Application of sintered mesh to remove impurities from pharmaceutical materials

Sintered mesh filter elements are popularly used with dryers and mills in the pharmaceutical plants. When these screens are used with these systems, they are attributed with reverse air jet collectors comprising several filter elements. They are used to collect powders to prevent it moving back into the process. The reason of using sintered mesh filter screens with dryers and mills is because these elements alloy the complete system to be cleaned in place, which then prevents the need to break the containment of the system. However the need of reversal air jet system in the collector and clean in place methods needs discussion, this issue can be prevented. The systems equipped with sintered mesh can be validated and meet the needs of advanced product manufacturing process as demanded in the pharmaceutical plants.

Over the years, the pharmaceutical plants have been looking to replace the large clean rooms with contained systems. This contained system can be configured in a room at lower atmospheric quality when the need to open the system is reduced.

The key reason to open the system is to clean the equipment. It can be overcome by offering local secondary containment or by using clean-in place system.

Collectors in dryers and mills are used to remove the product powder from vapor and gas flows and return maximum of power to the process. These equipments have filter screens to remove the accumulated powder layer through air jet. They can be mad suitable for in-place cleaning when the sintered metal filter elements are used.

The reverse air jet has following parts- housing, plenum across housing, mesh screen, a mechanism for offering a reverse air jet. A collector is required to create a clean in place system.

Powder containing gas passes through the bottom, and particles accumulate on the filter screen. First, some particles may flow through the medium, however once particles’ deposition started, they improve the filter performance. When the filtration continues, the cake becomes thicker and over the time when the pressure drop becomes very high, it is essential to remove the cake from the mesh.

Reverse air jet stream is used to remove powder adequately to stabilize the pressure drop of the screen throughout the service. Further, it allows returning of as much of material as feasible to the group and hence maximize product output.

During the filtration, the contaminants are trapped in the filter screen by adhesive force, and cake formation is sustained by cohesive forces between the particles, assisted by pressure exterted by the gas flow across the filter medium. The bonding forces hence produced can be highly strength, specifically if the particles can partly penetrate into the filter medium. The powder removal requires to restore the filtration rate to an economically suitable level. For this, it should offer sufficient disruptive forces to separate the cake from the filter. It is performed by reverse flow. In this way, the filtration of gas media is performed to receive the pure gas flow throughout the system.