Rice hull-based silicon dioxide aerogel normal pressure drying device

Abstract

The application discloses a rice hull-based silicon dioxide aerogel normal-pressure drying device, which comprises a drying bin and at least one drying pipe, and is characterized in that the central axis of the drying bin is provided with an up-and-down through-type placing channel, the drying pipe is arranged in the drying bin around the placing channel, the drying pipe comprises an adiabatic pipe, a fluid-permeable pipe and a sulfuric acid discharge pipe, the fluid-permeable pipe is coaxially arranged in the adiabatic pipe, the sulfuric acid discharge pipe is coaxially arranged in the fluid-permeable pipe, the outer wall of the sulfuric acid discharge pipe is provided with a spiral push plate, the outer peripheral wall of the drying bin is provided with an inlet and discharge assembly at a position corresponding to the fluid-permeable pipe, an acid treatment device is arranged in the placing channel, at least one retractable lining plate is arranged on the lower peripheral wall of the fluid-permeable pipe, a fluid pump is arranged in the placing channel, the fluid pump is connected with the annular gap between the adiabatic pipe and the fluid-permeable pipe, the drying, treatment and washing processes of the rice hull raw material are continuously carried out, the material does not need to be repeatedly placed and taken out from the device, and the extraction efficiency of the silicon dioxide is greatly improved.

Description

Technical Field

[0001] This invention relates to the field of rice husk-based silica aerogel preparation technology, and more particularly to an atmospheric pressure drying device for rice husk-based silica aerogel. Background Technology

[0002] Silica aerogel is a solid material with a three-dimensional nanoporous structure composed of stacked nanoparticles. It has properties such as chemical inertness, thermal insulation, sound insulation and noise reduction, shock absorption and energy absorption, and selective adsorption. It has been applied in batches in many fields such as industrial thermal insulation and energy saving, power battery safety and fire protection, automotive energy saving and sound insulation, building energy saving, spacecraft thermal insulation and cold insulation, and refrigerator cold preservation, and has a very broad application potential.

[0003] Rice husks, a member of the biomass family, have gained favor among researchers due to their abundant quantity, low cost, easy availability, cleanliness, and renewability. Rice husks consist of approximately 80% organic matter and 20% inorganic matter. The composition varies depending on the species and geographical conditions, but generally includes: lignin 21%-26%, cellulose 35.5%-45%, pentosans 16%-21%, ash 11%-22%, and small amounts of fat and protein. Rice husks contain about 20% silica, existing in a hydrated amorphous state through biomineralization. Extracting silica from rice husks and preparing high-value-added silica aerogels can further explore the economic value of rice husks.

[0004] The most important step in preparing rice husk-based silica aerogel is to extract silica from the rice husk. In existing technologies, the rice husk is generally treated by extraction, acid washing, and carbonization to obtain silica. This process requires the obtained material to be washed and dried multiple times, which requires the material to be frequently placed into and removed from the drying device, which greatly reduces the extraction efficiency of silica.

[0005] Meanwhile, the temperature inside the drying device is easily lost during material removal and insertion, which further increases the energy consumption of silica extraction and the extraction cost of silica. Summary of the Invention

[0006] To address the problems mentioned in the background section, this invention provides an atmospheric pressure drying device for rice husk-based silica aerogel.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] An atmospheric pressure drying device for rice husk-based silica aerogel includes a drying chamber and at least one drying tube. The drying chamber has a vertically penetrating placement channel at its central axis. The drying tube is arranged around the placement channel inside the drying chamber. The drying tube includes an insulating tube, a fluid permeation tube, and a sulfuric acid discharge tube. The fluid permeation tube is coaxially arranged inside the insulating tube. The sulfuric acid discharge tube is coaxially arranged inside the fluid permeation tube. A spiral pusher plate is provided on the outer wall of the sulfuric acid discharge tube.

[0009] The outer periphery of the drying chamber is equipped with a feeding and discharging assembly at the position corresponding to the fluid permeation pipe, an acid treatment device is installed in the storage channel, and at least one take-up and release liner is installed on the lower periphery of the fluid permeation pipe.

[0010] A fluid pump is installed in the storage channel, and the fluid pump connects the annular gap between the insulation pipe and the fluid permeation pipe.

