An exhaust gas heating unit for an engine includes a housing and a heating element. The housing includes a tubular peripheral wall and has an interior hollow space. The heating element has first and second ends and extends longitudinally therebetween to form a spiral shape within the interior hollow space. The heating element includes a thermally conductive sheath, an electrically conductive resistance element that extends longitudinally within the external sheath, and an electrically insulating material disposed about the resistance element between the resistance element and the sheath. A heat transfer member is positioned within the interior hollow space and is formed from one or more strips of thermally conductive material. The strips contact the external sheath at a plurality of locations between the first end and the second end. The heat transfer member has a corrugated shape that follows the spiral shape of the heating element.

A heating apparatus for heating fluid includes a container body, a plurality of electric heater elements, and a support structure. The container body defines a perimeter of a flow path for a fluid flowing through the container body. The plurality heater elements are exposed to the flow path. Each heater element includes a resistance element, sheath, and insulating material disposed about the resistance element between the resistance element and the sheath. The support structure includes a plurality of support sheets. The heater elements extend transversely through each support sheet and contact each support sheet to restrict movement of the heater elements and support the heater elements in the container body. The support sheets contact the sheaths of the electric heater elements to increase heat transfer to the fluid flowing through the flow path. Opposite ends of each support sheet are connected to the container body.

A heating apparatus for heating fluid includes a container body, a plurality of electric heater elements, and a support structure. The container body defines a perimeter of a flow path for a fluid flowing through the container body. The plurality heater elements are exposed to the flow path. Each heater element includes a resistance element, sheath, and insulating material disposed about the resistance element between the resistance element and the sheath. The support structure includes a plurality of support sheets. The heater elements extend transversely through each support sheet and contact each support sheet to restrict movement of the heater elements and support the heater elements in the container body. The support sheets contact the sheaths of the electric heater elements to increase heat transfer to the fluid flowing through the flow path. Opposite ends of each support sheet are connected to the container body.

A heating apparatus for a fluid flow system having a container body includes a heater element and a strip. The heater element is within the container body and includes an electrical resistance element, a sheath, and an insulating material. The sheath extends along a predefined path through the container body and surrounds the electrical resistance element along the predefined path. The insulating material is disposed about the electrical resistance element between the electrical resistance element and the sheath. The insulating material electrically insulates the electrical resistance element from the sheath. The strip is disposed inside the container body and defines a tortuous geometry that follows the predefined path. The strip defines a plurality of openings at discrete locations along the strip. The heater element extends through the plurality of openings and is configured to contact the strip at the discrete locations.

A heating apparatus for a fluid flow system having a container body includes a heater element and a strip. The heater element is within the container body and includes an electrical resistance element, a sheath, and an insulating material. The sheath extends along a predefined path through the container body and surrounds the electrical resistance element along the predefined path. The insulating material is disposed about the electrical resistance element between the electrical resistance element and the sheath. The insulating material electrically insulates the electrical resistance element from the sheath. The strip is disposed inside the container body and defines a tortuous geometry that follows the predefined path. The strip defines a plurality of openings at discrete locations along the strip. The heater element extends through the plurality of openings and is configured to contact the strip at the discrete locations.

A DC plasma arc furnace, a method of co-processing waste and metal, a method of producing energy by processing material using the furnace, and the products produced by the furnace are provided. Metal may be efficiently processed by the furnace via an increased organic content in other feedstock fed into the furnace.

A DC plasma arc furnace, a method of co-processing waste and metal, a method of producing energy by processing material using the furnace, and the products produced by the furnace are provided. Metal may be efficiently processed by the furnace via an increased organic content in other feedstock fed into the furnace.

In the case of mono sewage sludge incineration, a solution may be created that enables sewage sludge ash, which may still have a low proportion of unburned carbon, to be discharged from a mono sewage sludge incineration plant. This is achieved by a method for the post-combustion of sewage sludge ash obtained in a mono sewage sludge incineration in a rotary kiln by means of a hot and a low oxygen content, such as an oxygen content of 5-10 vol. % oxygen. The gas stream from the rotary kiln may escape the sewage sludge ash and is fed to the gas flow. This sufficiently hot gas flow may cause oxidation or afterburning of unburned carbon contained in the sewage sludge ash.

A heating apparatus for a fluid flow system having a fluid conduit includes at least one heater element and a support member within the conduit. The at least one heater element includes a resistance wire, a sheath, and an electrically insulating material. The sheath has a closed profile shape that extends along a tortuous path through the container body and surrounds the resistance wire along the tortuous path. The insulating material is disposed about the wire between the wire and the sheath. The support member restricts movement of the at least one heater element relative to the fluid conduit. The support member defines a corrugated geometry that follows the tortuous path while contacting the sheath along a majority of a length of the sheath. The support member increases heat transfer from the at least one heater element to a fluid flowing through the fluid conduit.

A heating apparatus for a fluid flow system having a fluid conduit includes at least one heater element and a support member within the conduit. The at least one heater element includes a resistance wire, a sheath, and an electrically insulating material. The sheath has a closed profile shape that extends along a tortuous path through the container body and surrounds the resistance wire along the tortuous path. The insulating material is disposed about the wire between the wire and the sheath. The support member restricts movement of the at least one heater element relative to the fluid conduit. The support member defines a corrugated geometry that follows the tortuous path while contacting the sheath along a majority of a length of the sheath. The support member increases heat transfer from the at least one heater element to a fluid flowing through the fluid conduit.