Deriming is a industrial process used to remove build-ups of wax and hydrates in the gas streams of Printed Circuit Heat Exchangers (PCHEs).
These unwanted substances can be extremely detrimental to the overall performance of a PCHE and this can cause operators to lose time and money as a result of reduced efficiency.
The cold stream portion of a PCHE is either temporarily disabled or diverted so that only the hot water is populating the stream matrix inside the heat exchanger.
As a result, wax and hydrates inside the PCHE are soon subjected to high temperatures which cause them to be released from the internal metal surfaces.
When a heat exchanger is taken offline, some of the substances inside may begin to break away simply as a result of changes caused from the ambient temperature.
For materials unaffected by this, deriming is a specialist yet easy method to ensure thorough cleaning in an otherwise inaccessible area of the exchanger.
Whilst clean water is the most common liquid used in deriming, solvents such as kerosene are viable alternatives which may prove to be more effective dependent on your requirements.
However, irrespective of the solution used, it is vital to ensure all fluids sent through the exchanger streams are non-scaling and have a maximum chloride content of 30ppm (parts per million) in order to protect its internal architecture.
Whilst deriming is a powerful maintenance technique, it is fundamentally important to investigate how the exchanger streams have become polluted in order to prevent further build-ups from occurring.
Identifying causal factors for the presence of unwanted contaminants can help increase the overall uptime of your equipment as well as extending the effective life of your PCHE.
As a result, this will reduce the total overheads associated with cleaning and maintenance work as well as maximising the overall operating time for your exchanger.
Deriming is ideal for occasional maintenance of PCHEs to remove large quantities of unwanted substances from the exchangers’ streams; however, we advise against using it a as a frequent maintenance technique.
This is because the high temperatures required for deriming can cause thermal fatigue and, over time, minor damage to the construction of Heatric PCHEs if conducted too often.
Depending the exchanger and its surrounding environment, it can even be possible to complete the deriming process whilst the the machine is online, reducing the overall downtime associated with conducting extensive cleaning work.
Deriming is a relatively simple way to remove contaminants from your PCHE and will allow you to continue operating with the same effectiveness for extended periods of time.