Air Filtration by Membrane AS PER USFDA GUIDELINE
Air Filtration by Membrane – A compressed gas should pass for purity test to ensure it is free from oil and meets the required standards for microbiological and particle quality after filter. The quality of the compressed gas should be at least equal to the air quality in the surrounding environment where it is introduced.
Membrane filters are commonly used to filter a compressed gas to meet a high-quality Standard.
Membrane filters are frequently used to produce sterile compressed gas for carrying out operations that involve sterile materials, including components and equipment. For example, we recommend that sterile membrane filters be used for autoclave airlines, lyophilizer vacuum breaks, and tanks that hold sterilized materials.
Sterilized holding tanks and contained liquids should be held under positive pressure and properly sealed to prevent microbial contamination. To prevent contamination caused by the backflow of nonsterile air or liquid, it is essential to have safeguards in place that prevent any pressure changes.
Also Read – High-Efficiency Particulate Air (HEPA)
Gas filters (including vent filters) should be dry. Condensate on a gas filter can cause blockage during use or allow for the growth of microorganisms. The use of hydrophobic filters, as well as the use of heat to these filters where appropriate, prevents problematic moisture residues.
We recommend that filters that serve as sterile boundaries or supply sterile gases that can affect the product be integrity tested upon installation and periodically thereafter (e.g., end of use). Integrity tests are also recommended after activities that may damage the filter. Integrity test failures should be investigated, and filters should be replaced at appropriate, defined intervals.
What is the concept of membrane filtration and how does it operate?
Membrane filter refers to the process of passing a single feed stream through a membrane system, which effectively separates it into two distinct streams called the permeate and the retentate. This membrane acts as a physical barrier with specialized characteristics, allowing only specific components in the feed stream to pass through.
The membrane material contains incredibly small pores, measured in Angstrom (10-10 m), and the application of pressure is necessary to push the liquid through these pores. The pores in membranes used for nanofilter and reverse osmosis are so minuscule that they cannot even be observed with a scanning electron microscope.
There are four widely recognized categories of membrane filters, which are classified based on the size of the substances they are designed to separate from the liquid being processed. These four categories are reverse osmosis, nanofiltration, ultrafiltration, and microfiltration, arranged in ascending order according to the size of their pores. Our range of products includes flat sheet membranes and spiral wound membranes, which cater to these various types of membrane filters.
Cross-flow filters and dead-end filters are two different methods of membrane filtration.
Cross-flow filter offers several advantages compared to dead-end filtration. One of the main advantages is that it eliminates the formation of a filter cake, which can cause fouling and uneven flow. In cross-flow filtration, the liquid being processed flows continuously across the membrane, allowing for a consistent and controllable product quality. This method also does not require the use of filter aids and extends the lifespan of the membranes.
In contrast, dead-end filtration involves the liquid being filtered and passing directly through the membrane, resulting in the accumulation of a filter cake. This can lead to fouling and a decrease in filtration efficiency.
Due to its numerous benefits, cross-flow filtration is widely used in industrial membrane filtration processes. In this method, the liquid flows parallel to the membrane at a high velocity and under pressure. This allows for efficient and automated filtration, ensuring a reliable and high-quality end product.
