Totally-closed flame-retardant drying device
The fully enclosed flame-retardant drying device with a fully enclosed design and real-time monitoring solves the problem of difficult-to-control oxygen concentration in large rotary drum dryers, achieves an oxygen-deficient state in the drying drum, prevents explosion accidents, reduces production and operating costs, and improves drying efficiency and uniformity.
Patent Information
- Application Number
- CN202521918266.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-08
- Publication Date
- 2025-10-21
- Estimated Expiration
- 2035-09-08
AI Technical Summary
It is difficult to ensure that the internal oxygen content of large rotary drum dryers is lower than the combustion limit, which can easily cause combustion or explosion accidents, and the sealing method increases production and operating costs.
A fully enclosed flame-retardant drying device is designed. The wet material is fed into the device through a shaftless blade pusher. The combustion furnace generates low-oxygen hot air, which is further burned in the hot gas expansion box to generate carbon dioxide, ensuring that the oxygen concentration in the drying cylinder is in an oxygen-deficient or oxygen-deficient state. Oxygen and temperature sensors are set for real-time monitoring to control the oxygen concentration and temperature of the drying process.
Ensure that the oxygen concentration in the drying cylinder is far below the combustion limit, prevent explosion accidents, reduce electricity and operating costs, improve heat transfer efficiency and drying uniformity, and achieve safe production.
Smart Images
Figure CN223460752U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a kind of totally enclosed flame-retardant drying device, belong to drying equipment technical field. BACKGROUND
[0002] Large rotary drum dryer is a kind of continuous drying equipment widely used in chemical industry, metallurgy, building materials and other industries. Large rotary drum dryer usually adopts semi-closed design, which includes a rotating steel cylinder with an inclination to the horizontal plane; two rolling rings are installed on the outer wall of the rotating cylinder, and the weight of the entire rotating cylinder is supported by the two rolling rings and the supporting wheel; a gear is provided at the waist of the rotating cylinder, and the rotating cylinder is slowly rotated by driving the gear to rotate by a driving motor; a fixed scoop is provided on the inner wall of the rotating cylinder; a hot air blower is provided on one side of the discharge end of the rotating cylinder; sealing devices are provided at both ends of the rotating cylinder, and the sealing method uses one of the following four methods: labyrinth, axial contact, radial contact and positive pressure air seal. The operation process of the large rotary drum dryer is as follows: wet material is added from the feed end of the rotating cylinder, and is continuously scooped up and evenly spread by the rotating cylinder, the wet material moves from the feed end to the discharge end and is discharged, and the hot air blown by the hot air blower enters the rotating cylinder from the discharge end and is in countercurrent contact with the wet material for heat exchange, and the exhaust gas after heat exchange is discharged from the feed end of the rotating cylinder. This large rotary drum dryer has the following defects:
[0003] 1. Oxygen concentration is difficult to control: the semi-closed rotating cylinder is difficult to ensure that the internal oxygen content is below 12%, i.e. the internal oxygen concentration is in a lean oxygen or oxygen-deficient state, which is prone to cause combustion or explosion accidents;
[0004] 2. High cost: on the one hand, the rotating cylinder needs to be driven by a driving motor, which increases the electricity cost; on the other hand, when the sealing method at both ends of the rotating cylinder is mechanical sealing or air sealing, the sealing material of the mechanical sealing needs to be replaced regularly, and the air sealing consumes compressed air, so the production and operation cost is also increased. INVENTION CONTENTS
[0005] The utility model aims at providing a kind of totally enclosed flame-retardant drying device, solve the problem that oxygen concentration is difficult to control, ensure that the oxygen concentration in drying cylinder is in a lean oxygen or oxygen-deficient state, prevent the explosion accident from occurring in drying process.
[0006] In order to achieve the above purpose, the technical scheme adopted by the utility model is:
[0007] The application relates to a totally-enclosed flame-retardant drying device, which comprises a drying cylinder, a feeding port and a material and waste heat gas discharging port arranged at two ends of the drying cylinder respectively, an axisless blade pusher arranged at the feeding port, a transmission shaft arranged in the drying cylinder, a plurality of scoops arranged on the transmission shaft, a driving device connected to one end of the transmission shaft, a combustion furnace arranged outside the drying cylinder, a combustion hot gas expansion tank connected to one side of the combustion furnace, the combustion hot gas expansion tank being communicated with one end of the drying cylinder close to the feeding port, and a fuel conveying tank connected to the other side of the combustion furnace.
