Russell Re-evap

Hi everyone,

Russell used to offer (or still is, not sure) something they called Re-evap, basically a heat exchanger used for avoiding liquid floodback when performing hot gas defrost. As the literature explains, there is a manual valve, as far as I understand, the main function for this valve must be insuring that oil does not get caught in this heat exchanger. Has anyone used them ? Do they perform well ? Also I do not quite understand how they are built, does liquid line run inside as a straight tube inside the heat exchanger or is there a spiral or something inside the tube ?

Regards

José

"Re-Evap System—Uses three pipes, one for the liquid, one for the suction and one for the hot
gas. In addition, a heat exchanger/re-evaporator issued at the suction line outlet of the evaporator and is piped exactly the same as an ordinary liquid/suction heat exchanger. The hot gas is taken from the discharge line between the compressor and the condenser, through a hot gas solenoid valve, then through the hot gas line to the unit cooler. On low temperature SDG units, the hot gas enters the unit at the drain pan loop before going to the side inlet of the distributor. On all medium temperature units the hot gas goes directly to the side inlet of the distributor. The hot gas for all units then goes thru the coil in the same direction as the normal refrigeration flow. The condensed refrigerant is trapped in the re-evaporator as it leaves the coil, there to be metered as a heavy vapor into the suction line flow back to the compressor"

The remainder of the literature with piping schematics can be found via the provided link (pg4).
http://69.41.183.10/documents/SuperEasy%20IOM.pdf

Dear passandscore

Thanks for your answer. Since I do not have the chance to look at one of these re-evaps heat exchangers (I work and live in Argentina) I need some feedback from someone actually working with them. What makes me curious is the schematic drawing (Figure 3) which shows how suction outlet is taken from the top of the heat exchanger (as with a regular suction accumulator) while liquid line seems to get mixed with the suction line, I guess the schematic is simply omitting a dashed line showing that there is tube inside the main shell.

Couple of questions: is the heat exchanger shell a copper tube or a steel tube ? Regarding the tube through the drain pan, have you noticed how it is fixed to the pan ( I am guessing how long it takes copper, aluminun and maybe a steel fix to start a corrosion process in presence of water).

Regards

José