The Prophet

Many factors go into the rate of recovery on an extraction system. Not only is the pump size important, but also the evaporation rate of the solvents. If the solvents aren’t able to evaporate fast enough there will be nothing for the pump to transfer. Larger pumps have the capacity to transfer solvents faster, but only if the solvents are in an evaporated state. Because these pumps are so large they have a tendency to outpace the evaporation rate of most extraction systems. This lowers the inlet pressure (and the collection vessel pressures) which aids in speeding up the evaporation rate. Propane weighs less per gallon than butane (4.2 vs 4.9), however the vapor pressure is higher which generally results in a higher inlet pressure, and therefor a faster recovery per pound of gas used. These pumps are sized large enough to recover on the largest extraction systems with the highest evaporation rates, or can be used on multiple extraction systems at one time. For example this pump was used to recover 5lbs of butane on a 6” vessel with 70° of temperature. The process took ~12 minutes. However increasing the process to 3x 6” vessels with 5lbs of butane each(15lbs total), the process also took ~12 minutes. This is because the pump exceeds the evaporation rate of a single 6” column at 70° by more than 3x. Because the pump exceeds the evaporation rate a vacuum is pulled against the collection vessel, which in turn speeds up the evaporation rate. However once vacuum equilibrium is achieved, increasing the pump size will not speed up the process, but will allow for larger (or multiple) processes to be preformed in the same time frame. The next tab shows a table of recovery capacity with regards to inlet pressures. Higher inlet pressures result in substantially faster recovery times. Higher inlet pressures can be achieved by evaporating solvents faster by higher temperatures in collection vessels, or more surface area in collection vessels (larger diameter vessels, falling flim, etc).