[0011] Preferably, the peripheral wall of the fluid permeable tube allows only fluid to pass through while intercepting solids, the outer edge of the spiral pusher plate is in close contact with the inner wall of the fluid permeable tube, and the outer wall of the sulfuric acid discharge pipe is provided with an acid outlet between each turn of the spiral pusher plate.

[0012] Preferably, the feeding and discharging assembly includes a connecting pipe, a pusher plate, a feed pipe, and a discharge pipe. The connecting pipe is connected to the fluid permeable pipe, and the outer peripheral wall of the pusher plate is in close contact with the inner wall of the connecting pipe. The pusher plate is driven to move toward or away from the fluid permeable pipe.

[0013] Preferably, the acid treatment device includes an acid supply pipe, a diversion head, and a drive shaft. The drive shaft passes through the side wall of the storage channel and is connected to the sulfuric acid discharge pipe. A drive motor capable of driving the drive shaft to rotate axially is installed inside the diversion head. The drive shaft has a diversion pipe connected to the sulfuric acid discharge pipe inside. The diversion pipe is connected to the acid supply pipe and can rotate axially together with the sulfuric acid discharge pipe.

[0014] Preferably, the retractable liner includes a control seat, a telescopic rod, and a telescopic plate. The control seat is fixedly installed on the lower peripheral wall of the fluid permeable pipe and controls the extension and retraction of the telescopic rod. The telescopic plate is installed on both sides of the control seat and connected to the telescopic rod.

[0015] Preferably, an air guide groove is provided on the outer peripheral wall of the drying chamber at a position corresponding to the drying pipe, and the end of the heat insulation pipe is connected to the air guide groove.

[0016] Preferably, the connecting pipe passes through the inner cavity of the air guide channel and connects with the fluid through pipe, and a switching valve is provided around the part of the connecting pipe inserted into the air guide channel.

[0017] Preferably, the outer peripheral wall of the drying chamber is provided with at least one reflux heating window corresponding to the air guide slot, and the reflux heating window has a dehumidification plate and a heating wire.

[0018] Preferably, a drying plate is provided inside the drying chamber, and a reflux device is installed on the bottom plate of the drying chamber. The reflux device has a pipeline connected to a fluid pump.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. This invention integrates the drying, processing and washing processes of rice husk materials. After drying, the rice husk material can be directly acid-treated in the fluid permeation pipe. After acid treatment, the fluid pump can directly inject deionized water into the insulated pipe for washing. The drying, processing and washing processes are carried out continuously, without the need to repeatedly put the material into and take it out of the drying device, which greatly improves the extraction efficiency of silica.

[0021] 2. The hot airflow used in the drying device of the present invention can be continuously circulated in the drying chamber and drying tube by the fluid pump, and the moisture is removed by the reflux heating window and reflux device to maintain the drying effect. When preparing rice husk-based silica aerogel, the drying operations of rice husk material and pickling material can be carried out simultaneously, which further improves the production efficiency of the product.

[0022] 3. This invention avoids the frequent loading and unloading of materials from the drying device, and the hot airflow circulates within the drying chamber and drying tube to complete the drying process. The hot airflow has little heat loss except for heat exchange with the material, thus reducing the energy consumption in the preparation of rice husk-based silica aerogel and reducing the extraction cost of rice husk-based silica aerogel. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the external structure of an atmospheric pressure drying device for rice husk-based silica aerogel according to the present invention.

[0025] Figure 2 This is a cross-sectional view of the atmospheric pressure drying device for rice husk-based silica aerogel according to the present invention.

[0026] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle;

[0027] Figure 4 This is a schematic diagram of the acid treatment device described in this invention;

[0028] Figure 5 This is a schematic diagram of the retractable liner structure described in this invention.

