Selection principles for compressors in synthetic ammonia plants with an annual capacity of less than 180,000 tons!

This post was last edited by 654262293 on 2010-12-14 08:06. Centrifugal compressors have a low failure rate, require little maintenance, have long service intervals and low energy consumption; the oil-free nature of the output gas helps to protect catalysts. However, they demand high levels of management, are expensive, and generally do not come with backup units； Piston compressors are easy to adjust in terms of gas flow rate and inexpensive, but they have high energy consumption. They also suffer from a high rate of operational failures, have short service life, and require high levels of energy. The gas they produce often contains oil, which can end up in the gas fed into the synthesis tower. Generally, large-scale installations use centrifuges, without considering backup units; while small and medium-sized installations use piston compressors along with backup units (so that if there is a problem with the main compressor, the backup unit can take over without disrupting the long-term operation of the main installation).

This post was last edited by 654262293 on 2010-12-14 08:06. The selection of a compressor depends mainly on the production capacity of the installation, as well as the quality and properties of the gas. Typically, reciprocating compressors are suitable for compressing gases with large pressure differences, low flow rates, poor gas quality, and low average molecular weights ； Centrifugal compressors are suitable for applications involving large volumes of gas to be compressed, low pressure differences, and high-quality gas. They offer advantages such as a large volume of gas that can be compressed per unit time, reduced maintenance needs, no requirement for backup units, the possibility of being driven by steam turbines to improve energy conversion efficiency, and high overall efficiency.

Reply 2# FEIJING: Which is the best option for 100,000 tons?

In terms of system stability, if gas production is carried out using pressurized continuous gas from space furnaces or similar devices, then the use of a centrifuge is beneficial for ensuring stable system operation. If gas production is done via fixed-bed batch processes, it is better not to use a centrifuge; conversely, if a centrifuge is used, it is better not to rely on fixed-bed batch gas production.

Synthesis ammonia plants with a capacity of less than 180,000 tons cannot go much further in terms of technology; reciprocating compressors are still the better choice, and steam turbines can also be used to assist in driving them. For those compressors where the inlet pressure is above 4 MPa, centrifugal compressors are obviously the better option, as this results in a significantly lower overall compression ratio.

But I’ve heard that piston-type compressors produced by domestic manufacturers are more reliable, as they are easier to maintain.

The selection of a compressor is primarily determined based on the actual conditions of one’s own organization, such as production capacity and the production processes used.

Reply to 4# Hard times yield good times: It’s best to choose a piston machine or the Nanhua Machine TC620