Product Overview:
Overview of belt dryer, also known as mesh belt dryer or belt drying oven. The dried and baked material continuously enters from the feeding port, passes through the heating tunnel at a constant speed through the mesh belt conveyor, and runs towards the discharging port. The material is heated during operation, and the moisture or solvent is evaporated before being discharged outdoors. Generally, it is a single-layer structure. Sometimes, in order to save space and increase production, it is designed and manufactured as a three-layer or five layer structure.
A belt dryer consists of several independent unit segments. Each unit segment includes a circulating fan, heating device, separate or shared fresh air intake system, and exhaust system. The operating parameters of drying medium quantity, temperature, humidity, and exhaust gas circulation can be independently controlled to ensure the reliability of the dryer operation and optimize the operating conditions. The operation of the dryer is flexible, and the wet material is fed. The drying process is carried out in a completely sealed box with good working conditions, avoiding the leakage of dust. Belt dryer is a continuous drying equipment used in batch production, used for drying sheet, strip, and granular materials with good breathability. It is particularly suitable for dehydrated vegetables, catalysts, traditional Chinese medicine decoction pieces, and other materials with high moisture content and material temperature not allowed to be high; This series of dryers has the advantages of fast drying speed, high evaporation intensity, and good product quality. For dehydrated filter cake like paste materials, they need to be granulated or made into strips before drying.

Characteristics of belt dryer
1. The vibration and impact of the material on the belt dryer are slight, and the material particles are not easy to pulverize and break, so it is also suitable for drying certain materials that do not allow fragmentation.
2. The belt dryer not only provides drying for materials, but sometimes can also perform baking, roasting, or curing operations on materials.
3. The structure of the belt dryer is not complicated, easy to install, and can operate for a long time. In case of malfunction, it can enter the interior of the box for maintenance, making it easy to repair.
4. It has the advantages of high drying rate, high evaporation intensity, and stable product quality.

Scope of application of belt dryer
Belt dryer is widely used in industries such as traditional Chinese medicine, food, chemical, electronics, hardware, etc. It is an ideal equipment for continuous drying and baking in large quantities. Used for drying sheet, strip, granular, and partially paste like materials with good breathability. It is particularly suitable for dehydrated vegetables, traditional Chinese medicine decoction pieces, and other materials with high moisture content and heat sensitivity. For the paste like material of dehydrated filter cake, it can also be dried after granulation or shaping into a rod shape.
Belt dryer is widely used in industry, mainly for drying small pieces of materials and fibrous materials
The material dried by a belt dryer must have a certain shape and still maintain a certain shape after drying.
Working principle of belt dryer
The materials are evenly spread on the mesh belt by the feeder, and the mesh belt is made of 12-120 mesh stainless steel wire mesh. Dragged by the transmission device to move inside the dryer. The dryer consists of several units, with each unit having independent hot air circulation. Some of the exhaust gas is discharged by a servo dehumidifier, and the exhaust gas is controlled by a regulating valve. The hot air passes through the material laid on the mesh belt from bottom to top or from top to bottom, heating and drying while removing moisture. The mesh belt moves slowly, and the running speed can be freely adjusted according to the material temperature. The dried finished product continuously falls into the feeder. The upper and lower loop units can be flexibly equipped according to user needs, and the number of units can be selected as needed.

