A roasting drying and steam drying integrated drying system and method
The drying system, which combines a series roasting furnace and a steam rotary drying unit with automated control, solves the problems of low thermal efficiency and dust explosion risk in the drying of high-moisture materials, and achieves efficient, safe and continuous material drying. It is suitable for the processing of high-moisture materials in chemical, metallurgical and other fields.
Patent Information
- Application Number
- CN202610617032.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-05-07
- Publication Date
- 2026-06-12
AI Technical Summary
Existing drying processes suffer from low thermal efficiency, high risk of dust explosion, large equipment size and high energy consumption when handling high-humidity materials. Furthermore, existing equipment combinations lack systematic thermal integration and process optimization.
An integrated drying system consisting of a roasting furnace unit and a steam rotary drying unit connected in series is adopted. The system is connected by a sealed conveyor hood and combined with a controller to achieve automated control. The high-temperature exhaust gas from the roasting furnace is used to preheat the steam pipe rotary drying unit to achieve efficient and safe material drying.
It significantly improves thermal efficiency, reduces equipment footprint, lowers energy consumption, avoids dust leakage and explosion risks, and achieves continuous, efficient, gentle and deep drying of materials. It has a wide range of applications and a high degree of automation.
Smart Images
Figure CN122191961A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the technical field of industrial drying, and in particular to an integrated drying system and method that combines roasting drying and steam drying in series. Background Technology
[0002] In chemical, metallurgical, and mineral processing industries, drying high-moisture materials such as lignite, metal concentrates, and industrial sludge is one of the most energy-intensive processes. Traditional drying processes typically employ single-stage direct drying methods, such as airflow dryers and drum dryers, which suffer from low thermal efficiency (usually only 50%–70%), a risk of dust explosions, and difficulties in exhaust gas treatment. Indirect drying methods are also used, commonly including rotary steam tube dryers and calcining furnaces. Rotary steam tube dryers indirectly heat materials through steam tube bundles within a rotating drum. While offering advantages such as high thermal efficiency (up to 80% or more), low exhaust gas volume, and minimal dust emission, they are prone to tube wall adhesion and reduced heat transfer efficiency when processing materials with a moisture content exceeding 30%. On the other hand, calcining furnaces (or roasting furnaces) can rapidly decompose organic matter and remove crystal water at high temperatures (400°C–1100°C), but when used alone, they have poor adaptability to the initial moisture content of materials, concentrated energy consumption, and difficulty in achieving gentle and deep drying.
[0003] While existing technologies have attempted to combine different drying equipment, these are mostly simple series connections, lacking systematic thermal integration and process optimization, resulting in bulky equipment and still high energy consumption. Therefore, the industry urgently needs to solve these technical problems. Summary of the Invention
[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a drying system integrating roasting drying and steam drying in series, including a roasting furnace unit and a steam rotary drying unit, wherein the output end of the roasting furnace unit is sealed to the input end of the steam rotary drying unit through a sealed conveying cover; The roasting furnace unit includes a furnace body and a first drive mechanism. The furnace body extends horizontally and is inclined relative to the horizontal plane. First roller brackets are provided at both ends of the furnace body. First rollers are rotatably connected to the first roller brackets and the first rollers are in rolling cooperation with the outer wall of the furnace body. A burner is provided at the lower middle part of the furnace body. The first drive mechanism is used to drive the furnace body to rotate. The steam rotary drying unit includes a cylinder and a second drive mechanism. The cylinder extends horizontally and is inclined relative to the horizontal plane. Second support roller brackets are provided at both ends of the cylinder, and second support rollers are rotatably connected to the second support roller brackets. The second support rollers are in rolling engagement with the outer wall of the cylinder. The second drive mechanism is used to drive the cylinder to rotate. A cooler is connected to the output port of the cylinder. A dust collector, an induced draft fan, and a chimney are sequentially connected to the exhaust port of the cooler. A packaging device is connected to the discharge port of the cooler.
