Heating cable
AssigneeThermon Manufacturing Company
InventorsWells Whitney, Umesh Sopory
Life of this patent
Estimating the term…
Abstract
A heating cable includes a bus wire structure that includes a plurality of bus wires. An insulation layer is provided to insulate the plurality of bus wires. A plurality of node areas exposes portions of the bus wires from the insulation. A heating element is wrapped around the bus wire structure in a helical manner. The heating element includes an insulating core and one or more resistance wires wrapped around the core in a helical manner. The heating element is electrically coupled to the nodes of the bus wire structure at the plurality of node areas. The insulating core may be made of a folded-over tape made of a cloth material, such as glass cloth. Pluralities of redundant paths in between two nodes are provided to allow for current to flow in a zone if one of the redundant paths is broken.
Claims20
A heating cable for high temperature environments, the heating cable comprising:
- a bus wire structure comprising:
- a plurality of bus wires;
- and
- a first insulation layer for the plurality of bus wires, the insulation layer including a plurality of node areas, the node areas exposing portions of the bus wires from the insulation;
- a heating element wrapped around the bus wire structure in a helical manner, the heating element comprising:
- an insulating core;
- and
- a plurality of resistance wires wrapped around the insulating core in a helical manner;
- a second insulation layer comprising a tape wrapped around the bus wire structure and the heating element;
- and
- a corrugated metal sheath enclosing the bus wire structure and the heating element,
- wherein the heating element is electrically coupled to the nodes of the bus wire structure by coupling the plurality of resistance wires to the bus wires at the plurality of node areas to create a plurality of resistance zones, wherein a plurality of redundant paths in between two nodes are provided to allow for current to flow in a zone if one of the redundant paths is broken.
A method for manufacturing a heating cable for high temperature environments, the method comprising:
- providing a plurality of bus wires including an insulation layer for the plurality of bus wires;
- forming a plurality of node areas in the insulation layer, the node areas exposing portions of the bus wires from the insulation;
- wrapping a heating element around the bus wires in a helical manner, wherein the heating element comprises an insulating core and a plurality of resistance wires wrapped around the core in a helical manner;
- wrapping a second insulation layer comprising a tape around the bus wire structure and the heating element;
- and
- enclosing the bus wire structure and the heating element with a corrugated metal sheath,
- placing the heating element on the bus wire structure such that the plurality of resistance wires are electrically coupled to the bus wires to one or the other bus wires at the plurality of node areas to create a plurality of resistance zones, wherein a plurality of redundant paths in between two nodes are provided to allow for current to flow in a zone if one of the redundant paths is broken.
Dependencies are inferred from the claim text.