Crude Exchanger TESTIMONIAL " This process has been proved to be successful and gave reduced cleaning time and minimum mechanical intervention. There is no doubt it cut down our time compared to traditional bundle pulling and jetting " Area Manager
No.4 CASESTUDY
GRANGEMOUTH REFINERY
OVERVIEW Denholm were tasked with improving the efficiency of the crude unit pre-heat exchangers between major turnarounds without pulling the tube bundles for jetting in order to maintain satisfactory operating performance. CHALLENGES Problems were regularly experienced with exchanger fouling which severely reduced performance and significantly reduced throughput. This caused unplanned outages while exchanger bundles were pulled, jetted and reinstated. Site were keen to establish a procedure for restoring exchanger performance which was quick and effective and negated the need to pull the tube bundles. PAST PROCEDURE Previous attempts at improving performance by flushing and purging showed only temporary marginal improvements. In the absence of any viable alternative operation area engineers and managers decided that bundle pulling and jetting was the best option despite the lengthy downtime that this involved, and this was the accepted method of exchanger performance improvement in between planned outages.
DECON SOLUTION In order to alleviate the exchanger performance issue Denholm proposed to steam through the exchangers shell and tube sides from top to bottom whilst injecting Zyme-Flow® UN657 at a controlled rate for 6 hours. Steam from the process was vented via the bottom drain points on both sides of the exchangers into hydrocarbon skips for disposal. On completion of steaming the exchangers were drained, purged to remove any residual aqueous condensate then returned to service. RESULTS It was established that once the heat exchangers were returned to service the performance was greatly improved and this enabled the crude unit to return to normal throughput. The increase was maintained over several months thus giving significant time and cost savings over bundle pulling and jetting. This procedure achieved the desired aim of restoring heat exchanger performance with minimal downtime.
SEE TRUE PERFORMANCE RESULT BELOW FROM CLIENT
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