[0005] Furthermore, the furnace body's input port is equipped with a quantitative feeder. The input end of the quantitative feeder is sequentially connected to a hopper and a belt conveyor. The outlet of the hopper is positioned opposite the input end of the belt conveyor, and the output end of the belt conveyor is positioned opposite the inlet of the quantitative feeder. This effectively controls the continuous and stable input of materials, ensuring drying efficiency and avoiding energy waste or insufficient material drying.
[0006] Furthermore, the first driving mechanism includes a first mounting base, on which a first driver and a first reducer are mounted. A first coupling connects the output shaft of the first driver to the input end of the first reducer. A first gear is fixedly connected to the output end of the first reducer. A first gear ring meshing with the first gear is fixedly provided on the outer wall of the furnace body. This effectively drives the furnace body, allowing it to rotate smoothly and accurately control its rotation speed and material residence time, thus ensuring the drying effect and efficiency of the material.
[0007] Furthermore, the second drive mechanism includes a second mounting base, on which a second driver and a second reducer are mounted. A second coupling connects the output shaft of the second driver to the input end of the second reducer. A second gear is fixedly connected to the output end of the first reducer, and a second gear ring meshing with the second gear is fixedly provided on the outer wall of the cylinder. This effectively drives the cylinder, allowing it to rotate smoothly and accurately, thus ensuring the drying effect and efficiency of the material.
[0008] Furthermore, the inner lining of the sealed conveyor cover is lined with heat-insulating material to prevent air leakage and material spillage.
[0009] Furthermore, the slope of the furnace body relative to the horizontal plane is set to 3%-3.5%. This allows it to adapt to the drying of different materials and has a wide range of applications.
[0010] Furthermore, a protective cover is provided above the middle of the furnace body. This enhances safety and reliability, preventing burns.
[0011] Furthermore, it also includes a controller, a temperature sensor, and a pressure sensor. The temperature sensor is installed in both the cylinder and the furnace body, and the pressure sensor is installed in the cylinder body. The temperature sensor, the pressure sensor, the first drive mechanism, and the second drive mechanism are electrically connected to the controller. The system can detect data from each sensor and then feed it back to the controller, which can then perform sequential closed-loop control to achieve automated control with high precision, ensuring drying efficiency and avoiding energy waste.
[0012] The present invention also provides a method for using the above-mentioned integrated drying system of roasting drying and steam drying in series, comprising the following steps: Step 1: The wet material is quantitatively fed into the roasting furnace unit, and the material is heated to 300℃-600℃ to remove the surface moisture of the material and initially complete the pyrolysis. The residence time is controlled at 25min-30min, so that the moisture content of the material is 15%-20%, and the initial drying is completed. Step 2: After preliminary drying, the material is conveyed through a sealed conveyor hood to the steam rotary drying unit, where the steam tube bundle inside the cylinder is heated to 100℃-200℃ and the cylinder speed is controlled at 2rpm-8rpm. After heat exchange drying, the material has a moisture content of 5%-8%, thus completing the drying process. Step 3: The dried material is fed into the cooler. After the material is cooled to below 80°C, it is discharged and packaged. At the same time, the exhaust gas from the cooler passes through the dust collector, the induced draft fan and the chimney before being discharged.
