Circulating mill, application method thereof and product machined by circulating mill

Abstract

According to the circulating mill disclosed by the invention, the purging air holes are formed in the shell of the centrifugal fan, and fly ash in the bag type dust collector is premixed with high-humidity and high-viscosity materials, so that the problem that the circulating mill is hung on a wall when being used for processing the high-humidity and high-viscosity materials is solved; during discharging, an internal circulation channel can be blocked, so that materials can be quickly discharged out of a main machine, and when the device is used for processing konjac powder, the probability that glucomannan is crushed to be too fine to become fly ash can be greatly reduced, and the yield of the konjac powder is improved; according to the processing method of the konjac powder, the fresh konjac is directly and rapidly prepared into the konjac powder, the konjac processing efficiency is improved, and the invention further provides a method for improving the yield of the konjac powder, the Yunjie konjac powder, the processing method of the Yunjie powder and the Yunjie powder.

Description

Technical Field

[0001] This invention relates to a circulating mill, its application method, and products processed by the circulating mill. It belongs to the fields of circulating fluidized bed technology, drying and grinding technology, energy-saving and environmental protection technology, and agricultural product processing technology, and particularly to the field of konjac flour processing technology. Background Technology

[0002] A circulating fluidized bed mill, also known as a circulating mill or circulating fluidized bed mill, is a technology that uses a centrifugal fan and its high-speed airflow to fluidize materials and achieve drying and / or grinding through high-speed circulation within a circulating channel. In a circulating mill, large particles are mainly crushed by impeller impact, while ultrafine powders are crushed primarily through friction between the material and the surfaces of the blades and volute during high-speed flow. This crushing action continuously disperses the material into a fluidized state, resulting in a high-speed circulating flow. The mass-energy exchange area increases geometrically, the gas-solid boundary layer thins, and the exchange rate of water (mass) and heat (energy) between the material and the airflow is maximized, leading to a very fast drying speed. This circulating mill project focuses on the drying and grinding of fresh agricultural products, exploring the factors affecting drying and grinding efficiency. Due to the presence of wall adhesion issues, these influencing factors are more easily exposed and can be addressed specifically, with the aim of developing a highly efficient drying and grinding solution. The three core technical challenges in drying and grinding fresh agricultural products are reliability, economy, and grading. Fresh agricultural products, after being crushed by the impeller, become a slurry that adheres to the machine and stops circulating, a process known as "wall adhesion." Once this wall adhesion stabilizes, the circulation channel will eventually become blocked, causing equipment failure and preventing the drying and grinding process from being achieved. Wall adhesion is essentially a reliability issue. Prior to this application, the circulating mill employed a combination of two technologies to address reliability: first, the impact of high-speed fluidized material on the wall adhesion prevents its stable formation; second, the return of dry powder (return material) from the auxiliary device is mixed with the existing material to reduce moisture content and improve wall adhesion performance. The former is fundamental, while the latter is a strengthening measure. With the latter's support, even if liquid is added, increasing the return material volume can definitely solve the wall adhesion problem. Economy primarily concerns energy consumption, and grading involves separating and discharging qualified material from the circulation channel.

[0003] The inventions disclosed in CN107694135B and WO2020057617 are circulating mills. CN107694135B relies on the combined effect of centrifugal force and the drag force exerted on the particles by the classifying airflow to achieve classification. When the drag force is greater than the centrifugal force, the particles are carried out by the classifying airflow through the space between the classifying blades. When the drag force is less than the centrifugal force, the particles enter the circulation pipe and reach the mill inlet for circulating drying and grinding. Under the condition of fixed rotational speed and impeller diameter, the centrifugal force depends on the particle diameter and moisture content, while the drag force depends on the velocity of the classifying airflow. The velocity of the classifying airflow depends on the pressure difference between the inlet and outlet of the Yunjie mill main unit. The magnitude and direction of this pressure difference depend on the difference between the outlet diameter on the middle cover and the inlet diameter on the front cover. The larger the difference, the greater the pressure difference. When the difference is positive, the airflow flows from the main unit inlet to the outlet; when the difference is negative, the airflow flows from the main unit outlet to the inlet. The problems with CN107694135B are as follows: First, the staged airflow weakens the impact of fluidized material on the inner surface of the volute corresponding to the staged blades, making this area almost a dead zone, where wall deposits can easily and stably form. This defect is due to the solution to the staged problem. Second, the circulation pipe of a single circulating mill host is a bent pipe, which is more prone to wall deposit formation. Two Yunjie mill hosts and a centrifugal fan are needed in series to make the circulation pipe a straight pipe, which increases the equipment cost.

[0004] Invention patent WO2020057617 improved upon this, disclosing six types of circulating mill main units. The common feature of these six circulating mill main units is that they rely on the pressure difference between the inlet and outlet of the centrifugal fan and the cyclone classification effect within the feed pipe to achieve classification. In the first, second, third, and sixth types of the Yunjie mill main units, the circulation pipe becomes a straight pipe, improving the wall adhesion within the circulation pipe and eliminating the near-dead zone area found in CN107694135B. However, the classification problem solution in WO2020057617 increases the internal pressure, hindering the rotation of the impeller. This increases the mill's energy consumption because the air velocity in the feed pipe at the outlet of the circulating mill generally exceeds 50 m / s, resulting in significant resistance in the cyclone classification. The auxiliary mill further pressurizes the mill on top of the high pressure at the main mill outlet. A similar problem exists in CN107694135B, where centrifugal force hinders the classifying airflow, increasing the pressure within the mill. Furthermore, the kinetic energy recovery technology proposed in WO2020057617 consumes energy itself, resulting in a very small net energy recovery margin, rendering it practically meaningless. The biggest problem is that while the solutions to the wall adhesion issue in WO2020057617 and CN107694135B are theoretically sound, they still present two practical issues: first, when there is insufficient powder for return material at the beginning of operation, materials with a moisture content exceeding 60% often cannot operate normally due to wall adhesion; second, a large amount of return material worsens the mill's economic efficiency. To address these issues, invention patent 2023110971097 and prior application 2024105785134 have proposed further solutions. Among them, the solution proposed in prior application 2024105785134 has certain advantages due to its simple structure and high efficiency.