[0008] Wet material is sent into the drying cylinder from the closed feeding port through the axisless blade pusher (so that the amount of oxygen brought by the wet material is very limited), and then the wet material is scooped up and scattered through the rotation of the transmission shaft and the plurality of scoops driven by the driving device. Fuel is conveyed from the fuel conveying tank to the combustion furnace, and hot air after full combustion (at this time, the oxygen concentration is between 2% and 6%) in the combustion furnace is sent to the combustion hot gas expansion tank. A small amount of oxygen in the hot air is further combusted in the combustion hot gas expansion tank to generate carbon dioxide and expand, so that the oxygen concentration in the hot air entering the drying cylinder is extremely low or even zero, and the carbon dioxide has a fire extinguishing function. At the same time, the pressure in the drying cylinder is kept in a positive pressure state, so that external air is prevented from entering the drying cylinder, the oxygen concentration in the drying cylinder is ensured to be in a lean oxygen or oxygen-deficient state, a flame-retardant effect is achieved, the hot air dries the wet material into dry material and drives the dry material to be discharged from the discharging port of the drying cylinder. Through the design of the drying cylinder into a totally-enclosed structure with only two entrances of the feeding and hot air, the totally-enclosed flame-retardant drying device solves the problem of difficult oxygen concentration control, ensures the oxygen concentration in the drying cylinder to be in a lean oxygen or oxygen-deficient state, and prevents the occurrence of deflagration accidents in the drying process.
[0009] Further, oxygen sensors are arranged at the material and waste heat gas discharging port and at the connection between the combustion hot gas expansion tank and the drying cylinder respectively, the oxygen sensors are connected with a control system, and the control system is electrically connected with the axisless blade pusher and the combustion furnace.
[0010] Further, temperature sensors are arranged at the material and waste heat gas discharging port and at the connection between the combustion hot gas expansion tank and the drying cylinder respectively, the temperature sensors are connected with a control system, and the control system is electrically connected with the axisless blade pusher and the combustion furnace.
[0011] Further, the combustion hot gas expansion tank is communicated with one end of the drying cylinder close to the feeding port through a hot air inlet. In order to make the hot air flow spirally in the drying cylinder, the outer wall inner surface of the hot air inlet is tangentially arranged with the outer wall inner surface of the drying cylinder, and the rotating direction of the hot air inlet is kept consistent with the rotating direction of the scoops, so that the wet material is fully heated under the action of the force, and the water in the wet material is evaporated into superheated steam.
[0012] Further, in order to heat the wet material uniformly, a plurality of scoops are arranged at different angles along the radial direction of the transmission shaft, and the scoops at adjacent radial sections of the transmission shaft are arranged at staggered angles, and the scoops are arranged vertically to the transmission shaft.
[0013] Further, in order to separate the dried material and purify the waste gas in the tail gas of the exhaust port, a cyclone separator is arranged outside the drying cylinder and is communicated with the material and waste heat gas exhaust port, and the tail gas after dust removal of the cyclone separator is communicated with the combustion furnace through a pipeline, so that the waste gas in the tail gas is burned by the combustion furnace.
[0014] Compared with the prior art, the full-closed flame-retardant drying device has the following beneficial effects:
[0015] 1. The full-closed flame-retardant drying device ensures that the drying cylinder is in an oxygen-deficient or oxygen-lean state, and the sum of the two inlet oxygen inlets in the drying cylinder is far below the combustion limit value of 12%, thereby ensuring that the drying process will not deflagrate, and ensuring the safety production of the drying process.
[0016] 2. The full-closed flame-retardant drying device is monitored in real time by the oxygen sensor, further ensuring that the drying cylinder is in an oxygen-deficient or oxygen-lean state, and preventing the occurrence of deflagration accidents.
[0017] 3. The full-closed flame-retardant drying device is monitored in real time by the temperature sensor, so that the hot air inlet temperature of the drying cylinder is maintained between 230 DEG C and 250 DEG C, the drying tail gas outlet temperature is maintained between 120 DEG C and 150 DEG C, the moisture in the tail gas is discharged as superheated steam, and the fuel amount of the combustion furnace and the amount of wet material are adjusted according to the monitored temperature.
[0018] 4. The full-closed flame-retardant drying device communicates the combustion hot gas expansion tank with one end of the drying cylinder close to the feeding port, and sets the hot air sent out by the combustion hot gas expansion tank to enter the drying cylinder from the tangent direction, so as to ensure that the movement direction of the hot air and the wet material is consistent, the contact is more sufficient, and the heat transfer efficiency and the drying uniformity are improved.