[0013] Furthermore, controlling the oxygen concentration inside the cylinder to be below 5% can effectively suppress the risk of dust explosion; the carrier gas flow rate inside the cylinder is 10%-20% of the exhaust gas flow rate of the furnace, which can ensure that the system has high thermal efficiency.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: First, by connecting the calcination furnace unit and the steam rotary drying unit in series and integrating them into a single structure, the overall size of the drying system is effectively reduced, the floor space and intermediate conveying links are reduced, and the material can be first dehydrated and pyrolyzed at high temperature and then dried at low temperature, thereby achieving continuous, efficient, gentle and deep drying, significantly improving thermal efficiency, and solving the problems of wall sticking and dust in the drying process of high-moisture materials; Secondly, it can make full use of the high-temperature tail gas of the roasting furnace unit to preheat the steam pipe of the rotary drying unit for feeding or supplementing the carrier gas, effectively improving thermal efficiency and saving more energy than single-stage drying, thus realizing the cascade utilization of thermal energy. Third, the calcination furnace unit and the steam rotary drying unit are connected by a sealed conveyor hood, which allows the entire system to operate in a relatively closed manner without dust leakage, and controls the oxygen content inside the cylinder, which can effectively suppress the risk of dust explosion. Fourth, through the coordinated control of the controller, the rotational speed of the furnace body and cylinder, as well as the temperature and carrier gas flow rate, can be controlled. This allows it to adapt to materials with different initial temperatures and particle sizes, and the product moisture content fluctuation range is controlled within ±0.5%, making it widely applicable. Moreover, the entire drying process is automatically closed-loop controlled by the controller, enabling unmanned operation and a high degree of automation, thus solving the technical problems in the prior art. Overall, this invention has the advantages of safety and reliability, wide applicability, high thermal efficiency, and high degree of automation. It can effectively reduce the system's footprint and achieve continuous, efficient, and safe automated drying of materials. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partially enlarged schematic diagram of the present invention.
[0016] The reference numerals in the attached drawings are explained as follows: 1-Roasting furnace unit; 11-Furnace body; 12-First drive mechanism; 121-First mounting base; 122-First driver; 123-First reducer; 124-First coupling; 125-First gear; 126-First gear ring; 13-First support roller bracket; 14-First support roller; 15-Burner; 16-Protective cover; 2-Steam rotary drying unit; 21-Cylinder; 22-Second drive mechanism; 221-Second mounting base; 222-Second driver; 223-Second reducer; 224-Second coupling; 225-Second gear; 226-Second gear ring; 23-Second support roller bracket; 24-Second support roller; 3-Sealed conveyor cover; 4-Cooler; 5-Dust collector; 6-Exhaust fan; 7-Chimney; 8-Quantitative feeder; 9-Hill; 10-Belt conveyor. Detailed Implementation
[0017] To facilitate understanding of the present invention, a more detailed description is provided below with reference to the accompanying drawings and specific embodiments. It should be noted that when an element is described as being "fixed to" another element, it can be directly on the other element, or one or more intermediate elements may exist between them. When an element is described as being "connected to" another element, it can be directly connected to the other element, or one or more intermediate elements may exist between them. The terms "upper," "lower," "left," "right," "inner," "outer," and similar expressions used in this specification are for illustrative purposes only.
[0018] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.
[0019] like Figure 1 and Figure 2 As shown, the present invention provides a drying system integrating roasting drying and steam drying in series, including a roasting furnace unit 1 and a steam rotary drying unit 2. The output end of the roasting furnace unit 1 is sealed to the input end of the steam rotary drying unit 2 through a sealed conveying cover 3. The roasting furnace unit 1 includes a furnace body 11 and a first drive mechanism 12. The furnace body 11 extends horizontally and is inclined relative to the horizontal plane. First support roller brackets 13 are respectively provided at both ends of the furnace body 11. First support rollers 14 are rotatably connected to the first support roller brackets 13. The first support rollers 14 roll with the outer wall of the furnace body 11. A burner 15 is provided at the lower middle part of the furnace body 11. The first drive mechanism 12 is used to drive the furnace body 11 to rotate. The steam rotary drying unit 2 includes a cylinder 21 and a second drive mechanism 22. The cylinder 21 extends horizontally and is inclined relative to the horizontal plane. Second roller supports 23 are provided at both ends of the cylinder 21, and second rollers 24 are rotatably connected to the second roller supports 23, with the second rollers 24 rolling in contact with the outer wall of the cylinder 21. The second drive mechanism 22 drives the cylinder 21 to rotate. A cooler 4 is connected to the output port of the cylinder 21. A dust collector 5, an induced draft fan 6, and a chimney 7 are sequentially connected to the exhaust port of the cooler 4. A packaging device is connected to the discharge port of the cooler 4. In practical applications, by directly connecting the calcining furnace unit 1 and the steam rotary drying unit 2 in series, intermediate conveying links can be reduced, and the floor space is reduced by 30% compared to a split-type device.
