Partition temperature control type pigment belt dryer
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CROWN CHEMICAL CORP
- Filing Date
- 2025-08-29
- Publication Date
- 2026-07-21
AI Technical Summary
Traditional drying equipment lacks zoned temperature control design, resulting in uneven drying of pigment filter cakes, internal adhesion and residue problems. At the same time, it is not equipped with waste heat recovery devices, resulting in heat waste and increased energy consumption.
The design incorporates a zoned temperature-controlled pigment belt dryer, including a low-temperature pre-drying zone, a medium-temperature shaping zone, and a high-temperature drying zone. Combined with waste heat recovery components, closed-loop temperature control and waste heat recovery are achieved through humidity sensors and PID controllers. Teflon-modified conveyor belts are used to prevent sticking.
This technology enables gradient heating and drying of pigment filter cakes, avoiding drying cracks and heat waste, reducing production energy consumption, and improving product quality stability.
Smart Images
Figure CN224534707U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of pigment drying technology, specifically to a zoned temperature-controlled pigment belt dryer. Background Technology
[0002] Pigment filter cake, a key intermediate in the pigment production process, is usually in paste or block form. It is characterized by high humidity, easy adhesion, and high drying requirements, and requires drying treatment by a dryer.
[0003] Traditional drying equipment has significant shortcomings when processing pigment filter cakes: due to the lack of zoned temperature control design, the filter cake is prone to surface drying too quickly while internal moisture evaporation is delayed during the drying process, resulting in uneven drying, decreased pigment performance, and even problems such as internal adhesion and residue, affecting product quality and stability.
[0004] Meanwhile, traditional equipment is not equipped with waste heat recovery devices, resulting in the direct emission of large amounts of high-temperature waste gas, which wastes heat energy, increases production energy consumption, increases the cost burden on enterprises, and puts pressure on the environment.
[0005] In summary, a zoned temperature-controlled pigment belt dryer needs to be developed to solve the above problems. Utility Model Content
[0006] To address the shortcomings of existing technologies, the technical solution adopted by this utility model is: a zoned temperature-controlled pigment belt dryer, comprising a support frame, a drying chamber, and a feed inlet. The drying chamber contains a drying mechanism, which further includes: A conveying component, the conveying component including a conveyor belt, wherein drive rollers are rotatably connected to both the left and right sides of the inner surface of the conveyor belt; The drying chamber is divided into a low-temperature pre-drying zone, a medium-temperature setting zone, and a high-temperature drying zone along the conveying direction. The temperature control unit also includes a return air duct. The low-temperature pre-drying zone serves as the first stop for the pigment filter cake entering the dryer, its core function being to gently remove free moisture from the material surface, preparing it for subsequent deep drying. The medium-temperature setting zone further dehydrates the material and gradually stabilizes its internal structure. The high-temperature drying zone aims to rapidly remove bound water from the material, achieving the final degree of dryness required by the process.
[0007] A waste heat recovery component is included to guide the exhaust gas from the high-temperature drying zone into the low-temperature pre-drying zone for heating. This component includes a humidity sensor with an inlet pipe mounted on its outer surface and an exhaust pipe at the top. A support frame is installed on the lower surface of the drying chamber to support it. A feed inlet facilitates the addition of pigment filter cakes and works with a conveyor to transport the pigments. A zoned temperature control component divides the conveyor belt into three temperature zones, each independently controlled by ±2°C, addressing the issue of filter cake cracking during drying. The process requires 6 hours of drying. The waste heat recovery component is designed to save energy and reduce energy consumption.
[0008] Furthermore, motors are installed at both ends of the drive roller, and heat-insulating baffles are provided above and below the conveyor belt. The conveyor belt uses an anti-stick coating and is a Teflon-modified conveyor belt to reduce pigment residue.
