Abstract: A crushable ceramic heater core for an electric heater device which has a cylinder-like body of crushable ceramic material and grooves along the periphery of the body, the grooves being key shaped and adapted to receive a conductive pin in a groove. The invention also includes an electric heater device where such a core has been wound with heater wire and the conductive pin has been inserted in a core groove in contact with the wire, and the wire wound core has been installed in a sheath which has been filled with electoral insulating material. The sheath and its contents are swaged to create a compacted unitary heater assembly. The invention also includes the process for making the wire wound grooved core having a conductive pin therein in contact with the wire winding, and a method for making a heating device having such a core and which has been compacted to a theoretical density. The heater assembly and the method may also include installation of temperature sensing devices.

Abstract: The invention relates to a heating rod for a pressurizer of a primary cooling system of a pressurized-water nuclear reactor, the rod comprising a metal outer shell (36) of longitudinally elongate shape having an external surface (62), and a heating element (40) mounted inside the shell (36). It comprises an anti-corrosion coating (60) covering at least part of the external surface (62) of the shell (36).

Abstract: A heating apparatus including a housing defining a volume of air therein having an inlet and an outlet aperture. The heating apparatus also includes a heat generator having an elongate tubular metal sheath extending between an inner end and an outer end, a resistive wire within the sheath, and a substantially nonconducting material for electrically isolating the sheath relative to the resistive wire. The heat generator includes a terminal portion at the inner end and a heating portion extending between the terminal portion and the outer end of the sheath. The terminal portion is adapted for connection to a source of electrical power. Also, the heating portion of the heat generator is positioned in the housing to heat the volume of air. The heating apparatus also includes one or more insulators for electrically isolating the sheath relative to the housing.

Abstract: A heater strip for use as a heating element in an electric heater is made up of a profiled strip made of a flat metallic material forming a resistor section and of mounting elements extending over one common longitudinal side and they are manufactured as one piece with the resistor section for mounting the heater strip to a support. The strip has a zigzag-shaped structure. The mounting elements are provided only on the flat leg sections of the zigzag-shaped heater strip.

Abstract: A multicell heater is shown with typically round outer tubing, containing a plurality of resistive heating elements having a common inner sheath. The inner sheath has a preferably non-circular cross-section and is given a hairpin bend to form a “U” shape. The resulting configuration, which is much less expensive than conventional multicell heaters, provides efficient heating at the toe end—a usually unheated (“cold”) zone in conventional multicell heaters.

Abstract: A sheath heater includes a metal sheath, a coil-like heater, and a heat-resistant insulating powder. The starting form of the metal sheath has a small-diameter cylindrical portion at its distal end and is formed to have a substantially tubular shape as a whole. The heater is fabricated by inserting the coil-like heater in the sheath. The heat-resistant insulating powder is charged in the sheath and holds the coil-like heater in the sheath so that the coil-like heater is electrically insulated from the sheath. The distal end portion of the sheath is melted and so that the confronting end of the coil-like heater is buried so as not to be exposed on the outer wall of a closing portion at the distal end of the sheath. The melting of the sheath end can be done by using plasma, electron-beam or laser welding techniques.

Abstract: A cartridge heater includes an inner casing in which a heating element is accommodated. This inner casing is surrounded by an coaxially arranged outer casing of larger diameter so that an annular space is defined between the inner and outer casings. In the space a helical coolant piping is arranged, embedded in a highly heat-conductive substance of granular and/or pulverulent form so as to allow excess heat to be carried away.

Abstract: A cylindrical core of a ceramic such as alumina (Al.sub.2 O.sub.3) has grooves in the form of a double lead thread. A coil of Nichrome V is placed in the grooves, starting in one lead of the thread and returning in the other. A split ring of a ceramic such as beryllia surrounds the core. The heater is enclosed in a housing of a metal such as Inconel 600. The entire cartridge is only one inch long and 3/16 inch diameter. It is used as a catalyst bed heater for a satellite thruster.

