| 摘要 |
PURPOSE:To automate change-over of tanks and drawing out of a liquid chemical in a feeding device through safe and secure operation, by providing an emptiness detector, and a device memorizing a stage for drawing out the liquid chemical in plural liquid chemical storage tanks. CONSTITUTION:A tank 1 is pressurized by introduction of a pressurized gas through an inlet 7' in drawing out a liquid chemical by closing a release valve 6-2 and opening a pressurizing valve 6-1. The liquid chemical is drawn out by opening a liquid chemical valve 5 through a pipe 2 from an outlet 4. When the tank 1 becomes empty, an emptiness detector 3 is actuated, and a liquor storage tank 1' is also actuated to act likewise. A device for memorizing the stage of drawing out operation of the tank is provided in this feeding device. For example, the tank 1 is set in operation and the tank 1' is reset, and the use conditions of them are memorized. When the liquid chemical in the tank 1 is used up, the detector 3 is actuated to turn the tank 1 to a reset state, and the tank 1' is pressurized and a liquid chemical valve 5' is opened to draw the liquid. |