[0019] 5. The full-closed flame-retardant drying device sends the hot air in the expansion tank into the drying cylinder, so that the gas pressure of the hot air in the drying cylinder is greater than the gas pressure outside the drying cylinder, so that the oxygen in the external air cannot enter the drying cylinder, further ensuring that the drying cylinder is in an oxygen-deficient or oxygen-lean state, and preventing the occurrence of deflagration accidents.
[0020] 6. The full-closed flame-retardant drying device is designed to have only two full-closed structures of feeding and hot air entering the two inlets, and the drying cylinder does not rotate during the drying process, thereby saving the electricity, production and operation costs. BRIEF DESCRIPTION OF DRAWINGS
[0021] Figure 1 is a three-dimensional structure schematic diagram of an embodiment of the present utility model;
[0022] Figure 2 is a cross-sectional structure schematic diagram of the present utility model at the drying cylinder;
[0023] Figure 3 is a cross-sectional structure schematic diagram of the present utility model at the drying cylinder in A-A direction;
[0024] Figure 4 is an electric principle schematic diagram of the explosion-proof alarm automatic control of the present utility model;
[0025] Figure 5 is an electric principle schematic diagram of the drying cylinder temperature automatic control of the present utility model;
[0026] In the drawing: 1, wet material box; 2, shaftless blade pusher; 3, drying cylinder; 31, material and waste heat gas discharge port; 4, hot air inlet; 5, combustion hot gas expansion tank; 6, combustion furnace; 7, fuel delivery tank; 71, fuel inlet; 8, cyclone separator; 81, dry material outlet end; 9, transmission shaft; 10, scoop plate; 11, driving device; 12, feeding motor; 13, feeding speed reducer; 14, oxygen sensor; 15, temperature sensor; 16, combustion furnace controller; 17, feeding motor controller; 18, explosion-proof alarm automatic controller; 19, drying cylinder temperature automatic controller. DETAILED DESCRIPTION
[0027] The present utility model will be described in further detail below in combination with the drawings.
[0028] Referring to Figures 1 to 3 , the present embodiment provides a totally-enclosed flame-retardant drying device. The totally-enclosed flame-retardant drying device comprises a wet material box 1, a shaftless blade pusher 2, a drying cylinder 3, a combustion hot gas expansion tank 5, a combustion furnace 6, a fuel delivery tank 7, and a cyclone separator 8. The wet material box 1 is used to provide wet material to the drying cylinder 3 through the shaftless blade pusher 2. The drying cylinder 3 is provided with a feeding port and a material and waste heat gas discharge port 31 at two ends respectively, and is provided with a transmission shaft 9 inside, a plurality of scoop plates 10 are arranged in the radial direction of the transmission shaft 9, and a driving device 11 is connected to one end of the transmission shaft 9 on the side of the discharge port 31. The combustion hot gas expansion tank 5, the combustion furnace 6, and the fuel delivery tank 7 are sequentially connected and located outside the drying cylinder 3, and the combustion hot gas expansion tank 5 is communicated with one end of the drying cylinder 3 close to the feeding port through a hot air inlet 4. The fuel delivery tank 7 is provided with a fuel inlet 71 at one end, which is used to provide fuel to the combustion furnace 6. The cyclone separator 8 is located outside the drying cylinder 3, and is communicated with the material and waste heat gas discharge port 31 of the drying cylinder 3, and the tail gas after dust removal of the cyclone separator 8 is sent to the combustion furnace 6.
[0029] Referring toFigure 1 The combustion hot gas expansion tank 5 is a hollow tank structure. The 2%-6% oxygen and a small amount of carbon monoxide in the hot air after full combustion from the combustion furnace 6 continue to burn and expand in the combustion hot gas expansion tank 5, so that the oxygen concentration in the hot air entering the fully-closed drying cylinder 3 is extremely low or even zero, i.e. in an oxygen-deficient or oxygen-lean state.
[0030] Referring to Figure 1 and Figure 2 , the shaftless blade pusher 2 is arranged at one end in the wet material tank 1 and extends to the feeding port at the other end, and is driven to rotate by the feeding motor 12 and the feeding speed reducer 13. The scraper 10 is arranged perpendicularly to the transmission shaft 9. The gap between the scraper 10 and the wall of the drying cylinder 3 is 10 mm, and the scraper 10 rotates at a speed of 3 r / min-8 r / min under the driving of the transmission shaft 9, lifts and sprinkles the wet material, and the wet material directly contacts with the hot air for heat exchange, and the water in the wet material evaporates into superheated steam and is sucked into the cyclone separator 8 together with the dry material for gas-solid separation. The driving device 11 includes a driving speed reducer and a driving motor connected with the transmission shaft 9.