[0009] Furthermore, the conveyor belt is located inside the drying chamber, the motor is mounted on the inner wall of the drying chamber, and multiple heat-insulating baffles are arranged at intervals along the length of the drying chamber. The heat-insulating baffles are positioned between the three temperature zones to prevent direct heat transfer between them. They are made of a high-temperature resistant, low-thermal-conductivity material, namely aluminum carbonate fiberboard, to minimize heat transfer. The gap between the heat-insulating baffles and the upper and lower surfaces of the conveyor belt is 5-10 mm, ensuring a heat rejection rate ≥90% and a conveyor belt running resistance ≤5N, without obstructing the operation of the conveyor belt or the passage of material above it.
[0010] Furthermore, a return air duct is installed on one side of the return air channel, and an exhaust fan is fixedly connected to the end of the return air duct away from the return air channel. An insulation board is installed around the exhaust fan, and a temperature sensor is installed at the bottom of the insulation board. The temperature sensor is electrically connected to a PID controller via wires. The return air channel is located below the conveyor belt to collect exhaust gas that has decreased in temperature and increased in humidity after penetrating the material. The exhaust fan serves as the power source for driving airflow circulation to extract the exhaust gas from the return air channel. The insulation board is made of high-temperature resistant heat-insulating material to prevent heat loss and guide airflow. The temperature sensor detects the temperature of the circulating gas in real time and feeds it back to the PID controller. The PID controller uses an algorithm with a proportional gain Kp=0.5, an integral time Ti=120s, and a derivative time Td=10s. It compares the detected value with the set temperature (low-temperature pre-drying zone: 50±2℃, medium-temperature shaping zone: 80±2℃, high-temperature drying zone: 110±2℃) and outputs a PWM signal to dynamically adjust the power of the electric heating tube to achieve closed-loop temperature control.
[0011] The mounting ring has an electric heating element mounted on its inner surface. This electric heating element serves as the core heat source, and its energization and power output are controlled by the output commands of a PID controller. The electric heating element is powered by an external power distribution cabinet, which is not fully shown in this paper as it is existing technology.
[0012] Furthermore, multiple sets of return air ducts are provided, and the return air channels are located below the conveyor belt and fixedly connected to the inner wall of the drying chamber. The return air ducts correspond to multiple independent temperature zones within the drying chamber.
[0013] Furthermore, the exhaust fan is installed on the inner surface of the top of the drying chamber, and the upper surface of the insulation board is fixedly connected to the top of the inner wall of the drying chamber.
[0014] Furthermore, the PID controller is installed on the outer surface of the drying chamber, and the electric heating element is positioned below the exhaust fan. The PID controller is installed on the outer surface of the drying chamber to avoid the high temperature and vibration environment inside, ensuring the stability and reliability of the control system; the electric heating element is positioned so that the airflow blown out by the exhaust fan passes through the electric heating element and is heated.
[0015] Furthermore, an electric regulating valve is installed on the outer surface of the exhaust pipe, and a fresh air duct is installed on the outer surface of the end of the exhaust pipe away from the air inlet pipe. A humidity sensor is used to detect the humidity of the exhaust gas, and its probe extends into the interior of the air inlet pipe; the air inlet pipe serves as the exhaust gas extraction channel; the humidity sensor detects the humidity of the exhaust gas and transmits it to the PID controller. When the humidity is >70%RH, the PID controller outputs a 4-20mA signal, linearly adjusting the opening of the electric regulating valve to 30%-100%, maintaining the humidity at 50±5%RH; the fresh air duct is used to introduce fresh outdoor air; the function of the exhaust pipe is to ensure that each temperature zone is independently maintained in a suitable humidity environment, preventing pigment cracking and ensuring product quality, because humidity is closely related to temperature.
[0016] Furthermore, a heat pipe heat exchanger is installed at the end of the exhaust pipe away from the air inlet pipe, and a circulating fan is installed at the end of the heat pipe heat exchanger away from the exhaust pipe. A recovery pipe is installed at the air outlet of the circulating fan. The heat pipe heat exchanger enables the exchange of heat between the exhaust air and the fresh, cool air in the fresh air duct, while physically isolating the two to avoid cross-contamination.
