{"id":5453,"date":"2019-08-12T20:17:13","date_gmt":"2019-08-12T19:17:13","guid":{"rendered":"http:\/\/www.crowave.com\/blog\/?p=5453"},"modified":"2020-12-28T05:21:05","modified_gmt":"2020-12-28T04:21:05","slug":"magnetska-mijesalica-sa-grijacem","status":"publish","type":"post","link":"https:\/\/www.crowave.com\/blog\/2019\/08\/12\/magnetska-mijesalica-sa-grijacem\/","title":{"rendered":"Magnetska mije\u0161alica sa grija\u010dem"},"content":{"rendered":"\r\n<p>Danas je nabavljena laboratorijska magnetska mije\u0161alica sa grija\u010dem \u010de\u0161kog proizvo\u0111a\u010da LP &#8211; Laboratorn\u00ed p\u0159\u00edstroje (Laboratorijski instrumenti) iz 1960-tih godina.<\/p>\r\n<p>&nbsp;<\/p>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5454\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02-1024x1013.jpg\" alt=\"\" width=\"1024\" height=\"1013\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02-1024x1013.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02-300x297.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02-768x760.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_02.jpg 1210w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5455\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03-1024x778.jpg\" alt=\"\" width=\"1024\" height=\"778\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03-1024x778.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03-300x228.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03-768x584.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_03.jpg 1449w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<p>&nbsp;<\/p>\r\n<p>Princip rada magnetskih mije\u0161alica je vrlo jednostavan. Mije\u0161alica stvara okretno magnetsko polje, naj\u010de\u0161\u0107e pomo\u0107u rotacije permanentnog magneta koji je postavljen na osovinu elektromotora, koje se prenosi na drugi magnet uronjen u teku\u0107inu koju \u017eelimo mije\u0161ati. Prednosti ovakvih mije\u0161alica su jednostavnost upotrebe i odr\u017eavanja, mogu se koristiti za mije\u0161anje u zatvorenim posudama, nemaju kriti\u010dnih pokretnih dijelova, dijelova osjetljivih na tro\u0161enje, brtvi i sli\u010dno. Osnovna ograni\u010denja ovakve mije\u0161alice su mala snaga, mali domet i osjetljivost na magnetske materijale izme\u0111u magneta. Stoga se ovakve mije\u0161alice koriste za mije\u0161anje teku\u0107ina manjih volumena i gusto\u0107a, a posuda u kojoj se nalazi teku\u0107ina sa uronjenim magnetom ne smije biti od magnetskog materijala, odnosno ne smije upijati ili blokirati magnetsko polje.<\/p>\r\n<p>&nbsp;<\/p>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5456\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04-806x1024.jpg\" alt=\"\" width=\"806\" height=\"1024\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04-806x1024.jpg 806w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04-236x300.jpg 236w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04-768x976.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_04.jpg 978w\" sizes=\"auto, (max-width: 806px) 100vw, 806px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5457\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05-1024x768.jpg\" alt=\"\" width=\"1024\" height=\"768\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05-1024x768.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05-300x225.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05-768x576.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_05.jpg 1728w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<p>&nbsp;<\/p>\r\n<p>Magnetske mije\u0161alice naj\u010de\u0161\u0107e se koriste u kemijskim laboratorijima za ubrzavanje kemijskih reakcija teku\u0107ina mije\u0161anjem, a tako\u0111er i grijanjem ukoliko je plo\u010da mije\u0161alice na koju se stavlja posuda sa teku\u0107inom opremljena sa grija\u010dem. Naj\u010de\u0161\u0107e se koriste staklene ili plasti\u010dne posude. Magneti koji se ubacuju u posude obi\u010dno su \u0161tapi\u0107astog oblika (kru\u017enog ili osmerokutnog presjeka)veli\u010dine od nekoliko milimetara do nekoliko centimetara. Ti magneti su presvu\u010deni slojem nekog izolacijskog, kemijski inertnog materijala (plastika ili staklo) kako uronjeni u teku\u0107ine ne bi ulazili u kemijske reakcije.<\/p>\r\n<p>&nbsp;<\/p>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5458\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06-1024x1019.jpg\" alt=\"\" width=\"1024\" height=\"1019\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06-1024x1019.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06-150x150.jpg 150w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06-300x300.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06-768x764.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_06.jpg 1206w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n\r\n\r\n<p>Na\u0161a mije\u0161alica ima tri kontrole: uklju\u010denje rotacije magneta, pode\u0161avanje brzine rotacije magneta i uklju\u010denje ili isklju\u010denje grija\u010da. Na ku\u0107i\u0161tu je tako\u0111er utor za postavljanje nosa\u010da (\u0161ipke sa hvataljkom) ukoliko se koriste tikvice ili neke sli\u010dne kemijske posude koje na plo\u010di mije\u0161alice ne mogu stajati samostalno.<\/p>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5459\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07-1024x691.jpg\" alt=\"\" width=\"1024\" height=\"691\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07-1024x691.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07-300x202.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07-768x518.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_07.jpg 1680w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5460\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08-1024x579.jpg\" alt=\"\" width=\"1024\" height=\"579\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08-1024x579.