What is a membrane dryer?

A membrane dryer is a type of compressed air dryer that removes moisture from compressed air using a selectively permeable membrane. It operates on the principle of selective permeation, where water vapor molecules pass through the membrane while larger compressed air molecules are retained. The membrane dryer consists of a hollow fibre membrane module, typically made of polymer materials. Compressed air enters the membrane module, and as it passes through the hollow fibres, water vapor molecules are selectively removed and vented to the atmosphere. The dried compressed air continues its flow, exiting the dryer with reduced moisture content. Membrane dryers are known for their simplicity, compact size, and low maintenance requirements. They do not require electricity, refrigerants, or desiccant materials like other types of dryers. However, they have limitations in terms of the amount of moisture they can effectively remove and their ability to handle high ambient temperatures or oil vapor present in the compressed air stream. Membrane dryers are commonly used in applications where low dew points are not required but where a significant reduction in moisture content is desired. They are suitable for point-of-use drying, small-scale operations, and locations where power availability or space constraints may be a concern.