Acid preparation and material conveying device and method for furfural production

Abstract

The invention relates to the technical field of material conveying, and provides an acid preparing and material conveying device and method.The acid preparing and material conveying device for furfural production comprises an acid preparing barrel and a material conveying pipe, the material conveying pipe is communicated with the bottom of the acid preparing barrel, and a valve is installed on the material conveying pipe; the acid preparation device further comprises a feeding mechanism, a stirring assembly, a first heat preservation cover, a second heat preservation cover, a temperature adjusting pipe and a temperature sensor, the feeding mechanism is used for adding materials into the acid preparation barrel, the stirring assembly is arranged in the acid preparation barrel and used for mechanically stirring the materials, and the first heat preservation cover fixedly sleeves the material conveying pipe and communicates with a water inlet pipe; the second heat preservation cover is fixedly arranged outside the acid preparation barrel in a sleeving mode and communicated with the first heat preservation cover, and the temperature sensor is installed in the acid preparation barrel. By means of the technical scheme, the technical problem that in the prior art, the temperature of raw materials in all positions in an acid preparation device is not uniform is solved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of material conveying, and specifically, to an acid mixing and material conveying device and method for furfural production. Background Art

[0002] Furfural is an organic compound mainly used as an industrial solvent. The production of furfural mainly consists of the following processes: crushing, conveying, acid mixing, and acid stirring; hydrolysis process; distillation process; refining process. During the production of furfural, the uniformity of acid mixing can directly affect the production quality of furfural. Therefore, an acid mixing device is required to mix raw materials and dilute sulfuric acid. After the sulfuric acid is metered, it is sent to an acid mixing tank and uniformly mixed with water to form a dilute sulfuric acid solution with a concentration of 5%. The corncobs flow from a screw conveyor into an acid stirring vehicle and are stirred with sulfuric acid. The corncobs after acid stirring directly enter a hydrolysis kettle to mix the raw materials and dilute sulfuric acid.

[0003] The basic principle of furfural production is to use plant corncobs rich in pentosan as raw materials, and under the presence of a catalyst (5% dilute sulfuric acid), high-temperature heating is carried out to hydrolyze the pentosan, and then under the same conditions, the pentose is dehydrated to produce furfural. The raw materials and dilute sulfuric acid are mixed inside the acid mixing device. The temperature change during the mixing process is relatively important for furfural production. Currently, a simple heater is generally used to control the temperature inside the acid mixing device, and the temperature uniformity of the internal raw materials is relatively low, with certain differences in temperature at various places. Moreover, there are also certain differences in the temperature of the materials inside the pipeline when conveying the materials, resulting in differences in furfural production and poor quality stability of production. Summary of the Invention

[0004] To overcome the above defects, the present invention provides an acid mixing and material conveying device and method for furfural production, which is used to solve the technical problem that the temperatures of raw materials at various places inside the existing acid mixing device are relatively uneven.

[0005] According to one aspect, at least one embodiment of the present disclosure provides an acid-mixing and feeding device for furfural production, including an acid-mixing cylinder and a feeding pipe. The feeding pipe is communicated with the bottom of the acid-mixing cylinder, and a valve is installed on the feeding pipe. The device further includes a feeding mechanism, a stirring assembly, a first heat-insulating cover, a second heat-insulating cover, a temperature-regulating pipe and a temperature sensor. The feeding mechanism includes a feeding hopper and a spraying pipe. The feeding hopper is communicated with the top of the acid-mixing cylinder, and the spraying pipe extends into the interior of the acid-mixing cylinder. The stirring assembly includes a stirring shaft and stirring rods. The stirring shaft is rotatably arranged inside the acid-mixing cylinder. There are multiple stirring rods, and the stirring rods are fixedly connected to the outside of the stirring shaft. The first heat-insulating cover is fixedly sleeved on the outside of the feeding pipe, and the first heat-insulating cover is communicated with a water inlet pipe. The second heat-insulating cover is fixedly sleeved on the outside of the acid-mixing cylinder, and the second heat-insulating cover is communicated with the first heat-insulating cover. The temperature-regulating pipe is located inside the second heat-insulating cover, and the temperature-regulating pipe is communicated with the stirring assembly. Specifically, the temperature-regulating pipe is rotationally communicated with the stirring shaft. Both the stirring shaft and the stirring rods are of hollow structures, and the stirring rods are communicated with the stirring shaft. The temperature sensor is installed inside the acid-mixing cylinder.