[0031] Referring to Figure 3 , four scrapers 10 are installed on the same radial section of the transmission shaft 9, and the included angle between each two scrapers 10 is 90°, and the adjacent scrapers 10 on the transmission shaft 9 are arranged with a 45° offset.
[0032] Referring to Figure 3 , the drying cylinder 3 is in a cylindrical shape. The axis of the hot air inlet 4 is perpendicular to the axis of the drying cylinder 3. The inner surface of the outer wall of the hot air inlet 4 is tangentially arranged with the inner surface of the outer wall of the drying cylinder 3, i.e. the inner surface of the outer wall of the hot air inlet 4 is the inner surface of the outer wall farthest from the center axis of the drying cylinder 3 (i.e. the center of the circle). By arranging the hot air inlet 4 in the tangential direction of the drying cylinder 3, the hot air flows in a spiral in the drying cylinder 3 and keeps consistent with the rotation direction of the scraper 10. Figure 3
[0033] Referring to Figure 1 , Figure 4 and Figure 5 At the material and waste heat gas outlet 31 and at the hot air inlet 4, oxygen sensors 14 and temperature sensors 15 are provided, which are connected to a control system. The control system comprises an explosion-proof alarm automatic controller 18 and a drying cylinder temperature automatic controller 19. The explosion-proof alarm automatic controller 18 is electrically connected to the oxygen sensor 14 at the material and waste heat gas outlet 31, the oxygen sensor 14 at the hot air inlet 4, the combustion furnace controller 16 electrically connected to the combustion furnace 6, and the feeding motor controller 17 electrically connected to the feeding motor 12, respectively. The drying cylinder temperature automatic controller 19 is electrically connected to the temperature sensor 15 at the material and waste heat gas outlet 31, the temperature sensor 15 at the hot air inlet 4, and the combustion furnace controller 16 electrically connected to the combustion furnace 6, respectively. The combustion furnace controller 16 is used to control the air volume of the fan in the combustion furnace 6 and the amount of fuel, and the feeding motor controller 17 is used to control the amount of wet material.
[0034] Referring to Figure 4 , when implemented, the principle of the explosion-proof alarm automatic control is as follows:
[0035] When the oxygen sensor 14 detects that the oxygen concentration at the hot air inlet 4 exceeds 6%, the combustion furnace controller 16 will adjust the air volume of the fan in the combustion furnace 6 and the amount of fuel to change the combustion condition of the combustion furnace 6, so that the oxygen in the combustion furnace 6 is fully burned into carbon dioxide, thereby strictly controlling the oxygen content in the hot air inlet 4 to be below 6%. In addition, when the oxygen sensor 14 detects that the oxygen concentration at the material and waste heat gas outlet 31 exceeds 10%, the feeding motor controller 17 slows down the pushing speed of the shaftless blade pusher 2 to reduce the feeding of wet material. When the oxygen concentration at the material and waste heat gas outlet 31 reaches 12%, the shaftless blade pusher 2 is closed by the feeding motor controller 17 and the combustion furnace 6 is closed by the combustion furnace controller 16, and an audible and visual alarm is issued, so as to ensure that the drying cylinder 3 is in an oxygen-poor or oxygen-free state, to ensure that the system operates within a safe range, thereby preventing the occurrence of explosion accidents.
[0036] Referring to Figure 5 , when implemented, the principle of the drying cylinder temperature automatic control is as follows:
[0037] When the temperature sensor 15 measures the temperature of the hot air inlet 4 to be lower than 230℃, the burner controller 16 increases the flame temperature of the burner 6 to raise the temperature of the hot air inlet 4; when the temperature of the hot air inlet 4 reaches 250℃, the burner controller 16 reduces the flame of the burner 6 to maintain the temperature of the hot air inlet 4 of the drying cylinder 3 between 230℃ and 250℃. When the temperature sensor 15 measures the temperature of the material and waste heat gas outlet 31 to be lower than 120℃, the burner controller 16 increases the air volume of the burner 6 to raise the temperature in the drying cylinder 3; when the temperature of the material and waste heat gas outlet 31 is higher than 150℃, the burner controller 16 reduces the flame of the burner 6 to lower the temperature of the drying cylinder 3, so as to maintain the temperature of the material and waste heat gas outlet 31 of the drying cylinder 3 between 120℃ and 150℃.
[0038] By maintaining the temperature of the material and waste heat gas outlet 31 between 120℃ and 150℃, the water in the wet material is ensured to be discharged in the form of superheated steam, and the system is ensured to operate within a safe range, so as to prevent the occurrence of explosion accidents.
