Regarding Article 7.2.15 of the Petrochemical Code GB50160
Thread Content
1. Is this applicable to all devices? If the tower also follows this rule, for a distillation tower, the upper section (distillation section) contains liquefied hydrocarbons while the lower section (stripping section) contains the solvent (Methanol B); in that case, the pump used to extract the material from the bottom of the tower probably doesn’t need to comply with this rule, right? Since the upper section of the tower contains liquefied hydrocarbons, does the top circulation pump in that upper section need to follow this requirement? 2. “Regarding the case where the equipment volume exceeds 40 m3 and the distance to the pump is less than 15 m”, does this equipment volume refer to the amount of liquid required for the normal operation of the equipment, or to the total volume of the equipment? (1) For example, as mentioned in point 1 above, in a distillation tower, the liquid obtained from the bottom of the tower is generally of type A or B; it is neither above its auto-ignition temperature nor a liquefied hydrocarbon. However, the liquid circulating at the top of the tower is a liquefied hydrocarbon. So, for a top circulation pump, should an EBV valve be installed, and how is this volume determined? Is it based on the total volume of the tower, or? (2) For a distillation column whose bottom contains materials whose operating temperature is above their auto-ignition point, but whose upper sections contain ordinary oils (neither liquefied hydrocarbons nor materials with a temperature above their auto-ignition point), should the bottom product pump comply with this requirement? As for whether to install an EBV valve, should it be based on the total volume of the column, or on the maximum liquid volume in the column bottom + the estimated liquid volume in the downcomer during normal operation + the estimated liquid volume on the trays during normal operation?
Personal opinion: 1. It is suitable for all types of equipment, mainly container-based devices (such as towers, storage tanks, etc.). For a distillation column, the upper section (distillation section) contains liquefied hydrocarbons; the top recirculation pump in this upper section needs to operate according to these requirements. The lower section (stripping section) contains the solvent (Methanol B), and whether this pump needs to operate depends on whether the operating temperature at the bottom of the column exceeds the auto-ignition point of the solvent (Methanol B). 2. The equipment volume refers to the effective volume of the equipment: (1) based on the volume of the top recirculation tank (or buffer tank); (2) based on the maximum liquid volume in the column bottom + the estimated volume of liquid in the downcomer during normal operation + the estimated volume of liquid on the tray surfaces during normal operation
1. I also tend to agree with what you said. However, there are still the following points regarding towers that would like to be discussed: (1) What should be considered when there are no buffer tanks in many top circulation systems? (2) For the maximum liquid level in the tower bottom, should it be based on the maximum liquid level under normal operational conditions, or calculated using the level gauge, or based on the distance from the liquid surface to the lowest tray? (3) The liquid level on the tray and the liquid level in the downcomer can only be estimated; if the total amount calculated comes close to the limit, should it not be adjusted upward?
(1) There is no buffer tank in the top circulation system; the calculation is based on the maximum amount of liquefied hydrocarbons that can be stored in the tower. (2) It is also taken into account the maximum amount that the equipment can hold
I am consulting with the standards development team to see what’s going on.