Long-term operation of ethylene cracking gas compressor

“Is “long-term operation of the pyrolysis gas compressor” a technical issue or a management issue? Or both?

The pyrolysis gas compressor is an important piece of equipment in the ethylene industry, as it is crucial for ensuring the safe long-term operation of the facility. We welcome everyone to actively participate in discussions in order to improve operational standards together.

The pyrolysis gas compressor is the heart of the ethylene plant; its proper operation has a direct impact on the ability to operate for extended periods of time

I believe that for a pyrolysis gas compressor to operate over long periods of time, the following steps must be taken: 1. Take advantage of downtime for maintenance to repair the unit and resolve the issues identified during the previous cycle； 2. Carry out regular maintenance of the unit to ensure it operates in good condition ； 3. Conduct proper online monitoring of the unit’s status, so as to promptly monitor changes in parameters such as the bearing temperature, vibration, shaft displacement, and the amount of nitrogen used for the dry gas seal. Analyze these changes promptly and take appropriate actions in a timely manner. 4. Regularly apply oil and water to prevent the formation of polymers and their accumulation in the compressor flow channels.

The explanation provided by the student on the 5th floor is quite comprehensive. Regarding oil and water injection, I believe it is best to use hydrogenated oil to prevent coking on the impeller, and for water injection, it is advisable to use deionized water or add scale inhibitors, so as to avoid any adverse effects of these substances on the compressor.

Boiler feed water is the best choice. For scale inhibitors, it’s better not to use them if there is no clear indication to do so.

Come and take a look, learn a bit,, thanks

Regarding the issues that affect the long-term operation of compressors, from a technical perspective, it is necessary to set various parameters properly, such as various interlock values, including the liquid level in the pipes between different sections, as well as the suction pressure and temperature at the inlet of each section. Prevent compressor surge, as surge has a significant impact on the compressor’s lifespan. If it is operated in a chain manner properly, it is not prone to surge. There are also various monitoring and alarm systems available; compressors are typically equipped with systems for monitoring shaft temperature, shaft vibration, and shaft displacement, so that any abnormalities can be addressed promptly. Another key issue is management: operators need to pay close attention to parameters such as the compressor speed and inlet pressure, especially when switching the cracking furnace. Additionally, pyrolysis gas compressors are generally driven by ultra-high pressure steam generated as a by-product of the pyrolysis furnace; the quality of this steam has a significant impact on the turbine. Therefore, it is essential to strictly control the quality of the boiler feed water (BFW) in order to prevent scaling in the compressor turbine. When the compressor is severely scaled, Lanhua’s online cleaning technology can be employed for cleaning without shutting down the unit, and it has shown excellent results in practical applications. There are some other related questions as well, but due to space constraints.

I agree with the view from floor 9. To operate units that use pyrolysis gas effectively is not only a technical issue but also a management issue. There are many factors that influence performance, and many of these factors are difficult to control by the unit itself, such as fluctuations in the quality of ultra-high pressure steam and changes in the composition of the pyrolysis gas. It is necessary to continuously gain experience based on actual production conditions