In many industrial processes it is necessary that gases be compressed. Typically turbine compressors, centrifugal compressors, pumps, screw compressors and the like may be used for this purpose. Such equipment is referred to herein generally as compressors. The compressors typically include seals for the passage of rotary components through sidewalls, ends or the like of the compressors. These seals are typically designed to permit leakage of small amounts of compressed gases through the seal. Many times the passage of the gas is due to wear of the seal but in many instances seals are designed to permit leakage of a selected quantity of gas in normal operation.
The seal leak gas in many instances may be harmful to the environment or constitute a valuable product which is desired to be recovered. In either event, it is typically recovered by positioning covers over the seal areas to sealingly contain the area around the seal with the cover positioned so that the seal leak gas is collected inside the cover. The cover may include a passageway, including a seal, for a rotary component passing through the cover into the compressor. Covers can be of a wide variety of configurations so long as they are effective to sealingly contact the unit containing the seal so that the gas is recovered in the cover. The cover typically has included a line for the passage of the gas into the atmosphere or more frequently to a stack or the like where the gas can be burned or passed to a gas processing system. The seal at the passageway does not present a leakage problem since the gas inside the cover is typically at a low pressure.
Since this seal gas is at relatively low pressures, it typically does not flow readily to further treatment. Usually the seal gas is vented or combusted at atmospheric or near atmospheric pressure. Accordingly, a pump or a fan system is typically required to move the seal leak gas to a treatment area, stack area, or the like if the system is at any level of positive pressure. It is difficult to economically recompress the gas for reuse, if it is a desirable gas. The economics dictate that the gases be sent to a flare for burning or the like even if they are valuable in view of the expense to recover the gases and pass them back for reuse.
Accordingly, a continuing search has been directed to the development of a method and system for economically collecting such gases and increasing their pressure so that they may be either reused or readily passed to further treatment.