Abstract: A system and method of use of same for cooling process vessels, particularly those having reactor beds inside such as hydrotreaters, hydrocrackers, and catalytic reformers as part of processing units, during unit turnarounds. While the process vessel is in normal operation or in a preliminary cool down phase, quench gas flow is routed through a bypass flow path while a recirculating gas cooling system is installed in the primary flow path, requiring no unit downtime. During a turnaround, the process vessel temperature is lowered to a desired temperature, permitting entry and replacement of catalyst inventory, using the existing hydrogen recirculating (recycle gas) compressor to circulate a recirculating gas stream through the recirculating gas cooling system, the process vessel, and back through the compressor and recirculating gas cooling system. The cooling system removes heat from the circulating flowstream, thus lowering the process vessel temperature, faster than cold nitrogen injection methods.

Abstract: A system and method of use of same for cooling process vessels, particularly those having reactor beds inside such as hydrotreaters, hydrocrackers, and catalytic reformers as part of processing units, during unit turnarounds. While the process vessel is in normal operation or in a preliminary cool down phase, quench gas flow is routed through a bypass flow path while a recirculating gas cooling system is installed in the primary flow path, requiring no unit downtime. During a turnaround, the process vessel temperature is lowered to a desired temperature, permitting entry and replacement of catalyst inventory, using the existing hydrogen recirculating (recycle gas) compressor to circulate a recirculating gas stream through the recirculating gas cooling system, the process vessel, and back through the compressor and recirculating gas cooling system. The cooling system removes heat from the circulating flowstream, thus lowering the process vessel temperature, faster than cold nitrogen injection methods.