[0017] Furthermore, the end of the air inlet pipe furthest from the exhaust pipe is fixedly connected to the side of the return air duct closest to the return air pipe. The circulating fan is installed on the upper surface of the top of the drying chamber, and the end of the recovery pipe furthest from the outlet of the circulating fan is installed in the low-temperature pre-drying zone of the drying chamber. The circulating fan provides airflow power to overcome the resistance of the heat pipe heat exchanger and delivers the preheated fresh air. The fresh air passing through the heat pipe heat exchanger is then supplied to the low-temperature pre-drying zone, which requires the most heat, thus achieving cascaded energy utilization.
[0018] Compared with the prior art, the beneficial effects of this utility model are as follows: 1. This utility model achieves gradient temperature control of the pigment filter cake drying process by designing a low-temperature pre-drying zone, a medium-temperature shaping zone, and a high-temperature drying zone that are sequentially divided along the conveying direction, and by cooperating with independent zone temperature control components. This solves the problem of drying cracking caused by the formation of a crust on the surface of the material and the inability of internal moisture to escape due to sudden temperature changes, and also avoids product quality defects caused by a single high-temperature drying method.
[0019] 2. This utility model effectively blocks heat radiation and convection transfer between the three temperature zones in the drying oven by setting heat insulation baffles made of aluminum carbonate fiberboard above and below the conveyor belt in each temperature zone, thus solving the problem of temperature fluctuation and mutual interference caused by heat exchange between the temperature zones; in particular, an appropriate gap is maintained between the heat insulation baffles and the conveyor belt, further avoiding the problem of affecting the normal operation of the conveyor belt and the passage of materials while isolating heat.
[0020] 3. This utility model, by designing a waste heat recovery component consisting of a humidity sensor, an electric regulating valve, a heat pipe heat exchanger, and a fresh air duct, realizes the use of waste heat from the high-humidity exhaust gas in the high-temperature drying zone to preheat and supplement the fresh air in the low-temperature pre-drying zone, thus avoiding the problem of increased energy consumption.
[0021] 4. This utility model achieves effective separation of materials from the belt surface during conveying and drying by using a conveyor belt with a Teflon-modified anti-stick coating, solving the problem that pigment filter cake is prone to sticking and remaining on the conveyor belt surface due to its high viscosity; in particular, the anti-stick coating reduces the difficulty of cleaning and maintenance and product loss, and avoids the problem of pigment production being affected by the accumulation of residues. Attached Figure Description
[0022] Figure 1 This is the front view of this utility model; Figure 2 This is a cross-sectional view of the drying oven of this utility model; Figure 3 This is a schematic diagram of the structure of the zoned temperature control component of this utility model; Figure 4 This is a cross-sectional view of the insulation board of this utility model; Figure 5 This is a schematic diagram of the waste heat recovery component of this utility model; Figure 6 This is a schematic diagram of the structure of the electric regulating valve of this utility model.
[0023] In the diagram: 1. Support frame; 2. Drying oven; 3. Feed inlet; 4. Drying mechanism; 44. Conveying components; 441. Conveyor belt; 442. Drive roller; 443. Motor; 444. Heat insulation baffle; 45. Zoned temperature control components; 451. Return air channel; 452. Return air duct; 453. Exhaust fan; 454. Insulation board; 455. Temperature sensor; 456. PID controller; 457. Mounting ring; 458. Electric heating element; 46. Waste heat recovery components; 461. Humidity sensor; 462. Air inlet pipe; 463. Exhaust pipe; 464. Electric regulating valve; 465. Fresh air duct; 466. Heat pipe heat exchanger; 467. Circulating fan; 468. Recovery pipe. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. The embodiments of the present invention are given for illustrative and descriptive purposes only, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments were chosen and described to better illustrate the principles and practical applications of the present invention, and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for a particular purpose. Example 1
[0025] Please see Figure 1 - Figure 2 This utility model provides a technical solution: a zoned temperature-controlled pigment belt dryer, including a support frame 1, a drying chamber 2, and a feed inlet 3. A drying mechanism 4 is installed inside the drying chamber 2, and the drying mechanism 4 further includes: The conveying component 44 includes a conveyor belt 441, and transmission rollers 442 are rotatably connected to both the left and right sides of the inner surface of the conveyor belt 441. The zoned temperature control component 45 is divided into a low-temperature pre-drying zone, a medium-temperature setting zone, and a high-temperature drying zone along the conveying direction inside the drying chamber 2. The zoned temperature control component 45 is equipped with a return air channel 451. Among them, the low-temperature pre-drying zone serves as the first station for pigment filter cakes entering the dryer, and its core function is to gently remove free moisture from the surface of the material to prepare for subsequent deep drying. The medium-temperature setting zone further dehydrates the material and gradually stabilizes its internal structure. The high-temperature drying zone aims to quickly remove bound water from the material to achieve the final degree of dryness required by the process.