[0029] In the diagram: 1. Drying chamber; 101. Storage channel; 11. Drying plate; 12. Reflux device; 2. Drying pipe; 21. Insulation pipe; 22. Fluid permeable pipe; 23. Sulfuric acid discharge pipe; 24. Spiral pusher plate; 25. Acid outlet head; 3. Feed and discharge assembly; 31. Connecting pipe; 32. Pusher plate; 33. Feed pipe; 34. Discharge pipe; 4. Acid treatment device; 41. Acid supply pipe; 42. Diverter head; 43. Drive shaft; 44. Drive motor; 45. Diverter pipe; 5. Liner plate; 51. Control seat; 52. Telescopic rod; 53. Telescopic plate; 6. Fluid pump; 601. Pumping port; 7. Air guide duct; 8. Switching valve; 9. Reflux heating window. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Reference Figure 1-5 An atmospheric pressure drying device for rice husk-based silica aerogel includes a drying chamber 1 and at least one drying tube 2. The drying chamber 1 has a vertically penetrating placement channel 101 at its central axis, and the drying tube 2 is arranged inside the drying chamber 1 around the placement channel 101.

[0033] The drying tube 2 includes an insulating tube 21, a fluid permeation tube 22, and a sulfuric acid discharge tube 23. The insulating tube 21 is fixedly installed on the side wall of the storage channel 101. The fluid permeation tube 22 is coaxially arranged inside the insulating tube 21. The sulfuric acid discharge tube 23 is coaxially arranged inside the fluid permeation tube 22. A spiral pusher plate 24 is provided on the outer wall of the sulfuric acid discharge tube 23. The outer edge of the spiral pusher plate 24 is in close contact with the inner wall of the fluid permeation tube 22. An acid outlet 25 is provided on the outer wall of the sulfuric acid discharge tube 23 between each turn of the spiral pusher plate 24. The sulfuric acid discharge tube 23 can be driven to rotate axially. Sulfuric acid for processing rice husk raw materials can be injected into the sulfuric acid discharge tube 23. The sulfuric acid injected into the sulfuric acid discharge tube 23 is discharged into the fluid permeation tube 22 through the acid outlet 25.

[0034] The outer peripheral wall of the drying chamber 1 is equipped with a feeding and discharging assembly 3 at a position corresponding to the fluid permeation pipe 22. The feeding and discharging assembly 3 includes a connecting pipe 31, a pusher plate 32, a feeding pipe 33, and a discharging pipe 34. The connecting pipe 31 is connected to the fluid permeation pipe 22. The outer peripheral wall of the pusher plate 32 is in close contact with the inner wall of the connecting pipe 31. The pusher plate 32 is driven to move toward or away from the fluid permeation pipe 22. The feeding pipe 33 and the discharging pipe 34 are vertically aligned. The pusher plate 32 can move to the side of the feeding pipe 33 and the discharging pipe 34 away from the fluid permeation pipe 22, so that the rice husk material to be processed can be pushed toward the fluid permeation pipe 22 by the pusher plate 32 after being fed to the connecting pipe 31 by the feeding pipe 33.

[0035] The perimeter of the fluid permeation pipe 22 only allows fluid to pass through and will intercept solids. Valves are installed at the connection between the feed pipe 33 and the discharge pipe 34 and the connecting pipe 31. The valve installed on the feed pipe 33 intermittently releases a portion of rice husk material, which is pushed to the opening of the fluid permeation pipe 22 by the pusher plate 32. At this time, the sulfuric acid discharge pipe 23 rotates once, and the spiral pusher plate 24 will transport the rice husk material pushed by the pusher plate 32 to the storage channel 101 for a certain distance. Then the feed pipe 33 continues to release a portion of rice husk material, and the sulfuric acid discharge pipe 23 rotates once again, and so on, until each interval of the spiral pusher plate 24 is filled with rice husk material.

[0036] Example 2

[0037] Reference Figure 2 and Figure 4 Based on Embodiment 1, an acid treatment device 4 is installed in the storage channel 101. The acid treatment device 4 includes an acid supply pipe 41, a diverter head 42, and a drive shaft 43. The drive shaft 43 passes through the side wall of the storage channel 101 and is connected to the sulfuric acid drain pipe 23. A drive motor 44 capable of driving the drive shaft 43 to rotate axially is installed in the diverter head 42, so as to drive the sulfuric acid drain pipe 23 to rotate by means of the drive shaft 43. The drive shaft 43 has a diverter pipe 45 connected to the sulfuric acid drain pipe 23. The diverter pipe 45 is connected to the acid supply pipe 41 and can rotate axially together with the sulfuric acid drain pipe 23.

