| 摘要 |
PURPOSE:To prolong the life of a pressure container and to improve detection precision by connecting a detecting means for the gas in a pressure container to the upper end part of the pressure container, and incorporating a cylinder for differential pressure detection in the pressure container. CONSTITUTION:Pressure-reduced towers 15a-15c each consists of the pressure container 15 composed of, for example, a container body 33 and a container head 34. Then, a piping connection port 42 for gas pressure detection which detects the gas pressure in the pressure container 15 and a piping connection port 41 for gas pressure detection which detects the gas pressure in the cylinder 40 for differential pressure detection are formed at the container head 34. Then, variation in liquid level is detected as the differential pressure of gas due to a head difference. Thus, an error from a reference liquid level is also checked without bringing a pressure receiving diaphragm into contact with corrosive liquid to prolong the life of the pressure container and improve the detection precision. |
