A method and system for drying wood chips for a pulp mill
By adding a buffer chamber and supporting components to the dryer head, wood chips can be dried quickly and smoothly in a single pass, solving the problem of low efficiency of existing dryers, reducing fuel consumption and environmental pollution, and meeting the moisture control requirements of pulp mills.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGXI ZHAOYI INVESTMENT CO LTD
- Filing Date
- 2026-04-23
- Publication Date
- 2026-06-05
AI Technical Summary
Existing dryers are not ideal for single-pass drying of wood chips, resulting in high fuel consumption, increased costs, and environmental pollution. Furthermore, conventional stage drying processes cannot meet the moisture control requirements of pulp mills for wood chips.
The single-pass drying process is adopted. By adding a buffer chamber and supporting components at the head of the dryer, the wood chips to be dried are evenly conveyed and scattered inside the dryer. With appropriate airflow temperature and speed, the wood chips are dried quickly and smoothly.
This technology enables one-time drying of wood chips to meet standards, reducing fuel consumption, improving energy efficiency, reducing environmental pollution, and meeting the moisture control requirements of pulp mills.
Smart Images
Figure CN122149169A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of raw material drying technology, specifically relating to a method and system for drying and preparing wood chips for pulp mills. Background Technology
[0002] Wood chips are the main raw material for pulp mills. Pulp mills have very high requirements for controlling the moisture content of wood chips. Generally, the moisture content of chemically pulped wood chips is controlled at 8% to 15%, while that of mechanically pulped wood chips is controlled at 18% to 25%.
[0003] Undried wood chips have a moisture content far exceeding the requirements of pulp mills, thus necessitating drying. Currently available dryers are not ideal for single-pass drying of wood chips. The applicant's analysis indicates that this is because a large amount of wood chips accumulates at the dryer head, preventing them from entering the drying drum smoothly and promptly. Furthermore, the accumulation of material obstructs hot air flow, thus affecting the drying effect. The conventional approach is to configure two drying systems, performing the drying operation in two stages: a slow drying stage followed by a high-temperature, rapid drying stage, to meet the pulp mill's requirements. However, this staged drying process results in high fuel consumption, leading to higher drying costs and environmental pollution. Summary of the Invention
[0004] The purpose of this invention is to provide a method and system for drying and preparing wood chips for pulp mills, which adjusts the existing staged drying process to a single-pass drying process, and with corresponding hardware modifications, achieves the goals of energy saving, emission reduction, and improved energy efficiency. The specific technical solution to achieve this goal is as follows:
[0005] A method for drying and preparing wood chips for pulp mills includes the following steps:
[0006] S1 starts the boiler system and dryer. The stable drying airflow generated by the boiler system enters from the head of the dryer and exits from the tail of the dryer to preheat the dryer.
[0007] After the S2 heating and preheating is completed, the boiler system and dryer continue to operate, and the wood chips to be dried are evenly and continuously conveyed to the buffer chamber at the head of the dryer, and the drop point of the wood chips to be dried is controlled in the middle of the buffer chamber.
[0008] S3 conveys the wood chips to be dried in the buffer chamber of the dryer evenly and continuously to the drying area in the middle section of the dryer, and guides the movement trajectory of the wood chips to be dried during the conveying process.
[0009] S4 The wood chips to be dried enter the middle drying area of the dryer and maintain the state of moving towards the discharge port at the tail of the dryer. Before reaching the discharge port, they exchange heat with the drying airflow and continuously throw and break up the wood chips to be dried.
[0010] S5 wood chips reach the discharge port, complete the drying process, and are discharged from the dryer for collection.
[0011] Furthermore, the temperature of the drying airflow is 400~450℃.
[0012] Furthermore, the flow rate of the drying airflow is 3-4 m / s.
[0013] Furthermore, the dryer rotates at a speed of 3~4.5 r / min.
[0014] A drying and preparation system for wood chips used in pulp mills includes:
[0015] The drum dryer has a through-channel structure. "L"-shaped lifting plates for throwing materials are fixedly installed on the walls of the internal channel. "M"-shaped dispersing frame for breaking up materials is fixedly installed in the center of the internal channel along the inlet and outlet directions. The wood chips to be dried exchange heat with the drying airflow inside the dryer to achieve wood chip drying.