[0005] Konjac flour, due to its virtually calorie-free composition, high water absorption and swelling rate, and high viscosity, has important applications in the health food and chemical industries. Konjac flour is derived from konjac. Currently, most konjac flour is produced as follows: fresh konjac slices - dried fresh konjac slices - pulverized dried konjac slices - sieving to obtain konjac flour and fly ash. The main component of konjac flour is glucomannan, the most valuable component of konjac. Fly ash is mainly composed of starch and other components besides glucomannan. Due to the low moisture content of dried konjac slices, some glucomannan particles are pulverized to a very fine size during the pulverizing process and cannot be separated from the fly ash, reducing the yield of konjac flour and seriously affecting the economic benefits of konjac flour processing. Public data shows that the average yield of dried konjac slices is 14.28%, and the average glucomannan content in dried konjac is greater than 57.5%. Based on this, the theoretical minimum average yield of pure glucomannan is 14.28%. 57.5The yield is 8.21%. According to the national standard GB / T 18104-2000 for konjac flour, the glucomannan content of premium konjac flour is 70%. The theoretical minimum yield of premium konjac flour is 14.28% * 57.5% / 70% = 11.73%. In reality, the average yield of most konjac flour producers is less than 8.5%, which is much lower than the theoretical minimum yield. Developing new konjac flour processing equipment to improve the yield of konjac flour has significant economic implications. Summary of the Invention

[0006] The purpose of this invention is to address the problems described in the background art by inventing a circulating mill based on invention patent 2024105785134, and providing a method for using the circulating mill and products processed by the circulating mill.

[0007] The technical measures taken to achieve the purpose of this invention are as follows: a circulating mill includes a circulating mill main unit, a positive pressure circulating pipe, a cyclone dust collector, a bag filter, a negative pressure circulating pipe, and a screw feeder. The circulating mill main unit consists of a centrifugal fan and an internal circulating pipe. A coarse material outlet is provided on the volute of the centrifugal fan, and an internal circulating pipe interface is provided in the area corresponding to the impeller inlet on the front cover of the centrifugal fan. The coarse material outlet, the inlet of the internal circulating pipe, the outlet of the internal circulating pipe, and the internal circulating pipe interface are sequentially connected to form the internal circulating channel of the circulating mill main unit. The outlet of the centrifugal fan is the outlet of the circulating mill main unit, and the inlet of the centrifugal fan is the inlet of the circulating mill main unit; the negative pressure circulating... The outlet of the ring pipe, the inlet of the circulating mill main unit, the outlet of the circulating mill main unit, the inlet of the positive pressure circulating pipe, the outlet of the positive pressure circulating pipe, and the air inlet of the cyclone dust collector are connected in sequence. The ash discharge port of the cyclone dust collector is the first discharge port of the circulating mill. There is a feeding device interface on the negative pressure circulating pipe. There is also a return interface between the discharge port and the feed port on the screw feeder conveying pipe. There is a star-shaped discharge valve on the ash discharge port of the bag filter. The air outlet of the cyclone dust collector, the air inlet of the bag filter, the outlet of the star-shaped discharge valve, the return interface of the screw feeder, the discharge port of the screw feeder, and the feeding device interface on the negative pressure circulating pipe are connected in sequence to form a return circulation channel.

[0008] In order to quickly discharge the material in the internal circulation channel, the internal circulation pipe is provided with a first type of internal circulation channel cut-off device. The first type of internal circulation channel cut-off device is a discharge air hole connected to compressed air through valve A. The discharge air hole is configured such that the direction of the airflow it sprays is opposite to the direction of the airflow in the internal circulation channel and can block the flow of fluidized material in the internal circulation channel; or, the internal circulation pipe is provided with a second type of internal circulation channel cut-off device, which is valve B installed on the internal circulation pipe.

[0009] To address the issue of material adhering to the walls, the centrifugal fan casing is equipped with purge air holes. The position and direction of these purge air holes are configured such that the high-speed airflow emitted can blow off the material adhering to the walls of the circulating mill. The opening and closing of the purge air holes are controlled by a pulse controller via pulse valves.

[0010] In order to discharge the fly ash in the bag filter while prioritizing the return material, the bag filter also includes a fly ash discharge screw. The conveying pipe of the fly ash discharge screw passes through the small end of the ash hopper of the bag filter. The conveying pipe of the fly ash discharge screw located in the ash hopper of the bag filter is completely cut off, and the cut-off part becomes the feed inlet of the fly ash discharge screw. The outlet of the fly ash discharge screw is the fly ash discharge outlet.

[0011] Under most operating conditions, the material entering the external circulation channel is not fully dried. To ensure that the discharged material is fully dried, the negative pressure circulation pipe is also equipped with a cyclone dust collector ash discharge port. The circulating mill also includes a discharge tee, one port of which is connected to the ash discharge port of the cyclone dust collector, and another port of which has a discharge valve A. The outlet of discharge valve A is connected to the ash discharge port of the cyclone dust collector. The third port of the discharge tee has a discharge valve B, and the outlet of discharge valve B is the second discharge port of the circulating mill. The outlet of the circulating mill main unit, the inlet of the positive pressure circulation pipe, the outlet of the positive pressure circulation pipe, the air inlet of the cyclone dust collector, the ash discharge port of the cyclone dust collector, one port of the discharge tee, the outlet of discharge valve A, the ash discharge port of the cyclone dust collector, the outlet of the negative pressure circulation pipe, and the inlet of the circulating mill main unit are connected in sequence to form the external circulation channel of the circulating mill.

[0012] By replacing the discharge tee and discharge valve A with a straight pipe, the circulating mill can be used for drying and pulverizing most fresh agricultural products, as well as grinding most dry materials; disconnect the connection between the outlet of the star discharge valve and the return port, remove the fly ash discharge screw, and use the outlet of the star discharge valve as the discharge port; when processing dry materials, since there is no wall adhesion problem, the purging air hole is no longer a necessary component and can be omitted.

[0013] To ensure stable and efficient material discharge, the circulating mill also includes a discharge dust collector. The discharge dust collector has a discharge valve C at its exhaust port, and the outlet of the discharge valve C is connected to the negative pressure circulation pipe. The discharge dust collector also has a discharge valve D at its ash discharge port, and the outlet of the discharge valve D is the third discharge port of the circulating mill. The air inlet of the discharge dust collector is connected to the outlet of the discharge valve B.

[0014] To enhance the grading effect of the internal circulation channels, the circulating mill host can have multiple internal circulation channels.

[0015] To achieve closed-loop operation, the circulating mill also includes a heat exchanger, a condenser, and a heater. The exhaust port of the bag filter, the inlet and outlet of the heat exchanger's heat medium channel, the inlet and outlet of the condenser's heat medium channel, the inlet and outlet of the heat exchanger's refrigerant channel, the inlet and outlet of the heater's refrigerant channel, and the inlet of the negative pressure circulation pipe are connected in sequence to form the closed-loop circulation channel of the circulating mill. The circulating mill with a closed-loop circulation channel makes it economically possible to use inert gases such as nitrogen as the working medium to solve the oxidation and discoloration problem in konjac flour processing, and also solves problems such as material aroma loss and contamination of the product by impurities in the air.

