Novel protective rotary kiln equipment

Abstract

The invention relates to novel protective rotary kiln equipment which comprises a rotary kiln body, a transmission device, a sealing device and a shell, the rotary kiln body and the sealing device are both located in the shell, and the whole or part of the transmission device is located in the shell; the transmission device is used for driving the rotary kiln body to rotate, and the shell is static and keeps a sealed state in the production period. The shell can provide heat preservation, wind prevention, rain prevention, dust prevention, confidentiality improvement, energy conservation and protection for the rotary kiln body, leaked gas or solid can enter the shell even if the rotary kiln body leaks, the shell is kept in a sealed state in the production period, the gas or solid leaked from the rotary kiln body can be kept in the shell, and the rotary kiln body is prevented from being damaged. And the rotary kiln body is isolated from the external environment and is not in contact with the shell, so that the production safety can be essentially ensured, the shell is static and does not need to be maintained basically, and the rotary kiln can be safely used for a long time.

Description

Technical Field

[0001] The invention belongs to the technical field of rotary kilns, and in particular relates to a novel protective rotary kiln device. Background Art

[0002] Rotary kiln, also known as rotary kiln, is widely used in cement, chemical, building materials, drying and many other industries. Rotary kiln equipment includes a cylinder, a supporting device, a transmission device, a sealing device, a heating device, a feeding device and a discharging device. Generally, the volume and weight of rotary kiln equipment are large, and the large-diameter rotary kiln used in industry is even heavier. Therefore, it is a critical issue to maintain good sealing at both ends of the equipment while the rotary kiln is rotating. At present, the sealing technology of rotary kiln mainly includes: (1) using the downward pressure of the cylinder or gravity to tighten the friction plate and the friction ring, so as to form a good contact dynamic seal between the contact surface of the friction plate and the friction ring; (2) using high-pressure compressed air to form a high-pressure compressed air environment between the fixed kiln tail and the rotating cylinder to prevent the gas in the cylinder from leaking out; (3) using a labyrinth structure and a multi-stage packing sealing method to extend the distance that gas and material need to leak through and increase the number and length of sealing surfaces.

[0003] However, in industrial applications, the cylinder of the rotary kiln will experience thermal expansion and contraction. In addition, the cylinder is generally heated unevenly in the axial and radial directions, causing the cylinder to deform under high temperature and heavy weight. Sometimes, the sealing surface will be corroded by the material in the cylinder. The above factors will gradually damage the sealing surfaces at both ends of the cylinder, causing the seal to gradually fail and be damaged, and the production safety of the rotary kiln equipment cannot be guaranteed. With the advancement of science and technology and society, environmental protection requirements are becoming higher and higher, and the reactions carried out in the rotary kiln are becoming more and more diverse, which puts higher sealing requirements on the rotary kiln equipment. For example, hydrogen reduction reaction and silane deposition to prepare silicon-carbon negative electrode materials are carried out in the rotary kiln equipment. Silane and hydrogen are extremely flammable and explosive substances. It is necessary to ensure zero leakage of the rotary kiln, which is a technical problem in this field. Summary of the invention

[0004] In view of the above problems, the present invention provides a novel protective rotary kiln equipment, including a rotary kiln body, a transmission device, a sealing device and a shell, wherein the rotary kiln body and the sealing device are both located inside the shell, and the transmission device is located in whole or in part inside the shell; the transmission device is used to drive the rotary kiln body to rotate, and the shell is stationary and remains sealed during production.

[0005] The transmission device may be entirely or partially located inside the shell. Optionally, when the transmission device is partially located inside the shell, the rotating parts of the transmission device in contact with the rotary kiln body are located inside the shell, and the other parts of the transmission device are located outside the shell, and the transmission parts of the transmission device penetrate into the shell, and the penetration position is sealed.

[0006] Optionally, the bottom of the shell is supported by the ground or a base is provided to improve the stability of the shell.

[0007] Optionally, a supporting component is provided inside the shell, the bottom of the supporting component is fixedly connected to the bottom of the shell, and the top of the supporting component is rotatably connected to the rotating kiln body, so as to support the rotating rotating kiln body and improve the stability and safety of the rotating kiln body.