[0016] Boiler system, burns fuel, heats airflow;
[0017] The air supply system, including the fan and air duct, stably delivers the hot air generated by the boiler system from the head of the drum dryer to the inside of the drum dryer;
[0018] The conveying system, including a material conveyor belt, a feeding hopper, and a discharging hopper, is used for the uniform and stable conveying of fuel, materials to be dried, and materials to be dried.
[0019] The dust collection system, including a cyclone separator and a bag filter, is used to collect dust and soot generated during the operation of the drum dryer.
[0020] The feature is that a buffer chamber connected to the internal drying area is added to the head of the drum dryer. The shape and radial specifications of the buffer chamber are consistent with those of the dryer. Guide plates are fixed at intervals on the inner wall of the head end of the buffer chamber, and connecting lifting plates are fixed at intervals on the inner wall of the tail end of the buffer chamber. The guide plates, connecting lifting plates, and the inner wall of the buffer chamber together form a spiral material guiding channel.
[0021] The buffer hopper is also equipped with a discharge hopper at the head end, and the discharge point of the discharge hopper is located in the middle section of the buffer hopper.
[0022] Furthermore, the axial dimension of the buffer chamber is 15% to 25% of the overall axial dimension of the drum dryer.
[0023] Furthermore, the distance between the material drop point of the hopper and the head end of the buffer bin is 55% to 60% of the axial dimension of the buffer bin.
[0024] Compared with the prior art, the beneficial effects of the present invention are:
[0025] By increasing the size of the drying drum and adding a buffer chamber and supporting components at the head of the dryer, the material to be dried can enter the drying drum quickly and smoothly. Smooth material transport also ensures smooth airflow within the dryer. Combined with appropriate industrial control parameters, this achieves one-time drying of wood chips to meet standards, reducing costs, increasing efficiency, and saving energy and reducing emissions. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the drying preparation system.
[0027] Figure 2 This is a schematic diagram of the internal structure of the buffer compartment;
[0028] Figure 3 This is a schematic diagram showing the positional relationship between the buffer bin and the discharge hopper;
[0029] The meanings of the symbols in the image are as follows:
[0030] Rotary drum dryer (1), buffer hopper (101), guide plate (102), lifting plate (103), guide channel (104), discharge hopper (105), boiler system (2), air supply system (3), conveying system (4), dust collection system (5). Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0032] Example 1:
[0033] In this embodiment, the dryer has a diameter of 3.2 meters and a length of 24 meters. The wood chips to be dried are eucalyptus chips with a moisture content of 48% before drying. The feeding speed is 8 tons / hour, and the customer requires the finished product to have a moisture content of 18% to 25%.
[0034] Specifically, the method for drying and preparing wood chips for pulp mills includes the following steps:
[0035] S1 starts the boiler system and dryer. The stable drying airflow generated by the boiler system enters from the head of the dryer and exits from the tail of the dryer to preheat the dryer.
[0036] After the preheating of S2 is completed, the boiler system and the dryer continue to operate. The wood chips to be dried are evenly and continuously conveyed into the buffer bin at the head of the dryer, and the feeding point of the wood chips to be dried is controlled in the middle section of the buffer bin.
[0037] S3: The wood chips to be dried in the buffer bin of the dryer are evenly and continuously conveyed to the drying area in the middle section of the dryer, and the movement trajectory of the wood chips to be dried is guided during the conveying process.
[0038] S4: When the wood chips to be dried enter the drying area in the middle section of the dryer, the state of the wood chips to be dried moving towards the discharge port at the tail of the dryer is maintained. Before reaching the discharge port, heat exchange is carried out with the drying air flow, and the wood chips to be dried are continuously sprinkled and dispersed.
[0039] S5: When the wood chips reach the discharge port, drying is completed, and the wood chips are discharged from the dryer through the discharge port for collection.
[0040] In the preferred case, the temperature of the drying air flow is 400°C and the flow rate is 3 m / s.
[0041] In the preferred case, the rotation speed of the dryer is 4.5 r / min.