[0016] In order to apply vacuum technology to the circulating mill, the absolute pressure at the inlet of the circulating mill main unit is set to 1000-30000Pa.

[0017] This invention also provides a method for processing konjac flour, which uses the aforementioned circulating mill as the main equipment to directly process fresh konjac into konjac flour, characterized by the following steps: S1. Drying and grinding fresh konjac into powder: S101. Equipment Start-up: Ensure that discharge valves B, C and A are closed and discharge valve A is open. Start the equipment after starting the pulse controller and start the screw feeder. S102. Adding fly ash to the bag filter: Fly ash is added through a screw feeder. The added fly ash enters the bag filter through the exhaust port of the cyclone dust collector and is collected in the ash hopper of the bag filter. This step can be omitted if there is sufficient fly ash in the ash hopper of the bag filter. S103. Feeding: Start the star-shaped discharge valve and add the prepared fresh konjac blocks through the feeding port of the screw feeder. The star-shaped discharge valve sends the fly ash in the bag filter into the conveying pipe of the screw feeder. The fresh konjac blocks and fly ash are mixed in the conveying pipe of the screw feeder and then sent into the negative pressure circulation pipe. S104. Crushing and drying process in the circulating mill main unit: Fresh konjac blocks continuously enter the circulating mill main unit, are crushed and dispersed by the impeller of the blower, and enter the centrifugal blower diffuser chamber with the airflow and flow at high speed along the impeller rotation direction. Large particles with high moisture content enter the inner circulation channel due to the greater centrifugal force and are continuously dried and dispersed during the high-speed circulation. Small particles with low moisture content enter the outer circulation channel from the outlet of the circulating mill main unit due to the less centrifugal force. A small portion of large particles with high moisture content also enters the outer circulation channel, and a small portion of small particles with low moisture content also enters the inner circulation channel. Among them, non-glucomannan components are separated from glucomannan particles due to impact and friction and are dried into fly ash. Relatively speaking, glucomannan particles are not easy to crush, especially when the moisture content is high. S105, Solution to the wall adhesion problem: The material adhering to the wall inside the circulating mill is blown off by the high-speed airflow periodically ejected from the purging air holes. Adjusting the opening and closing time and cycle of the purging air holes, as well as adjusting the return material amount and the rotation speed of the main mill, can completely solve the wall adhesion problem inside the circulating mill. S106. Grading process in cyclone dust collector: The material entering the external circulation channel continues to be dried due to rapid flow. Particles with smaller diameter and lower moisture content enter the bag filter with the exhaust airflow of the cyclone dust collector and become fly ash. Most of the material that can enter the bag filter with the exhaust airflow of the cyclone dust collector is fly ash, and there is also a very small part of broken glucomannan microparticles. Glucomannan particles, particles with high moisture content and large diameter, and a small part of fly ash enter the negative pressure circulation pipe through the outlet of discharge valve A to continue circulating, drying and grinding. S2. Discharge program: As the drying and grinding process proceeds, more and more material is added to the external and internal circulation channels, and the current of the circulating mill main unit gradually increases. When the current of the circulating mill main unit rises to 70-95% of the rated current value, the discharge program is executed. S201. Stop feeding: Close the screw feeder and the rotary valve, and ensure that the discharge valve D is closed; S202. Reduce the speed of the circulating mill main unit: Reduce the speed of the circulating mill main unit to 60-80% of the speed of the drying and grinding condition; Since no fresh konjac is added, the material in the inner and outer circulation channels is quickly dried, and the moisture of the glucomannan particles is quickly reduced. At this time, the glucomannan particles become easier to crush. Reducing the speed of the circulating mill main unit is to reduce the degree and probability of glucomannan being crushed. S203. Continued separation of fly ash: Due to impact and friction, the fly ash in the inner and outer circulation channels continuously falls off and is carried away by the exhaust airflow of the cyclone dust collector and separated from the outer circulation channel. S204 Discharge: When the moisture content of the material in the circulation channel drops below 12%, open discharge valves B and C, open valve A, and close discharge valve A. The material in the inner and outer circulation channels quickly enters the discharge dust collector and is collected in the discharge dust collector. S205. End the discharge procedure: Close discharge valves B and C, close valve A, open discharge valve A, and discharge is complete; Then, steps S103 to S205 are performed sequentially, and the operation is repeated in this cycle. S3, Fly Ash Discharge: Activating the fly ash discharge screw can discharge the fly ash collected in the bag filter. The fly ash discharged by the star-shaped discharge valve is called return material. Return material is one of the technical measures to solve the problem of wall adhesion in the process of making konjac flour from fresh konjac. The fly ash discharge screw and the star-shaped discharge valve are set to give priority to ensuring the amount of return material, and only the excess fly ash will be discharged by the fly ash discharge screw. S4. Removal of coarse and fine powder: The material collected by the discharge dust collector is called coarse and fine powder. Opening the discharge valve D allows the coarse and fine powder in the discharge dust collector to be removed. S5. Sieving: The coarse and fine powder obtained in S4 is sieved to obtain konjac flour.

[0018] The present invention also provides a method for improving the yield of konjac flour. The technical measure is to use the circulating mill described in this case to process konjac flour. Specifically, the aforementioned processing method for konjac flour can be used to produce konjac flour.

[0019] The key to improving the yield of konjac flour lies in ensuring that the glucomannan particles are not crushed too finely so that they cannot be separated from the fly ash. Practice shows that before glucomannan is completely dry, when the moisture content is higher than 15%, its properties are similar to Q-candy. It is not easily crushed by the impeller impact in the circulating mill. It is only after it is completely dry that it is easily crushed.

[0020] During the discharge process, since no fresh konjac is added, the moisture content of the konjac particles in the internal circulation channel quickly drops to 10%, and the glucomannan particles become easier to crush. Therefore, step S202 is required in the aforementioned konjac flour processing method.

[0021] This invention also provides Yunjie konjac flour, which is konjac flour processed by the circulating mill described in this invention, and also includes konjac flour processed by the aforementioned konjac flour processing method, as well as konjac flour produced by the aforementioned method for improving the yield of konjac flour.

[0022] The present invention also provides a circulating mill host, which is a centrifugal fan with a purge air hole on the casing. The position and direction of the purge air hole are set so that the high-speed airflow ejected can blow off the material attached to the wall inside the centrifugal fan.

