Efficiency describes the relationship between the net and gross output. For 1 t of grey cast iron, approx. 370 kWh of energy are required. In a crucible furnace, between 470 and 540 kWh\/t are required, depending on the construction features and capacity of the furnace. This corresponds to an efficiency level of between 0.79 and 0.69. Due to the optimum design of a furnace with regard to its heat losses and economical dimensions, this gives a ratio of 1.13:1 between active induction coil length and coil diameter. <\/p>\n\n\n\n
The purely electrical efficiency level depends on the coil length or height. With the same crucible capacity and same electrical output, this can be explained by means of 3 versions of a 13-t crucible furnace. The crucible wall thickness is in this case 140 mm. If one considers the magnetic field and the lines of flux in a completely molten furnace, there is a transverse field at the upper and lower end of the coil, and a longitudinal field in the centre of the coil. At the same electrical output, the sectors of the transverse fields are of equal length, i.e. with a coil length of approx. 1,300 mm there are transverse fields each of approx. 300 mm at top and bottom, and a 700 mm longitudinal field in the centre. These assumptions give an efficiency level of approx. 75%.<\/p>\n\n\n\n
If the coil length, for the same crucible capacity within the coil of 10 t, is changed, this gives, in the case of a reduction to approx. 1100 mm coil length, a transverse field at top and bottom of 300 mm each and a longitudinal field of 500 mm, resulting in a theoretical electrical efficiency level of approx. 69%.<\/p>\n\n\n\n
In case of the extension of the coil to a height of 1,700 mm, this would give a longitudinal field of approx. 1,100 mm and an electrical efficiency level of approx. 81%.<\/p>\n","protected":false},"excerpt":{"rendered":"
Efficiency describes the relationship between the net and gross output. For 1 t of grey cast iron, approx. 370 kWh of energy are required. In a crucible furnace, between 470 and 540 kWh\/t are required, depending on the construction features and capacity of the furnace. This corresponds to an efficiency level of between 0.79 and … Continue reading Efficiency<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[2],"tags":[],"class_list":["post-1925","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"acf":[],"_links":{"self":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1925","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/comments?post=1925"}],"version-history":[{"count":1,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1925\/revisions"}],"predecessor-version":[{"id":1926,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1925\/revisions\/1926"}],"wp:attachment":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/media?parent=1925"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/categories?post=1925"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/tags?post=1925"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}