Solution to process compressor fouling
05.08.25
Unfortunately, process compressor fouling and its negative impact on efficiency, reliability, and safety are unavoidable. Fortunately, there is a cost-effective solution.
At Rochem, we’re industry experts in process compressor cleaning and are here to explain all about and how different washing methods are the answer you’ve been looking for.
What is process compressor fouling?
Essentially, process compressor fouling is the buildup of contaminants inside the compressor.
This fouling causes friction, which reduces flow and can cause internal recirculation, both of which compromise the capacity and productivity of the process compressor.
Common causes of fouling
It can be hard to imagine the inside of your process compressor becoming dirty when everything you put into it seems clean. Even with filtration systems in place, microscopic contaminants are unavoidable and accumulate under high-pressure conditions. Sources of fouling include:
Inorganic solids
Introduced via the process gas
- Corrosive products
- Oxides
- Carbonates
- Sulfates
- Silica
Organic solids
- Light hydrocarbons
- Polymeric compounds
- Coke
- Lubricants/grease
Production chemicals
- Corrosion inhibitor
- Hydrate inhibitor
- Defoamer
Signs of fouling
The impact of fouling can gradually increase without you necessarily noticing. Keep logs of your equipment’s performance and look out for the following indicators of fouling:
Reduced:
- Head
- Capacity
- Efficiency
- Pressure ratio
- Intercooler pressure
Increased:
- Speed
- Temperature
- Power consumption
- Vibration, thrust bearing load
- Balancing line differential pressure
- Risk of equipment damage
- Unplanned shutdowns
If you’re in any doubt, a borescope inspection will reveal any issues.
How to minimize and eradicate foulants
While fouling is unavoidable, there are .
Your first step to reduce the introduction of foulants and their likelihood to adhere to internal surfaces is to upstream conditioning and/or filtering the process gas, altering the composition of the process gas, adjusting the process parameters, and improving the finish/coating of the internal surfaces.
Next, implement an appropriate cleaning regime to remove foulants and prevent them from building up.
For this step, you have two options:
- On-line cleaning
- Off-line cleaning
are not mutually exclusive, and we often recommend a combination of both in your cleaning schedule for the best results.
Online process compressor cleaning
is carried out during normal operation. Specialized nozzles spray cleaning solution directly into the process compressor, washing away foulants and preventing their accumulation. This is a fantastic way of maintaining a level of cleanliness without interrupting production.
There are important considerations when introducing online washes, such as the seal types. Process compressors with oil seals or self-acting dry gas seals are generally suitable for this type of cleaning. However, those with clearance seals are likely to accumulate flushed foulants at these points, compromising their function.
At Rochem, we recognize that each site and process compressor application is different, and we provide a bespoke cleaning recommendation suitable for your site. Often, small amendments such as swapping some seal types facilitate on-line cleaning.
Note: on-line cleaning should not be carried out during recycle mode as the effectiveness of the anti-surge system could be compromised resulting in a safety risk.
Offline process compressor cleaning
The second cleaning method involves shutting down and isolating the process compressor and filling the casing with cleaning solution while slowly rotating the rotor. This ‘soak wash’ should be carried out for at least 15 minutes before draining the solution away.
A sample of drained solution should be analyzed to determine the amount of suspended and dissolved particles, and a repeat wash carried out as necessary.
The disadvantages of off-line cleaning are that the compressor must be taken off-line and out of service, and that the process compressor may only be filled with wash solution to the outer diameter level of shaft end seals i.e. parts of the compressor will not be cleaned.
As mentioned, we often recommend a combination of on-line and off-line washes for best results, maintaining the performance and lifespan of your equipment.
Find out more
Hopefully, we’ve shed some light on process compressor fouling, its causes, and what to do about it. You may not even realize your site is suffering; lots of engineers don’t appreciate the extent of the issue until their equipment suffers significant, sometimes irreversible damage. Take action before this stage and regain lost efficiency at the same time.
We are industry leaders in , supplying our equipment, , and other services to sites around the globe. We carry out a thorough assessment for each customer, making bespoke recommendations of products and washing regimes to obtain the best results.
If you have any questions or would like to find out how we can help, .
