Cleanrooms are divided into several types based on the flow state of the airflow

2023-04-28 1780

According to the activity state of airflow, there are mainly three types of cleanrooms with dispersed airflow:

(1) Non unidirectional flow cleanroom: Once commonly referred to as turbulent flow cleanroom, the airflow inside the room does not move in a single direction. There are several common features of non unidirectional flow cleanrooms: the terminal filter (high efficiency or sub high efficiency) is located as close as possible to the cleanroom, and it can be either a supply air outlet or a continuous supply air outlet, or connected to the room's supply air static pressure box; The return air ports are all located at the lower part of the clean room to avoid the phenomenon of "dust lifting". Eddy currents exist in non unidirectional flow cleanrooms and are not suitable for use in high cleanliness cleanrooms. They are suitable for use in cleanrooms of grades 6-9.

(2) Unidirectional flow cleanroom: The characteristic of airflow in a unidirectional flow cleanroom is that the streamline is parallel, moving in a single direction, and the wind speed is consistent across the cross-section. There are straight unidirectional cleanrooms, quasi straight unidirectional flow, horizontal unidirectional flow cleanrooms, etc.

                       广东净化工程

(3) Vector cleanroom: Air is supplied to the upper corner of the room, using a fan-shaped high-efficiency filter or a general high-efficiency filter with a fan-shaped air outlet. A return air outlet is installed at the lower part of the other side. The height to length ratio of the room is generally between 0.5 and 1. This cleanroom can also achieve a cleanliness level of 5 (100).

The flow patterns in clean rooms are basically the three types mentioned above, but in practical applications, they can evolve into many forms. A clean room can be a mixed flow pattern that combines unidirectional and non unidirectional flow to achieve high-end cleanrooms in certain areas (unidirectional flow portion). For example, in a clean room, a horizontal unidirectional flow "tunnel" (with one side open) is set up, and the rest of the clean room follows a vortex unidirectional flow pattern, thereby achieving a cleanliness level of 5 or above in the "tunnel" section. The workbench is then set up inside the "tunnel".


The article originates from Guangdong Purification Engineering: http://www.jmyujie.com/