drying tube 3. A dewatering chamber 81 and a starch chamber 82 are provided inside the pre-drying cylinder 8 from the inside to the outside. The tops of the dewatering chamber 81 and the starch chamber 82 are connected. A drainage pipe 10 is provided at the bottom of the dewatering chamber 81. The starch chamber 82 is connected to the air outlet pipe 2 through a starch pipe 9. A slurry inlet pipe 84 is provided on the outer side of the dewatering chamber 81. A compressor 6 is installed at the air outlet end of the cyclone separator 5. The compressor 6 is connected to the pre-drying cylinder 8 through a high-pressure air pipe 7.

[0023] Furthermore, a driving motor 21 is fixedly installed on the outer side of the air outlet pipe 2, and a driving wheel 22 is fixedly installed on the output end of the driving motor 21. A transmission gear ring 33 is fixedly installed on the outer side of the bottom end of the drying pipe 3, and the transmission gear ring 33 is meshed with the driving wheel 22. The radius of the driving wheel 22 is smaller than the maximum radius of the transmission gear ring 33. Through this design, the rotation speed of the drying pipe 3 can be reduced. A pressure sensor is provided on the top of the pre-drying cylinder 8, and solenoid valves 11 are installed on the starch tube 9 and the drain pipe 10. The pressure sensor is electrically connected to the solenoid valve 11 through a controller.

[0024] When the equipment is started, the hot air furnace 1 sends the hot air into the drying tube 3 through the air outlet pipe 2, and then enters the cyclone separator 5 through the connecting pipe 4, and then enters the pre-drying cylinder 8 through the compressor 6 and the high-pressure air pipe 7. At the same time, the pea starch slurry enters the dewatering chamber 81 through the slurry inlet pipe 84. At this time, the driving motor 21 is energized, the driving motor 21 drives the driving wheel 22 to rotate, the driving wheel 22 drives the transmission gear ring 33 to rotate, the transmission gear ring 33 drives the drying tube 3 to rotate, and the drying tube 3 drives the spiral filter 31 to rotate. At this time, the starch is heated to high temperature and high pressure. The starch is filtered under the adjustment, and the starch remains on the upper surface of the spiral filter 31, and the separated water remains at the bottom of the water removal chamber 81. Since the starch has a large viscosity, it will clump on the spiral filter 31. Therefore, during the filtration process, the sealing slide 35 is controlled to slide up and down, and the sealing slide 35 drives the breaking wheel 37 to roll up and down along the spiral filter 31 to break up the starch agglomerated on its surface. The dehydration efficiency of the starch after breaking up is higher, and the starch can be ensured to be transported upward. When the air pressure in the pre-drying cylinder 8 reaches the preset value, the pressure sensor is fed back to control The device controls the electromagnetic valve 11 to open, and the electromagnetic valve 11 opens the drain pipe 10, and the water filtered at the bottom is taken out by the high-pressure gas, and the drainage efficiency is high. After draining for a period of time, the electromagnetic valve 11 is closed. During the drainage process, the airflow in the water removal chamber 81 will flow quickly, which can further improve the starch separation efficiency. The dehydrated starch is lifted to the top of the water removal chamber 81 through the spiral filter plate 31, and then freely falls into the starch chamber 82. When the electromagnetic valve 11 is opened, the starch tube 9 is opened, and the dehydrated starch in the starch chamber 82 is brought into the air outlet pipe 2 by the high-pressure gas. Under the action of the high-pressure airflow, the large clumps of starch are directly broken up, and the small clumps of starch will also be broken up when impacting the inner wall of the air outlet pipe 2. Therefore, the starch will be evenly brought into the drying pipe 3 by the hot air, and the dehydrated starch will be dried. The dried starch enters the cyclone separator 5 and is separated. The separated hot air continues to be compressed by the compressor 6, and then enters the pre-drying cylinder 8, so that the hot air continues to circulate in the equipment, and the residual starch in the hot air will be merged into the dehydrated starch again, and no starch waste will be caused.

[0025] The dehydration structure of the present invention is arranged outside the drying tube 3, which can fully utilize the waste heat of the drying tube 3 and the waste heat of the tail gas, has high energy utilization rate, and the equipment is integrated to simplify the pea starch powder drying process.

[0026] Embodiment 2, based on the above embodiment, further includes a tilted design of the bottom end of the pre-drying cylinder 8, through which the starch can be concentrated at the starch tube 9, and the filtered water can be concentrated at the drain pipe 10, so that the starch and water can be discharged more effectively.

[0027] Embodiment three, on the basis of the above embodiment, further includes: the inner wall of the starch chamber 82 is provided with a dispersion ring 83, and the dispersion ring 83 is designed to be inclined downward. Through the setting of the dispersion ring 83, the starch discharged from the dewatering chamber 81 can be repeatedly dropped on the dispersion ring 83, and further broken up and dried to reduce the water content, and when the solenoid valve 11 is opened, the airflow will accelerate the falling of the starch to ensure that the starch will not remain on the dispersion ring 83, and the drying effect is better.

