Patents by Inventor N. Robert Crain

N. Robert Crain has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 4667609
    Abstract: A sealed, negative pressurized, high temperature furnace, through which hydrocarbon contaminated soil is conveyed, is operated in the near-infrared heating region at radiation wavelengths between about 0.75 and about 3.0 um. The furnace, rotary sealed at the input and exit ports and maintained at a negative pressure, is in the form of an elongated cylinder, divided into four series-arranged heating zones, each of which is separately fed by a preferably stoichiometric mixture of a combustible gas, preferably propane and air. The flow of the gas/air mixture into each of the heating zones is regulated so that the first zone is maintained at about 2900.degree. F. normally, (3000.degree. F. maximum), the second zone is maintained at about 2900.degree. F. normally, and the third and fourth heating zones are maintained at about 2900.degree. F. normally.
    Type: Grant
    Filed: September 8, 1986
    Date of Patent: May 26, 1987
    Inventors: Robert Hardison, N. Robert Crain
  • Patent number: 4517448
    Abstract: An infrared furnace has a housing with insulated walls defining an elongated straight tunnel disposed on a longitudinal axis between an entrance and an exit. A conveyor continuously moves through the tunnel along the longitudinal axis between the entrance and the exit. A first plurality of elongated tubular infrared heating elements are disposed in the tunnel above the conveyor in spaced apart parallel relationship transverse to the longitudinal axis. A second plurality of tubular elongated infrared heating elements are disposed in the tunnel below the conveyor in spaced apart parallel relationship transverse to the longitudinal axis. The housing has insulated walls each comprising a porous insulative inner panel and a non-porous outer panel. At least one of the outer panels is spaced from its associated inner panel to form a plenum chamber therebetween. The insulated walls define an elongated tunnel in which a source of infrared radiation is disposed.
    Type: Grant
    Filed: November 6, 1981
    Date of Patent: May 14, 1985
    Assignee: Radiant Technology Corporation
    Inventors: N. Robert Crain, Carson T. Richert
  • Patent number: 4460821
    Abstract: An infrared furnace has a firing chamber in which a source of infrared energy is disposed and an elongated envelope transparent to the infrared energy extending through the firing chamber. The envelope has first and second open ends outside the firing chamber. First and second baffle chambers surround the respective first and second ends of the envelope. A product conveyor travels through the furnace via the baffle chambers and the envelope. Gas flow is prevented from the exterior of the furnace into the baffle chambers and from the firing chamber into the baffle chambers. Non-atmospheric gas is supplied to the baffle chambers so as to create therein a superatmospheric pressure which prevents gas flow into the baffle chambers from the exterior of the furnace. The non-atmospheric gas is exhausted from one of the baffle chambers, thereby inducing flow of the non-atmospheric gas from the other baffle chamber through the envelope.
    Type: Grant
    Filed: May 25, 1982
    Date of Patent: July 17, 1984
    Assignee: Radiant Technology Corporation
    Inventors: N. Robert Crain, Robert P. Hardison
  • Patent number: 4406944
    Abstract: Mounting devices are provided for mounting the end portions of a replaceable infrared lamp on the sidewalls of heating chamber formed of a compressed insulation material with sheet metal covers on the outer surface thereof. Each mounting device comprises a ceramic holder having a hollow cylindrical body with a shoulder on the outer end thereof and a bottom wall on the inner end thereof. The bottom wall has a concentric circular opening with diametrically disposed notches. One of the ceramic holders is positioned in each of a pair of opposing holes in the sidewalls with its shoulder secured to the sheet metal cover by a sealant. The lamp is held with its end portions extending through the circular openings in the bottom walls of the ceramic holders so that the metal terminals of the lamp protrude outside the sidewalls.
    Type: Grant
    Filed: March 23, 1981
    Date of Patent: September 27, 1983
    Assignee: Radiant Technology Corp.
    Inventors: N. Robert Crain, Robert P. Hardison
  • Patent number: 4103319
    Abstract: A hazard prevention control circuit is provided for an electric heater having heating coils enclosed in a quartz tube immersed in a tank of solution. A circuit breaker is connected in series with a contactor coil controlling a set of contacts connecting the main lines of a power supply to the heating coils of the heater. Upon sensing a hazard condition, the control circuit causes excess current to flow through the circuit breaker to open the circuit and deenergize the contactor coil so as to open the contacts connecting the power to the heating coils. Transformers are provided for coupling power supplied by the main lines to the control circuit and the contactor coil and for coupling the pulse output of the control circuit to trigger a triac which conducts the excess current through the circuit breaker.
    Type: Grant
    Filed: June 27, 1977
    Date of Patent: July 25, 1978
    Assignee: Radiant Technology Corporation
    Inventors: N. Robert Crain, Joseph S. Romance, Carson T. Richert