[0026] Waste heat recovery component 46 is used to introduce the exhaust gas from the high-temperature drying zone into the low-temperature pre-drying zone for heating. Waste heat recovery component 46 includes a humidity sensor 461, with an air inlet pipe 462 mounted on its outer surface and an exhaust pipe 463 mounted at the top of the air inlet pipe 462. Support frame 1 is installed on the lower surface of the drying chamber 2 to support it. Feed inlet 3 facilitates the input of pigment filter cake and works with conveyor component 44 to convey the pigment. Zone temperature control component 45 divides the conveyor belt 441 into three temperature zones, each with independent temperature control of ±2℃, solving the problem of filter cake cracking during drying. The process requires 6 hours of drying. The waste heat recovery component 46 is designed to save energy and reduce energy consumption.
[0027] Motors 443 are installed at both ends of the drive roller 442, and heat insulation baffles 444 are installed above and below the conveyor belt 441. The conveyor belt 441 adopts an anti-stick coating and is a Teflon-modified conveyor belt 441 to reduce pigment residue.
[0028] The conveyor belt 441 is installed inside the drying chamber 2, and the motor 443 is installed on the inner wall of the drying chamber 2. Multiple heat-insulating baffles 444 are arranged at intervals along the length of the drying chamber 2. The heat-insulating baffles 444 are positioned between the three temperature zones to prevent direct heat transfer between them. They are made of a high-temperature resistant, low-thermal-conductivity material, namely aluminum carbonate fiberboard, to minimize heat transfer. The gap between the heat-insulating baffles 444 and the upper and lower surfaces of the conveyor belt 441 is 5-10 mm, ensuring a heat rejection rate ≥90% and a running resistance of the conveyor belt 441 ≤5N, without obstructing the operation of the conveyor belt 441 or the passage of material above it.
[0029] The working principle is as follows: First, the pigment filter cake is fed into the feed port 3 and evenly spread on the running conveyor belt 441. The conveyor belt 441 is driven by the motor 443 and the transmission roller 442 to feed the material into the low temperature pre-drying zone, the medium temperature shaping zone and the high temperature drying zone at a constant speed.
[0030] When the material enters the low-temperature pre-drying zone, the hot air temperature is controlled to gently remove a large amount of free moisture from the surface of the filter cake. This stage avoids surface crusting caused by sudden high temperatures, thus preventing cracking during subsequent drying. Subsequently, the material enters the medium-temperature setting zone, where the temperature rises moderately, causing internal moisture to gradually migrate to the surface and evaporate. This initial setting of the material's internal structure reduces the risk of deformation and cracking. Finally, the material enters the high-temperature drying zone, where a higher temperature is used to quickly and thoroughly evaporate any remaining bound water, bringing the material to its final drying requirements.