Abstract: The heating element has an outer connector assembly including a cylindrical threaded portion adapted to be threaded into a boss on the heater water tank and a sheathed continuous electric resistance heating rod which has both ends secured to the connector assembly and which extends generally perpendicular to the heater tank centerline when installed. The heating rod is formed in a serpentine, generally W-shaped pattern with respect to the centerline of the cylindrical threaded portion, which provides the heating rod with an effective length greater than the inside diameter of the water tank, permits the heating rod to be inserted and withdrawn through the bore of the tank boss and permits the heater rod to be rotated, as the connector assembly is being threaded into and out of the tank boss, without striking any obstructions inside the water tank, such as the cold water dip tube, the hot water pipe and the anticorrosion anode.

Abstract: A cartridge-type electric immersion heating element having an integrally contained, self-limiting thermostatic control included in its electrical circuit includes an electric resistance heating element embedded in compacted powdered insulating material partially filling a tubular metallic sheath open at one end. A preset thermostat is located within a thermostat sleeve positioned in close proximity with the sheath wall and has an end embedded in the insulating material. The thermostat is connected in series circuit with the heating element and the ends of power supply leads enter the sheath through the open end thereof. A body of potting compound, such as epoxy resin, completely fills the remainder of the sheath, seals the open end thereof and encapsulates the other end of the sleeve and the power supply lead ends whereby the sleeve and thermostat are securely held in position in the sheath.

Abstract: An electrical heater comprising a heating element, a sheath surrounding the heating element and spaced therefrom, the sheath having an end spaced from an end of the heating element, electrical insulation between the heating element and the sheath, an internal lead pin electrically connected to the heating element and extending toward the end of the sheath, an electrically insulating end plug within said sheath at the end thereof and an external lead having an inner terminal. The insulating end plug has an opening in its inner face into which the end of the pin is received, and a hole in its outer face having its centerline offset from the centerline of the pin but laterally bounded in part by a lateral surface of the pin, the hole in the end plug receiving the inner terminal of an external lead.

Abstract: The invention is directed to a termination for a surface unit having a flat spiralled active heating portion and a single, downward and laterally-extending terminal leg. The termination is particularly adapted for a surface unit of the type shown in U.S. Pat. No. 4,010,350, issued Mar. 1, 1977, to Donald M. Cunningham, and assigned to the assignee of this application.

Abstract: A cartridge heater with improved thermocouple comprising a tubular metal sheath with a front end having a central opening therein, a metal plug engaged in and closing said opening, a filler of dielectric material in the sheath rearward of the plug, a resistance wire within and extending longitudinally of the sheath and supported by said filler, said plug having a pair of circumferentially spaced axially extending and radially outwardly opening grooves, a pair of elongate thermocouple wires supported by the filler within the sheath and having front end portions tightly engaged in and between in said opening and grooves, and an annular weld about the foremost line of contact between said sheath and plug and across the forward ends of said grooves.

Abstract: An electric heating element of the metal sheathed type, particularly a range surface unit comprising a spiralled metal tube having one closed end and containing compacted refractory insulation material and a helical coil of resistor alloy insulated from the tube and connected at one end to a center return conductor and having both electrical terminations extending from the other end of the tube, the construction being such that in the event of failure of the heating element, the failure will be in a passive manner.

Abstract: An electric cartridge heater having a metallic tubular metal sheath with an elongate heating element of generally circular cross section therein, the heating element being substantially coaxial with the sheath with an annular space between the sheath and the heating element. Particulate electrical insulating material, such as magnesium oxide (MgO), fills the annular space providing a conductive heat transfer path between the heating element and the sheath and electrically insulating the heating element from the sheath. The sheath, with the heating element in place and with the particulate insulating material surrounding the heating element in the sheath, is compressed by a diameter reduction process (e.g., swaging) thereby to compress the particulate insulative material and the heating element.