This article was originally published in the April 1907 edition of the Electrochemical & Metallurgical Industry magazine. Information within this article is therefore correct as of 1907. The publication of this material aims to provide historical insight on the subject and its place in industry.
The following details refer to a Kjellin induction furnace for laboratory purposes, which was exhibited at Sheffield during October last, and which presents some interesting features.
The adjoining illustration gives a view of the furnace.
The furnace has a maximum capacity of 15 kw., and is designed for a frequency of 150 to 200 cycles per second. The induction furnace has been specially built for this high frequency to suit the conditions at the laboratory in which it was to be installed after the exhibition. It is, of course, well understood that the design of an electric induction furnace is rendered very much more difficult by use of a high frequency, and for this reason the behavior of the furnace, as given in the record of tests below, is remarkably good and the power factor very satisfactory, in view of the high frequency and the comparatively small size of furnace.
The furnace was originally intended for melting platinum, but at the exhibition was used for melting steel, and for this purpose it proved a thorough success, several castings being made on several days of the exhibition. A furnace of the size exhibited will pour an ingot of about 30 pounds.
The furnace is built as a tilting furnace, just like the Kjellin furnace now in industrial operation for steel refining in the steel works at Voelklingen, as described and illustrated in our last issue, page 92. It is. of course, easy to change the design as to use currents of lower frequency than 150 to 200 cycles.
The lining is mode of magnesite and gave no trouble.
The Kjellin induction furnace is built in this country by the American Grondal-Kjellin Co., of 45 Wall Street, New York City, and we hope to report on some interesting developments on a commercial scale in one of our next issues.