[0006] To improve the stirring effect on the material, multiple air outlet pipes are communicated with the stirring rods.

[0007] To avoid excessive pressure inside the acid-mixing cylinder, a circulation pipe is communicated with the top of the acid-mixing cylinder. The circulation pipe is communicated with the temperature-regulating pipe, and an axial flow fan is installed inside the circulation pipe.

[0008] To further avoid excessive pressure inside the acid-mixing cylinder, a pressure relief valve is installed on the top of the acid-mixing cylinder.

[0009] To improve the heat-insulating effect on the feeding pipe, multiple retaining rings are fixedly connected inside the first heat-insulating cover. The retaining rings are fixedly sleeved on the outside of the feeding pipe, and diversion openings are formed on the retaining rings. The diversion openings on two adjacent retaining rings are arranged staggeredly.

[0010] To improve the temperature-regulating effect on the temperature-regulating pipe, the temperature-regulating pipe is arranged in a spiral shape inside the second heat-insulating cover.

[0011] To convey and stir the material, a conveying blade is rotatably arranged inside the feeding pipe, and the conveying blade is in transmission connection with the stirring shaft.

[0012] An acid-mixing and feeding method for furfural production uses the above-mentioned acid-mixing and feeding device for furfural production, and includes the following steps: S1. Feeding: Add the material into the interior of the acid-mixing cylinder through the feeding hopper, and spray sulfuric acid inside the acid-mixing cylinder through the spraying pipe to mix with the material. S2. Mixing: The stirring shaft drives the stirring rod to mix the materials and sulfuric acid. At the same time, the axial flow fan sends air into the inside of the temperature regulating pipe and the stirring shaft, and the gas is sent into the materials being mixed through the air outlet pipe to perform pneumatic stirring on the materials. S3. Temperature regulation: The temperature sensor monitors the temperature inside the acid preparation cylinder, sends constant temperature water into the inside of the first heat preservation cover and the second heat preservation cover, so that the temperature inside the material conveying pipe and the acid preparation cylinder is in a stable state. At the same time, the constant temperature water in the second heat preservation cover regulates the temperature of the gas, so that the constant temperature gas enters the inside of the acid preparation cylinder, and the materials at each position are in a constant temperature state. S4. Discharging: Open the valve to make the mixed materials fall into the inside of the material conveying pipe. The stirring shaft drives the stirring blades to rotate, conveying and stirring the materials, and conveying the materials to the subsequent processes.

[0013] The beneficial effects of the embodiments of the present invention are as follows: In the present invention, materials and dilute sulfuric acid are added into the acid preparation cylinder through the feeding mechanism, the materials in the acid preparation cylinder are mechanically stirred and mixed through the stirring assembly, the temperature inside the acid preparation cylinder is monitored by the temperature sensor, and the temperature inside the material conveying pipe and the acid preparation cylinder is regulated by sending constant temperature water into the inside of the first heat preservation cover and the second heat preservation cover, so that it is in a relatively stable temperature environment. At the same time, the constant temperature water in the second heat preservation cover regulates the temperature of the gas in the temperature regulating pipe, and the constant temperature gas enters the inside of the stirring assembly and comes into full contact with the materials, performing relatively comprehensive and sufficient temperature regulation on the materials, ensuring the temperature uniformity of the materials at each position. The mixed materials fall into the inside of the material conveying pipe, and the conveying blades rotate to convey the materials. At the same time, the conveying blades stir the materials, ensuring the uniformity during the material conveying process, thereby ensuring the stability of the quality of furfural production. Description of the Drawings

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the following drawings are only some exemplary embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the exemplary embodiments of the present invention and these drawings.

