How to purge catalytic cracking.

Purging can generally be carried out using various media such as air, steam, or nitrogen, with the choice depending on actual needs. The purpose of purging is to remove impurities from the pipelines and prepare them for inspection and maintenance. Pressure testing refers to the process of checking the pressure resistance of pressure vessels or pipelines and identifying any leaks, usually requiring the pressure to be maintained for a certain period of time.

The reaction regeneration system is purged with air, while the others are purged and pressure-tested with steam.

Reuse the main air flow for cleaning, and use soapy water for the airtightness test. For other systems, purging with 1.0 MPa steam is sufficient; maintain the system pressure and check for leaks at all sealing points.

It depends on the specific position; the operating procedures clearly state everything.

This post was last edited by Bai Wentu on 2010-8-27 at 22:20. For initial distillation purging, the control valve is removed, the flange at the pump inlet is unscrewed, as well as the flange at the heat exchanger inlet. The instruments are turned off, the flow meter is removed along with the orifice plate, and purging can be carried out by allowing air to flow from the top of the distillation tower downward. Venting is done at the areas where the flanges have been removed, followed by purging under pressure. Do anyone have any suggestions?

Are there any new tricks? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?

Is the poster referring to the initial startup of a new installation or the maintenance of an existing one? For the two vessels used in the initial startup phase, purging is generally not carried out; only a leak test is performed, using main air for this purpose – a pressure of 0.2 MPa is sufficient. After that, the blind flanges on the oil and gas lines as well as the manholes in the inlet pipelines of the exhaust fan are opened to remove any debris from inside (this is very important). For other process pipelines, steam is first used to blow out the slag and rust inside, and then non-purified air or nitrogen is used to remove any water accumulated there. In the case of equipment maintenance, when the lift pipe is shut down and feeding is stopped, it is usually necessary to keep the system fluidized and allow coking to occur for a while. During this time, the oil and gas are generally blown away from the distillation tower (after oil has been removed from the tower, stirring steam is used for purging from the bottom of the tower). Once the oil has been removed and the pumps can no longer deliver sufficient flow, the pumps are stopped and steam is used for purging. For the distillation tower, manholes can be opened for maintenance only after blind plates are installed at each outlet following vaporization and washing of the tower. For other tank towers, steam cleaning and tower washing are required before installing blind flanges to allow access for maintenance. Process pipelines are generally purged with steam; in those areas where direct purging is not possible, the tanks and other containers are first purged, and then the contents are pumped out before steam purging is carried out. Finally, purge with nitrogen to displace the air, apply blind plates, and then work on maintenance with an open flame

There was a minor oversight: in catalytic cracking, due to the presence of turbines, the 3.5 MPa steam pipelines must be purged using shot blasting. The most demanding aspects in catalytic cracking are the 3.5 MPa steam pipeline and the flue gas turbine inlet pipeline! These two pipelines must be cleaned thoroughly, as this is related to the service life of your turbines and exhaust engines; it is also the reason why the inlet pipelines for the exhaust engines lack lining!

Blow out with main air and steam, and test for leaks with soapy water.