Electrical heating element

An improved electrical heating element for a radiant tube heater in a high temperature furnace or the like, comprising:

• at least three axially spaced insulating discs each having a [plurality] pair of rows of spaced apertures parallel to the axis of the disc;
• a plurality of insulating spacers interposed between adjacent discs and spacing the discs from one another;
• a plurality of conductive metal rods each having elongated straight legs and a base bight portion, the straight rod legs being inserted through aligned apertures in each of the discs to extend axially of the disc-spacer assembly and radially outwardly of the spacer and the bight portion of each rod lying beyond the confines of the end most disc;
• and
• conductive means retaining the rods, the discs and the spacers in assembly and interconnecting the rods to provide a single continuous electrical flow path through each of said rods.

In an electrical heating element for a radiant tube heater or the like comprising a plurality of hollow, non-conductive, longitudinally aligned spacers;

• a series of thin, flat, non-conductive plates each having a plurality of apertures extending axially therethrough, the apertures in each plate being arranged in a plurality of rows;
• said plates being maintained in a parallel, spaced apart relationship by the spacers interposed therebetween with the apertures in the plates being axially aligned;
• the improvement of:
• a plurality of elongated electrically conductive rods each formed in a U-shaped configuration with a short base and parallel elongated legs;
• each leg of each rod being inserted axially through the aligned apertures in the series of plates to lie radially outwardly of the spacers;
• the bases of the rods extending beyond the end plate;
• said end plate including a central axial bore radially interiorly of the spacer;
• and
• an additional non-conductive plate identical to said end plate, and an additional spacer for further supporting the heating element and for isolating the bases of the rods from contacting the radiant tube, the additional plate being positioned away from said end plate and secured thereto by an axial pin extending through said spacer and the central axial bore of the end plate and the additional plate, said axial pin secured inwardly of the end plate and outwardly of the additional plate;
• and
• means for electrically interconnecting the free end of each rod leg, with the exception of two legs of different rods, to the free end of a leg of a different rod at a first end of the heating element, to form the rods into a single electrical path, the remaining two rod legs being adapted for connection to an electrical power source.

In a high temperature closed radiant tube furnace, the improvement of an electrical heating element positioned in said closed radiant tube, said radiant tube operable at temperatures in excess of 1500.degree. F. comprising:

• a support structure comprising a plurality of plate-spacer units, each plate thereof being thin, flat, non-conductive and having a [plurality] pair of spaced rows of apertures therethrough parallel to the axis of the plate, and each spacer thereof being non-conductive and of a size smaller than said plates, said plate-spacer units being positioned so that a spacer thereof is between each pair of adjacent plates, and
• an electrical heating element assembly having a plurality of elongated rigid electrical conductors, each extending through at least one corresponding aperture in each plate radially outwardly of said spacers, each conductor being straight between adjacent plates, each of said conductors being supported by and extending between said plates;
• said straight rigid conductors being free of contact with said radiant tube;
• the ends of the conductors being interconnected so that the interconnected conductors define a single tortuous electrical path radially outwardly of said spacers;
• the conductors as interconnected maintaining said support structure in assembly.

An improved electric heating element for a radiant tube heater in a high temperature furnace or the like comprising:

• at least three insulating disc-spacer units each disc thereof having a [plurality] pair of spaced apart rows of apertures extending therethrough parallel to the axis of the disc;
• the disc-spacer units being positioned so that a spacer thereof is interposed between adjacent discs thereof to space the discs from one another;
• a plurality of conductive metal rods each having a pair of elongated rigid legs interconnected by a rigid base portion, the rigid legs being inserted through corresponding aligned apertures in each of the discs of the disc-spacer units to extend parallel to the longitudinal axis of the discs thereof and radially outwardly of the spacers thereof, and the rigid base portion of each rod lying beyond the confines of the disc of the end most disc-spacer unit;
• and
• conductive means retaining the rods and the disc-spacer units in assembly and interconnecting the rods to provide a single continuous electrical flow path through each of said rods.