[0015] Figure 1 It is a schematic structural diagram of the whole from the first perspective in an embodiment of the present invention; Figure 2 For Figure 1 is a schematic structural diagram of a partial cross-section in the embodiment of Figure 3 For Figure 1 is a schematic structural diagram of the acid preparation cylinder, the feeding hopper, the spraying pipe and the temperature sensor in the embodiment of Figure 4 ForFigure 1 Schematic structural diagram of the temperature control pipe, air supply seat, air outlet pipe and circulation pipe in the embodiment of Figure 5 For Figure 1 Schematic structural diagram of the first heat preservation cover, water inlet pipe, second heat preservation cover and retaining ring in the embodiment of Figure 6 For Figure 1 Schematic structural diagram of the conveying blade, driven bevel gear, transmission rod and driving bevel gear in the embodiment of Figure 7 For Figure 1 Schematic structural diagram of the overall second perspective in the embodiment of Figure 8 For Figure 1 Schematic diagram of the enlarged partial structure at position A in Figure 9 For Figure 1 Schematic diagram of the enlarged partial structure at position B in Figure 10 For Figure 1 Schematic structural diagram of the transmission rod and transmission box in the embodiment of

[0016] In the figure: 1, acid mixing cylinder; 2, feeding pipe; 3, valve; 4, feeding hopper; 5, spraying pipe; 6, stirring shaft; 7, stirring rod; 8, motor; 9, driving gear; 10, driven gear; 11, first heat preservation cover; 12, water inlet pipe; 13, second heat preservation cover; 14, retaining ring; 15, temperature control pipe; 16, air supply seat; 17, air outlet pipe; 18, circulation pipe; 19, axial flow fan; 20, pressure relief valve; 21, temperature sensor; 22, conveying blade; 23, driven bevel gear; 24, transmission rod; 25, driving bevel gear. Detailed implementation manners The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention.

[0017] To make the drawings concise, only the parts related to the invention are schematically shown in each drawing, and they do not represent the actual structure of the product. In addition, to make the drawings concise and easy to understand, in some drawings, parts with the same structure or function are only schematically shown for one of them, or only one of them is marked. In this article, "one" not only means "only this one", but also means "more than one" situation, and "several" includes "two" and "more than two".

[0018] In this text, it should be noted that unless otherwise clearly stipulated and defined, the terms "install", "connect", and "link" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] In the present invention, unless otherwise clearly stipulated and defined, the first feature being "above" or "below" the second feature can include the direct contact between the first and second features, or can also include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0020] In the description of this embodiment, the orientation or positional relationships such as "up", "down", "left", and "right" are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0021] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0022] Such as Figures 1 to 10As shown, it shows an acid-mixing and feeding device for furfural production in one embodiment of the present invention, including an acid-mixing cylinder 1 and a feeding pipe 2, the feeding pipe 2 is connected to the bottom of the acid-mixing cylinder 1, a valve 3 is installed on the feeding pipe 2, and also includes a feeding mechanism, a stirring component, a heat preservation cover 11, a heat preservation cover 2 13, a temperature regulating pipe 15 and a temperature sensor 21. Compared with the acid-mixing and feeding device for furfural production in the prior art, the present invention monitors the temperature in the acid-mixing cylinder 1 through the temperature sensor 21, and controls the temperature of the acid-mixing cylinder 1 by conveying constant temperature water to the inside of the heat preservation cover 1 11 and the heat preservation cover 2 13. The acid cylinder 1 and the feed pipe 2 are insulated to maintain their internal temperature in a stable state. The material and sulfuric acid are evenly mixed by the rotation of the stirring shaft 6 and the stirring rod 7. At the same time, gas is transported to the inside of the stirring rod 7 to pneumatically stir the material. The fluidity of the material is enhanced and the temperature of the material at each position is promoted to converge. At the same time, the constant temperature water in the insulation cover 13 regulates the temperature of the gas transported to the acid preparation cylinder 1, so that the material in the acid preparation cylinder 1 is fully in contact with the constant temperature gas, further improving the control effect of the material temperature and ensuring the stability of the quality of furfural production.

[0023] like Figures 1 to 3 As shown, the feeding mechanism includes a feeding hopper 4 and a spray pipe 5. The feeding hopper 4 is connected to the top of the acid preparation cylinder 1. The spray pipe 5 extends into the interior of the acid preparation cylinder 1. A closing cover is installed on the top of the feeding hopper 4. Corn cob raw materials are added to the interior of the acid preparation cylinder 1 through the feeding hopper 4. The spray pipe 5 is connected to the delivery pump. The delivery pump sprays the proportioned dilute sulfuric acid into the interior of the acid preparation cylinder 1. The spray pipe 5 faces the outlet of the feeding hopper 4. When adding materials, the dilute sulfuric acid can be sprayed on the surface of the materials to facilitate the full mixing of the materials and the dilute sulfuric acid.

