Hello

I need to recover large amounts of refrigerant, and I need a simple to use, not too large, and reliant unit.

I've tried units based on Bitzer compressors. They work fine, and are quite fast. The problem is oil from the compressor tends to end up at the recieving end. Despite filters, and oil separators.

I've also tried those small portable devices with oil free compressors. They don't work as fast as the first mentioned units, and they tend to overheat.
The problem here is that they are not built for running continously for many hours. (5-15 hours is normal) We often need to empty 60 litre cylinders of about 40 kgs of refrigerant each, or 900 litre drums of 30-600 kgs of refrigerant. Mostly 30-100 kgs from the drums. (The heel).

Does anybody know of any reliable, and effective unit for my purposes?