Direct resistance heating electrical furnace assembly and method of operating same
AssigneeMintek
InventorPetrus J. Van Staden
Life of this patent
Estimating the term…
Abstract
A direct resistance heating electrical furnace of the type in which a bed of electrically conductive elements are located between two spaced electrodes in the furnace, and a method of controlling the operation of same, are provided. The furnace is of the type having a generally tubular heating chamber with a pair of spaced electrodes associated therewith and conveniently located one at each end of the tubular heating chamber. The furnace has feed or discharge control means and the rate of feed or discharge is controlled according to the electrical resistance or current flow between the electrodes. No temperature measurement is required to control the furnace operation.
Claims19
A direct resistance heating electrical furnace, comprising:
- a heating chamber having an inlet for feeding material thereto and an outlet for discharging heated material therefrom, the heating chamber constituting means for receiving an electrically conductive bed of solid particulate material;
- a pair of spaced electrodes associated with the chamber;
- means for determining a variable electrical quantity selected from a group consisting of current flow between the spaced electrodes, and (2) electrical resistance at a predetermined voltage across the spaced electrodes;
- and
- control means, coupled to the determining means, for controlling the feed and discharge of material to and from the heating chamber according to the variable electrical quantity;
- wherein operation of the control means is carried out independently of direct temperature measurements of the electrically conductive bed of solid particulate material.
A furnace as claimed in claim 7 in which the heating chamber is a substantially vertically orientated tubular heating chamber.
A method of controlling operation of a direct resistance heating electrical furnace having a heating chamber with an inlet and an outlet, a pair of spaced electrodes associated with the chamber, means for determining a variable electrical quantity selected from a group consisting of current flow and electrical resistance between the spaced electrodes, and control means coupled to the determining means for controlling operation of the furnace, the method comprising the steps of:
- feeding into the heating chamber electrically conductive solid particulate material;
- discharging heated particulate material from the heating chamber;
- heating the particulate material by passing an electrical current through the particulate material between the electrodes;
- determining a variable electrical quantity which is one of the group consisting of (1) electrical resistance at a predetermined voltage across the electrodes, and (2) electrical current flowing between the electrodes;
- and
- controlling the feed and discharge of particulate material to and from the heating chamber according to the variable electrical quantity, independently of direct measurement of the temperature of the particulate material.
Dependencies are inferred from the claim text.