[0038] After the fluid permeation pipe 22 is filled with rice husk material, concentrated sulfuric acid is sent to the sulfuric acid discharge pipe 23 through the acid supply pipe 41 and the diversion pipe 45, and then evenly distributed to the fluid permeation pipe 22 through the acid outlet 25 so as to make even and sufficient contact with the rice husk material to carbonize the rice husk material.

[0039] Example 3

[0040] Reference Figure 5Based on Embodiment 2, at least one retractable liner 5 is installed on the lower peripheral wall of the fluid permeation pipe 22. The retractable liner 5 includes a control seat 51, a telescopic rod 52, and a telescopic plate 53. The control seat 51 is fixedly installed on the lower peripheral wall of the fluid permeation pipe 22 and controls the extension and retraction of the telescopic rod 52. The telescopic plate 53 is installed on both sides of the control seat 51 and connected to the telescopic rod 52 so as to expand and contract under the action of the telescopic rod 52. When the telescopic plate 53 is expanded, it can wrap around the lower part of the fluid permeation pipe 22 and form a barrier to prevent the sulfuric acid from flowing down in the lower part of the fluid permeation pipe 22, so that the sulfuric acid will not flow down and be lost during the carbonization of rice husk materials, thereby allowing the sulfuric acid to fully participate in the production reaction and avoiding waste.

[0041] A fluid pump 6 is installed inside the storage channel 101. The outer peripheral wall of the fluid pump 6 has a pumping port 601. The shape and position of the pumping port 601 correspond to the annular gap between the insulation pipe 21 and the fluid permeation pipe 22. The pumping port 601 passes through the side wall of the storage channel 101 and connects to the insulation pipe 21. After the rice husk material is carbonized, the control seat 51 drives the telescopic rod 52 to shorten the telescopic plate 53 so that a gap is created between each of the retractable and dispensing liner plates 5. At this time, the fluid pump 6 continuously sends deionized water into the insulation pipe 21 through the pumping port 601 to wash the material. During washing, the spiral pusher plate 24 moves to the position furthest away from the storage channel 101, and at the same time, the valve of the discharge pipe 34 is opened so that the washing liquid is discharged through the discharge pipe 34.

[0042] The outer periphery of the drying chamber 1 is provided with an air guide groove 7 at a position corresponding to the drying pipe 2. The end of the heat insulation pipe 21 is connected to the air guide groove 7. The connecting pipe 31 also passes through the inner cavity of the air guide groove 7 and is connected to the fluid permeable pipe 22. The part of the connecting pipe 31 inserted into the air guide groove 7 is surrounded by a switching valve 8. When the material is being washed, the switching valve 8 is switched to a state that prohibits fluid passage, so that the washing waste liquid can only flow through the connecting pipe 31 to the discharge pipe 34 for discharge. After the material is washed, the fluid pump 6 continuously delivers drying gas at 80-100°C to the heat insulation pipe 21 to dry the washed carbonized material. At this time, the switching valve 8 is switched to a state that allows fluid passage, and the valves of the feed pipe 33 and the discharge pipe 34 are closed. The hot air flow entering the heat insulation pipe 21 will pass through the switching valve 8 and enter the air guide groove 7 after drying the carbonized material.

[0043] The outer peripheral wall of the drying chamber 1 is provided with at least one reflux heating window 9 corresponding to the air guide slot 7. The hot airflow that enters the air guide slot 7 after drying the carbonized material will pass through the reflux heating window 9 and be discharged into the drying chamber 1. The reflux heating window 9 has a dehumidification plate and a heating wire. The airflow passing through the reflux heating window 9 will have moisture removed and be heated.

[0044] After drying, the carbonized material is pushed by the spiral pusher plate 24 to the discharge pipe 34 and discharged. After being impregnated and calcined, it is pickled to obtain pickled material. This pickled material will be sent back to the drying plate 11 suspended in the drying chamber 1. The ventilation mesh of the drying plate 11 is directly opposite the recirculation heating window 9, so that the drying hot air flow discharged from the recirculation heating window 9 can effectively dry the pickled material.