[0020] A quantitative feeder 8 is installed at the input port of the furnace body 11. A hopper 9 and a belt conveyor 10 are sequentially arranged at the input end of the quantitative feeder 8. The discharge port of the hopper 9 is positioned opposite the input end of the belt conveyor 10, and the output end of the belt conveyor 10 is positioned opposite the inlet of the quantitative feeder 8. The quantitative feeder 8 is preferably a screw type.
[0021] Specifically, the roasting furnace unit 1 adopts an indirect heating rotary kiln structure with an operating temperature of 400℃-1100℃; while the steam rotary drying unit 2 also includes a steam tube bundle, a carrier gas system, and a condensate recovery device, with an operating temperature of 100℃-300℃. The steam tube bundle is arranged concentrically inside the cylinder 21, and the steam tubes adopt a combination of smooth tubes and finned tubes, as well as a self-cleaning device to effectively prevent high-moisture materials from sticking or adhering to the wall; and the tilt angle of the cylinder 21 is adjustable. This drying system is also equipped with a waste heat recovery device, which preheats the feed or supplementary heat source of the steam rotary drying unit through a heat exchanger using the high-temperature exhaust gas generated by the furnace 11, and recovers the condensate for use in the boiler system.
[0022] In some embodiments, the angle between the axis of the cylinder 21 and the horizontal plane is 1°-6°, and this angle can be automatically adjusted. Specifically, the second support roller bracket 23 at one end is configured to be height-adjustable (actually using a hydraulic rod or a mechanical height adjustment rod). Under the control of the controller, the height can be automatically adjusted to match the actual material being dried, so that the tilt angle of the cylinder 21 is adapted accordingly. Of course, the same or similar structure can also be used for the furnace body 11 to achieve automatic slope matching.
[0023] The first drive mechanism 12 includes a first mounting base 121, on which a first driver 122 and a first reducer 123 are mounted. A first coupling 124 is connected between the output shaft of the first driver 122 and the input end of the first reducer 123. A first gear 125 is fixedly connected to the output end of the first reducer 123. A first gear ring 126 that meshes with the first gear 125 is fixedly provided on the outer wall of the furnace body 11.
[0024] The second drive mechanism 22 includes a second mounting base 221, on which a second driver 222 and a second reducer 223 are mounted. A second coupling 224 is connected between the output shaft of the second driver 222 and the input end of the second reducer 223. A second gear 225 is fixedly connected to the output end of the first reducer 123. A second gear ring 226 that meshes with the second gear 225 is fixedly provided on the outer wall of the cylinder 21.
[0025] The inner lining of the sealed conveyor hood 3 is lined with heat-insulating material. Preferably, the sealed conveyor hood 3 is made of high-temperature resistant stainless steel, and a material buffer device is also provided at the sealed conveyor hood 3 to stabilize the flow rate and ensure drying efficiency. The high-temperature exhaust gas generated by the furnace body 11 is partially introduced into the cylinder 21 as carrier gas, and the carrier gas flow rate is controlled by an automatic valve to create a slightly negative pressure operating environment.
[0026] The slope of the furnace body 11 relative to the horizontal plane is set to 3%-3.5%. A protective cover 16 is provided above the middle of the furnace body 11. The inner lining of the protective cover 16 is lined with heat insulation material to reduce heat loss and prevent burns.
[0027] The drying system also includes a controller, temperature sensors, and pressure sensors. Temperature sensors are installed in both the cylinder 21 and the furnace body 11, and a pressure sensor is installed in the cylinder 21. The temperature sensors, pressure sensors, first drive mechanism 12, and second drive mechanism 22 are electrically connected to the controller. By real-time detection of the steam pressure in the cylinder 21 by the pressure sensor, the controller controls the corresponding solenoid valves or flow valves to maintain the pressure value within the set range, ensuring safety and drying efficiency. By real-time detection by the temperature sensor, the temperature inside the cylinder 21 and furnace body 11 can be obtained. The controller uses this information to control the firepower of the burner 15 and the speed of the first drive mechanism 12 and the second drive mechanism 22, thereby adjusting the residence time of the material in the furnace body 11 or the cylinder 21 to ensure drying effect and efficiency.
