Reducing the frequency of preventative maintenance inspections of spray dryers and other vessels can often have a negative impact. Implementing a more frequent annual inspection routine gives companies numerous benefits such as;
Increased life span of assets, reduction of costs long term by discovering issues in their early stages, improves budgeting/planning strategies for major corrective actions, lowers overall operating costs, reduces cross contamination and product recall risks, increases productivity long term, improved reliability and customer confidence.
After completing a repeat inspection of a spray dryer for a client in January 2021, Bioscan’s findings resulted in the client facing major corrective actions. In total there was an area of 25cm x 3m in the upper chamber which required immediate attention. This area had developed severe stress corrosion cracking in the weld seams, which was unable to be repaired without the requirement of cutting out the parent metal and replacing it for new. The client had not planned for this amount of repair works to be performed during their 72-hour shutdown schedule.
Photos of the unrepairable stress corrosion defects found:
The client was now facing a lengthy shutdown period and extensive costs for the corrective actions. Costs that could have been either significantly reduced or eradicated altogether if a more frequent annual inspection programme had been implemented.
In addition, a further 50 cracks were identified in the 2021 inspection. During the previous inspection performed in 2016, a total of only 15 defects were found and repaired. Bioscan determined that as the client had decided upon an inspection frequency of 5 years for the spray dryer, the issues found in 2021 could have been resolved in their earlier stages or better planned for with an annual inspection.
This low-cost short term thinking towards inspections had led to very high costs and an increased shutdown to perform the required corrective actions, this in turn had a negative overall impact on the productivity of the plant.