1. Strict control of the pressure difference between the purification workshop and the adjacent rooms is also an important link to ensure the cleanliness of the air in the production room.
2. When the air cleanliness requirement is 10000 and 100000, non-unidirectional flow is adopted, and the ventilation times are more than 25 times/hour and 15 times/hour respectively (the ventilation times of 300000 grades are not less than 12 times/hour), so as to take away the dust and dust generated in the production process in time and maintain the cleanliness of the dust-free workshop environment.
3. When the air cleanliness requirement for injection production is 100 grades, the vertical and horizontal unidirectional flow patterns are adopted, and the air flow velocities are greater than 0.25 m/s and 0.35 m/s, respectively.
4. Before and after each production cycle, the number of dust particles in the cleaned workshop should be measured under static conditions in order to evaluate and master the content of dust particles in the workshop. The pressure difference between clean and non-clean zones of different cleanliness levels should be greater than 5 Pascal, the pressure difference between clean zones and outdoor zones should be greater than 10 Pascal, and the opening and closing of supply, return and exhaust systems should be interlocked and operated in sequence, so as to avoid air backflow and reduce the pollution of low-grade dust to the environment of clean workshop.