[0023] This invention also provides a method for processing Yun Jie powder, which uses the aforementioned circulating mill that can be used for drying and pulverizing most fresh agricultural products, or uses the circulating mill main unit with "a centrifugal fan with purge air holes on the casing, the position and direction of which are set so that the high-speed airflow can blow off the material adhering to the wall inside the casing" instead of the circulating mill main unit that can be used for drying and pulverizing most fresh agricultural products, and performs the operation according to the following steps: S1. Feeding: The material is added through the feeding port of the screw feeder; S2. Drying and Grinding Process: When using a circulating mill, which is used for drying and grinding most fresh agricultural products, the material is dried and ground during high-speed circulation in the inner and outer circulation channels. Qualified powder is separated by a cyclone dust collector and enters a bag filter with the exhaust airflow from the cyclone dust collector. When using a circulating mill main unit that is a centrifugal fan with purge air holes on the casing, and the position and direction of the purge air holes are set so that the high-speed airflow can blow off the material hanging on the wall inside the casing, instead of the circulating mill main unit used for drying and grinding most fresh agricultural products, the material is dried and ground during high-speed circulation in the outer circulation channel. Qualified powder is separated by a cyclone dust collector and enters a bag filter with the exhaust airflow from the cyclone dust collector. S3. Discharge: The qualified powder collected by the bag filter is discharged by the fly ash discharge screw.

[0024] The present invention also provides a Yunjie powder, which is a powder processed by the above method and a circulating mill.

[0025] This invention discloses a circulating mill that solves the reliability problem of processing high-moisture and high-viscosity materials by setting purge air holes on the centrifugal fan casing and pre-mixing fly ash from the bag filter with high-moisture materials. By setting an internal circulation channel cut-off device, the internal circulation channel can be blocked during discharge to quickly discharge the material from the main unit. When used in konjac flour processing, it can significantly reduce the probability of glucomannan being pulverized too finely and becoming fly ash, thereby improving the yield of konjac flour. The provided method for processing konjac flour directly and quickly turns fresh konjac into konjac flour, improving the efficiency of konjac processing. Attached Figure Description

[0026] Figure 1 It is a circulating mill used for processing konjac flour; Figure 2 It is a circulating mill main unit with an internal circulation channel; Figure 3 Example 3 is a circulating mill main unit with two internal circulation channels; Figure 4 Example 4 describes a circulating mill including a discharge tee for processing konjac flour; Figure 5 Example 5 is a circulating mill for processing konjac flour, which includes a discharge dust collector; Figure 6 Example 6 describes a sulfur-free konjac flour processing device.

[0027] Example 1: A circulating mill for processing konjac flour, see [link to example]. Figure 1The system includes a circulating mill main unit 1, a positive pressure circulation pipe 2, a cyclone dust collector 3, a bag filter 4, a negative pressure circulation pipe 12, and a screw feeder 9. The circulating mill main unit 1 has two internal circulation channels, and the outlet of the negative pressure circulation pipe 12, the inlet of the circulating mill main unit 1, the outlet of the circulating mill main unit 1, the inlet of the positive pressure circulation pipe 2, the outlet of the positive pressure circulation pipe 2, and the air inlet of the cyclone dust collector 3 are connected in sequence. The ash discharge port of the cyclone dust collector 3 is the first discharge port of the circulating mill. 1. The negative pressure circulation pipe 12 has a feeding device interface 10. The screw feeder 9 has a return interface 8 between the discharge port and the inlet port 6 on its conveying pipe. The bag filter 4 has a star-shaped discharge valve 7 at its ash discharge port. The exhaust port of the cyclone dust collector 3, the inlet of the bag filter 4, the outlet of the star-shaped discharge valve 7, the return interface 8 of the screw feeder 9, the discharge port of the screw feeder, and the feeding device interface 10 on the negative pressure circulation pipe are connected in sequence to form a return circulation channel. In order to discharge the fly ash in the bag filter 4 while prioritizing the return of material, the bag filter 4 also includes a fly ash discharge screw 5. The conveying pipe of the fly ash discharge screw 5 passes through the small end of the ash hopper of the bag filter. The conveying pipe of the fly ash discharge screw located in the ash hopper of the bag filter 4 is completely cut off. The cut-off part becomes the inlet of the fly ash discharge screw 5, and the outlet of the fly ash discharge screw 5 is the fly ash discharge port.

[0028] Example 2: A circulating mill main unit, see [link to example]. Figure 2 The system consists of a centrifugal fan and an internal circulation pipe A15. The centrifugal fan casing has a coarse material outlet 16, and the impeller inlet area on the front cover of the centrifugal fan has an internal circulation pipe interface 19. The coarse material outlet 16, the inlet of the internal circulation pipe A15, the outlet of the internal circulation pipe A15, and the internal circulation pipe interface 19 are connected in sequence to form the internal circulation channel of the circulating mill host. The outlet of the centrifugal fan is the outlet 14 of the circulating mill host, and the inlet of the centrifugal fan is the inlet 18 of the circulating mill host. The internal circulation pipe A15 is equipped with an internal circulation channel cut-off device, which is a discharge air hole 17 connected to compressed air via valve A. The discharge air hole A17 is configured such that the direction of the airflow it emits is opposite to the direction of the airflow in the internal circulation channel and can block the flow of fluidized material in the internal circulation channel. The internal circulation channel cut-off device can also be a valve B installed on the internal circulation pipe. Valve B is used to control the opening and closing of the internal circulation channel. The centrifugal fan casing is also equipped with a purge air hole. The position and direction of the purge air hole are set so that the high-speed airflow ejected can blow off the material attached to the wall inside the circulating mill. The opening and closing of the purge air hole is controlled by a pulse controller through a pulse valve.

[0029] Example 3: A circulating mill main unit with two internal circulation channels, see [link to example]. Figure 3 The circulating mill host is formed by adding an internal circulation channel 20 to the circulating mill host described in Example 2. The internal circulation pipe B of the internal circulation channel B20 is also provided with a discharge air hole B21.

[0030] The circulating mill with only one internal circulation channel discharged from the first discharge port in Example 1 still contains a relatively large amount of wet material, indicating that its classification effect is not good enough. The classification effect will be better when using a circulating mill with more than one internal circulation channel, so that it can be expected that the wet material in the material discharged from the first discharge port in Example 1 can be reduced to an acceptable level. In this way, when applied to konjac flour processing, the material that has been dried to a certain degree can be discharged continuously and in a timely manner, which can prevent the glucomannan particles from being crushed too finely and improve the yield of konjac flour.

