An important aspect to keep heat exchangers in tip-top condition is routine maintenance through heat exchanger cleaning. However, this vital service, which is more necessary in refinery and other industrial organizations, is often not given its due importance, though production remains vital. Hence, there are regular built-up of fouling, and this will be a major cause of drain of money in the form of asset life, lost energy, runtime, etc. and this is more to be seen in exchangers upstream of the fired heater, (which remains as the biggest energy consumer within the plant itself) due to its harder firing to make up poor performance of the heat exchanger. Every year, hundreds of thousands of dollars are lost due to shutdown resulting from the failure of the heat exchanger, and which becomes annoying in the procedure which is technically quite intensive.
To Water Jet or Not to Water Jet
One of the popular heat exchanger cleaning methods is water jet cleaning process consists of multi-lance water jetting at high pressure. If the heat exchanger is lightly or heavily fouled, the first choice should be polishing and projectiles, as they have shown effective and environmentally-friendly. Although the process is costlier, it still gives a better return on investment as the result of cleanliness is of higher degree, which will result in the run-time getting extended, provided the operation is done effectively.
With a pressure of 60,000 psi maximum and 4 liters per minute, the cleaning remains as one of the safest methods that a competent person can work with. This results in lowering the cost of maintenance by not requiring the use of hazardous chemical disposal services, and not requiring the need for cleaning of the heat exchangers when the integrity of the asset is tested by the use of Eddy Current or IRIS.
The usual temptation when it comes to cleaning heat exchangers is to make use of traditional or insufficient equipment or heat exchanger cleaning chemicals is quite a common feature if the site engineers fail to supervise it, and could render damages while doing shell and tube heat exchanger maintenance while leaving the exchanger uncontaminated.
With over 250 years of combined, professional experience, Thompson Industrial Services firmly believe that three cleaning systems in combination, including Ultra-high-pressure water, rotary projective methods, and Mechanical high-speed rotary polishing should be the best choice of cleaning, as the method is already proved to be quicker in comparison to the lancing method, as there is removal of the right fouling to the right technology. Any wrong choice is a costly matter, especially, if there is a wait time of 4 years for the next shutdown.
Keep Cleaning on Schedule
As per the schedule, routine maintenance is executed, but this should be performed using the right cleaning techniques. As per the particular heat exchanger that needs to be cleaned, it is necessary to define correct timings. The difficulty comes up in that neither the onsite maintenance team nor the manufacturer will come to know or have direct experience in cleaning, and in the process leave it to the contractor to make the choice, with the hope that the right cleaning method is selected.
Routine cleaning benefits in that the downtime is saved considerably. With proper execution, the deposit formation is delayed, lessen the under-scale corrosion, extend run time and asset life, while performing inspection the first time as well as every time without requiring the execution of re-cleaning. Performing cleaning and inspection in combination ensures the full operation of the equipment while meeting the first time regulatory standards without any form of delay occurring.
Why dismantle when you can clean in-situ without Pulling
It is possible to clean heat exchanger and inspection maintenance by making use of robotic heat exchanger cleaning technique without the need to pull out the exchangers. This is undoubtedly a great cost saving option to lessen the downtime and related costs for plant operators, by making use of the scaffold, gaskets, bolts, risks of pulling, 3d party costs, etc.
There are many specialists in heat exchanger cleaning companies that do the cleaning of the heat exchanger by doing it at their own facility, and in the process, incur unnecessary downtime. If you heat exchanger is not possible to be cleaned by your contractor in place, you would do well to seek a second opinion from other heat exchanger cleaning professionals who may be using other cleaning methods that can execute the job on-site, and in the process, lessen the time to complete the project.
Heat Exchanger CIP
An effective cleaning method that is often considered in the case of heat exchangers is the Cleaning-in-place (CIP). This method is quite effective in removing mineral scale along with the biological build up within the exchangers within a short time (usually, cleaning is done in eight hours) there are instances when mechanical cleaning remain as effective for certain exchangers. Usually, this service is executed along with a cooling tower cleaning and was executed on-site. However, it is found that even after doing a physical cleaning, the heat exchanger surfaces contain mineral scale that provided considerable resistance to transfer of heat.
Now CIP cleaning is provided for heat exchangers and chillers to every customer. With CIP, it is possible to bring on-site factory reconditioning quality, nearer to customers and in the process, reduce downtime. The whole process of cleaning in place of the heat exchanger or chiller is quite easy. At the start, the approximate volume of heat exchanger is determined, along with the possible fouling mechanism like biological fouling, mineral scale, iron scale, or others, the locations of isolation valves, as well as where it is possible to tap into the line to help in the movement of the cleaning chemicals (usually, a gauge tap or thermowell).
All this information helps in providing a proposal for heat exchanger cleaning, visit on-site and does the cleaning of the heat exchangers. The chemicals are either delivered to the job site or else, they are brought by the technicians. On arrival, the process is reviewed along with the customer. As the cleaning solution is moved around the heat exchanger cleaning equipment, samples of pH are regularly tested to find the cleaning progress. After completion of cleaning, there is neutralization of the cleaning solutions, which is then sent to the local drain.