Fluid friction heater

A fluid friction heater comprising:

• a housing having a cylindrical inner surface with a plurality of parallel, circular, closely spaced grooves formed therein, the depth of said grooves being small relative to the diameter of the cylindrical inner surface;
• means for supplying a liquid to the housing at one end and exhausting the liquid from the housing at the other end;
• a drum mounted within the housing and having a cylindrical outer surface in close proximity to the cylindrical inner surface of the housing to define a narrow annular space therebetween, said drum having a plurality of radially disposed impeller blades at one end proximate said one end of the housing to force the liquid through the annular space between the outer surface of the drum and the inner surface of the housing, the cylindrical outer surface of the drum having at least one tightly wound spiral groove formed therein, the depth of said grooves being small relative to the diameter of the outer surface of the drum;
• and
• means for rotating the drum so that the pitch of the groove in the drum tends to advance the liquid through the annular space between the housing and the drum, the rotation of the drum relative to the housing subjecting the liquid to agitation and shearing action which heats the liquid as it passes through the annular space between the housing and the drum.

A heating system for a dwelling in which hot water is consumed and a heated liquid is used in a closed loop system for heating or like purposes, said system comprising:

• a drum having a cylindrical outer surface;
• a housing having a cylindrical heat conductive portion with cylindrical inner and outer surfaces circumscribing the drum so that the cylindrical inner surface of the housing is closely adjacent the cylindrical outer surface of the drum to define an annular space therebetween, said housing further having an inlet for the liquid proximate one end and an outlet for said liquid proximate its other opposite end to allow the liquid to flow through the annular space between the drum and the housing;
• a jacket circumscribing the housing and having a cylindrical inner surface closely adjacent the cylindrical outer surface of the housing to define an annular space therebetween, said jacket including an inlet for the water proximate one end and an outlet for said water proximate the other end to allow the water to flow through the annular space between the jacket and the housing;
• and
• means for rotating the drum to heat the liquid as it passes through the annular space between the drum and the housing, said water being heated as well by heat conduction through the cylindrical portion of the housing, wherein the outer surface of the drum and the inner surface of the housing have at least nearly circumferential, closely spaced grooves formed therein, the depth of said grooves being small relative to the diameter of said surfaces, the pitch of the grooves in the inner surface of the housing being different from the pitch of the grooves in the outer surface of the drum so that the grooves cross one another as the surface move relative to each other.