In an electrical heating element for a radiant tube heater or the like comprising a plurality of non-conductive plate-spacer units, each spacer thereof being hollow, each plate thereof being thin, flat and having a plurality of apertures extending axially therethrough, the apertures in each plate thereof being arranged in a plurality of rows;

• said plates thereof being maintained in a parallel, spaced apart relationship by the spacers thereof with the apertures in the plates being aligned;
• the improvement of:
• a plurality of pairs of elongated electrically conductive rigid rods, each rod being inserted axially through the aligned apertures in the plates to lie radially outwardly of the spacers;
• each pair of rods interconnected by a base, the bases extending beyond the end most plate-spacer unit, said end most plate including a central axial bore radially interiorly of its spacer;
• and
• an additional non-conductive thin flat apertured plate having a central axial bore and being spaced apart from said end most plate for further supporting the heating element and for isolating the bases from contacting the radiant tube, the additional plate being positioned away from said end most plate and secured thereto by an axial pin extending through its spacer and the central axial bore of said end most plate and of said additional plate, said axial pin secured inwardly of the end most plate and outwardly of the additional plate;
• and
• means for electrically interconnecting the free end of each rod, with the exception of two rods of different pairs of rods, to the free end of a rod of a different pair of rods at a first end of the heating element, to form the rods into a single electrical path, the remaining two rods being adapted for connection to an electrical power source.

An electrical heating element for a radiant tube heater comprising a plurality of hollow, non-conductive, longitudinally aligned spacers;

• a series of thin, flat, non-conductive plates each having a plurality of apertures extending axially therethrough, the apertures in each plate being arranged in a pair of circular rows;
• said plates being maintained in a parallel, spaced apart relationship by the spacers interposed therebetween with the apertures in the plates being axially aligned;
• a plurality of elongated electrically conductive rods each formed in a U-shaped configuration with a short base and parallel elongated legs;
• each leg of each rod being inserted axially through the aligned apertures in the series of plates to lie radially outwardly of the spacers;
• each leg of a rod inserted through a different row of apertures than the other leg of said rod;
• the bases of the rods extending beyond the end plate;
• said end plate including a central axial bore located radially interiorly of the spacer;
• an additional non-conductive plate identical to said end plate, an additional spacer for further supporting the heating element and for isolating the base of the rods from contacting the radiant tube, the additional plate being positioned away from said end plate and secured thereto by an axial pin extending through said spacer and the central axial bore of the end plate and the additional plate, said axial pin being secured inwardly of the end plate and outwardly of the additional plate;
• and means for electrically interconnecting the free end of each rod leg, with the exception of two legs of different rods, to the free end of a leg of a different rod at a first end of the heating element, to form the rods into a single electrical path, the remaining two rod legs being adapted for connection to an electrical power source.

An electrical heating element for a radiant tube heater comprising a plurality of non-conductive plate-spacer units, each spacer thereof being hollow, each plate thereof being thin, flat and having a plurality of apertures extending axially therethrough, the apertures in each plate thereof being arranged in a pair of circular rows;

• said plates thereof being maintained in a parallel, spaced apart relationship by the spacers thereof with the apertures in the plates being aligned;
• a plurality of pairs of elongated electrically conductive rigid rods, each rod being inserted axially through the aligned apertures in the plates to lie radially outwardly of the spacers;
• each pair of rods interconnected by a base, the bases extending beyond the end most plate-spacer unit;
• said end most plate including a central axial bore radially interiorly of its spacer;
• an additional non-conductive thin flat apertured plate having a central axial bore and being spaced apart from said end most plate for further supporting the heating element and for isolating the bases from contacting the radiant tube, the additional plate being positioned away from said end most plate and secured thereto by an axial pin extending through its spacer and the central axial bore of said end most plate and of said additional plate, said axial pin secured inwardly of the end most plate and outwardly of the additional plate;
• and means for electrically interconnecting the free end of said rod, with the exception of two rods of different pairs of rods, to the free end of a rod of a different pair of rods at a first end of the heating element, to form the rods into a single electrical path, the remaining two rods being adapted for connection to an electrical power source.