[0031] Throughout the process, the heat insulation baffles 444, positioned between the three temperature zones, effectively block heat radiation and convection between them, ensuring that the temperatures of the three zones are essentially independent and do not interfere with each other, thus providing physical protection for zoned temperature control. The Teflon-modified conveyor belt 441 operates continuously, and its anti-stick coating reduces the adhesion and residue of pigment filter cake. Example 2
[0032] Please see Figure 1 - Figure 6 This utility model provides a technical solution: Based on Embodiment 1, a return air duct 452 is installed on one side of the return air channel 451. An exhaust fan 453 is fixedly connected to the end of the return air duct 452 away from the return air channel 451. An insulation board 454 is provided around the exhaust fan 453. A temperature sensor 455 is installed at the bottom of the insulation board 454. The temperature sensor 455 is electrically connected to a PID controller 456 through a wire. The return air channel 451 is located below the conveyor belt 441 to collect materials that have decreased in temperature and increased in humidity after passing through them. Heavy exhaust gas; the exhaust fan 453 serves as the power source for driving airflow circulation, used to extract the exhaust gas from the return air channel 451; the insulation board 454 is made of high-temperature resistant heat insulation material to prevent heat loss and guide airflow; the temperature sensor 455 detects the temperature of the circulating gas in real time and transmits it to the PID controller 456. The PID controller 456 uses an algorithm with proportional gain Kp=0.5, integral time Ti=120s, and derivative time Td=10s to compare the detected value with the set temperature (low temperature pre-baking zone: 50±2℃, medium temperature shaping zone: 80±2℃, high temperature drying zone: 110±2℃), and outputs a PWM signal to dynamically adjust the power of the electric heating tube 458 to achieve closed-loop temperature control.
[0033] Mounting ring 457, with an electric heating element 458 mounted on its inner surface. This electric heating element 458 serves as the core heat source, and its energization and power level are controlled by the output command of PID controller 456. An external power distribution cabinet provides power to the electric heating element 458. Since the power distribution cabinet is existing technology, it is not fully shown in this paper.
[0034] Multiple sets of return air ducts 452 are provided, and the return air channel 451 is located below the conveyor belt 441 and is fixedly connected to the inner wall of the drying chamber 2. The recovery pipes 468 correspond to multiple independent temperature zones within the drying chamber 2.
[0035] The exhaust fan 453 is installed on the inner surface of the top of the drying chamber 2, and the upper surface of the insulation board 454 is fixed to the top of the inner wall of the drying chamber 2.
[0036] The PID controller 456 is mounted on the outer surface of the drying chamber 2, and the electric heating element 458 is positioned below the exhaust fan 453. The PID controller 456 is mounted on the outer surface of the drying chamber 2 to avoid the high temperature and vibration environment inside the chamber, ensuring the stability and reliability of the control system. The electric heating element 458 is positioned so that the airflow blown out by the exhaust fan 453 passes through the electric heating element 458 and is heated.
[0037] The working principle is as follows: In each temperature zone, after the exhaust fan 453 is started, it generates power within the system to draw in the humid and low-temperature exhaust gas that has penetrated the material from the bottom return air channel 451, and then pump it to the top through the return air pipe 452. The airflow then first passes through the electric heating tube 458, where the heat supply is precisely controlled by the PID controller 456: the temperature sensor 455 monitors the return air temperature in real time and feeds it back to the PID controller 456, which compares and calculates it with the set temperature value, and dynamically adjusts the power of the electric heating tube 458 to heat the airflow to the precise target temperature. The heated clean hot air, under the pressure of the fan, is blown onto the material on the conveyor belt 441 through the surrounding air duct formed by the insulation plate 454, completing the penetration drying.
[0038] This closed-loop design allows for full utilization of heat, and the independent circulation system ensures stable operating conditions in each temperature zone.
[0039] An electric regulating valve 464 is installed on the outer surface of the exhaust pipe 463, and a fresh air duct 465 is installed on the outer surface of the end of the exhaust pipe 463 away from the air inlet pipe 462. A humidity sensor 461 is used to detect the humidity of the exhaust gas, and its probe extends into the interior of the air inlet pipe 462; the air inlet pipe 462 serves as the exhaust gas extraction channel. The humidity sensor 461 detects the humidity of the exhaust gas and transmits it to the PID controller 456. When the humidity > 70%RH, the PID controller 456 outputs a 4-20mA signal, linearly adjusting the opening of the electric regulating valve 464 to 30%-100%, maintaining the humidity at 50±5%RH. The fresh air duct 465 is used to introduce fresh outdoor air. The function of the exhaust pipe 463 is to ensure that each temperature zone is independently maintained in a suitable humidity environment, preventing pigment cracking and ensuring product quality, because humidity is closely related to temperature.