[0008] Optionally, the shell is made of stainless steel and is connected to an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to a protective gas source device for inputting protective gas into the shell, and the air outlet pipe is connected to an exhaust gas treatment device for collecting, storing or treating exhaust gas discharged from the shell.

[0009] Further optionally, the protective gas is a gas that does not contain oxygen. Preferably, the protective gas is an inert gas that does not contain oxygen.

[0010] Further optionally, when production starts, the air pressure in the shell is lower than the air pressure inside the rotary kiln body, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time;

[0011] When the sealing device of the rotary kiln body fails, the gas in the rotary kiln body leaks into the shell, causing the air pressure in the shell to increase. When the air pressure in the shell rises to the same as the pressure in the rotary kiln body, the gas in the rotary kiln body stops leaking.

[0012] Further optionally, when production starts, the air pressure in the shell is higher than the air pressure inside the rotary kiln body, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time;

[0013] When the sealing device of the rotary kiln body fails, the protective gas in the shell enters the rotary kiln body and the air pressure in the shell decreases. When the pressure gauge detects the decrease in air pressure in the shell, it is judged that the rotary kiln body is leaking.

[0014] Optionally, the lines of the transmission device and the rotary kiln body pass through the shell and are then connected to an external power supply device. The position where the lines pass through the shell is sealed to prevent leakage of the shell.

[0015] Optionally, the shell is provided with an openable and closable inspection door to facilitate the inspection and maintenance of the equipment inside the shell; the shell is provided with a window to facilitate observing the working conditions of the equipment inside the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of a new type of protective rotary kiln equipment;

[0017] Figure 2 It is a structural schematic diagram of another new type of protective rotary kiln equipment;

[0018] Figure 3 It is a structural schematic diagram of another new type of protective rotary kiln equipment.

[0019] In the attached drawings, 1-rotating kiln body, 2-transmission device, 3-shell, 4-support component, 5-air inlet pipe, 6-air outlet pipe, 7-base. DETAILED DESCRIPTION

[0020] This embodiment provides a new type of protective rotary kiln equipment, such as Figure 1-Figure 3 As shown, it includes a rotary kiln body 1, a transmission device 2, a sealing device and a shell 3. The rotary kiln body 1 and the sealing device are both located inside the shell 3, and the transmission device 2 is located inside the shell 3 in whole or in part. The transmission device 2 is used to drive the rotary kiln body 1 to rotate, and the shell 3 is stationary and remains sealed during production.

[0021] The present invention sets the shell 3 outside the conventional rotary kiln device, and covers the rotary kiln body 1 and the sealing device inside the shell 3. The shell 3 can not only provide heat preservation and protection for the rotary kiln body 1, but also does not require too high requirements for the rotary kiln body 1 and the sealing device. Even if the rotary kiln body 1 leaks, the leaked gas or solid can enter the shell 3. During production, the shell 3 remains sealed, and the gas or solid leaked from the rotary kiln body 1 can be kept in the shell 3 and will not leak to the outside of the shell 3. The rotary kiln body 1 is isolated from the external environment, and the rotary kiln body 1 and the shell 3 are not in contact, which can essentially ensure the safety of production. The shell 3 is stationary, basically does not require maintenance, and can be used safely for a long time. When in use, the reaction material can be added to the rotary kiln body 1 first, and then the rotary kiln body 1 is closed and sealed, and then the shell 3 is closed, and then the protective gas is input into the shell 3, and the rotary kiln body 1 is heated, and the reaction starts. In addition, the shell is windproof, rainproof and dustproof, which prevents the external environment from interfering with the internal rotating kiln body, improves safety, and can also increase the confidentiality of the rotating kiln body, preventing the structure of the rotating kiln body from being peeped from the outside.

[0022] The transmission device 2 may be entirely or partially located inside the shell 3. Optionally, when the transmission device 2 is partially located inside the shell 3, the rotating parts of the transmission device 2 that are in contact with the rotary kiln body 1 are located inside the shell 3, and the other parts of the transmission device 2 are located outside the shell 3, and the transmission parts of the transmission device 2 penetrate into the shell 3, and the penetration position is sealed.