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08-300x170.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08-768x434.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_08.jpg 1725w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<p>&nbsp;<\/p>\r\n<p>Unutra\u0161njost mije\u0161alice sastoji se od tri osnovna elementa: jednofaznog kaveznog motora na \u010diju osovinu je pri\u010dvr\u0161\u0107en potkovi\u010dasti magnet, reostata za regulaciju brzine okretanja motora i elektri\u010dnog grija\u010da. Prema natpisnoj plo\u010dici ukupna potro\u0161nja mije\u0161alice je 76 W gdje se ve\u0107ina snage odnosi na grija\u010d.<\/p>\r\n<p>&nbsp;<\/p>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5461\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09-996x1024.jpg\" alt=\"\" width=\"996\" height=\"1024\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09-996x1024.jpg 996w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09-292x300.jpg 292w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09-768x790.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09.jpg 1260w\" sizes=\"auto, (max-width: 996px) 100vw, 996px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5462\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10-1024x718.jpg\" alt=\"\" width=\"1024\" height=\"718\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10-1024x718.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10-300x210.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10-768x538.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_10.jpg 1728w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<div class=\"wp-block-image\">\r\n<figure class=\"aligncenter\"><a href=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11.jpg\" rel=\"lightbox[5453]\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter wp-image-5463\" src=\"http:\/\/www.crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11-1024x872.jpg\" alt=\"\" width=\"1024\" height=\"872\" srcset=\"http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11-1024x872.jpg 1024w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11-300x255.jpg 300w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11-768x654.jpg 768w, http:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_11.jpg 1459w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/a><\/figure>\r\n<\/div>\r\n\r\n\r\n\r\n<p>Ovime smo se upoznali sa jednim specifi\u010dnim tipom mije\u0161alice koja iskori\u0161tava rotacijsko magnetsko polje, a to je ideja koja potje\u010de jo\u0161 iz 1917. godine te je prvi put patentirana 1944. godine. Rotacijsko magnetsko polje, osim vrtnjom permanentnog magneta, u nekim suvremenim tipovima magnetskih mije\u0161alica realizira se skupom kru\u017eno postavljenih nepokretnih elektromagneta (obi\u010dno tri ili vi\u0161e) koji se posebnom upravlja\u010dkom elektronikom naizmjeni\u010dno uklju\u010duju tako da zajedno stvaraju rotacijsko magnetsko polje.<\/p>\r\n\r\n\r\n\r\n<p>Na\u0161oj magnetskoj mije\u0161alici potrebna je kompletna zamjena dotrajalog o\u017ei\u010denja, a i \u0161amotna oplata grija\u010da po\u010dela se raspadati. Kad bismo istu htjeli restaurirati za ponovno kori\u0161tenje svakako bi bilo dobro i pobolj\u0161ati sistem regulacije brzine motora. Kao \u0161to se vidi na slikama koristi se mali jednofazni asinkroni kavezni motor kod kojeg se regulacija broja okretaja vr\u0161i smanjivanjem napona pomo\u0107u reostata, no time se onda ujedno i smanjuje snaga motora. Bolji na\u010din regulacije bio bi promjenom frekvencije izmjeni\u010dnog napona kojim napajamo motor, dakle upotrebom nekog frekvencijskog pretvara\u010da. S obzirom da za sada ne vidim gdje bi ova mije\u0161alica bila iskoristiva u elektroni\u010dkoj radionici (osim za mije\u0161anje teku\u0107ina ili rastvora za jetkanje plo\u010dica ;-)) smjestiti \u0107emo ju negdje na policu sa ostalim elektrokemijskim laboratorijskim ure\u0111ajima barem dok se za istu ne na\u0111e neka bolja primjena \ud83d\ude42<\/p>\r\n","protected":false},"excerpt":{"rendered":"<p>Danas je nabavljena laboratorijska magnetska mije\u0161alica sa grija\u010dem \u010de\u0161kog proizvo\u0111a\u010da LP &#8211; Laboratorn\u00ed p\u0159\u00edstroje (Laboratorijski instrumenti) iz 1960-tih godina. &nbsp; &nbsp; Princip rada magnetskih mije\u0161alica je vrlo jednostavan. Mije\u0161alica stvara okretno magnetsko polje, naj\u010de\u0161\u0107e pomo\u0107u rotacije permanentnog magneta koji je postavljen na osovinu elektromotora, koje se prenosi na drugi magnet uronjen u teku\u0107inu koju \u017eelimo [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":5461,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[62],"tags":[],"class_list":{"0":"post-5453","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-labnaprave","8":"czr-hentry"},"jetpack_featured_media_url":"https:\/\/crowave.com\/blog\/wp-content\/uploads\/2019\/08\/magnetska_mijesalica_09.jpg","_links":{"self":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/5453","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/comments?post=5453"}],"version-history":[{"count":3,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/5453\/revisions"}],"predecessor-version":[{"id":9888,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/posts\/5453\/revisions\/9888"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media\/5461"}],"wp:attachment":[{"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/media?parent=5453"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/categories?post=5453"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.crowave.com\/blog\/wp-json\/wp\/v2\/tags?post=5453"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}