四(si)環(huan)凍(dong)干機也叫四(si)環(huan)冷凍(dong)干燥機利用冷凍(dong)再升華的原理來干燥樣品物料，把物料的水分(fen)從內(nei)往外利用真空負(fu)壓捕取掉(diao)，然(ran)后(hou)吸附到冷井(jing)上。

實(shi)驗(yan)室四環(huan)(huan)凍(dong)(dong)(dong)干(gan)機(ji)設(she)備是一種(zhong)用于實(shi)驗(yan)室內(nei)少量樣品(pin)冷(leng)(leng)(leng)(leng)(leng)凍(dong)(dong)(dong)干(gan)燥的(de)(de)小(xiao)型凍(dong)(dong)(dong)干(gan)機(ji)，包括(kuo)殼體(ti)(ti)(ti)、制(zhi)(zhi)冷(leng)(leng)(leng)(leng)(leng)機(ji)組、真空(kong)(kong)(kong)泵、冷(leng)(leng)(leng)(leng)(leng)阱(jing) ，電控(kong)系統(tong)。這種(zhong)四環(huan)(huan)凍(dong)(dong)(dong)干(gan)機(ji)制(zhi)(zhi)冷(leng)(leng)(leng)(leng)(leng)機(ji)組設(she)置在(zai)殼體(ti)(ti)(ti)內(nei)；冷(leng)(leng)(leng)(leng)(leng)阱(jing)設(she)在(zai)殼體(ti)(ti)(ti)上部；真空(kong)(kong)(kong)泵通(tong)過真空(kong)(kong)(kong)管(guan)道連(lian)(lian)通(tong)冷(leng)(leng)(leng)(leng)(leng)阱(jing)；制(zhi)(zhi)冷(leng)(leng)(leng)(leng)(leng)機(ji)組具有壓(ya)縮(suo)機(ji)、換熱器(qi)(qi)、膨脹閥、蒸發(fa)(fa)器(qi)(qi)；還包括(kuo)物料放(fang)置裝置，物料放(fang)置裝置安(an)裝在(zai)冷(leng)(leng)(leng)(leng)(leng)阱(jing)上方及殼體(ti)(ti)(ti)上，且(qie)與冷(leng)(leng)(leng)(leng)(leng)阱(jing)上端連(lian)(lian)通(tong)；蒸發(fa)(fa)器(qi)(qi)為蒸發(fa)(fa)盤管(guan)，其(qi)設(she)置在(zai)冷(leng)(leng)(leng)(leng)(leng)阱(jing)內(nei)。將蒸發(fa)(fa)器(qi)(qi)改(gai)設(she)成蒸發(fa)(fa)盤管(guan)，且(qie)設(she)置在(zai)冷(leng)(leng)(leng)(leng)(leng)阱(jing)內(nei)，降(jiang)溫(wen)速(su)度(du)快(kuai)。實(shi)驗(yan)室四環(huan)(huan)凍(dong)(dong)(dong)干(gan)機(ji)整機(ji)體(ti)(ti)(ti)積小(xiao)、能耗(hao)低、結構穩定(ding)、操作方便(bian)、擴展性強，實(shi)驗(yan)室內(nei)擺放(fang)方便(bian)，便(bian)于實(shi)驗(yan)室少量物料凍(dong)(dong)(dong)干(gan)及相(xiang)關工(gong)藝(yi)摸索(suo)。冷(leng)(leng)(leng)(leng)(leng)凍(dong)(dong)(dong)式干(gan)燥機(ji)采(cai)用了降(jiang)溫(wen)結露的(de)(de)工(gong)作原理(li)，主(zhu)要由(you)熱交(jiao)(jiao)(jiao)換系統(tong)、制(zhi)(zhi)冷(leng)(leng)(leng)(leng)(leng)系統(tong)和電氣(qi)(qi)(qi)(qi)控(kong)制(zhi)(zhi)系統(tong)三部分(fen)組成。壓(ya)縮(suo)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)首先進(jin)(jin)入預冷(leng)(leng)(leng)(leng)(leng)卻(que)器(qi)(qi)進(jin)(jin)行氣(qi)(qi)(qi)(qi)-氣(qi)(qi)(qi)(qi)或氣(qi)(qi)(qi)(qi)-水(shui)的(de)(de)熱交(jiao)(jiao)(jiao)換，除去一部分(fen)熱能，然(ran)后(hou)進(jin)(jin)入冷(leng)(leng)(leng)(leng)(leng)熱空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)交(jiao)(jiao)(jiao)換器(qi)(qi)，和已經從蒸發(fa)(fa)器(qi)(qi)出(chu)來被冷(leng)(leng)(leng)(leng)(leng)卻(que)到壓(ya)力露點的(de)(de)冷(leng)(leng)(leng)(leng)(leng)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)進(jin)(jin)行熱交(jiao)(jiao)(jiao)換，使壓(ya)縮(suo)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)的(de)(de)溫(wen)度(du)進(jin)(jin)一步降(jiang)低。之后(hou)壓(ya)縮(suo)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)進(jin)(jin)入蒸發(fa)(fa)器(qi)(qi)，與制(zhi)(zhi)冷(leng)(leng)(leng)(leng)(leng)劑進(jin)(jin)行熱交(jiao)(jiao)(jiao)換，壓(ya)縮(suo)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)的(de)(de)溫(wen)度(du)降(jiang)至(zhi)0-8℃，空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)中(zhong)的(de)(de)水(shui)份在(zai)此(ci)溫(wen)度(du)下析(xi)出(chu)，通(tong)過氣(qi)(qi)(qi)(qi)水(shui)分(fen)離器(qi)(qi)分(fen)離后(hou)，經過自動(dong)排水(shui)器(qi)(qi)排出(chu)。而干(gan)燥的(de)(de)低溫(wen)空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)則進(jin)(jin)入冷(leng)(leng)(leng)(leng)(leng)熱空(kong)(kong)(kong)氣(qi)(qi)(qi)(qi)交(jiao)(jiao)(jiao)換器(qi)(qi)進(jin)(jin)行熱交(jiao)(jiao)(jiao)換，溫(wen)度(du)升高(gao)后(hou)輸出(chu)。