[0023] Optionally, the bottom of the shell 3 is supported by the ground or a base 7 is provided to improve the stability of the shell 3.

[0024] Further optionally, if the shell 3 is supported by the ground, a sealing component is provided at the position where the bottom of the shell 3 contacts the ground to maintain the airtightness of the shell 3. The bottom surface of the shell 3 is replaced by the ground, which can reduce the weight of the shell 3 and reduce the cost.

[0025] Optionally, a supporting component 4 is provided inside the shell 3, the bottom of the supporting component 4 is fixedly connected to the bottom of the shell 3, and the top of the supporting component 4 is rotatably connected to the rotary kiln body 1, so as to support the rotating rotary kiln body 1 and improve the stability and safety of the rotary kiln body 1.

[0026] The position where the support component 4 is connected to the rotary kiln body 1 is different from the position where the transmission device 2 is connected to the rotary kiln body 1, so that the transmission device 2 drives the rotary kiln body 1 to rotate without being affected by the support component 4, and the support component 4 plays a role similar to a bearing, and the support component 4 is stationary. The form of the support component 4 is not limited, as long as it can adapt to the shape of the shell 3 and the rotary kiln body 1.

[0027] The volume of the shell 3 is definitely larger than that of the rotary kiln body 1. The shell 3 is arranged on the ground or on a base and remains stationary, and has higher stability than the rotary kiln body 1 and the transmission device 2. The shell 3 is hollow inside, which reduces the deadweight of the shell 3. The shape of the shell 3 is not limited, and it can adapt to the shape of the rotary kiln body 1 and the sealing device, which reduces the cost and processing difficulty of the shell 3, and also facilitates the on-site transformation of the installed and running rotary kiln body 1. The shell 3 has a simple structure and is always stationary, which is easy to install and maintain. After the support component 4 is installed in the shell 3, since the support component 4 is also stationary, the counterweight in the lower part of the shell 3 is increased, which can further enhance the stability of the shell 3.

[0028] Optionally, the shell 3 is made of stainless steel and is connected to an air inlet pipe 5 and an air outlet pipe 6. The air inlet pipe 5 is connected to a protective gas source device for inputting protective gas into the shell 3, and the air outlet pipe 6 is connected to an exhaust gas treatment device for collecting, storing or treating exhaust gas discharged from the shell.

[0029] Further optionally, the protective gas is a gas without oxygen, preferably, the protective gas is an inert gas without oxygen. The high-temperature gas or solid leaking from the rotary kiln body 1 enters the shell 3 and meets the gas in the shell 3. There is no oxygen in the shell 3, so the material is prevented from deflagration or explosion.

[0030] Further optionally, when production starts, the air pressure in the shell 3 is lower than the air pressure inside the rotary kiln body 1, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time;

[0031] When the sealing device of the rotary kiln body fails, the gas in the rotary kiln body leaks into the shell, causing the air pressure in the shell to increase. When the air pressure in the shell rises to the same as the pressure in the rotary kiln body, the gas in the rotary kiln body stops leaking.

[0032] Further optionally, when production starts, the air pressure in the shell is higher than the air pressure inside the rotary kiln body, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time;

[0033] When the sealing device of the rotary kiln body fails, the protective gas in the shell enters the rotary kiln body and the air pressure in the shell decreases. When the pressure gauge detects the decrease in air pressure in the shell, it is judged that the rotary kiln body is leaking.

[0034] Optionally, the transmission device 2 and the circuit of the rotary kiln body 1 pass through the shell 3 and are connected to an external power supply device, and the position where the circuit passes through the shell 3 is sealed to prevent leakage of the shell 3. If the rotary kiln body 1 has an external heating device, the heating device is also arranged inside the shell 3, and the circuit of the heating device passes through the outer shell.