[0042] The drying preparation system for wood chips used in a pulp mill includes:
[0043] The drum dryer 1 has an overall through-channel structure. On the inner wall of its internal channel, "L"-shaped lifting plates for sprinkling materials are fixedly installed. Along the inlet and outlet directions of its internal channel, a "cross"-shaped dispersing frame for material dispersion is fixedly installed. The wood chips to be dried and the drying air flow conduct heat exchange inside it to achieve the drying of the wood chips.
[0044] The boiler system 2 burns fuel to heat the air flow.
[0045] The air supply system 3 includes a fan and a duct, and stably conveys the hot air flow generated by the boiler system into the drum dryer 1 from the head of the drum dryer 1.
[0046] The conveying system 4 includes a material conveyor belt, a feeding hopper, and a discharging hopper, and is used for the uniform and stable conveyance of fuel, wood chips to be dried, and dried materials.
[0047] The dust collection system 5 includes a cyclone separator and a bag filter, and is used for collecting dust and soot generated during the operation of the drum dryer 1.
[0048] The feature is that a buffer chamber 101 connected to the internal drying area is added to the head of the drum dryer 1. The shape and radial specifications of the buffer chamber 101 are consistent with those of the dryer 1. Guide plates 102 are fixed at intervals on the inner wall of the head end of the buffer chamber 101, and connecting lifting plates 103 are fixed at intervals on the inner wall of the tail end of the buffer chamber 101. The guide plates 102, the connecting lifting plates 103, and the inner wall of the buffer chamber 101 together form a spiral material guiding channel 104.
[0049] The buffer chamber 101 is also equipped with a discharge hopper 105 at its head end, and the discharge point of the discharge hopper 105 is located in the middle section of the buffer chamber 101.
[0050] In a preferred embodiment, the axial dimension of the buffer chamber 101 is 15% of the overall axial dimension of the drum dryer 1.
[0051] In a preferred embodiment, the distance between the discharge point of the discharge hopper 105 and the head end of the buffer chamber 101 is 55% of the axial dimension of the buffer chamber 101.
[0052] After the drying process was completed, a portable testing instrument was used at the work site to test the moisture content of the wood chips, which was found to be 23%.
[0053] Example 2:
[0054] In this embodiment, the dryer has a diameter of 3.2 meters and a length of 24 meters. The wood chips to be dried are eucalyptus chips with a moisture content of 50% before drying. The feeding speed is 8 tons / hour, and the customer requires the finished product to have a moisture content of 18% to 25%.
[0055] Specifically, the method for drying and preparing wood chips for pulp mills includes the following steps:
[0056] S1 starts the boiler system and dryer. The stable drying airflow generated by the boiler system enters from the head of the dryer and exits from the tail of the dryer to preheat the dryer.
[0057] After the S2 heating and preheating is completed, the boiler system and dryer continue to operate, and the wood chips to be dried are evenly and continuously conveyed to the buffer chamber at the head of the dryer, and the drop point of the wood chips to be dried is controlled in the middle of the buffer chamber.
[0058] S3 conveys the wood chips to be dried in the buffer chamber of the dryer evenly and continuously to the drying area in the middle section of the dryer, and guides the movement trajectory of the wood chips to be dried during the conveying process.
[0059] S4 The wood chips to be dried enter the middle drying area of the dryer and maintain the state of moving towards the discharge port at the tail of the dryer. Before reaching the discharge port, they exchange heat with the drying airflow and continuously throw and break up the wood chips to be dried.
[0060] The S5 wood chips reach the discharge port, complete drying, are discharged from the dryer through the discharge port, and are collected.
[0061] In a preferred case, the temperature of the drying air flow is 420 °C and the flow rate is 3.6 m / s.
[0062] In a preferred case, the rotation speed of the dryer is 4 r / min.
