May I ask, since the pressure in the exhaust gas adsorption tower is between -0.01 and 0.1 MPa, can it be considered a vessel under normal pressure?

According to the general definition, a pressure vessel at atmospheric pressure (also known as an atmospheric vessel) is a vessel whose designed operating pressure is less than or equal to 0.1 MPa (i.e., 1 atmosphere or 1.01325 bar), and whose medium is gas or liquid. If the operating pressure range of the exhaust gas adsorption tower is between -0.01 MPa (relative vacuum condition) and 0.1 MPa, this range generally meets the definition of a pressure vessel at normal pressure. However, the official classification still needs to be determined in accordance with local safety regulations and industry standards. For example, in China, according to the \"Regulations on Safety Inspection of Pressure Vessels\" (TSG R0004-2009), gas or liquid vessels with a design pressure of 0.1 MPa or less are defined as atmospheric pressure vessels; however, it is also necessary to take into account their operating temperature and whether the medium contained within them is hazardous. In practical applications, it is necessary to determine whether the waste gas adsorption tower can be used as a pressure-free vessel based on specific regulatory requirements, operating conditions, and safety considerations. If in doubt, you can consult relevant professionals or regulatory authorities. .

It can only be said that it is not considered a pressure vessel; a vessel at normal pressure generally refers to one with a design pressure of ≤6.7 kPa