Purification workshop usually refers to the air purification project in the workshop. It refers to the circulation purification of the air in the sealed space to reduce and control the dust particles, planktonic bacteria, bacteria and other substances in the air in the space within the fixed control value. Two points need to be paid special attention to in the design of purification workshop project:
I. air flow speed / air change times of purification workshop
Air velocity / air change rate has always been a concern in the engineering design of the purification workshop. With the increase of the control effect of pollution sources in the purification workshop and the improvement of the efficiency of the final filter, the noise, damage and maintenance problems that people are worried about in the application of FFU have been solved in practice. With the continuous improvement of FFU, it is also a hot spot to use FFU return air system: suspended molecules The control of pollution (AMC) has been put on the agenda in microelectronics and IC industry, and has attracted more and more attention.
II. Air velocity
The determination of air flow velocity under a certain cleanliness in the purification workshop varies with the specific conditions such as the use of the purification workshop. It is not only affected by the amount of dust generated in the workshop and the efficiency of the filter, but also by other factors. As far as the engineering design of the industrial purification workshop is concerned, the factors that affect the cleanliness and the selection of air flow velocity are as follows:
(1) indoor pollution sources: building components, number of personnel and operation activities, process equipment, process materials and process processing itself are all dust release sources, which vary greatly according to specific conditions;
(2) indoor air flow pattern and distribution: unidirectional flow requires uniform and equal streamline, but it will be interfered by the layout of process equipment, location change and personnel activity to form local eddy current; instead of unidirectional flow, it requires filling and mixing to avoid dead angle and temperature stratification;
(3) control requirements of self purification time (recovery time): in the purification workshop, the accidental release or the interruption of pollutants or air flow, or the intermittent convection air flow during normal operation, or the movement of people and equipment, etc. will cause the deterioration of cleanliness. The self purification time to restore the original cleanliness depends on the air flow speed; the control requirements of self purification time depend on the time frame.（ The ability to bear the impact on the quality of product production and yield under the deteriorated cleanliness;
(4) efficiency of the final filter: under a certain amount of indoor dust generation, the filter with higher efficiency can be used to reduce the air flow speed; in order to save energy, the filter with higher efficiency should be used to reduce the air flow speed, or the filter with lower efficiency should be used with higher air flow speed to minimize the product of flow and resistance;
(5) economic considerations: the increase of investment and operation cost caused by excessive air velocity. The appropriate air velocity is a reasonable combination of the above factors. Too much air velocity is often unnecessary and not necessarily effective;
(6) for clean rooms with low cleanliness requirements, sometimes the number of air changes is determined by the indoor heat removal requirements.
Clean workshop, clean room, purification workshop, GMP certified standard workshop, laminar flow operating room and other purification projects are all within the scope of purification workshop engineering. We are more professional and welcome to inquire. For more knowledge of medical purification industry, please pay attention to wechat public number: aide-188 (ED purification oxygen supply)