[0028] The present invention also provides a method for using the above-mentioned integrated drying system of roasting drying and steam drying in series, comprising the following steps: Step 1: Wet material (such as lignite or concentrate with a moisture content of 25% to 40%) is quantitatively fed into roasting furnace unit 1, and the material is heated to 300℃-600℃ to remove the surface moisture of the material and initially complete pyrolysis. The residence time is controlled at 25 min-30 min, so that the moisture content of the material is 15%-20%, and the initial drying is completed. Step 2: After preliminary drying, the material is conveyed through the sealed conveyor hood 3 to the steam rotary drying unit 2, where the steam tube bundle inside the cylinder 21 is heated to 100℃-200℃ and the rotation speed of the cylinder 21 is controlled at 2rpm-8rpm. After heat exchange drying, the moisture content of the material is 5%-8%, thus completing the drying process. Step 3: The dried material is fed into cooler 4. After the material is cooled to below 80°C, it is discharged and packaged. At the same time, the exhaust gas output from cooler 4 passes through dust collector 5, induced draft fan 6 and chimney 7 in sequence before being discharged.
[0029] The oxygen concentration inside the control cylinder 21 is kept below 5%, and the flow rate of the carrier gas in the cylinder 21 is 10%-20% of the tail gas volume of the furnace body 11. In practice, the thermal efficiency of this drying system can reach 85%-90%, which is more than 30% more energy-efficient than single-stage drying.
[0030] In some embodiments, the calcination furnace unit 1 has a diameter of 2.2 m, a length of 18 m, is indirectly heated by gas, operates at a temperature of 500℃~600℃, and rotates at 3 rpm; the steam rotary drying unit 2 has a diameter of 2.4 m, a length of 24 m, a steam pressure of 0.8 MPa, a temperature of 170℃, and its tube bundle is made of 304 stainless steel. The actual operation process is as follows: lignite with an initial moisture content of 35% is fed into roasting furnace unit 1 at a rate of 10 t / h and held at 550 ℃ for 25 min, reducing the moisture content to 18%; The material enters the steam rotary drying unit 2 through the sealed conveyor hood 3. After exchanging heat with the steam tube bundle, the moisture content of the product is reduced to 8%. The dry coal enters cooler 4 to cool down to below 80°C before being packaged; The exhaust gas (approximately 300 °C) from the roasting furnace unit 1 is partially introduced into the steam rotary drying unit 2 as carrier gas, while the remaining exhaust gas is used to recover heat through a waste heat boiler. The system's exhaust gas is discharged after passing through a bag filter 5, an induced draft fan 6, and a chimney 7, with a dust concentration below 20 mg / Nm3. In actual feedback, the drying system consumes only 0.55 t of steam per ton of lignite, a 22% reduction compared to a single-stage steam pipe dryer; the product's calorific value is increased to 4500 kcal / kg, with no wall adhesion. It achieves efficient, safe, and continuous drying of high-moisture materials. The system combines energy saving, consumption reduction, prevention of wall adhesion, and a high degree of automation, making it particularly suitable for the large-scale processing of high-moisture bulk materials such as lignite, mineral concentrates, and chemical filter cakes.
[0031] In summary, the technical solution of this invention can fully and effectively achieve the above-mentioned objectives. Furthermore, the structure and functional principles of this invention have been fully verified in the embodiments, achieving the expected effects and objectives. Without departing from the principles and essence of this invention, various changes or modifications can be made to the embodiments. Therefore, this invention includes all substitutions within the scope mentioned in the patent application claims, and any equivalent changes made within the scope of this patent application are within the scope of the patent application.
