Introduction
Vacuum filter drums, also known as vacuum belt filter drums, are widely used in the filtration process of liquid or solid-liquid mixtures. They are considered efficient, economical and low cost solutions as they are easy to operate, maintain and control. Vacuum filter drums are mainly utilised in the handling of biological and chemical wastes and the concentration of slurries containing insoluble matter.
Design
A Vacuum filter drum consists of a perforated drum, a filtration membrane, a vacuum source and necessary operating controls. The filtration membrane is partially submerged in the feed material in the perforated drum and the applied vacuum helps to create a pressure differential across the membrane. This causes the liquid or solid-liquid mixture in the feed material to be filtered in order to remove any particles. The filtration is carried out as a continuous process as the drum continually rotates and moves the membrane through the feed material.
Applications
Vacuum filter drums are typically used to filter and concentrate slurries containing insoluble matter. They are commonly used in the wastewwater treatment, chemical, food and beverage, textiles, pulp and paper, and mineral processing industries. They are often used to recover solids such as lead, silver and gold from leaching solutions.
Operation
Vacuum filter drums are designed to continuously filter and concentrate a material as long as there is an adequate supply of feed material. The drums are operated using a combination of vacuum pressure and drum rotation. The perforated drum rotates and the membrane is continuously submerged in the feed material. As the membrane passes of the perforations in the drum, the material is forced through the membrane and the vacuum is applied to the opposite side of the membrane to draw the filtrate through. The speed of rotation and the effective membrane surface area are key factors that determine the rate of filtration.
Advantages
The main advantages of vacuum filter drums over other filtration techniques are their simplicity of operation, low cost, wide range of materials and sizes, and their ability to filter wet or dry material. Vacuum filter drums are also relatively easy to maintain and control. They are suitable for both large and small scale filtration applications.
Conclusion
Vacuum filter drums are an efficient, economical and low cost solution for the filtration of a wide range of liquid or solid-liquid mixtures. They are simple to operate, maintain and control and suitable for both small and large scale filtration applications. They are commonly used in the wastewater treatment, chemical, food and beverage, textiles, pulp and paper, and mineral processing industries.