[0063] A drying preparation system for wood chips used in a pulp mill, comprising:
[0064] A drum dryer 1, which is of an overall through-channel structure, on the wall of its internal channel is fixedly installed an "L"-shaped material spreading plate for spreading materials, and along the inlet and outlet directions of its internal channel, a "rice"-shaped material dispersing frame for material dispersion is fixedly installed at the center. The wood chips to be dried and the drying air flow conduct heat exchange inside it to achieve wood chip drying;
[0065] A boiler system 2, which burns fuel to heat the air flow;
[0066] A air supply system 3, which includes a fan and a air duct, and stably conveys the hot air flow generated by the boiler system into the drum dryer 1 from the head of the drum dryer 1;
[0067] A conveying system 4, which includes a material conveyor belt, a feeding hopper, and a discharging hopper, and is used for the uniform and stable conveyance of fuel, the wood chips to be dried, and the dried materials;
[0068] A dust collection system 5, which includes a cyclone separator and a bag filter, and is used for collecting dust and soot generated during the operation of the drum dryer 1;
[0069] It is characterized in that a buffer bin 101 communicating with the internal drying area is installed at the head of the drum dryer 1. The shape and radial specifications of the buffer bin 101 are the same as those of the dryer 1. Guide plates 102 are fixedly installed at intervals on the inner wall of the head end of the buffer bin 101, and connecting material spreading plates 103 are fixedly installed at intervals on the inner wall of the tail end of the buffer bin 101. The guide plates 102, the connecting material spreading plates 103 and the inner wall of the buffer bin 101 together form a spiral guide channel 104.
[0070] A blanking hopper 105 is further arranged at the head end of the buffer bin 101, and the blanking point of the blanking hopper 105 is located in the middle section of the buffer bin 101.
[0071] In a preferred case, the axial dimension of the buffer bin 101 is 20% of the overall axial dimension of the drum dryer 1.
[0072] In a preferred case, the distance between the blanking point of the blanking hopper 105 and the head end of the buffer bin 101 is 56% of the axial dimension of the buffer bin 101.
[0073] After the drying operation is completed, a portable detector is used for detection at the operation site, and the moisture content of the wood chips is 24%.
[0074] Example 3:
[0075] In this example, the dryer has a size of 3.2 meters in diameter and 24 meters in length. The wood chips to be dried are eucalyptus wood chips, with a moisture content of 53% before drying, a feeding speed of 10 tons per hour, and the customer requires the moisture content of the finished product to be between 18% and 25%.
[0076] Specifically, the method for drying and preparing wood chips used in a pulp mill includes the following steps:
[0077] S1 Start the boiler system and the dryer. The stable drying air flow generated by the boiler system enters from the head of the dryer and exits from the tail of the dryer to preheat the dryer.
[0078] S2 After the preheating is completed, the boiler system and the dryer continue to operate. The wood chips to be dried are evenly and continuously conveyed into the buffer bin at the head of the dryer, and the dropping point of the wood chips to be dried is controlled in the middle section of the buffer bin.
[0079] S3 The wood chips to be dried in the buffer bin of the dryer are evenly and continuously conveyed to the drying area in the middle section of the dryer, and the movement trajectory of the wood chips to be dried is guided during the conveying process.
[0080] S4 When the wood chips to be dried enter the drying area in the middle section of the dryer, maintain the state of the wood chips to be dried moving towards the discharge port at the tail of the dryer. Before reaching the discharge port, conduct heat exchange with the drying air flow, and continuously sprinkle and disperse the wood chips to be dried.
[0081] S5 When the wood chips reach the discharge port, the drying is completed, and they are discharged from the dryer through the discharge port for collection.
[0082] Preferably, the temperature of the drying air flow is 450 °C and the flow rate is 4 m / s.
[0083] Preferably, the rotation speed of the dryer is 3 r / min.
[0084] The drying and preparation system for wood chips used in a pulp mill includes:
[0085] A drum dryer 1, which is a through-channel structure as a whole. On the wall of its internal channel, an "L"-shaped material-sprinkling plate for sprinkling materials is fixedly installed, and in the center of its internal channel along its inlet and outlet directions, a "cross"-shaped material-dispersing frame for dispersing materials is fixedly installed. The wood chips to be dried and the drying air flow conduct heat exchange inside it to achieve the drying of the wood chips.
[0086] A boiler system 2, which burns fuel to heat the air flow.
[0087] The air supply system 3, which includes a fan and an air duct, stably transports the hot air generated by the boiler system from the head of the drum dryer 1 to the drum dryer 1.
[0088] Conveying system 4 includes a material conveyor belt, a feeding hopper, and a discharging hopper, used for the uniform and stable conveying of fuel, materials to be dried, and materials to be dried;
[0089] Dust collection system 5, including a cyclone separator and a bag filter, is used to collect dust and soot generated during the operation of drum dryer 1.