[0035] Optionally, the shell 3 is provided with an openable and closable inspection door to facilitate the inspection and maintenance of the equipment inside the shell 3; the shell 3 is provided with a window to facilitate observing the working conditions of the equipment inside the shell 3.

[0036] Optionally, the rotary kiln body 1 may be connected to a feed pipe and a discharge pipe for respectively inputting materials into the rotary kiln body and discharging products. The rotary kiln body may also be connected to an air supply pipe and an exhaust pipe for respectively inputting reaction gas into the rotary kiln body and discharging waste gas.

[0037] Optionally, a heat-insulating material is laid on the outer side and / or the inner side of the shell to further insulate the internal rotary kiln body.

[0038] The rotary kiln body, transmission device, sealing device and supporting components of the present invention are all conventional industrial equipment in the industrial field, such as cylindrical rotary kiln, cement rotary kiln, gear transmission device, roller transmission device, flexible sealing device, labyrinth sealing device, cylinder sealing device, spring lever sealing device, asbestos rope end face friction sealing device, graphite block sealing device, movable slip ring sealing device, laminated spring plate sealing device, etc., which can be improved by applying the technology of the present invention.

[0039] The novel protective rotary kiln equipment of the present invention also has the following beneficial effects:

[0040] 1. Heat preservation and energy saving and emission reduction: At present, the thermal efficiency of industrial rotary kilns is generally between 50-85%, and the total power is hundreds of kilowatts to thousands of kilowatts. Especially for large industrial kilns, the energy consumption cost is very high. The present invention can reduce heat loss and energy consumption by adding a shell outside the rotary kiln body, which has good economic efficiency.

[0041] 2. Wind and rain protection: Industrial rotary kilns are large in size and tens of meters in length. Considering the cost of plant construction, they are generally arranged outdoors. The housing of the present invention can prevent the influence and damage of wind, rain and snow on the rotary kiln body;

[0042] 3. Dust prevention: The working environment in industrial workshops is complex and usually accompanied by dust. The rotary kiln is a large system. After long-term operation, dust will accumulate in components such as motors. Some conductive metal dust or carbon dust will cause hazards such as motor short circuits.

[0043] 4. Prevention of harmful gases: The environment in the workshop is complex, and the air usually contains various small amounts of harmful gas components, such as acidic gases (HCl, H2S), alkaline gases (NH3, etc.), sulfide gases, etc. There are many parts of the rotary kiln body, sealing device and transmission device, as well as various electrical appliances and motors, which are easily affected by harmful gases. For example, metal structural parts will be corroded and aged faster. The housing of the present invention can prevent harmful gases from invading the internal equipment;

[0044] 5. Increase the confidentiality of the process system: The research and development of large kilns is hard-won and involves many technical secrets and technical details. After adding the shell, the exposure of internal equipment is greatly reduced, which is conducive to increasing the confidentiality of the equipment;

[0045] 6. Enhanced protection for workers: Rotary kilns usually work at high temperatures. By setting up a shell on the outside, workers are not likely to touch the internal equipment, which can enhance the safety of the working environment, avoid burns and high temperature injuries, and provide better protection for workers.

[0046] Example 1

[0047] This embodiment provides a new type of protective rotary kiln equipment for producing carbon nanotubes. As mentioned above, the rotary kiln and its supporting heating furnace, transmission device, and sealing device are all placed inside the shell. The rotary kiln is a horizontal cylindrical shape with a diameter of 1.5 meters and a length of 20 meters. It is made of 20mm thick, 310S stainless steel, and the effective reaction length is 15 meters. The heating furnace is arranged outside the rotary kiln. The length of the heating furnace is 18 meters and the outer diameter is 2.7 meters. The two ends of the rotary kiln are respectively provided with a kiln head and a kiln tail. The kiln head and the kiln tail are sealed with the middle part of the rotary kiln by a combined scale structure. The two ends of the rotary cylinder are respectively connected with conventional transmission devices, including gears, supporting wheels, and motors, which are used to drive the rotary kiln to rotate.