[0031] Example 4: A circulating mill including a discharge tee for konjac flour processing, see [link to example]. Figure 4 This invention is based on the circulating mill for konjac flour processing described in Example 1, with the addition of a discharge tee 26. The negative pressure circulating pipe is equipped with a cyclone dust collector ash discharge interface. One port of the discharge tee 26 is connected to the ash discharge port 25 of the cyclone dust collector, and another port of the discharge tee 26 has a discharge valve A27. The outlet of the discharge valve A27 is connected to the ash discharge interface of the cyclone dust collector. The third port of the discharge tee has a discharge valve B28, and the outlet of the discharge valve B28 is the second discharge port 29 of the circulating mill. The outlet of the circulating mill main unit, the inlet of the positive pressure circulating pipe, the outlet of the positive pressure circulating pipe, the air inlet of the cyclone dust collector, the ash discharge port 25 of the cyclone dust collector, one port of the discharge tee, the outlet of the discharge valve A27, the ash discharge interface of the cyclone dust collector, the outlet of the negative pressure circulating pipe, and the inlet of the circulating mill main unit are connected in sequence to form the outer circulation channel of the circulating mill.

[0032] By replacing the discharge tee 26 and discharge valve A27 in Example 4 with a straight pipe, the circulating mill can be used for drying and pulverizing most fresh agricultural products. In this method of using the circulating mill, qualified powder is graded by a cyclone dust collector and enters a bag filter with the exhaust airflow of the cyclone dust collector. Unqualified materials enter the negative pressure circulation pipe through the straight pipe for circulating drying and grinding. Qualified powder collected by the bag filter is discharged by the fly ash discharge screw.

[0033] Example 5: A circulating mill for processing konjac flour, including a discharge dust collector, see [link to example]. Figure 5 The method described in Example 4 is to add a discharge dust collector 32 to the circulating mill for konjac flour processing, which includes a discharge tee. The discharge dust collector 32 has a discharge valve C35 at its exhaust port, and the outlet 34 of the discharge valve C35 is connected to the negative pressure circulation pipe. The discharge port of the discharge dust collector has a discharge valve D37, and the outlet of the discharge valve D37 is the third discharge port 36 of the circulating mill. The air inlet 33 of the discharge dust collector is connected to the outlet of the discharge valve B.

[0034] Example 6: A sulfur-free konjac flour processing equipment, see [link / reference] Figure 6The circulating mill described in Example 5 is formed by adding a heat exchanger 42, a condenser 45, and a heater 47. The exhaust port 4 of the bag filter, the inlet and outlet 44 of the heat medium channel of the heat exchanger 42, the inlet and outlet 43 of the heat medium channel of the condenser 45, the inlet and outlet 46 of the refrigerant channel of the heat exchanger 42, the inlet and outlet 48 of the refrigerant channel of the heater 47, and the inlet of the negative pressure circulation pipe are connected in sequence to form a closed-loop circulation channel for the circulating mill.

[0035] Example 7: A vacuum circulating mill, wherein air-sealing devices are installed at the feed inlet of the screw feeder and the fly ash discharge outlet of the fly ash discharge screw of the sulfur-free konjac flour processing equipment described in Example 6, and the absolute pressure at the inlet of the circulating mill main unit is set to 1000-30000 Pa, thus the sulfur-free konjac flour processing equipment becomes a vacuum circulating mill. In traditional vacuum drying equipment, heat transfer mainly relies on conduction and radiation. The vacuum circulating mill operates under a rough vacuum state, and due to the high-speed circulation of the airflow, heat transfer becomes forced convection heat transfer.

[0036] This equipment uses nitrogen as the working medium to inhibit enzymatic browning reactions and solve the problem of oxidative browning in konjac flour processing by isolating oxygen. It eliminates the need for sulfur dioxide fumigation for color protection and also solves the problems of aroma loss and air pollution of other fresh agricultural products. It can also recover evaporated water in liquid form.

[0037] Example 8: A method for processing konjac flour, using the circulating mill described in Example 5, which includes a discharge dust collector and a konjac flour processing unit, to directly process fresh konjac into konjac flour, comprising the following steps: S1. Drying and grinding fresh konjac into powder: S101. Equipment Start-up: Ensure that discharge valves B, C and A are closed and discharge valve A is open. Start the equipment after starting the pulse controller and start the screw feeder. S102. Adding fly ash to the bag filter: Fly ash is added through a screw feeder. The added fly ash enters the bag filter through the exhaust port of the cyclone dust collector and is collected in the ash hopper of the bag filter. This step can be omitted if there is sufficient fly ash in the ash hopper of the bag filter. S103. Feeding: Start the star-shaped discharge valve and add the prepared fresh konjac blocks through the feeding port of the screw feeder. The star-shaped discharge valve sends the fly ash in the bag filter into the conveying pipe of the screw feeder. The fresh konjac blocks and fly ash are mixed in the conveying pipe of the screw feeder and then sent into the negative pressure circulation pipe. S104. Crushing and drying process in the circulating mill main unit: Fresh konjac blocks continuously enter the circulating mill main unit, are crushed and dispersed by the impeller of the blower, and enter the centrifugal blower diffuser chamber with the airflow and flow at high speed along the impeller rotation direction. Large particles with high moisture content enter the inner circulation channel due to the greater centrifugal force and are continuously dried and dispersed during the high-speed circulation. Small particles with low moisture content enter the outer circulation channel from the outlet of the circulating mill main unit due to the less centrifugal force. A small portion of large particles with high moisture content also enters the outer circulation channel, and a small portion of small particles with low moisture content also enters the inner circulation channel. Among them, non-glucomannan components are separated from glucomannan particles due to impact and friction and are dried into fly ash. Relatively speaking, glucomannan particles are not easy to crush, especially when the moisture content is high. S105, Solution to the wall adhesion problem: The material adhering to the wall inside the circulating mill is blown off by the high-speed airflow periodically ejected from the purging air holes. Adjusting the opening and closing time and cycle of the purging air holes, as well as adjusting the return material amount and the rotation speed of the main mill, can completely solve the wall adhesion problem inside the circulating mill. S106. Grading process in cyclone dust collector: The material entering the external circulation channel continues to be dried due to rapid flow. Particles with smaller diameter and lower moisture content enter the bag filter with the exhaust airflow of the cyclone dust collector and become fly ash. Most of the material that can enter the bag filter with the exhaust airflow of the cyclone dust collector is fly ash, and there is also a very small part of broken glucomannan microparticles. Glucomannan particles, particles with high moisture content and large diameter, and a small part of fly ash enter the negative pressure circulation pipe through the outlet of discharge valve A to continue circulating, drying and grinding. S2. Discharge program: As the drying and grinding process proceeds, more and more material is added to the external and internal circulation channels, and the current of the circulating mill main unit gradually increases. When the current of the circulating mill main unit rises to 70-95% of the rated current value, the discharge program is executed. S201. Stop feeding: Close the screw feeder and the rotary valve, and ensure that the discharge valve D is closed; S202. Reduce the speed of the circulating mill main unit: Reduce the speed of the circulating mill main unit to 60-80% of the speed of the drying and grinding condition; Since no fresh konjac is added, the material in the inner and outer circulation channels is quickly dried, and the moisture of the glucomannan particles is quickly reduced. At this time, the glucomannan particles become easier to crush. Reducing the speed of the circulating mill main unit is to reduce the degree and probability of glucomannan being crushed. S203. Continued separation of fly ash: Due to impact and friction, the fly ash in the inner and outer circulation channels continuously falls off and is carried away by the exhaust airflow of the cyclone dust collector and separated from the outer circulation channel. S204 Discharge: When the moisture content of the material in the circulation channel drops below 12%, open discharge valves B and C, open valve A, and close discharge valve A. The material in the inner and outer circulation channels quickly enters the discharge dust collector and is collected in the discharge dust collector. S205. End the discharge procedure: Close discharge valves B and C, close valve A, open discharge valve A, and discharge is complete; Then, steps S103 to S205 are performed sequentially, and the operation is repeated in this cycle. S3, Fly Ash Discharge: Activating the fly ash discharge screw can discharge the fly ash collected in the bag filter. The fly ash discharged by the star-shaped discharge valve is called return material. Return material is one of the technical measures to solve the problem of wall adhesion in the process of making konjac flour from fresh konjac. The fly ash discharge screw and the star-shaped discharge valve are set to prioritize the amount, and only the excess fly ash will be discharged by the fly ash discharge screw. S4. Removal of coarse and fine powder: The material collected by the discharge dust collector is called coarse and fine powder. Opening the discharge valve D allows the coarse and fine powder in the discharge dust collector to be removed. S5. Sieving: The coarse and fine powder obtained in S4 is sieved to obtain konjac flour.