[0024] like Figures 2 to 6 As shown, the stirring assembly includes a stirring shaft 6 and a stirring rod 7. The stirring shaft 6 is rotatably arranged inside the acid preparation cylinder 1. A plurality of stirring rods 7 are provided. The stirring rods 7 are fixedly connected to the outside of the stirring shaft 6. A motor 8 is installed on the top of the acid preparation cylinder 1. A driving gear 9 is fixedly connected to the output end of the motor 8. A driven gear 10 is fixedly sleeved on the outside of the stirring shaft 6. The driven gear 10 is meshed with the driving gear 9. The motor 8 drives the driving gear 9 to rotate, thereby driving the stirring shaft 6 and the stirring rod 7 to rotate, so as to stir and mix the raw materials and dilute sulfuric acid in the acid preparation cylinder 1.

[0025] like Figures 1 to 5As shown in the figure, the first heat preservation cover 11 is fixedly sleeved outside the material conveying pipe 2. The first heat preservation cover 11 is communicated with a water inlet pipe 12. The second heat preservation cover 13 is fixedly sleeved outside the acid mixing cylinder 1. The second heat preservation cover 13 is communicated with the first heat preservation cover 11. The water inlet pipe 12 is communicated with a water supply device. A water heater is installed inside the water supply device. The water is heated to a suitable temperature by the water heater. The water supply device conveys the constant temperature hot water to the inside of the first heat preservation cover 11 and the second heat preservation cover 13. Heat preservation layers are provided on the outside of both the first heat preservation cover 11 and the second heat preservation cover 13 to reduce the loss of heat of the hot water. The hot water heats and keeps warm the inside of the material conveying pipe 2 and the acid mixing cylinder 1, so that the inside is in a relatively stable temperature state, thus facilitating the normal and stable production reaction of furfural. The material conveying pipe 2 is located below the acid mixing cylinder 1. Therefore, the first heat preservation cover 11 is located below the second heat preservation cover 13. The hot water flows from bottom to top. The hot water fills the first heat preservation cover 11 and the second heat preservation cover 13 and flows back to the water heater from the top of the second heat preservation cover 13 for circulating heating. To improve the heat preservation effect on the material conveying pipe 2, a plurality of retaining rings 14 are fixedly connected inside the first heat preservation cover 11. The retaining rings 14 are fixedly sleeved outside the material conveying pipe 2. Flow guiding openings are formed in the retaining rings 14. The flow guiding openings on two adjacent retaining rings 14 are arranged staggeredly. When the hot water enters the first heat preservation cover 11, the hot water bends and flows inside the first heat preservation cover 11 under the action of the retaining rings 14 and the flow guiding openings, prolonging the residence time of the hot water inside the first heat preservation cover 11 and ensuring the heating and heat preservation effect on the material conveying pipe 2.

[0026] As Figures 1 to 4As shown in the figure, the temperature control pipe 15 is located inside the second heat preservation cover 13. The temperature control pipe 15 is arranged in a spiral shape inside the second heat preservation cover 13. The temperature control pipe 15 is rotationally connected to the stirring shaft 6. The top of the stirring shaft 6 is rotationally connected to an air supply seat 16. The temperature control pipe 15 is connected to the air supply seat 16. Both the stirring shaft 6 and the stirring rod 7 are hollow structures. The stirring rod 7 is connected to the stirring shaft 6. The stirring rod 7 is connected to a plurality of air outlet pipes 17. To prevent the pressure in the acid mixing cylinder 1 from being too high, the top of the acid mixing cylinder 1 is connected to a circulation pipe 18. The circulation pipe 18 is connected to the temperature control pipe 15. An axial flow fan 19 is installed inside the circulation pipe 18. A pressure relief valve 20 is installed at the top of the acid mixing cylinder 1. The axial flow fan 19 enables the gas to circulate between the acid mixing cylinder 1 and the temperature control pipe 15. The axial flow fan 19 sends air into the temperature control pipe 15. The hot water in the second heat preservation cover 13 heats the gas in the temperature control pipe 15 to keep it at a stable temperature. The hot air enters the inside of the stirring shaft 6 and the stirring rod 7 through the air supply seat 16 and is sent into the acid mixing cylinder 1 through the air outlet pipes 17. The hot air heats the stirring shaft 6 and the stirring rod 7 and controls the temperature of the material in contact with the stirring shaft 6 and the stirring rod 7. At the same time, the gas ejected from the air outlet pipes 17 mixes into the material. While pneumatically stirring the material, the hot gas and the material are in full contact, further improving the temperature control effect on the material. As the gas enters, the gas rises. Under the action of the axial flow fan 19, the excess gas re-enters the temperature control pipe 15 to realize the gas circulation, prevent the air pressure in the acid mixing cylinder 1 from increasing, and at the same time, the gas is circulated and heated, always at a relatively high temperature, reducing the gas heating time and facilitating the heating of the gas. At the same time, to prevent the air pressure in the acid mixing cylinder 1 from increasing due to heating, the excess gas is discharged through the pressure relief valve 20.

