| 摘要 |
<p>PURPOSE:To obtain a warehouse, in which the black flow of air is prevented and cleanliness is maintained, by openably installing a moving door mounted to an exhaust port, a pressure difference detecting sensor detecting the difference of pressure on the inside and outside of a warehouse set up at the specified position of a sidewall and a control section controlling the opening and closing of the moving door based on an output from the pressure difference detecting sensor. CONSTITUTION:A shifter includes a wire rope 41 connected to a moving door 40, a rail 42, which is disposed in the longitudinal direction of a wafer warehouse in the lower section of an exhaust port 10B and on which the moving door 40 is placed in a left and right movable manner, and a servomotor 45. Clean air A flowing from a ventilating port 10A falls down in the warehouse, and the greater part of air C are discharged to the outside through the exhaust port 10B and a grating 11, thus preventing adhesion of dust on wafers. Even when pressure in the warehouse is kept constant, the servomotor 45 is turned in the forward and opposite directions when pressure on the outside of the warehouse is fluctuated and pressure difference is deviated from a set value, and the moving door 40 is moved by a fixed quantity. Accordingly, the quantity of air C discharged is varied, and pressure difference on the inside and outside of the warehouse is returned to the set value, and held at a positive specified value.</p> |
