Abstract: A method and apparatus for fine grinding materials normally difficult to grind at ambient temperature, e.g. plastic and elastomeric materials in a fluid classification type impact mill utilizing liquid cryogen to pre-cool the material to be ground, to cool the material and the mill during grinding and to recycle vaporized cryogen from the mill back into the mill as the medium for conveying material to be ground into the mill.

Abstract: A method and apparatus for fine grinding materials normally difficult to grind at ambient temperature, e.g. plastic and elastomeric materials in a fluid classification type impact mill utilizing liquid cryogen to pre-cool the material to be ground, to cool the material and the mill during grinding and to recycle vaporized cryogen from the mill back into the mill as the medium for conveying material to be ground into the mill.

Abstract: A thermostatic trap for a heating system having a feed pipe connected to a source of steam and a discharge pipe for discharge of condensate. Included in the trap is a housing defining a volume and comprising a bowl shaped body, a removable cover therefor, a housing inlet pipe portion projecting from a side wall portion of the body and adapted for connection to the discharge pipe, a housing outlet pipe portion projecting from a bottom wall portion of the body, and an outlet orifice defined by the bottom wall portion and extending between the volume and the outlet pipe portion. Retained within the volume is a valve body means comprising an end wall, a side wall and a retaining ring portion that together define a valve chamber, the end wall defining a valve inlet opening communicating with the chamber and an annular valve seat within the chamber and encircling the valve inlet opening. The valve body means defines a valve outlet pipe opening into the chamber and retained in the outlet orifice.

Abstract: A thermostatic valve including a housing that defines a housing inlet and a housing outlet and a valve body having an end wall and a side wall that define a valve chamber within the housing. The end wall defines an annular valve seat and a valve inlet opening encircled thereby while the side wall defines a plurality of valve outlet openings communicating with the valve chamber. Retained within the valve chamber is a resilient, annular seal encircling the valve inlet opening and a bi-metallic disc substantially parallel to the valve seat and normally spaced therefrom by a distance greater than the thickness of the annular seal. In response to a predetermined ambient temperature the bi-metallic disc deflects concavely into the valve chamber and into fluid sealing engagement wih one end of the annular seal forcing an opposite end thereof into fluid sealing engagement with the valve seat.

Abstract: An auxiliary heating element acts on a steam trap connected to the return outlet of a radiator. A check valve placed between the trap and the radiator prevents dissipation of the steam generated by the auxiliary heating element into the radiator. A thermostat provides automatic control over the operation of the heating element and the radiator.