[0048] The shell is stationary and is made of stainless steel sheets welded together. The dimensions are 24 meters long, 5 meters high, and 5 meters wide. The bottom of the shell is supported by a support frame. The transmission device and the rotary kiln line pass through the shell and are connected to the external power supply device. The position where the line passes through the shell is sealed to prevent the shell from leaking. There are several windows on the top and sides of the shell.

[0049] The production process of carbon nanotubes requires the use of flammable and explosive hydrocarbon gases, such as methane, as a carbon source. In the process of using methane to produce carbon nanotubes, methane will crack and increase in volume, and the tail gas in the rotary kiln has a high content of hydrogen. If the tail gas in the rotary kiln leaks during the production process, it will be very dangerous because the explosion range of hydrogen is very wide and the lower explosion limit is particularly low, with an explosion range of 4% to 75%. Therefore, the sealing of the rotary kiln is particularly critical.

[0050] The two ends of the shell are respectively connected to the air inlet pipe and the air outlet pipe. The air inlet pipe is connected to the nitrogen cylinder, and the air outlet pipe is connected to the exhaust gas treatment device. Nitrogen is filled into the space between the shell and the rotary kiln. After repeated replacement, there is very little oxygen in the space between the shell and the rotary kiln, and the nitrogen pressure in the space is 0.005MPa.

[0051] The two ends of the rotary kiln are respectively connected to the raw gas pipe and the tail gas pipe, which pass through the shell and are respectively connected to the raw gas cylinder and the tail gas treatment device outside the shell. Seals are provided at the positions where the raw gas pipe and the tail gas pipe pass through the shell.

[0052] After the catalyst and reaction materials are put into the rotary kiln, it is sealed and the temperature is slowly raised for 5 hours. The rotary kiln is heated to 750℃ and natural gas is introduced through the raw gas pipe. The natural gas flow rate is 1098.8m 3 / h, the pressure in the rotary kiln is 0.010MPa. The tail gas is discharged through the tail gas pipe.

[0053] Since the air pressure in the shell is 0.005MPa and the pressure in the rotary kiln is 0.010MPa, if the fish scale sealing device at the head and tail of the kiln leaks, the gas in the rotary kiln will leak into the shell, and dangerous gases such as natural gas and hydrogen will not leak into the working environment outside the shell to prevent explosion. The shell is a static object and has good safety for long-term continuous use. A pressure gauge is set on the shell to monitor the pressure inside the shell in real time; when the sealing device of the rotary kiln fails, the gas in the rotary kiln leaks into the shell, causing the air pressure in the shell to increase. When the air pressure in the shell rises to the same as the pressure in the rotary kiln, the gas in the rotary kiln will no longer leak.

[0054] The shell of this embodiment can effectively prevent dust leakage in the rotary kiln, greatly improve the production environment, prevent workers from inhaling dust, and prevent product loss. At the same time, the shell can insulate the rotary kiln, improve thermal efficiency, reduce energy consumption, and directly save production costs.

[0055] Example 2

[0056] This embodiment provides a new type of protective rotary kiln equipment for limestone calcining experiments. As mentioned above, the lime calcining rotary kiln and its supporting roller transmission device and sealing device are placed inside the shell. The roller transmission device drives the lime calcining rotary kiln to rotate, and the sealing device seals the two ends of the horizontal rotary kiln in a conventional manner. The shell is stationary, and the bottom of the shell is supported by the ground. A sealing component is set at the position where the bottom of the shell contacts the ground to maintain the airtightness of the shell. A supporting component is also provided inside the shell. The bottom of the supporting component is set on the ground, and the top is rotatably connected to the lime calcining rotary kiln, which does not affect the rotation of the rotary kiln and only plays a role similar to a bearing. The lines of the transmission device and the rotary kiln pass through the shell and are then connected to an external power supply device. The position where the lines pass through the shell is sealed. The shell is provided with an openable and closable inspection door and window.

[0057] The shell is made of stainless steel, and both ends of the shell are respectively connected to an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to a nitrogen cylinder, and the air outlet pipe is connected to an exhaust gas treatment device.

