How To Solve The Problem With Wet Loads
As a manufacturer of steam sterilizers, we frequently hear feedback from current and prospective customers alike, regarding condensate issues (sterilizer wet loads) in their chamber post-sterilization impeding satisfactory processing results. In fact, it could very well be the single leading technical issue we have run into over 40 years of manufacturing such systems. To understand why that is, you really have to understand the myriad of potential causes, to appreciate the complexity of solving this simple problem.
When helping our clients identify the source of the issue, we begin by evaluation of the most common suspects first. Foremost among those suspects is the steam supply. Frequently we find that steam quality is the culprit in leading to excessive condensate formation within the autoclave. Our first recommendation to clients is to determine if you are placing excessive demand on the boiler (your maintenance personnel can check this for you).
Next, examine the steam circuit/supply and look for potential areas of condensate formation such as dead legs or improperly trapped or insulated piping. The duty of a steam trap is to discharge condensate while not allowing the escape of live steam. The further away the steam line is from the heating source/medium, the more likely condensate is to form, and require removal from the system. One should consider proper insulation for piping…the further away the steam line is, the more the need for insulation. Lastly, have your sterilizer service people check the jacket steam trap and check valve at the drain port to be sure they are clear and functioning properly.
If you or your staff have no experience with proper steam supply design/piping, we would recommend that you contact your local supplier (Armstrong, Spirax/Sarco, Nicholson & Sterling…) for an evaluation. One quick test they could employ to find out if your steam supply is the culprit is to measure the condensate discharge just ahead of the sterilizer in two locations. They can calculate steam quality or dryness fraction if overall steam flow rate is known and compare the result.
Calculating the “dryness fraction” is accomplished as follows.