[0040] A heat pipe heat exchanger 466 is installed at the end of the exhaust pipe 463 away from the air inlet pipe 462. A circulating fan 467 is installed at the end of the heat pipe heat exchanger 466 away from the exhaust pipe 463. A recovery pipe 468 is installed at the air outlet of the circulating fan 467. The heat pipe heat exchanger 466 can exchange heat between the exhaust air and the fresh cold air in the fresh air duct 465, and the two are physically isolated to avoid cross-contamination.
[0041] The end of the air inlet pipe 462 away from the exhaust pipe 463 is fixedly connected to the side of the return air duct 451 near the return air pipe 452. The circulating fan 467 is installed on the upper surface of the top of the drying chamber 2, and the end of the recovery pipe 468 away from the air outlet of the circulating fan 467 is installed in the low-temperature pre-drying zone of the drying chamber 2. The circulating fan 467 is used to provide airflow power to overcome the resistance of the heat pipe heat exchanger 466 and send out the preheated fresh air; the fresh air passing through the heat pipe heat exchanger 466 is replenished to the low-temperature pre-drying zone that needs the most heat, realizing the cascade utilization of energy.
[0042] The working principle is as follows: This component primarily addresses the issue of high energy consumption, achieving energy-saving effects. In the high-temperature drying zone, the portion of exhaust gas with the highest humidity is diverted to the exhaust pipe 463 through the intake pipe 462 during the circulation process. The humidity sensor 461 monitors the humidity value of this exhaust gas and sends a signal to the PID controller 456. The PID controller 456 controls the opening of the electric regulating valve 464 based on the signal feedback, thereby precisely controlling the amount of moisture discharged and maintaining the dryness level inside the system.
[0043] The high-temperature and high-humidity exhaust gas is not directly discharged, but is sent into the heat pipe heat exchanger 466. At the same time, fresh, cool outdoor air is introduced into the other side of the heat exchanger through the fresh air duct 465. Inside the heat pipe heat exchanger 466, the heat in the exhaust gas is efficiently transferred to the fresh air, and the two do not come into contact, thus eliminating pollution. After the heat exchange is completed, the cooled exhaust gas is finally discharged outdoors.
[0044] The preheated fresh air is directly supplied to the airflow inlet of the low-temperature pre-drying zone, which requires the most heat, by the circulating fan 467 through the recovery pipe 468. This means that the energy required to heat the fresh air in the low-temperature zone is reduced, thereby significantly reducing the overall energy consumption of the entire equipment and achieving the purpose of recovering waste heat and saving energy.
[0045] Combination Figure 3 and Figure 5 , Figure 6 It can be seen that return air duct 452 is installed in each zone. However, in the high-temperature drying zone, the exhaust duct 463 is directly connected to the electric regulating valve 464 for control. In the low-temperature pre-drying zone and the medium-temperature shaping zone, the heat of the exhaust gas discharged from these two zones is too low, i.e., high humidity and low temperature. The energy value generated by recovering them is often high, which is not economically or technically worthwhile.
[0046] Finally, the humidity sensor 461, temperature sensor 455, and PID controller 456 in this device are all supplied with a stable 24V DC power by a low-voltage DC power module. The input terminal of the low-voltage DC power module is connected to the control power circuit breaker inside the distribution cabinet. The circuit breaker converts the three-phase AC power of the distribution cabinet and supplies it as the low-voltage AC input required by the module. The control system of the drying chamber 2 is powered by the low-voltage AC power provided by the control transformer inside the distribution cabinet. Since the low-voltage DC power module, such as the distribution cabinet, is existing technology and its working principle is well known to those skilled in the art, this article does not fully illustrate this type of power supply device.