[0039] It should be particularly pointed out that the explosion-proof alarm automatic controller 18 has a higher priority than the drying cylinder temperature automatic controller 19.
[0040] Referring to Figure 1 The drying cylinder 3 is a fully enclosed device and is horizontally and statically placed. Since the drying cylinder 3 is designed to be fully enclosed, the operating cost of compressed air consumed by the gas sealing system when sealing is required is saved, and the production cost generated by mechanical sealing is also saved. Since the drying cylinder 3 does not rotate during the drying process, the original electricity cost is greatly reduced.
[0041] Referring to Figure 1 The waste heat gas and the dried material discharged from the material and waste heat gas outlet 31 are sucked into the cyclone separator 8. The dry material loses kinetic energy after being thrown to the wall under the action of centrifugal force in the cyclone separator 8 and slides to the lower dry material outlet end 81 of the cyclone separator 8, while the separated waste heat gas is discharged from the upper part of the cyclone separator 8, is dedusted, is sent to the burner 6, is further purified, and is recycled.
[0042] The movement principle of the wet material from the feeding port to the material and waste heat gas outlet 31 is as follows:
[0043] One is that the wet material rotates (i.e. scoops up, spills down) in the drying cylinder 3 under the driving of the scoop plate 10; two is that the tangential hot air spirally flows in the drying cylinder 3, and also drives the wet material to rotate, the rotating direction of the hot air is consistent with the rotating direction of the scoop plate 10 on the shaft; three is that the wet material scooped up by the scoop plate 10 will spill down under the action of gravity after reaching a certain angle; under the action of the three forces, the wet material moves from one end of the drying cylinder 3 close to the feeding port to the other end close to the discharge port 31. In the moving process, the hot air and the wet material in the drying cylinder 3 are in full contact, the heat transfer efficiency is high, and the drying is uniform, thereby solving the problem of uneven drying of the existing material.
[0044] The embodiments of the present application and the features in the embodiments can be combined with each other without conflict, and the embodiments of the present application and the features in the embodiments can be combined with each other without conflict. The specific embodiments described above are only illustrative, not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims.
Claims
1. A totally enclosed flame-retardant drying device, comprising a drying cylinder (3) having a feeding port and a material and waste heat gas discharge port (31) at each end, respectively, and an axleless blade pusher (2) at the feeding port; a transmission shaft (9) is arranged in the drying cylinder (3), a plurality of scoops (10) are arranged on the transmission shaft (9), and a driving device (11) is connected to one end of the transmission shaft (9); a combustion furnace (6) is arranged outside the drying cylinder (3); characterized in that, The combustion furnace (6) is connected with a combustion hot gas expansion tank (5) on one side, the combustion hot gas expansion tank (5) is communicated with the drying cylinder (3) near the feeding port end, and the combustion furnace (6) is connected with a fuel conveying tank (7) on the other side.
2. The fully-enclosed fire-retardant drying apparatus of claim 1, wherein, An oxygen sensor (14) is arranged at the material and waste heat gas exhaust port (31) and the connection between the combustion hot gas expansion tank (5) and the drying cylinder (3) respectively, the oxygen sensor (14) is connected with a control system, and the control system is electrically connected with the shaftless blade pusher (2) and the combustion furnace (6).
3. A fully-enclosed fire-retardant drying apparatus as claimed in claim 1 or 2, wherein, A temperature sensor (15) is arranged at the material and waste heat gas exhaust port (31) and the connection between the combustion hot gas expansion tank (5) and the drying cylinder (3) respectively, the temperature sensor (15) is connected with a control system, and the control system is electrically connected with the shaftless blade pusher (2) and the combustion furnace (6).
4. The totally enclosed fire rated drying apparatus as claimed in claim 1, wherein, The combustion hot gas expansion tank (5) is communicated with the drying cylinder (3) near the feeding port end through a hot air inlet (4), and the outer wall inner surface of the hot air inlet (4) is tangentially arranged with the outer wall inner surface of the drying cylinder (3).
5. The fully-enclosed fire-retardant drying apparatus of claim 4, wherein, A plurality of scoops (10) are arranged at different radial angles along the transmission shaft (9), the scoops (10) at adjacent radial sections of the transmission shaft (9) are arranged at staggered angles, and the scoops (10) are arranged perpendicularly to the transmission shaft (9).
6. The totally enclosed fire rated drying apparatus as claimed in claim 1, wherein, A cyclone separator (8) is arranged outside the drying cylinder (3), and the cyclone separator (8) is communicated with the material and waste heat gas exhaust port (31) and the combustion furnace (6) respectively.