{"id":1176,"date":"2018-10-09T09:40:43","date_gmt":"2018-10-09T09:40:43","guid":{"rendered":"https:\/\/aboutfoundry.com\/?p=1176"},"modified":"2018-10-09T12:06:44","modified_gmt":"2018-10-09T12:06:44","slug":"chip-melting-a","status":"publish","type":"post","link":"https:\/\/aboutfoundry.com\/en\/chip-melting-a\/","title":{"rendered":"Chip melting"},"content":{"rendered":"\n

Chip melting a<\/strong><\/p>\n\n\n\n

is associated with various difficulties due to the relatively low weight of the chips. Most customers have developed their own processes, which in combination with the available equipment are used quite successfully.The use of \u201cchip briquettes\u201d has not proven popular. The specific density or filling weight is too low for them to be immersed properly in the melt. The briquettes fall apart shortly after contact with the melt, and the chips spread out over the surface of the bath. In the case of channel melting furnaces, some success has been achieved with the use of mechan- ic stirring systems. Brass melting furnaces with channel inductors are for example equipped with concrete blocks, which cover approx. 80% of the surface, and which are installed by cranes for lowering onto the charged scrap.In crucible induction furnaces, the filling level in the coil should generally be 40%. With dry chips and high specific outputs, the chips can be charged in up to the upper edge of the coil.<\/p>\n\n\n\n

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Design of vat-shaped (IRV) and crucible-shaped (IRT) cannel-type furnaces<\/figcaption><\/figure>\n\n\n\n
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Cross-section through the vessel of a tub-shaped (left) and crucible-shaped channel-type furnace tub shape (IRV) – crucible shape (IRT)<\/figcaption><\/figure>\n\n\n\n
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Influences on the channel furnace<\/figcaption><\/figure>\n\n\n\n
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Charging of medium-frequency melting furnaces in charging\/melting mode with large sized and bulky charge material<\/figcaption><\/figure>\n\n\n\n
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Charging of medium-frequency melting furnaces in charging\/melting mode with normal sized and small charge material<\/figcaption><\/figure>\n\n\n\n

Chip melting b<\/strong><\/p>\n\n\n\n

In mains frequency furnaces, melting usually continues until a smooth bath sur-\nface appears before recharging. In foundries with medium-frequency furnaces,\nrecharging usually takes place earlier. With this procedure, melting can be con-\ntinued up to the upper edge of the furnace coil, before bringing the furnace up\nto the maximum melt level using compact scrap or pigs. With modified outputs\nand frequencies (240 kW\/t for low frequency, 540 kW at 250 Hz and 760 kW at\n500 Hz), continually charged chips charged in on top of the molten bath can be\nmelted from approx. 30 to 70% of the filling level. For brass or red cast, and using\nthis process at approx. 330 kW\/t and 960 kW furnace output with mains fre-\nquency in a 4-t furnace, approx. 1.6 t of chips can be melted in approx. 33 min.\nAn important factor here is that the chips must be fed evenly over the centre of\nthe bath at a rate of approx. 45 to 50 kg\/min.\n<\/p>\n\n\n\n

Trials with an 18-t brass-furnace at 3,500 kW have shown that this method of\nmelting works very well up to a rate of approx. 175 kg\/min. From approx. 200\nkg\/min of continuous charging, a ring formed around the crucible wall which\ncould no longer be melted, but had to be brought into the melt manually.\n<\/p>\n","protected":false},"excerpt":{"rendered":"

Chip melting a is associated with various difficulties due to the relatively low weight of the chips. Most customers have developed their own processes, which in combination with the available equipment are used quite successfully.The use of \u201cchip briquettes\u201d has not proven popular. The specific density or filling weight is too low for them to … Continue reading Chip melting<\/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-1176","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"acf":{"adresse":"","telefon":"","e-mail":"","webseite":""},"_links":{"self":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1176","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=1176"}],"version-history":[{"count":3,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1176\/revisions"}],"predecessor-version":[{"id":1189,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/posts\/1176\/revisions\/1189"}],"wp:attachment":[{"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/media?parent=1176"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/categories?post=1176"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/aboutfoundry.com\/en\/wp-json\/wp\/v2\/tags?post=1176"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}