[0027] As Figure 3 shown, the temperature sensor 21 is installed inside the acid mixing cylinder 1. The temperature inside the acid mixing cylinder 1 is monitored through the temperature sensor 21, and the temperature measurement data is transmitted to the connected controller. The heating temperature of the water heater is controlled through the controller to realize the regulation of the hot water temperature in the first heat preservation cover 11 and the second heat preservation cover 13, so as to regulate the temperature in the acid mixing cylinder 1 and the feeding pipe 2 and keep it in a stable temperature environment.

[0028] As Figure 6As shown, in order to convey and stir the material, a conveying blade 22 is rotatably provided inside the feed pipe 2, and the conveying blade 22 is transmission-connected to the stirring shaft 6. The conveying blade 22 is also an auger, and the end of the conveying blade 22 is fixedly connected to a driven bevel gear 23. The outside of the acid preparation cylinder 1 is rotationally connected to a transmission rod 24, and the bottom end of the transmission rod 24 is fixedly connected to a driving bevel gear 25, and the driving bevel gear 25 is meshed with the driven bevel gear 23. The top of the transmission rod 24 and the stirring shaft 6 are transmission-connected by a sprocket chain. When the motor 8 drives the stirring shaft 6 to rotate, the transmission rod 24 and the driving bevel gear 25 are driven to rotate through the sprocket chain, thereby driving the driven bevel gear 23 and the conveying blade 22 to rotate, and the valve 3 is opened to allow the stirred and mixed material to fall into the interior of the feed pipe 2, and the conveying blade 22 rotates to push the material and stir the material at the same time, so that the material can be conveyed to the subsequent process, refer to Figure 10 In order to ensure the stable cooperation between the driving bevel gear 25 and the driven bevel gear 23 and reduce the influence of external impurities on the cooperation between the two, a transmission box is fixedly connected to the conveying pipe 2, the driving bevel gear 25 and the driven bevel gear 23 are located inside the transmission box, and the transmission rod 24 and the conveying blade 22 are rotatably connected to the transmission box.

[0029] A method for preparing acid and feeding materials for furfural production, using the above-mentioned device for preparing acid and feeding materials for furfural production, comprises the following steps: S1, adding materials: adding materials into the acid preparation cylinder 1 through the feeding hopper 4, spraying sulfuric acid into the acid preparation cylinder 1 through the spraying pipe 5 to mix with the materials; S2, mixing: the stirring shaft 6 drives the stirring rod 7 to mix the material and sulfuric acid, and at the same time the axial flow fan 19 sends air to the interior of the temperature regulating tube 15 and the stirring shaft 6, and sends the gas into the mixing material through the air outlet pipe 17 to pneumatically stir the material; S3, temperature adjustment: the temperature sensor 21 monitors the temperature inside the acid preparation cylinder 1, and sends constant temperature water into the interior of the insulation cover 1 11 and the insulation cover 2 13, so that the internal temperature of the feed pipe 2 and the acid preparation cylinder 1 is in a stable state. At the same time, the constant temperature water in the insulation cover 2 13 adjusts the temperature of the gas, so that the constant temperature gas enters the interior of the acid preparation cylinder 1, so that the materials at various positions are in a constant temperature state; S4, discharging: opening the valve 3 to allow the mixed material to fall into the interior of the feeding pipe 2, and the stirring shaft 6 drives the stirring blades to rotate, so as to convey and stir the material, and convey the material to the subsequent process.