[0090] The feature is that a buffer chamber 101 connected to the internal drying area is added to the head of the drum dryer 1. The shape and radial specifications of the buffer chamber 101 are consistent with those of the dryer 1. Guide plates 102 are fixed at intervals on the inner wall of the head end of the buffer chamber 101, and connecting lifting plates 103 are fixed at intervals on the inner wall of the tail end of the buffer chamber 101. The guide plates 102, the connecting lifting plates 103, and the inner wall of the buffer chamber 101 together form a spiral material guiding channel 104.
[0091] The buffer chamber 101 is also equipped with a discharge hopper 105 at its head end, and the discharge point of the discharge hopper 105 is located in the middle section of the buffer chamber 101.
[0092] In a preferred embodiment, the axial dimension of the buffer chamber 101 is 25% of the overall axial dimension of the drum dryer 1.
[0093] In a preferred embodiment, the distance between the discharge point of the discharge hopper 105 and the head end of the buffer bin 101 is 60% of the axial dimension of the buffer bin 101.
[0094] After the drying process was completed, a portable testing instrument was used at the work site to test the moisture content of the wood chips, which was found to be 23%.
[0095] The above embodiments will be further explained below:
[0096] Regarding the temperature and flow rate of the drying airflow, the specific parameters are matched with the moisture content of the wood chips to be dried. The higher the moisture content of the wood chips to be dried, the higher the temperature and the faster the flow rate of the drying airflow, thereby ensuring the drying effect of the wood chips.
[0097] Regarding the dryer speed, the specific parameters are matched with the moisture content of the wood chips to be dried. The higher the moisture content of the wood chips, the lower the dryer speed, thereby extending the residence time of the wood chips in the dryer and ensuring the drying quality.
[0098] It should be noted that if the moisture content of the wood chips to be dried exceeds 65%, the moisture content needs to be controlled before drying by means of sun exposure or air drying to avoid affecting the drying effect.
[0099] Regarding the axial dimension of the buffer chamber 101, it should not be lower than the range, because an excessively small buffer space cannot effectively buffer the material and is prone to causing material blockage. It should also not be higher than the range, because an excessively large buffer space will prolong the time for the material to enter the buffer area and increase the consumption of drying airflow, thus reducing economic efficiency. As for how to choose within the range, it depends on the hourly feeding amount. If the feeding amount increases, the space of the buffer chamber 101 should also be increased accordingly.
[0100] The reason why the material drop point of the hopper 105 is to control the drop point to the middle section of the buffer chamber 101 is that when the material falls to the middle section of the buffer chamber 101, there is sufficient space in front and behind to buffer the material and avoid material accumulation. When the distance between the drop point of the hopper 105 and the head end of the buffer chamber 101 is 55% to 60% of the axial dimension of the buffer chamber 101, it can not only avoid material accumulation, but also shorten the time for the material to enter the drying area, improve efficiency, and save fuel.
[0101] Regarding the material guide channel 104, its spiral structure can effectively divert the material in the buffer chamber 101, preventing it from accumulating and entering the drying area. This allows both the material and the drying airflow to enter the drying area smoothly. As for the connecting lifting plate 103, it is designed to facilitate the smooth entry of material from the buffer chamber 101 into the drying area. The drying area is equipped with lifting plates and a dispersing frame. If the material guide plate 102 is directly connected to the drying area, the lifting plate at the head of the drying area will hinder the material from entering to some extent, causing material accumulation. When a connecting lifting plate 103, which belongs to the material guide channel 104, is set between the material guide plate 102 and the lifting plate at the head of the drying area, the material can smoothly enter the connecting lifting plate 103 section of the material guide channel 104 after leaving the material guide plate 102 section. The connecting lifting plate 103 then scatters the material, allowing some material to enter the drying area through the gap between the lifting plate and the dispersing frame, reducing material accumulation at the lifting plate at the head of the drying area.
[0102] In the case of the wood chip drying and preparation system for pulp mills, when it is in operation, the power is turned on to supply power to the electrical appliances, and then the equipment in the system is started through the corresponding controller. First, the drum dryer 1 is preheated. After the preheating is completed, the material enters the buffer chamber 101 through the discharge hopper 105. Since the buffer chamber 101 is integrated with the drum dryer 1, as the drum dryer 1 rotates, the spiral guide channel 104 continuously transports the material to the drying area of the drum dryer 1. After the material is dried, it is discharged from the tail of the drum dryer 1 for collection.