[0058] The particle size of limestone entering the kiln is 20-40mm, the mass is 85.6kg, and the calcination temperature is 1170℃. At the beginning of production, the air pressure in the shell is higher than the air pressure inside the rotary kiln. A pressure gauge is set on the shell to monitor the pressure inside the shell in real time. When the sealing device of the rotary kiln fails, the nitrogen in the shell enters the rotary kiln, causing the air pressure inside the shell to decrease. When the pressure gauge detects that the air pressure in the shell decreases, it is judged that the horizontal rotary kiln has a leak, and it can be repaired or wait until the air pressure in the shell decreases to the same as the pressure in the rotary kiln, and the gas in the lime calcining rotary kiln will no longer leak.

[0059] The shell of this embodiment can effectively prevent dust leakage from the lime calcining rotary kiln, greatly improve the production environment, and prevent workers from inhaling dust. At the same time, the shell can insulate the lime calcining rotary kiln experimental device, improve thermal efficiency, reduce energy consumption, and directly save production costs. The lime produced by calcination is of good quality, high purity, and good activity.

Claims

1. A new type of protective rotary kiln equipment, characterized in that: It includes a rotary kiln body, a transmission device, a sealing device and a shell. The rotary kiln body and the sealing device are both inside the shell, and the transmission device is wholly or partially inside the shell. The transmission device is used to drive the rotary kiln body to rotate, and the shell is stationary and remains sealed during production.

2. The novel protective rotary kiln equipment according to claim 1 is characterized in that: When the transmission device is partially inside the shell, the rotating parts of the transmission device in contact with the rotary kiln body are inside the shell, and the other parts of the transmission device are outside the shell. The transmission parts of the transmission device penetrate into the shell, and the penetration position is sealed.

3. The novel protective rotary kiln equipment according to claim 1 is characterized in that: The bottom of the shell is supported by the ground or a base, so as to improve the stability of the shell.

4. The novel protective rotary kiln equipment according to claim 1 is characterized in that: A supporting component is arranged inside the shell, the bottom of the supporting component is fixedly connected to the bottom of the shell, and the top of the supporting component is rotatably connected to the rotary kiln body, so as to support the rotating rotary kiln body and improve the stability and safety of the rotary kiln body.

5. The novel protective rotary kiln equipment according to claim 1 is characterized in that: The shell is made of stainless steel and is connected to an air inlet pipe and an air outlet pipe. The air inlet pipe is connected to a protective gas source device for inputting protective gas into the shell, and the air outlet pipe is connected to an exhaust gas treatment device for collecting, storing or treating exhaust gas discharged from the shell.

6. The novel protective rotary kiln equipment according to claim 5 is characterized in that: The protective gas is a gas that does not contain oxygen.

7. The novel protective rotary kiln equipment according to claim 5 is characterized in that: When production starts, the air pressure in the shell is lower than the air pressure inside the rotary kiln body, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time; When the sealing device of the rotary kiln body fails, the gas in the rotary kiln body leaks into the shell, causing the air pressure in the shell to increase. When the air pressure in the shell rises to the same as the pressure in the rotary kiln body, the gas in the rotary kiln body stops leaking.

8. The novel protective rotary kiln equipment according to claim 5 is characterized in that: When production starts, the air pressure in the shell is higher than the air pressure inside the rotary kiln body, and a pressure gauge is provided in the shell to monitor the pressure inside the shell in real time; When the sealing device of the rotary kiln body fails, the protective gas in the shell enters the rotary kiln body and the air pressure in the shell decreases. When the pressure gauge detects the decrease in air pressure in the shell, it is judged that the rotary kiln body is leaking.

9. The novel protective rotary kiln equipment according to claim 1 is characterized in that: The lines of the transmission device and the rotary kiln body pass through the shell and are then connected to an external power supply device. The position where the lines pass through the shell is sealed to prevent leakage of the shell.

10. The novel protective rotary kiln equipment according to claim 1 is characterized in that: The shell is provided with an openable and closable inspection door to facilitate the inspection and maintenance of the equipment inside the shell; the shell is provided with a window to facilitate observing the working conditions of the equipment inside the shell.

Images