JIUYI Dehydrator Equipment
In the starch processing industry, cassava, with its high yield and strong adaptability, has become an important raw material for starch production. However, for every ton of cassava starch produced, several tons of cassava starch residues with a water content as high as 80% – 90% are generated. These starch residues with high water content not only occupy a large amount of storage space, are prone to corruption and deterioration, pollute the environment, but also waste potential resources. Therefore, the dehydration treatment of cassava starch residues has become a key link in the industry to reduce costs, increase efficiency, and achieve green development, and the selection of suitable dehydration equipment is of paramount importance.
Analysis of the Dehydration Process of Cassava Starch Residues
The dehydration of cassava starch residues usually consists of three stages: pretreatment, mechanical dehydration, and deep drying. In the pretreatment stage, the main task is to break up and screen the starch residues, remove the remaining impurities and agglomerates, and make the materials more uniform, facilitating subsequent dehydration treatment. This process can be completed by using a screw conveyor in conjunction with a vibrating screen. The screw conveyor is responsible for transporting the materials, while the vibrating screen separates the impurities and large – sized materials that do not meet the requirements.
Mechanical dehydration is the core step in reducing the water content of starch residues, aiming to quickly remove a large amount of free water. The pretreated starch residues enter the dehydration equipment, and solid – liquid separation is achieved under the action of mechanical force, reducing the water content to 50% – 60%, which relieves the pressure on subsequent deep drying.
In the deep drying stage, the mechanically dehydrated starch residues need to be further dried to reduce their water content to 12% – 15%, meeting the standards for long – term storage and resource utilization. In this stage, methods such as hot air drying and low – temperature vacuum drying are commonly used.
Overview of Dehydration Equipment for Cassava Starch Residues
1.Belt Filter Press
The belt filter press is a commonly used equipment for dehydrating cassava starch residues. When it operates, the starch residues first enter the gravity dehydration zone. Under the action of gravity, a large amount of free water quickly drains through the gaps in the filter belt. Then, it enters the wedge – shaped pressing zone, where the two filter belts gradually come closer together to initially squeeze the materials. Finally, it enters the low – pressure and high – pressure pressing zones. Through the application of increasing pressure by rollers of different diameters on the filter belt, the water in the starch residues is fully squeezed out, forming filter cakes with a low water content. This equipment has a large processing capacity and can achieve continuous production, with a processing capacity of several tons per hour. It also has low energy consumption and controllable operating costs. Moreover, it is easy to operate and has a high degree of automation, requiring only a small amount of manual monitoring.
2.Plate and Frame Filter Press
The plate – and – frame filter press forms a filtration chamber by alternately arranging filter plates and frames. After pumping the cassava starch residues into the filtration chamber, under the action of pressure, the water passes through the filter cloth and is discharged, while the solids are retained in the filtration chamber to form filter cakes. After the filtration is completed, the filter cakes can be unloaded by loosening the plates and frames. It has a good dehydration effect and can reduce the water content of starch residues to a lower level. However, it is an intermittent operation, resulting in relatively low production efficiency. In addition, the replacement and cleaning of filter cloths are relatively cumbersome, and the labor intensity is relatively high.
3.Centrifuge
Centrifuges achieve solid – liquid separation by using the centrifugal force generated by high – speed rotation. Under the action of centrifugal force, the denser solid particles in the cassava starch residues are thrown towards the drum wall, and the water is discharged through the small holes in the drum. It has a high separation efficiency and fast dehydration speed, and can process a large amount of materials in a short time. However, the equipment investment cost is relatively high, the operation noise is large, and its adaptability to materials is limited. When processing starch residues with a high fiber content, blockage may occur.
4.Screw Extrusion Dehydrator
The screw extrusion dehydrator exerts a squeezing effect on the cassava starch residues through the advancement of the screw shaft and its variable – diameter structure. As the screw shaft advances, the space for the materials gradually becomes smaller, and the pressure continuously increases, squeezing out the water. This equipment has a compact structure, small footprint, and is easy to operate and maintain, making it suitable for small and medium – sized starch processing enterprises. However, its processing capacity is relatively small. If it processes high – fiber materials for a long time, the screw shaft and screen will wear out relatively quickly.
The dehydration of cassava starch residues is the key to realizing resource recycling and green development of the industry. Equipment such as belt filter presses, plate – and – frame filter presses, centrifuges, and screw extrusion dehydrators have their own advantages and disadvantages. Enterprises can comprehensively consider factors such as their production scale, budget costs, and material characteristics to select the most suitable dehydration equipment, improve production efficiency, reduce environmental pollution, and promote the sustainable development of the cassava starch processing industry.