[0038] On February 18, 2025, 200 kg of fresh Chuhua No. 2 konjac provided by the Chuxiong Prefecture Konjac Association was processed using the first commercial circulating mill engineering machine located in the Tuanjie Bio-industry Park in Xishan District, Kunming City, according to the method described in this embodiment. The fresh konjac had a moisture content of 80%, producing 24.35 kg of konjac flour, with a yield of 12.175%. Although this value is not representative due to the low moisture content of the fresh konjac, it is equivalent to 235.3 kg of fresh konjac with a yield of 10.35% when the moisture content is 83%; 250 kg with a yield of 9.74% when the moisture content is 84%; and 266.67 kg with a yield of 9.13% when the moisture content is 85%. All of these yields are far higher than the industry average of less than 8.5%.

[0039] Example 9: A method for improving the yield of konjac flour, wherein konjac flour is produced by using the circulating milling process described in Examples 1, 4, 5, 6, and 7, or by using the konjac flour processing method described in Example 8.

[0040] Example 10: A type of Yunjie konjac flour, which is konjac flour processed by the circulating mill described in Examples 1, 4, 5, 6 and 7; or, konjac flour processed by the konjac flour processing method described in Example 8; or, konjac flour produced by the method for improving the yield of konjac flour described in Example 9.

[0041] Example 11: A circulating mill main unit is a centrifugal fan with purge air holes on its casing. The position and direction of the purge air holes are set so that the high-speed airflow ejected can blow off the material attached to the wall inside the centrifugal fan. The inlet of the centrifugal fan is the inlet of the circulating mill main unit, and the outlet of the centrifugal fan is the outlet of the circulating mill main unit.

[0042] Compared with the circulating mill host described in Example 2, the circulating mill host described in this embodiment has no internal circulation pipe, has a simple structure, and is cheaper. Using it to replace the circulating mill host in the circulating mill described in Example 4 for drying and pulverizing materials with a moisture content of less than 60% can reduce equipment costs and simplify operation and control.

[0043] Example 12: A method for processing Yun Jie powder, using the circulating mill described in Example 4, which can be used for drying and pulverizing most fresh agricultural products, or using the circulating mill main unit described in Example 11 instead of the circulating mill main unit described in Example 4, which can be used for drying and pulverizing most fresh agricultural products, and proceeding according to the following steps: S1. Feeding: The material is added through the feeding port of the screw feeder; S2. Drying and grinding process: When the circulating mill described in claim 4 is used for operation, the material is dried and ground during the high-speed circulation flow in the inner and outer circulation channels. The qualified powder is separated by the cyclone dust collector and enters the bag filter with the exhaust airflow of the cyclone dust collector. When the circulating mill described in claim 10 is used instead of the main unit of the circulating mill described in claim 4 for operation, the material is dried and ground during the high-speed circulation flow in the outer circulation channel. The qualified powder is separated by the cyclone dust collector and enters the bag filter with the exhaust airflow of the cyclone dust collector. S3. Discharge: The qualified powder collected by the bag filter is discharged by the fly ash discharge screw.

[0044] Example 13, a circulating mill for dry material processing, has the following combination methods: (1) In Example 4, a circulating mill is formed by replacing the discharge tee 26 and discharge valve A27 with a straight pipe, and the discharge port of the fly ash discharge screw is used as the discharge port; (2) In Example 4, a circulating mill is formed by replacing the discharge tee 26 and the discharge valve A27 with a straight pipe, disconnecting the connection between the outlet of the star discharge valve and the return port, and using the outlet of the star discharge valve as the discharge port; (3) In Example 4, a circulating mill is formed by replacing the discharge tee 26 and discharge valve A27 with a straight pipe, disconnecting the connection between the outlet of the star discharge valve and the return port, removing the fly ash discharge screw, and using the outlet of the star discharge valve as the discharge port. (4) In Example 4, a circulating mill is formed by replacing the discharge tee 26 and discharge valve A27 with a straight pipe, disconnecting the connection between the outlet of the star discharge valve and the return port, removing the fly ash discharge spiral, using the outlet of the star discharge valve as the discharge port, and canceling the purging air hole. (5) In Example 4, a circulating mill was formed by replacing the discharge tee 26 and discharge valve A27 with a straight pipe, eliminating the purging air hole, and using the discharge port of the fly ash discharge spiral as the discharge port.

[0045] Example 14: A type of Yun Jie powder, which is a powder processed by a circulating mill, using the circulating mill main unit described in Example 11 instead of the circulating mill main unit described in Example 4, which can be used for drying and pulverizing most fresh agricultural products; or, a powder processed by a circulating mill as described in Example 4, which can be used for drying and pulverizing most fresh agricultural products; or, a powder processed by the processing method of Yun Jie powder described in Example 12; or, a powder processed by a circulating mill as described in Example 13, which is used for dry material processing.