[0030] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. An acid preparation and feeding device for furfural production, comprising an acid preparation cylinder (1) and a feeding pipe (2), wherein the feeding pipe (2) is communicated with the bottom of the acid preparation cylinder (1), and a valve (3) is installed on the feeding pipe (2), and is characterized in that, It further includes: A feeding mechanism for adding materials into the interior of the acid mixing cylinder (1); A stirring assembly disposed inside the acid mixing cylinder (1) for mechanically stirring the materials; A first heat preservation cover (11) fixedly sleeved outside the material conveying pipe (2), and the first heat preservation cover (11) is communicated with a water inlet pipe (12); A second heat preservation cover (13) fixedly sleeved outside the acid mixing cylinder (1), and the second heat preservation cover (13) is communicated with the first heat preservation cover (11); A temperature regulating pipe (15) located inside the second heat preservation cover (13), and the temperature regulating pipe (15) is communicated with the stirring assembly; A temperature sensor (21) installed inside the acid mixing cylinder (1).

2. The acid-mixing and feeding device for furfural production according to claim 1, characterized in that, The feeding mechanism includes: A feeding hopper (4) communicated with the top of the acid mixing cylinder (1); A spraying pipe (5) extending into the interior of the acid mixing cylinder (1).

3. The acid preparation and feeding device for furfural production according to claim 2, wherein, The stirring assembly includes: A stirring shaft (6) rotatably disposed inside the acid mixing cylinder (1); A plurality of stirring rods (7) fixedly connected to the outside of the stirring shaft (6).

4. A sulfuric acid feeding device for furfural production according to claim 3, characterized in that, A plurality of air outlet pipes (17) are communicated with the stirring rods (7).

5. A acid-mixing and feeding device for furfural production according to claim 4, characterized in that, A circulation pipe (18) is communicated with the top of the acid mixing cylinder (1), the circulation pipe (18) is communicated with the temperature regulating pipe (15), and an axial flow fan (19) is installed inside the circulation pipe (18).

6. The acid preparation and feeding device for furfural production according to claim 5, characterized in that, A pressure relief valve (20) is installed on the top of the acid mixing cylinder (1).

7. A sulfuric acid feeding device for furfural production according to claim 6, characterized in that, A plurality of retaining rings (14) are fixedly connected inside the first heat preservation cover (11), the retaining rings (14) are fixedly sleeved outside the material conveying pipe (2), and diversion openings are formed on the retaining rings (14), and the diversion openings on adjacent two retaining rings (14) are arranged staggeredly.

8. A sulfuric acid feeding device for furfural production according to claim 7, characterized in that, The temperature regulating pipe (15) is arranged in a spiral shape inside the second heat preservation cover (13).

9. The acid preparation and feeding device for furfural production according to claim 8, characterized in that, A conveying blade (22) is rotatably disposed inside the material conveying pipe (2), and the conveying blade (22) is in transmission connection with the stirring shaft (6).

10. A method for transporting acid mixture for furfural production, which uses the acid mixture transporting device for furfural production described in claim 9, is characterized in that, It includes the following steps: S1. Feeding: Add materials into the interior of the acid mixing cylinder (1) through the feeding hopper (4), and spray sulfuric acid inside the acid mixing cylinder (1) through the spraying pipe (5) to mix with the materials; S2. Mixing: The stirring shaft (6) drives the stirring rods (7) to mix the materials and sulfuric acid. At the same time, the axial flow fan (19) sends air into the interior of the temperature regulating pipe (15) and the stirring shaft (6), and the air is sent into the materials being mixed through the air outlet pipes (17) to perform pneumatic stirring on the materials; S3. Temperature adjustment: The temperature sensor (21) monitors the temperature inside the acid mixing cylinder (1), sends constant temperature water into the interiors of the first heat preservation cover (11) and the second heat preservation cover (13), so that the internal temperatures of the material conveying pipe (2) and the acid mixing cylinder (1) are in a stable state. At the same time, the constant temperature water in the second heat preservation cover (13) adjusts the temperature of the gas, so that the constant temperature gas enters the interior of the acid mixing cylinder (1), making the materials at each position in a constant temperature state; S4. Discharging: Open the valve (3) to make the mixed materials fall into the interior of the material conveying pipe (2). The stirring shaft (6) drives the stirring blades to rotate, conveying and stirring the materials, and conveying the materials to the subsequent processes.

Images