Flameless heater for operator's cab

摘要

A flameless heater for operator's cab having automatic heat control. A hydraulic pump provides pressurized fluid which flows through a fluid restrictive orifice to produce thermal energy and raise fluid temperature as a result of a drop in hydraulic pressure. The heated fluid flows through a heat exchanger where a fan blows air over the exchanger to provide hot air for the operator's cab. A spool valve connected in parallel with the orifice bypasses fluid around the orifice to limit the rise in fluid temperature. A temperature sensor selectively opens and closes the spool valve to keep fluid temperature within a high temperature limit and a low temperature limit.