Thermon Manufacturing Company

David C Goss

Chandrakant M Yagnik

Daniel R Springs

Richard A Hageman

Jone Edland

A flexible electric heating pad has a plurality of positive temperature coefficient (PTC) ceramic thermistor chip heating elements arranged in a two dimensional array between first and second flexible planar sheets of electrically conductive material, preferably woven of copper wire or other electrically conductive fibers. The PTC thermistor chips are disposed in spaced openings in a flexible dielectric separator disposed between the sheets and each chip has opposed planar surfaces soldered, welded or brazed to the sheets to establish electrical and thermal contact therewith. An outer flexible dielectric material covers the external surfaces of the sheets to prevent grounding or shock. A metallic enclosure, for example of stainless steel, can be formed over the outer dielectric material to add corrosion or abrasion resistance to the flexible heating pad.

Flexible electric heating pad using PTC ceramic thermistor chip heating

A flexible heating cable using positive temperature coefficient thermistors as a primary heat source with the thermistors being electrically and mechanically connected to substantially flat, preferably braided, electrical conductors with dielectric material preferably separating the conductors. A covering of dielectric material preferably is used to electrically separate the cable from the environment. The cable construction improves the heat transfer from the thermistors to the environment and improves the temperature distribution of the cable.

Flexible, elongated thermistor heating cable

A parallel, zoned heating cable wherein parallel electrical conductors are spaced outwardly from a central heating element preferably formed of a fibrous material containing carbon or graphite or coated with a conductive polymer. Heat conducting dielectric members are preferably located between the heating element and the electrical conductors for improved thermal distribution of the cable. The conductors are alternately connected by splices to the electrical conductors to produce heat of a constant wattage.

Elongated parallel, constant wattage heating cable

A skin effect heat generating pipe for use with a low frequency alternating current source includes a ferromagnetic pipe (e.g., steel) having thickness substantially greater than the penetration depth of the current of the frequency of the power source. A shunt conductor in the form of an electrically conductive metal layer (e.g., copper) is applied as a discrete layer to the inner surface of the pipe and in electrical contact therewith throughout the length of the shunt conductor, thereby forming a parallel resistance circuit wherein both the shunt conductor and pipe each are capable of conducting substantial current. One end of the pipe is electrically connectable to a first terminal of the power source. A return conductor installed in the pipe and electrically insulated therefrom has one end electrically connected to the second end of the pipe and its other end electrically connectable to the other terminal of the power source. The return conductor can be formed as a discrete inner liner conformed to the inner surface of the layer forming the shunt conductor. The shunt conductor allows a lower voltage level for a given pipe length or a longer pipe length for a given voltage level at the same power output levels.

Reduced resistance skin effect heat generating system

A new and improved heat transfer apparatus and method, wherein a heat tracing conduit assembly provides a self-contained closed conduit loop formed of two concentric tubular conduit members which may be laid as a single unit on the fluid pipe, thereby eliminating the need for a separately mounted return conduit.

Concentric tube heat tracing apparatus

A method and apparatus for parallel-type heating cables. In accordance with the present invention a heating core element is formed by connecting two essentially parallel bus wires with a plurality of electrically conductive splices to a centrally disposed resistive element and around which heating core element a protective sheath is formed. The present invention permits this heating core element to be formed by splicing the spaced apart, essentially parallel wire elements followed by a single extrusion application of a protective sheath.

Parallel-type heating cable

Parallel-type heating cable and method of making same

A heating assembly adapted to be releasably mounted externally of an instrument for the transfer of heat to the instrument by conduction to maintain the instrument at a desired temperature.

Growing community of inventors

San Marcos, TX, United States of America

David C Goss