[0028] Embodiment 4, based on the above embodiment, further includes that an upper baffle 32 is provided at the top of the spiral filter 31, and the upper baffle 32 extends into the starch cavity 82. Through the setting of the upper baffle 32, the starch can be better guided into the starch cavity 82.

[0029] Embodiment 5, on the basis of the above embodiments, further includes: a reset elastic rope 36 is arranged between the sealing slide 35 and the inner wall of the sliding port 34, a driving sprocket 312 and a driven sprocket 313 are rotatably installed inside the drying tube 3, an impeller 311 is fixedly installed on the outer side of the driving sprocket 312, the driving sprocket 312 and the driven sprocket 313 are connected by a transmission chain 314, a shifting rod 315 is fixedly installed on the outer side of the transmission chain 314, a shifting shaft 38 is fixedly installed on the side of the breaking wheel 37 close to the inside of the drying tube 3, and the axes of the driving sprocket 312 and the driven sprocket 313 are on the same horizontal plane.

[0030] Furthermore, a gear rod 310 is provided on the inner wall of the drying tube 3 , and a transmission gear 39 is fixedly mounted on the outer side of the shifting shaft 38 , and the transmission gear 39 is meshed with the gear rod 310 .

[0031] The airflow in the drying tube 3 rises, and the airflow drives the impeller 311 to rotate, and the impeller 311 drives the driving sprocket 312 to rotate, and the driving sprocket 312 drives the lever 315 to rotate, and the lever 315 drives the sealing slide 35 to slide upward along the sliding port 34 through the lever shaft 38. It should be noted that both ends of the sliding port 34 are provided with a storage cavity, so the length of the sealing slide 35 is set to be much larger than the length of the sliding port 34. When the sealing slide 35 slides, the sliding port 34 will not open, ensuring stable drying. Since the sliding port 34 is spirally upward, the axes of the driving sprocket 312 and the driven sprocket 313 are on the same On the horizontal plane, as the sealing slide 35 slides upward, the dial shaft 38 will rise relative to the dial rod 315. When the sealing slide 35 slides to the highest point, the dial rod 315 disengages from the dial shaft 38, and the sealing slide 35 slides downward and resets under the action of the reset elastic rope 36. Therefore, as the impeller 311 continues to rotate, the sealing slide 35 drives the breaking wheel 37 to move up and down along the upper surface of the spiral filter 31. At the same time, the breaking wheel 37 rotates under the action of the transmission gear 39 and the gear rod 310. It should be noted that the rotation speed of the breaking wheel 37 is relatively high, which can better break up the starch and has a high dehydration efficiency.

[0032] According to the arrangement of this embodiment, there is no need to set up an additional drive, and the sealing slide 35 and the breaking wheel 37 are driven by the dry airflow, and the structure is compact.

[0033] Embodiment 6, based on the above embodiment, further includes: a partition 316 is provided inside the drying tube 3, a sealed cavity is formed between the partition 316 and the inner wall of the drying tube 3, the driving sprocket 312, the driven sprocket 313 and the shift shaft 38 are all located in the sealed cavity, and the impeller 311 is located on the outside of the partition 316.

[0034] Furthermore, a guide vane 317 is disposed on the outer side of the partition 316 , and the guide vane 317 is disposed corresponding to the impeller 311 .

[0035] The partition 316 can be set to prevent dry starch from being contaminated on the structures such as the driving sprocket 312, the driven sprocket 313 and the shift shaft 38, so as not to cause starch waste. The guide plate 317 can be set to block the airflow on one side of the impeller 311, thereby achieving the effect of the rotation direction of the impeller 311.

[0036] Embodiment 7, a method for drying powder for producing pea starch, comprising the following steps: S1, dehydration: the starch slurry is injected into the dehydration chamber 81 through the slurry inlet pipe 84, the hot air furnace 1 sends the hot air into the drying pipe 3, and then enters the pre-drying cylinder 8 at high pressure through the cyclone separator 5 and the compressor 6. At the same time, the drying pipe 3 transports the slurry upward along the dehydration chamber 81 through the spiral filter 31. Under the conditions of temperature of 100℃-120℃ and pressure of 100-110kPa, the starch slurry is pre-dried to make the starch water content 35%-40%; S2, drying: the high pressure air inside the pre-drying cylinder 8 sprays the pre-treated starch into the air outlet pipe 2, and the starch is sent to the drying pipe 3 along with the hot air cup for drying, and then collected by the cyclone separator 5.