[0103] As for the structure and working principle of the drum dryer 1 itself, please refer to CN203024562U. The installation position of the lifting plate in this application can be referred to 2-lifting lifting plate in the reference. The installation position of the dispersing frame in this application can be referred to 3-uniform lifting plate in the reference. When the drum dryer 1 is working, the wood chips thrown by the lifting plate first collide with the dispersing frame to achieve dispersal, and then fall back to the bottom of the drum.
[0104] Obviously, the above embodiments of this application are merely examples for clear illustration and are not intended to limit the implementation of the application. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of the claims of this application.
Claims
1. A method for drying and preparing wood chips for pulp mills, characterized in that, Includes the following steps: S1 starts the boiler system and dryer. The stable drying airflow generated by the boiler system enters from the head of the dryer and exits from the tail of the dryer to preheat the dryer. After the S2 heating and preheating is completed, the boiler system and dryer continue to operate, and the wood chips to be dried are evenly and continuously conveyed to the buffer chamber at the head of the dryer, and the drop point of the wood chips to be dried is controlled in the middle of the buffer chamber. S3 conveys the wood chips to be dried in the buffer chamber of the dryer evenly and continuously to the drying area in the middle section of the dryer, and guides the movement trajectory of the wood chips to be dried during the conveying process. S4 The wood chips to be dried enter the middle drying area of the dryer and maintain the state of moving towards the discharge port at the tail of the dryer. Before reaching the discharge port, they exchange heat with the drying airflow and continuously throw and break up the wood chips to be dried. S5 wood chips reach the discharge port, complete the drying process, and are discharged from the dryer for collection.
2. The method for drying and preparing wood chips for pulp mills according to claim 1, characterized in that, The temperature of the drying airflow is 400~450℃.
3. The method for drying and preparing wood chips for pulp mills according to claim 1, characterized in that, The drying airflow velocity is 3-4 m / s.
4. The method for drying and preparing wood chips for pulp mills according to claim 1, characterized in that, The dryer operates at a speed of 3~4.5 r / min.
5. A drying preparation system based on the drying preparation method for wood chips for pulp mills according to claim 1, comprising: The drum dryer (1) has a through-channel structure. An "L"-shaped lifting plate for throwing materials is fixedly installed on the wall of the internal channel. A "rice"-shaped dispersing frame for dispersing materials is fixedly installed in the center of the internal channel along its inlet and outlet directions. The wood chips to be dried and the drying airflow exchange heat inside the dryer to achieve wood chip drying. Boiler system (2), burns fuel and heats the airflow; The air supply system (3), including a fan and air duct, stably transports the hot air generated by the boiler system from the head of the drum dryer (1) to the drum dryer (1); The conveying system (4) includes a material conveyor belt, a feeding hopper, and a discharging hopper, which are used for the uniform and stable conveying of fuel, materials to be dried, and materials to be dried; The dust collection system (5), including a cyclone separator and a bag filter, is used to collect dust and soot generated during the operation of the drum dryer (1); The feature is that a buffer chamber (101) connected to the internal drying area is installed at the head of the drum dryer (1). The shape and radial specifications of the buffer chamber (101) are the same as those of the dryer (1). Guide plates (102) are fixed at intervals on the inner wall of the head end of the buffer chamber (101), and connecting lifting plates (103) are fixed at intervals on the inner wall of the tail end of the buffer chamber (101). The guide plates (102), the connecting lifting plates (103) and the inner wall of the buffer chamber (101) together form a spiral guiding channel (104). The buffer chamber (101) is also equipped with a discharge hopper (105) at the head end, and the discharge point of the discharge hopper (105) is located in the middle section of the buffer chamber (101).
6. The drying and preparation system according to claim 5, characterized in that, The axial dimension of the buffer chamber (101) is 15% to 25% of the overall axial dimension of the drum dryer (1).
7. The drying and preparation system according to claim 5, characterized in that, The distance between the material drop point of the hopper (105) and the head end of the buffer chamber (101) is 55% to 60% of the axial dimension of the buffer chamber (101).