A portable dental delivery system is provided which is composed of a plurality of individual module sections. The portable delivery system provides all basic tools and accessories which are necessary for a dentist to perform all types of dental work which may be required by patients. The dental delivery system includes a quiet running, pressurized clean air supply system for operating the various tools and accessories utilized by the dentist. A hermetically enclosed refrigeration dental air compressor unit is modified to provide an adequate supply of pressurized air in an extremely quiet manner. The temperature of the compressor unit is maintained at a safe level by an oil cooling system. A pump draws oil from the base of the compressor unit, passes it through a radiator which is additionally cooled by an axial fan. The oil is returned to thedental air compressorunit at the top of the housing at a location which will cause the oil to impinge directly upon the cylinder head of the compressor. Oil entrained in the pressurized outlet air is collected in an oil coalescer. A check valve is provided downstream of the coalescer and ahead of an air storage tank. A normally closed solenoid is connected to the lowermost portion of the coalescer so that upon deenergization of the compressor unit the solenoid is automatically opened unloading the outlet pressure so as to drive any accumulated oil in the coalescer back into the oil return line for the housing.

A quiet, high capacity, pressurized clean air system for a portable dental delivery system, said portable dental delivery system having a plurality of modules which can be joined together in a stacked arrangement forming a work console, said console including air powered tools and accessories for use by a dentist, said pressurized system being built into one of said modules and connected so as to power said tools and accessories, said air system comprising:

(a) a modified hermetically enclosed refrigeration-typedental air compressorunit having a power driven gas compressor, saiddental air compressorunit being totally enclosed within a single thin shell housing means, said housing means containing a predetermined quantity of a suitable liquid coolant for absorbing heat energy and maintaining the temperature of said compressor unit during operation;

(b) an external cooling loop means attached to said housing means, said loop means including conduit means having an inlet end attached to a lower portion of said housing means and a return end attached to the upper portion of said housing means, said loop means further including a pump means attached to said conduit means near said inlet end for circulating the liquid coolant from the lower to the upper portion of the housing means, the return end of the conduit means being attached at a precise predetermined location on said housing means so that the returning liquid coolant impinges directly upon the top portion of the gas compressor whereby the coolant will absorb heat energy from thedental air compressorunit and maintain the temperature within the housing means at a suitable operating level;

(c) said housing means having an air inlet and outlet means connected to said dental air compressor unit, the air outlet means being connected to an oil coalescer means and a check valve means to prevent pressurized air from moving toward the compressor unit, said check valve means being arranged downstream of said coalescer means with the outlet means being terminated by a coupling means for quick coupling the air outlet means to a pressure storage tank; and

(d) said coalescer means including means for separating liquid coolant from the pressurized outlet air and collecting said coolant in a reservoir area, valve means connected to the coalescer means in communication with said reservoir area, said valve means being closed during operation of the air supply system and opened upon shut-down of the dental air compressor unit to unload air pressure from the outlet means and in turn force the collected coolant through a second conduit means connected between said valve means and the return end of said conduit means attached to the upper portion of said housing means.