[0037] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A powder drying device for producing pea starch, comprising a hot air furnace (1) and a cyclone separator (5), characterized in that: The outlet of the hot air furnace (1) is provided with an air outlet pipe (2), the air inlet end of the cyclone separator (5) is provided with a connecting pipe (4), a drying pipe (3) is rotatably mounted between the air outlet pipe (2) and the connecting pipe (4), a spiral filter (31) is arranged on the outside of the drying pipe (3), a plurality of groups of sliding openings (34) are provided on the outside of the drying pipe (3), a sealing sliding plate (35) is slidably connected inside the sliding opening (34), and a scattering wheel (37) is rotatably mounted on the outside of the sealing sliding plate (35); The outer side of the drying tube (3) is sleeved with a pre-drying tube (8), and the interior of the pre-drying tube (8) is provided with a water removal chamber (81) and a starch chamber (82) from the inside to the outside. The tops of the water removal chamber (81) and the starch chamber (82) are connected. A drainage pipe (10) is provided at the bottom of the water removal chamber (81). The starch chamber (82) is connected to the air outlet pipe (2) through a starch pipe (9). A pulp inlet pipe (84) is provided on the outer side of the water removal chamber (81). A compressor (6) is installed at the air outlet end of the cyclone separator (5), and the compressor (6) is connected to the pre-drying tube (8) through a high-pressure air pipe (7).

2. A powder drying device for pea starch production according to claim 1, characterized in that: The bottom end of the pre-drying cylinder (8) is designed to be inclined.

3. A powder drying device for pea starch production according to claim 2, characterized in that: The inner wall of the starch cavity (82) is provided with a dispersion ring (83), and the dispersion ring (83) is designed to be inclined downward.

4. A powder drying device for pea starch production according to claim 1, characterized in that: An upper baffle (32) is provided at the top end of the spiral filter plate (31), and the upper baffle (32) extends into the starch cavity (82).

5. A powder drying device for pea starch production according to claim 1, characterized in that: A reset elastic rope (36) is provided between the sealing slide (35) and the inner wall of the sliding opening (34); a driving sprocket (312) and a driven sprocket (313) are rotatably mounted inside the drying tube (3); an impeller (311) is fixedly mounted on the outer side of the driving sprocket (312); the driving sprocket (312) and the driven sprocket (313) are transmission-connected via a transmission chain (314); a shifting rod (315) is fixedly mounted on the outer side of the transmission chain (314); a shifting shaft (38) is fixedly mounted on one side of the scattering wheel (37) close to the interior of the drying tube (3); and the axes of the driving sprocket (312) and the driven sprocket (313) are on the same horizontal plane.

6. A powder drying device for pea starch production according to claim 5, characterized in that: The inner wall of the drying tube (3) is provided with a gear rod (310), and the outer side of the shifting shaft (38) is fixedly mounted with a transmission gear (39), which meshes with the gear rod (310).

7. A powder drying device for pea starch production according to claim 6, characterized in that: A partition (316) is provided inside the drying tube (3); a sealed cavity is formed between the partition (316) and the inner wall of the drying tube (3); the driving sprocket (312), the driven sprocket (313) and the shifting shaft (38) are all located in the sealed cavity; and the impeller (311) is located outside the partition (316).

8. A powder drying device for pea starch production according to claim 7, characterized in that: A guide vane (317) is provided on the outer side of the partition plate (316), and the guide vane (317) is provided corresponding to the impeller (311).

9. A powder drying device for pea starch production according to claim 1, characterized in that: A driving motor (21) is fixedly mounted on the outside of the air outlet pipe (2), a driving wheel (22) is fixedly mounted on the output end of the driving motor (21), a transmission gear ring (33) is fixedly mounted on the outside of the bottom end of the drying pipe (3), the transmission gear ring (33) is meshed with the driving wheel (22), the radius of the driving wheel (22) is smaller than the maximum radius of the transmission gear ring (33), a pressure sensor is arranged on the top of the pre-drying cylinder (8), and electromagnetic valves (11) are installed on both the starch pipe (9) and the drainage pipe (10), and the pressure sensor is electrically connected to the electromagnetic valve (11) through a controller.

10. A method for drying powder for producing pea starch, using a powder drying device for producing pea starch as claimed in any one of claims 1 to 9, characterized in that: The following steps are involved: S1, dehydration: the starch slurry is injected into the dehydration chamber (81) through the slurry inlet pipe (84), the hot air furnace (1) sends hot air into the drying pipe (3), and then passes through the cyclone separator (5) and the compressor (6) to enter the pre-drying cylinder (8) at high pressure. At the same time, the drying pipe (3) transports the slurry upward along the dehydration chamber (81) through the spiral filter (31). Under the conditions of temperature of 100° C.-120° C. and pressure of 100-110 kPa, the starch slurry is pre-dried to make the starch water content be 35%-40%; S2. Drying: The high pressure air inside the pre-drying cylinder (8) sprays the pre-treated starch into the air outlet pipe (2). The starch is sent to the drying pipe (3) through the hot air cup for drying and then collected by the cyclone separator (5).

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