[0045] The bottom plate of the drying chamber 1 is equipped with a reflux device 12. The reflux device 12 has a pipeline connected to the fluid pump 6. When drying the rice husk material and carbonized material, the fluid pump 6 draws the hot gas in the drying chamber 1 into the insulation pipe 21 through the pumping port 601. During the drawing process, the airflow will pass through the reflux device 12. The reflux device 12 is equipped with a dehumidifying plate to ensure that the hot airflow delivered to the insulation pipe 21 is dried.

[0046] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0047] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0048] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A normal pressure drying device for rice husk-based silica aerogel, comprising a drying chamber (1) and at least one drying tube (2), wherein the drying chamber (1) has a vertically penetrating placement channel (101) at its central axis, and the drying tube (2) is arranged inside the drying chamber (1) surrounding the placement channel (101), characterized in that: The drying tube (2) includes an insulation tube (21), a fluid permeation tube (22) and a sulfuric acid discharge tube (23). The fluid permeation tube (22) is coaxially arranged inside the insulation tube (21). The sulfuric acid discharge tube (23) is coaxially arranged inside the fluid permeation tube (22). The outer wall of the sulfuric acid discharge tube (23) is provided with a spiral pusher plate (24). The drying chamber (1) has a feeding and discharging assembly (3) installed on its outer peripheral wall at a position corresponding to the fluid permeation pipe (22), an acid treatment device (4) is installed in the storage channel (101), and at least one retractable liner (5) is installed on the lower peripheral wall of the fluid permeation pipe (22). A fluid pump (6) is installed in the storage channel (101), and the fluid pump (6) connects the annular gap between the heat insulation pipe (21) and the fluid permeation pipe (22).

2. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 1, characterized in that: The peripheral wall of the fluid permeation tube (22) allows fluid to pass through but intercepts solids. The outer edge of the spiral pusher plate (24) is in close contact with the inner wall of the fluid permeation tube (22). The outer wall of the sulfuric acid discharge tube (23) is provided with an acid outlet (25) between each turn of the spiral pusher plate (24).

3. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 1, characterized in that: The feeding and discharging assembly (3) includes a connecting pipe (31), a pusher plate (32), a feed pipe (33), and a discharge pipe (34). The connecting pipe 31 is connected to the fluid permeable pipe (22). The outer peripheral wall of the pusher plate (32) is in close contact with the inner wall of the connecting pipe (31). The pusher plate (32) is driven to move toward or away from the fluid permeable pipe (22).

4. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 1, characterized in that: The acid treatment device (4) includes an acid supply pipe (41), a diverter head (42), and a drive shaft (43). The drive shaft (43) passes through the side wall of the storage channel (101) and is connected to the sulfuric acid drain pipe (23). The diverter head (42) is equipped with a drive motor (44) that can drive the drive shaft (43) to rotate axially. The drive shaft (43) has a diverter pipe (45) inside that connects to the sulfuric acid drain pipe (23). The diverter pipe (45) connects to the acid supply pipe (41) and can rotate axially together with the sulfuric acid drain pipe (23).

5. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 1, characterized in that: The retractable liner (5) includes a control seat (51), a telescopic rod (52) and a telescopic plate (53). The control seat (51) is fixedly installed on the lower peripheral wall of the fluid permeable pipe (22) and controls the extension and retraction of the telescopic rod (52). The telescopic plate (53) is installed on both sides of the control seat (51) and connected to the telescopic rod (52).

6. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 3, characterized in that: The outer peripheral wall of the drying chamber (1) is provided with an air guide groove (7) at a position corresponding to the drying pipe (2), and the end of the heat insulation pipe (21) is connected to the air guide groove (7).

7. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 6, characterized in that: The connecting pipe (31) passes through the inner cavity of the air guide groove (7) and connects with the fluid permeable pipe (22). The part of the connecting pipe (31) inserted into the air guide groove (7) is surrounded by a switching valve (8).

8. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 6, characterized in that: The outer peripheral wall of the drying chamber (1) is provided with at least one reflux heating window (9) corresponding to the air guide groove (7), and the reflux heating window (9) has a dehumidification plate and a heating wire.

9. The atmospheric pressure drying device for rice husk-based silica aerogel according to claim 1, characterized in that: The drying chamber (1) is provided with a drying plate (11), and the bottom plate of the drying chamber (1) is equipped with a reflux device (12), which has a pipeline connected to the fluid pump (6).

Images