Claims

1. A circulating mill, comprising a circulating mill main unit, a positive pressure circulating pipe, a cyclone dust collector, a bag filter, a negative pressure circulating pipe, and a feeder; the outlet of the negative pressure circulating pipe, the inlet of the circulating mill main unit, the outlet of the circulating mill main unit, the inlet of the positive pressure circulating pipe, the outlet of the positive pressure circulating pipe, and the air inlet of the cyclone dust collector are connected in sequence; the ash discharge port of the cyclone dust collector is the first discharge port of the circulating mill; the negative pressure circulating pipe has a feeding device interface; a return interface is also provided between the discharge port and the inlet of the feeder's conveying pipe; the ash discharge port of the bag filter has a star-shaped discharge valve; the air outlet of the cyclone dust collector, the air inlet of the bag filter, the outlet of the star-shaped discharge valve, the return interface of the feeder, the discharge port of the feeder, and the feeding device interface on the negative pressure circulating pipe are connected in sequence to form a return circulation channel of the circulating mill; characterized in that... The circulating mill main unit includes a centrifugal fan and an internal circulation pipe. The centrifugal fan casing has at least one coarse material outlet. The area corresponding to the impeller inlet on the front cover of the centrifugal fan is provided with an internal circulation pipe interface. The coarse material outlet, the inlet of the internal circulation pipe, the outlet of the internal circulation pipe, and the internal circulation pipe interface are connected in sequence to form at least one internal circulation channel of the circulating mill main unit. The outlet of the centrifugal fan is the outlet of the circulating mill main unit, and the inlet of the centrifugal fan is the inlet of the circulating mill main unit. The centrifugal fan casing and / or the internal circulation pipe are also provided with purging air holes. The position and direction of the purging air holes are set so that the high-speed airflow ejected can blow off the wall-mounted material inside the circulating mill main unit.

2. The circulating mill according to claim 1, characterized in that, The internal circulation pipe is equipped with a first type of internal circulation channel cut-off device, which is a discharge air hole connected to compressed air through valve A. The discharge air hole is configured such that the direction of the airflow it emits is opposite to the direction of the airflow in the internal circulation channel and can block the flow of fluidized material in the internal circulation channel; or, the internal circulation pipe is equipped with a second type of internal circulation channel cut-off device, which is a valve B installed on the internal circulation pipe.

3. A circulating mill according to claim 1, characterized in that, The bag filter also includes a fly ash discharge spiral. The feed pipe of the fly ash discharge spiral passes through the small end of the ash hopper of the bag filter. The feed pipe of the fly ash discharge spiral located in the ash hopper of the bag filter is completely cut off. The cut-off part becomes the feed inlet of the fly ash discharge spiral, and the outlet of the fly ash discharge spiral is the fly ash discharge outlet. Alternatively, the negative pressure circulation pipe may also be equipped with a cyclone dust collector ash discharge port. The circulating mill may also include a discharge tee, one port of which is connected to the ash discharge port of the cyclone dust collector, another port of which has a discharge valve A, the outlet of which is connected to the ash discharge port of the cyclone dust collector, and a third port of which has a discharge valve B, the outlet of which is the second discharge port of the circulating mill. The outlet of the circulating mill main unit, the inlet of the positive pressure circulation pipe, the outlet of the positive pressure circulation pipe, the air inlet of the cyclone dust collector, the ash discharge port of the cyclone dust collector, one port of the discharge tee, the outlet of discharge valve A, the ash discharge port of the cyclone dust collector, the outlet of the negative pressure circulation pipe, and the inlet of the circulating mill main unit are connected in sequence to form the outer circulation channel of the circulating mill.

4. A circulating mill according to claim 3, characterized in that, The discharge tee and discharge valve A are replaced by a straight pipe. The external circulation channel is formed by the outlet of the circulating mill main unit, the inlet of the positive pressure circulation pipe, the outlet of the positive pressure circulation pipe, the air inlet of the cyclone dust collector, the ash discharge port of the cyclone dust collector, the inlet of the straight pipe, the outlet of the straight pipe, the ash discharge interface of the cyclone dust collector, the outlet of the negative pressure circulation pipe, and the inlet of the circulating mill main unit connected in sequence.

5. A circulating mill according to claim 4, characterized in that, (1) Disconnect the connection between the outlet of the star-shaped discharge valve and the return port, and use the outlet of the star-shaped discharge valve as the discharge port; Or (2) Disconnect the connection between the outlet of the star-shaped discharge valve and the return port, remove the fly ash discharge screw, and use the outlet of the star-shaped discharge valve as the discharge port; Or (3) disconnect the connection between the outlet of the star discharge valve and the return port, remove the fly ash discharge screw, use the outlet of the star discharge valve as the discharge port, and cancel the purging air hole; Or (4) Cancel the purge vent.

6. A circulating mill according to claim 3, characterized in that, The circulating mill also includes a discharge dust collector. The discharge dust collector has a discharge valve C at its exhaust port. The outlet of the discharge valve C is connected to the negative pressure circulation pipe. The discharge dust collector has a discharge valve D at its ash discharge port. The outlet of the discharge valve D is the third discharge port of the circulating mill. The air inlet of the discharge dust collector is connected to the outlet of the discharge valve B.

7. A circulating mill according to claim 1, characterized in that, The circulating mill also includes a heat exchanger, a condenser, and a heater. The exhaust port of the bag filter, the inlet and outlet of the heat exchanger's heat medium channel, the inlet and outlet of the condenser's heat medium channel, the inlet and outlet of the heat exchanger's refrigerant channel, the inlet and outlet of the heater's refrigerant channel, and the inlet of the negative pressure circulation pipe are connected in sequence to form a closed-loop circulation channel for the circulating mill. Alternatively, the circulating mill also includes a heat exchanger, a condenser, and a heater. The exhaust port of the bag filter, the inlet and outlet of the heat exchanger's heat medium channel, the inlet and outlet of the condenser's heat medium channel, the inlet and outlet of the heat exchanger's heat medium channel, the inlet and outlet of the heat exchanger's refrigerant channel, the inlet and outlet of the heater's refrigerant channel, and the inlet of the negative pressure circulation pipe are connected in sequence to form a closed-loop circulation channel for the circulating mill. During the operation of the circulating mill, the absolute pressure at the inlet of the circulating mill main unit is set to 1000-30000 Pa.

8. A circulating mill main unit, characterized in that, It is a centrifugal fan with purge air holes on its casing. The position and direction of the purge air holes are set so that the high-speed airflow ejected can blow off the materials attached to the walls inside the centrifugal fan.

