According to the air flow organization and the laying of various pipelines, as well as the layout requirements of the purification air conditioning system supply and return air outlet, lighting fixtures, alarm detectors, etc., the clean room is usually set up in the upper technical mezzanine, the lower technical mezzanine, the technical mezzanine or the technical shaft.
Technical mezzanine
Electrical pipelines in clean rooms should be located in technical mezzanines or tunnels. Low-smoke, halogen-free cables should be used. The threading conduits should be made of non-combustible materials. Electrical pipelines in clean production areas should be laid concealed, and reliable sealing measures should be taken at the joints between electrical pipeline openings and various electrical equipment installed on the wall. The upper power distribution method in clean room: low-voltage power transmission and distribution lines generally adopt two methods, namely, the cable bridge is laid to the distribution box, and the distribution box to the electrical equipment; or the closed bus duct ten plug-in box (the jack is blocked when not in use), from the plug-in box to the electrical control box of the production equipment or production line. The latter power distribution method is only used in electronic, communication, electrical equipment and complete machine factories with low cleanliness requirements. It can bring changes in production products, updates and changes in production lines, and shifts, additions and subtractions of production equipment. It is extremely convenient. There is no need to modify the power distribution equipment and wires in the workshop. You only need to move the busbar plug-in box or use the spare plug-in box to lead out the power cable.
Mezzanine wiring
Technical mezzanine wiring in clean room: It should be used when there is a technical mezzanine above clean room or when there is a suspended ceilings above clean room. Suspended ceilings can be divided into structural forms such as reinforced concrete sandwich and metal wall panels. Metal wall panel and suspended ceilings are commonly used in clean room.
Sealing treatment
The wiring method of the technical mezzanine in clean room is not much different from the above-mentioned power distribution method, but it should be emphasized that when wires and cable pipelines pass through the ceiling, they should be sealed to prevent dust and bacteria in ceiling from entering clean room and maintain the positive (negative) pressure of the clean room. For the upper mezzanine of a non-unidirectional flow clean room that only has an upper technical mezzanine, it is usually laid with air-conditioning ventilation ducts, gas power ducts, water supply ducts, electrical and communication strong and weak current pipelines, bridges, busbars, etc., and the ducts are often crisscrossed. It is very complex. Comprehensive planning is required during design, "traffic rules" are formulated, and comprehensive cross-section drawings of pipelines are required to arrange various pipelines in an orderly manner to facilitate construction and maintenance. Under normal circumstances, strong current cable trays should avoid air conditioning ducts, and other pipelines should avoid closed busbars. When the mezzanine on the clean room ceiling is high (such as 2m and above), lighting and maintenance sockets must be installed in ceiling, and fire alarm detectors must also be installed according to regulations.
Upper and lower technical mezzanine
Wiring in lower technical mezzanine of the clean room: In recent years, clean room for large-scale integrated circuit chip manufacturing and LCD panel manufacturing usually use multi-layer clean room with multi-layer layout, and upper technical mezzanines are set up on the upper and lower parts of the clean production layer, lower technical mezzanine, the floor height is above 4.0m.
Return air plenum
The lower technical mezzanine is usually used as the return air plenum of the purified air conditioning system. According to engineering design needs, electrical pipelines, cable trays and closed busbars can be laid in the return air plenum. The low-voltage power distribution method is not much different from the previous method, except that the return air plenum is an integral part of the clean room system. The pipelines, cables, and busbars laid in static plenum must be cleaned in advance before being installed and laid to facilitate daily cleaning. The low-tech mezzanine electrical wiring method transmits power to the electrical equipment in clean room. The transmission distance is short, and there are few or no exposed pipelines in clean room, which is beneficial to improving cleanliness.
Tunnel type clean room
The lower mezzanine of the clean room and the electrical wiring on the upper and lower floors of a multi-story clean room are in a clean workshop that adopts a tunnel-type clean room or a clean workshop with technical aisles and technical shafts. Since the tunnel-type clean room is arranged with a clean production area and auxiliary equipment area, and most of the auxiliary equipment such as vacuum pumps, control boxes (cabinets), public power pipelines, electrical pipelines, cable trays, closed busbars and distribution boxes (cabinets) are located in auxiliary equipment area. The auxiliary equipment can more easily connect power lines and control lines to electrical equipment in clean production area.
Technical shaft
When the clean room is equipped with technical aisles or technical shafts, the electrical wiring can be placed in corresponding technical aisles or technical shafts according to the layout of the production process, but attention should be paid to leaving necessary space for installation and maintenance. The layout, installation and maintenance space of other pipelines and their accessories located in the same technical tunnel or shaft should be fully considered. There should be overall planning and comprehensive coordination.
Post time: Nov-01-2023