Belt dryer structure
The entire equipment consists of a feeding section, a heating section, a constant temperature section, a cooling section, and a discharging section. It includes a heating system, insulation system, cooling system, hot air circulation system, dehumidification and sewage discharge system, transmission system, and electrical control system.
Single stage belt dryer: The dried material is evenly distributed onto the conveyor belt through the feeding device at the feeding end. Conveyor belts are usually made of perforated stainless steel sheets, driven by motors through gearboxes, and can be adjusted in speed. The interior of the drying machine is usually divided into several units for independent control of operating parameters and optimization of operations. There is an isolation section between the drying sections, where there is no circulation of drying medium.
Multi stage belt dryer: Multi stage belt dryer is essentially composed of several single-stage belt dryers connected in series, and its operating principle is the same as that of single-stage belt dryers.
Multi layer belt dryer: Multi layer belt dryer is commonly used in situations where the drying speed requirements are low, the drying time is long, and the process operating conditions can be maintained constant throughout the entire drying process. Set up partitions between layers to organize the directional flow of drying medium, ensuring uniform drying of materials. Multi layer belt dryer takes up less space, has a simple structure, and is widely used for drying grain materials. However, due to the need for multiple loading and unloading during operation, it is not suitable for dry and easily adhesive conveyor belts and materials that are not allowed to break.
Impact belt dryer: The impact belt dryer is suitable for drying surface coatings of fabrics, tobacco leaves, substrates, and other thin sheet materials. The impact belt conveyor usually consists of two conveyor belts. The impact belt conveyor can be divided into unit segments for independent control. After the drying medium is humidified, some of it is discharged, while the other part is returned and mixed with fresh drying medium before circulating.

Requirements for the production of belt dryers
Select the internal and external materials of the oven based on material characteristics and process requirements. Generally, belt dryers with no corrosion or cleanliness requirements are made of ordinary carbon steel plate surface rust prevention and then painted. The inner liner and air duct can also be made of galvanized sheet metal. There are corrosive volatiles and some requirements for the cleanliness inside the oven. Generally, 201, 202, and 304 stainless steel are used as the inner liner, and the outer shell is configured with a material lower than or equal to the inner liner material according to the workshop conditions and process requirements. Other materials such as 316 and 316L may also be used for special requirements.
The transmission method is mesh belt transmission, which mainly selects the mesh belt density based on the material form. Special materials also have structures covered with PTFE mesh on the mesh belt.
Heating elements mainly include: electric heating tube, far-infrared quartz tube, radiation tube, steam radiator, thermal oil conduction, hot water heating, external heating package air supply, etc.
The following process has requirements for the surface temperature of the material and requires the installation of a cooling device, usually an air-cooled structure.
Electrical control generally uses PID intelligent temperature controller with temperature control solid-state relay for temperature control, and can also be configured with PLC and printer for process recording, fixed process operation program, and higher requirements for electrical control.

Elements of belt dryer
Efficient heating mode: The belt dryer consumes a large amount of heat energy during operation. It is crucial to select heating elements correctly and scientifically distribute them. Choosing an appropriate heating mode will play a very important role in energy conservation and consumption reduction.
A reasonable hot air circulation system is the main means to improve heating efficiency and ensure uniform material drying. There are two types of hot air circulation in the machine: convection and laminar flow. A single-layer mesh belt dryer usually uses convection air, while a multi-layer mesh belt dryer prefers a laminar air structure.
Good insulation performance: The smaller the temperature rise on the surface of the oven, the less heat energy is lost. The correct selection of insulation materials and appropriate insulation layer thickness, as well as the elimination of thermal bridges, are the only means to ensure insulation performance.
A stable transmission system: The drive motor configuration must be accurate, ensuring torque while minimizing power. Regardless of the transmission method, there should be no deviation of the conveyor belt.
Accurate electrical control: Electrical control does not account for a high proportion of the total equipment cost, so selecting high-end configured components ensures long-term precise control without increasing much cost.

Selection elements of belt dryer:
1. Name and composition of the material being dried and baked;
2. Wet basis (proportion of water or solvent) before drying and baking of materials;
3. Wet base after drying and baking of materials;
4. Production per shift (8 hours) (weight of finished products);
5. The maximum working temperature that the material can withstand (heat resistance);
6. What kind of heat source can be provided;
7. The safety requirements for equipment in the workshop (explosion-proof, fireproof, moisture-proof, high-temperature resistant, limited charge, etc.);
8. Equipment utilization rate and requirements for spare parts and accessories.

Technical parameters: