Dynamic Pass Box Working Principle

  • 30, 12, 2020

Table of content

1. Dynamic pass box function

2. The working principle of dynamic pass box

3. Dynamic pass box features

Dynamic pass box function

Dynamic pass box is the self-cleaning transfer device in cleanrooms. Pass box function is to transfer items and to reduce the number of door openings in cleanroom. It's mainly installed between a cleanroom and a non-cleanroom, or between a high-level cleanroom and a low-level cleanroom.

Dynamic pass box has self-cleaning function, which purifies the air inside the pass box to create a high-cleanliness environment. It's used for pollution-free transmission. 

So what is the dynamic pass box working principle? 

Dynamic passbox includes HEPA filter, a fan and a return air grille. There is a ventilation gap between the inner liner and the outer frame of pass box. 

When the fan inside pass box blows, it sends air to HEPA filter. The filter clean air enters the inner space of passbox, dilutes and filters the air inside. Then it passes through the return air grille, circulates to the fan, then goes through HEPA filter. The air is sent into the inner space and the cycle continues until the surface of the conveyed item is purified. 

Dynamic pass box features

Because of small size, small circulating air volume of pass box, the purification effect can be achieved only by the inside air circulation. It does not need air outside. There is no great positive pressure or negative pressure difference. The function of the dynamic pass box only allows the passed items to stay for a while. 

Laminar airflow design is used in pass box. Up-feed and down-return mode allows unidirectional flow hoods and reduces the turbulent airflow. Dynamic pass box has double door interlocking system. Two doors cannot be opened simultaneously, which prevents cross-contamination during items transfer. 

Besides, dynamic pass box is made of stainless steel, which has good corrosion resistance. The smooth surface of the stainless steel pass box is good for maintaining cleanliness in cleanroom.  

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