Claims
1. A drying system integrating roasting drying and steam drying in series, comprising a roasting furnace unit and a steam rotary drying unit, characterized in that: The output end of the roasting furnace unit is sealed to the input end of the steam rotary drying unit through a sealed conveying cover; The roasting furnace unit includes a furnace body and a first drive mechanism. The furnace body extends horizontally and is inclined relative to the horizontal plane. First roller brackets are provided at both ends of the furnace body. First rollers are rotatably connected to the first roller brackets and the first rollers are in rolling cooperation with the outer wall of the furnace body. A burner is provided at the lower middle part of the furnace body. The first drive mechanism is used to drive the furnace body to rotate. The steam rotary drying unit includes a cylinder and a second drive mechanism. The cylinder extends horizontally and is inclined relative to the horizontal plane. Second support roller brackets are provided at both ends of the cylinder, and second support rollers are rotatably connected to the second support roller brackets. The second support rollers are in rolling engagement with the outer wall of the cylinder. The second drive mechanism is used to drive the cylinder to rotate. A cooler is connected to the output port of the cylinder. A dust collector, an induced draft fan, and a chimney are sequentially connected to the exhaust port of the cooler. A packaging device is connected to the discharge port of the cooler.
2. The integrated drying system combining roasting drying and steam drying according to claim 1, characterized in that: The furnace body is equipped with a quantitative feeder at its input port. The input end of the quantitative feeder is sequentially equipped with a hopper and a belt conveyor. The discharge port of the hopper is located opposite the input end of the belt conveyor, and the output end of the belt conveyor is located opposite the inlet of the quantitative feeder.
3. The integrated drying system combining roasting drying and steam drying according to claim 1, characterized in that: The first drive mechanism includes a first mounting base, on which a first driver and a first reducer are mounted. A first coupling is connected between the output shaft of the first driver and the input end of the first reducer. A first gear is fixedly connected to the output end of the first reducer. A first gear ring that meshes with the first gear is fixedly provided on the outer wall of the furnace body.
4. The integrated drying system combining calcination drying and steam drying according to claim 1, characterized in that: The second drive mechanism includes a second mounting base, on which a second driver and a second reducer are mounted. A second coupling is connected between the output shaft of the second driver and the input end of the second reducer. A second gear is fixedly connected to the output end of the first reducer. A second gear ring that meshes with the second gear is fixedly provided on the outer wall of the cylinder.
5. The integrated drying system combining calcination drying and steam drying according to claim 1, characterized in that: The inner lining of the sealed conveyor cover is provided with heat insulation material.
6. The integrated drying system combining calcination drying and steam drying according to claim 1, characterized in that: The slope of the furnace body relative to the horizontal plane is set to 3%-3.5%.
7. The integrated drying system combining calcination drying and steam drying according to claim 1, characterized in that: A protective cover is provided above the middle part of the furnace body.
8. The integrated drying system combining roasting drying and steam drying according to claim 1, characterized in that: It also includes a controller, a temperature sensor, and a pressure sensor. The temperature sensor is installed in both the cylinder and the furnace body, and the pressure sensor is installed in the cylinder body. The temperature sensor, the pressure sensor, the first drive mechanism, and the second drive mechanism are electrically connected to the controller.
9. A method using the integrated drying system of roasting drying and steam drying as described in any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: The wet material is quantitatively fed into the roasting furnace unit, where it is heated to 300℃-600℃ to remove the surface moisture and complete the initial pyrolysis. The residence time is controlled at 25min-30min to make the moisture content of the material 15%-20%, thus completing the initial drying. Step 2: After preliminary drying, the material is conveyed through a sealed conveyor hood to the steam rotary drying unit, where the steam tube bundle inside the cylinder is heated to 100℃-200℃ and the cylinder speed is controlled at 2rpm-8rpm. After heat exchange drying, the material has a moisture content of 5%-8%, thus completing the drying process. Step 3: The dried material is fed into the cooler. After the material is cooled to below 80°C, it is discharged and packaged. At the same time, the exhaust gas from the cooler passes through the dust collector, the induced draft fan and the chimney before being discharged.
10. A method for using a combined calcination drying and steam drying system according to claim 9, characterized in that: The oxygen concentration inside the cylinder is controlled to be below 5%, and the flow rate of the carrier gas inside the cylinder is 10%-20% of the exhaust gas volume of the furnace.