9. The method of using a circulating mill, characterized in that, (1) A method for processing konjac flour, using a circulating mill having the first type of internal circulation channel cutting device of claim 2, the fly ash discharge spiral of claim 3, an external circulation channel, and the discharge dust collector of claim 6 as the main equipment to directly process fresh konjac into konjac flour, comprising the following steps: S1. Drying and grinding fresh konjac into powder: S101. Equipment Start-up: Ensure that discharge valves B, C and A are closed and discharge valve A is open. Start the equipment after starting the pulse controller and start the screw feeder. S102. Adding fly ash to the bag filter: Fly ash is added through a screw feeder. The added fly ash enters the bag filter through the exhaust port of the cyclone dust collector and is collected in the ash hopper of the bag filter. This step can be omitted if there is sufficient fly ash in the ash hopper of the bag filter. S103. Feeding: Start the star-shaped discharge valve and add the prepared fresh konjac blocks through the feeding port of the screw feeder. The star-shaped discharge valve sends the fly ash in the bag filter into the conveying pipe of the screw feeder. The fresh konjac blocks and fly ash are mixed in the conveying pipe of the screw feeder and then sent into the negative pressure circulation pipe. S104. Crushing and drying process in the circulating mill main unit: Fresh konjac blocks continuously enter the circulating mill main unit, are crushed and dispersed by the impeller of the blower, and enter the centrifugal blower diffuser chamber with the airflow and flow at high speed along the impeller rotation direction. Large particles with high moisture content enter the inner circulation channel due to the greater centrifugal force and are continuously dried and dispersed during the high-speed circulation. Small particles with low moisture content enter the outer circulation channel from the outlet of the circulating mill main unit due to the less centrifugal force. A small portion of large particles with high moisture content also enters the outer circulation channel, and a small portion of small particles with low moisture content also enters the inner circulation channel. Among them, non-glucomannan components are separated from glucomannan particles due to impact and friction and are dried into fly ash. Relatively speaking, glucomannan particles are not easy to crush, especially when the moisture content is high. S105, Solution to the wall adhesion problem: The material adhering to the wall inside the circulating mill is blown off by the high-speed airflow periodically ejected from the purging air holes. Adjusting the opening and closing time and cycle of the purging air holes, as well as adjusting the return material amount and the rotation speed of the main mill, can completely solve the wall adhesion problem inside the circulating mill. S106. Grading process in cyclone dust collector: The material entering the external circulation channel continues to be dried due to rapid flow. Particles with smaller diameter and lower moisture content enter the bag filter with the exhaust airflow of the cyclone dust collector and become fly ash. Most of the material that can enter the bag filter with the exhaust airflow of the cyclone dust collector is fly ash, and there is also a very small part of broken glucomannan microparticles. Glucomannan particles, particles with high moisture content and large diameter, and a small part of fly ash enter the negative pressure circulation pipe through the outlet of discharge valve A to continue circulating, drying and grinding. S2. Discharge program: As the drying and grinding process proceeds, more and more material is added to the external and internal circulation channels, and the current of the circulating mill main unit gradually increases. When the current of the circulating mill main unit rises to 70-95% of the rated current value, the discharge program is executed. S201. Stop feeding: Close the screw feeder and the rotary valve, and ensure that the discharge valve D is closed; S202. Reduce the speed of the circulating mill main unit: Reduce the speed of the circulating mill main unit to 60-80% of the speed of the drying and grinding condition; Since no fresh konjac is added, the material in the inner and outer circulation channels is quickly dried, and the moisture of the glucomannan particles is quickly reduced. At this time, the glucomannan particles become easier to crush. Reducing the speed of the circulating mill main unit is to reduce the degree and probability of glucomannan being crushed. S203. Continued separation of fly ash: Due to impact and friction, the fly ash in the inner and outer circulation channels continuously falls off and is carried away by the exhaust airflow of the cyclone dust collector and separated from the outer circulation channel. S204 Discharge: When the moisture content of the material in the circulation channel drops below 12%, open discharge valves B and C, open valve A, and close discharge valve A. The material in the inner and outer circulation channels quickly enters the discharge dust collector and is collected in the discharge dust collector. S205. End the discharge procedure: Close discharge valves B and C, close valve A, open discharge valve A, and discharge is complete; Then, steps S103 to S205 are performed sequentially, and the operation is repeated in this cycle. S3, Fly Ash Discharge: Activating the fly ash discharge screw can discharge the fly ash collected in the bag filter. The fly ash discharged by the star-shaped discharge valve is called return material. Return material is one of the technical measures to solve the problem of wall adhesion. The fly ash discharge screw and the star-shaped discharge valve are set to give priority to ensuring the amount of return material. Only the excess fly ash will be discharged by the fly ash discharge screw. S4. Removal of coarse and fine powder: The material collected by the discharge dust collector is called coarse and fine powder. Opening the discharge valve D allows the coarse and fine powder in the discharge dust collector to be removed. S5. Sieving: The coarse and fine powder obtained in S4 is sieved to obtain konjac flour. Or (2) A method for improving the yield of konjac flour, wherein the konjac flour is processed by the circulating mill as described in claim 1 or 2 or 3 or 6 or 7, or konjac flour is prepared by the aforementioned processing method for konjac flour; Or (3) the first method for preparing Yun Jie powder, using the circulating mill described in claim 4, or using the circulating mill main unit described in claim 8 instead of the circulating mill main unit described in claim 4, and proceeding according to the following steps: S1. Feeding: The material is added through the feeding port of the screw feeder; S2. Drying and grinding process: When the circulating mill described in claim 4 is used for operation, the material is dried and ground during the high-speed circulation flow in the inner and outer circulation channels. The qualified powder is separated by the cyclone dust collector and enters the bag filter with the exhaust airflow of the cyclone dust collector. When the circulating mill described in claim 8 is used instead of the main unit of the circulating mill described in claim 4 for operation, the material is dried and ground during the high-speed circulation flow in the outer circulation channel. The qualified powder is separated by the cyclone dust collector and enters the bag filter with the exhaust airflow of the cyclone dust collector. S3, Discharge: The qualified powder collected by the bag filter is discharged by the fly ash discharge screw. Or (4) a second method for preparing Yunjie powder, using the four circulating mills described in claim 5 to prepare the powder.

10. A product processed by a circulating mill, characterized in that, (1) A Yunjie konjac flour, which is konjac flour produced by the method for improving the yield of konjac flour as described in claim 9; Or (2) the first type of rutin powder is a powder processed by the preparation method of the first type of rutin powder according to claim 9; Or (3) the second type of Yun Jie powder is a powder processed by the preparation method of the second type of Yun Jie powder according to claim 9.

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