[0047] Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art and related fields based on the embodiments of this utility model without creative effort should fall within the protection scope of this utility model. Structures, devices, and operating methods not specifically described and explained in this utility model, unless otherwise specified or limited, shall be implemented according to conventional means in the art.
Claims
1. A zoned temperature-controlled pigment belt dryer, comprising a support frame (1), a drying chamber (2), and a feed inlet (3), characterized in that: The drying chamber (2) is equipped with a drying mechanism (4), which also has: The conveying component (44) includes a conveyor belt (441), and transmission rollers (442) are rotatably connected to both the left and right sides of the inner surface of the conveyor belt (441). The partition temperature control component (45) is divided into a low temperature pre-drying zone, a medium temperature shaping zone and a high temperature drying zone in the drying oven (2) along the conveying direction. The partition temperature control component (45) is provided with a return air channel (451). Waste heat recovery component (46) is used to introduce the waste gas from the high temperature drying zone into the low temperature pre-drying zone for heating. The waste heat recovery component (46) includes a humidity sensor (461). An air inlet pipe (462) is installed on the outer surface of the humidity sensor (461). A dehumidification pipe (463) is installed at the top of the air inlet pipe (462).
2. The zone-controlled temperature-controlled pigment belt dryer according to claim 1, characterized in that: Motors (443) are installed at both ends of the transmission roller (442), and heat insulation baffles (444) are provided above and below the conveyor belt (441).
3. The zone-controlled temperature-controlled pigment belt dryer according to claim 2, characterized in that: The conveyor belt (441) is located inside the drying chamber (2), the motor (443) is installed on the inner wall of the drying chamber (2), and the number of heat insulation baffles (444) is set to multiple and arranged at intervals along the length of the drying chamber (2).
4. The zone-controlled temperature-controlled pigment belt dryer according to claim 1, characterized in that: A return air duct (452) is installed on one side of the return air duct (451). An exhaust fan (453) is fixed to the end of the return air duct (452) away from the return air duct (451). An insulation board (454) is provided around the exhaust fan (453). A temperature sensor (455) is installed at the bottom of the insulation board (454). The temperature sensor (455) is electrically connected to a PID controller (456) through a wire. Mounting ring (457), on the inner surface of which an electric heating tube (458) is mounted.
5. The zoned temperature-controlled pigment belt dryer according to claim 4, characterized in that: Multiple sets of return air ducts (452) are provided, and the return air channel (451) is located below the conveyor belt (441) and is fixedly connected to the inner wall of the drying box (2).
6. The zone-controlled temperature-controlled pigment belt dryer according to claim 5, characterized in that: The exhaust fan (453) is installed on the inner surface of the top of the drying box (2), and the upper surface of the insulation board (454) is fixed to the top of the inner wall of the drying box (2).
7. The zone-controlled temperature-controlled pigment belt dryer according to claim 6, characterized in that: The PID controller (456) is installed on the outer surface of the drying oven (2), and the electric heating tube (458) is located below the exhaust fan (453).
8. The zone-controlled temperature-controlled pigment belt dryer according to claim 1, characterized in that: An electric regulating valve (464) is installed on the outer surface of the exhaust pipe (463), and a fresh air pipe (465) is installed on the outer surface of the end of the exhaust pipe (463) away from the air inlet pipe (462).
9. The zone-controlled temperature-controlled pigment belt dryer according to claim 8, characterized in that: A heat pipe heat exchanger (466) is installed at the end of the exhaust pipe (463) away from the air inlet pipe (462). A circulating fan (467) is installed at the end of the heat pipe heat exchanger (466) away from the exhaust pipe (463). A recovery pipe (468) is installed at the air outlet of the circulating fan (467).
10. The zone-controlled temperature-controlled pigment belt dryer according to claim 9, characterized in that: The end of the air inlet pipe (462) away from the exhaust pipe (463) is fixedly connected to the side of the return air channel (451) near the return air pipe (452). The circulating fan (467) is installed on the upper surface of the top of the drying box (2). The end of the recovery pipe (468) away from the air outlet of the circulating fan (467) is installed in the low temperature pre-drying zone of the drying box (2).