Overview of Horizontal Boiling Drying Machine Equipment
The equipment designed according to the principle of fluidization, which uses a drying heat medium to dry solid particles in a fluidized state, is called a fluidized bed dryer, also known as a fluidized bed dryer.
The drying process of a fluidized bed involves placing granular materials on a gas distribution plate (such as a porous plate) and introducing gas from below. This causes the material particles to move on the gas distribution plate and remain suspended in the airflow, creating a mixed bed of material particles and gas, similar to liquid boiling. The material particles come into contact with gas while vigorously moving in this mixed bed, which is called a fluidized bed. Inject hot air to form a fluidized bed, and transfer heat and moisture between the material and the hot air.

Schematic diagram of the structure of a horizontal boiling dryer

Working principle of horizontal boiling dryer
The horizontal fluidized bed may be an early improvement of fluidized bed dryers, solving the problems of complex manufacturing and difficult operation control in traditional fluidized bed dryers. Due to its simple structure, convenient operation, and good performance, it quickly gained widespread application in the pharmaceutical industry and fine chemical industry.
A horizontal fluidized bed allows materials to be added from one end and discharged from the other end. For materials, it is equivalent to a series system of multiple square cross-section fluidized beds (gas is mostly in parallel). Its main feature is to improve the distribution of material residence time, thereby producing uniformly dried products. For this purpose, some also install baffles between adjacent rooms. Another advantage is that it is easy to combine the cooling and drying of materials in the same equipment, that is, to add a cooling chamber at the tail and directly package the discharged materials, simplifying the process and equipment investment. This type of dryer is currently widely used in industry, with successful examples including pesticides glyphosate, citric acid, oxalic acid, chlorinated rubber, as well as PVC, PE, PP resins, etc.
The horizontal multi chamber fluidized bed dryer can adjust the air volume in each chamber by dividing it into multiple chambers. At the same time, baffles have been added to the fluidized bed to prevent material from being discharged through short circuits, and the moisture content of the dried product is also relatively uniform. If the air volume and temperature of each room are adjusted in operation, or the hot air from the last few rooms is reused, the thermal efficiency can also be improved.

Process flow diagram of horizontal boiling dryer

Characteristics of horizontal boiling dryer equipment
1. Due to the counter current contact between gas and solid phases during the drying process, solid particles are suspended in the drying medium, resulting in a large contact surface between the fluid and solid. The volumetric heat transfer coefficient can reach 2000-6000 kcal/m3h ℃. At the same time, due to rapid heat transfer, it has a large processing capacity.
2. Due to the uniform temperature inside the fluidized bed and its ability to be freely adjusted, uniform dried products can be obtained.
3. Due to the adjustable retention time of materials ranging from a few minutes to tens of minutes, it is possible to produce dry products with extremely low moisture content.
4. Due to its liquid like state and function, fluidized beds are easy to handle and material transportation is simple.
5. The device has no moving parts, simple structure, and stable operation.
6. The processed materials are subject to certain restrictions and have certain usage conditions.
(1) The particle size of the material is generally greater than 30 μ m and less than 6mm, which is more suitable. A particle size that is too small is easily carried by the airflow, while a particle size that is too large is not easily fluidized.
(2) If several materials are mixed together for fluidized bed drying, it is required that the densities of the materials are relatively close. Otherwise, particles with lower density are more easily carried by the airflow than particles with higher density, which can also affect their dryness.
(3) Materials with high moisture content and easy to bond into clusters are generally not suitable.
(4) Materials that are prone to wall formation and agglomeration are prone to equipment wall formation and bed blockage during fluidized drying.
(5) The longitudinal backmixing of materials in the fluidized bed dryer bed is intense. For single-stage continuous drying, uneven residence time of materials in the equipment can result in uneven discharge of dry and wet products.
(6) Materials that require a visually appealing appearance for the product should not be used. For valuable and toxic materials, careful consideration should be given to a comprehensive recycling system.

Horizontal boiling dryer is suitable for materials
Drying operations for pharmaceuticals, chemical raw materials, food, grain processing, and feed. For example, drying and dehumidification of raw materials, tablet granules, traditional Chinese medicine granules, health foods, beverage granules, corn germ, feed, plastic resins, citric acid, and other powdered materials. The suitable material particle size is generally 0.1-6mm, with a preferred particle size of 0.5-3mm.
Technical parameter table of horizontal boiling dryer

Note: 1. Feeding method: ① Star shaped feeding; ② Combination of star shaped feeding and pneumatic conveying; ③ Belt conveyor; ④ User defined.
2、 Automated production can be achieved. 3、 In addition to the above models, special designs can be made for users. 4、 According to different materials, the fan power also varies.