| 摘要 |
According to an embodiment of the present invention, an apparatus for maintaining density includes: a housing which is located on an upper part of a drip pan, and comprises an accommodation space to accommodate a fluid and a spray nozzle on a lower plane; and an elevation member which can be elevated by being located in the housing, and can spray the fluid to the drip pan in case the elevation member descends toward the spray nozzle. The objective of the present invention is to improve quality and yield of a product by preventing a surface defect of a resin coated steel sheet. |
