On Air Shutter for Cold Storage Room

Abstract

Air curtains are frequently placed at doorway of cold storage room or freezing chamber. As an opening of jet flow in these air curtains is relatively narrow and speed of jet flow is fast, air entrained from surroundings increases in quantity. Therefore, we consider that jet flow with narrow opening can not effectively isolate inside air from the external atmosphere, but the one with relatively wide opening can decrease air entrained from surroundings.
Then, when air curtain which has a wide opening (we call it air shutter) is installed at cold storage room, and isolating performances of air shutter are compared with the air curtain. First, as various conditions can be easily changed in numerical calculation, we compare a velocity and temperature field in cold storage room under these conditions when velocity of jet flow is changed by using numerical method.
Second, we measure a temperature and velocity distribution in an actual cold storage room under three conditions (air shutter operates, air curtain operates and no operation).
From these results, it was found that air shutter is more efficient than air curtain.