Vapor Degreasing Series – Part 5

Q: The solvent recycling process sounds like the regular vapor degreaser’s process. Why can’t the degreaser handle the solvent recycling?

A: The long story short is that vapor degreasers are optimized for the cleaning of parts and not for the recycling of solvent. Most vapor degreasers don’t even have a boil down stage to extract the solvent that is trapped in the oil. Further, there is nowhere to dump the oil on most vapor degreasers. While it goes through the distillation process to separate the solvent from the oil, eventually, condensed solvent will return into the same bath of oil solvent mix that it was just separated from. So yes, the processes themselves are very similar. There are some larger vapor degreasers out there that even come with a built instill or distillation unit to recycle the solvent. But it ultimately comes down to what the machine is optimized for and if there is somewhere to send the oil after distillation.

Q: I have a small vapor degreasing application, so it has been difficult to justify the cost of a recycling unit. How would you recommend putting together an ROI estimate?

A: First, I would find out exactly how much solvent I throw away in a year. If you have a 5gallon sump and you have to dump the solvent every quarter because it is too dirty, you throw away 20 gallons of solvent in a year. So whatever dollar value you can attach to the solvent you throw away, is immediate savings in your ROI estimate because with a solvent recycler, you will never have to throw away solvent. That is the easiest starting point. Then you can move to maintenance downtime for when the machine has to be changed out – again, it won’t need to be changed out every quarter now. I would also expect for you to see cleaner parts coming out of your degreaser so, perhaps, you could run more parts at a time.

Q: Will the solvent last indefinitely if it is properly recycled?

A: Indefinitely is a long time – and most things in the world do not last indefinitely. However, my answer would be: “Yeah, pretty much”. While you won’t be throwing solvent away anymore, you will still be getting evaporation and drag out losses of solvent. So, you will still have to add make-up solvent to the degreaser to keep your solvent level high enough. With that said, over time it’s safe to say that the solvent you added five years ago is no longer in the system because it evaporated or was drug out and was replaced with newer solvent.