【正文】 ne concentrations increased to % (W), the urine into the melt pump sent to the granulation tower, from the rotating nozzle spray granulation. The reference plant design data, primarily through the evaporation stage of materials and heat balance, obtained access to all parts of evaporation stage of materials and energy, then the entire section in equipment a calculation is made on evaporation heater design. Key words： Aqueous solution total recycle； Material balance； Heat balance； Secondary evaporator heater 1 引 言 了解合成尿素在國內(nèi)外的發(fā)展現(xiàn)狀，以及國內(nèi)外尿素企業(yè)采用的工藝，了解各種工藝的優(yōu)缺點，并結(jié)合實際情況對水溶液全循環(huán)法制尿素蒸發(fā)系統(tǒng)工藝進(jìn)行合理的設(shè)計。由閃蒸槽流出的尿液進(jìn)入一段蒸發(fā) 器的加熱段加熱至 130℃ ，在 壓力下，尿素濃度達(dá)到 96％（ W） ， 進(jìn)入二段蒸發(fā)加熱器，加熱至 140℃ ，繼續(xù)減壓至 （絕），尿液濃度提高至 ％（ W），尿液進(jìn)入熔融泵送往造粒塔，由旋轉(zhuǎn)噴頭噴灑造粒。原料 CO2 由合成車間凈化工段送來，液氨由氨庫送來，兩種反應(yīng)物經(jīng)加壓加熱送入合成塔反應(yīng)生成尿素。 年產(chǎn) 20 萬噸水溶液全循環(huán)法制尿素 蒸發(fā)系統(tǒng)設(shè)計 The Design of Evaporation System in Aqueous Solution Total Recycle of Producing Urea 200Kt/a 目 錄 摘要 .................................................................................................................................................I Abstract. ...................................................................................................................................... II 引言 ................................................................................................................................................ 1 第 1章 緒論 ............................................................................................................................... 2 尿素的性質(zhì) ....................................................................................................................... 2 尿素的 應(yīng)用領(lǐng)域 ............................................................................................................... 2 尿素用作肥料 ................................................................................................................ 2 尿素用作工業(yè)原料 ........................................................................................................ 2 尿素的質(zhì)量指標(biāo) ............................................................................................................... 2 第 2章 國內(nèi)水溶液 全循環(huán)法發(fā)展過程 ............................................................................ 4 第 3章 水溶液全循環(huán)法工藝流程 ..................................................................................... 6 尿素的合成 ....................................................................................................................... 6 循環(huán)回收 ........................................................................................................................... 6 蒸發(fā)造粒 ........................................................................................................................... 7 尾氣吸收與解吸 ............................................................................................................... 8 第 4章 物料衡算和熱量衡算 .............................................................................................10 物料衡算 ......................................................................................................................... 10 計算條件的確定 .......................................................................................................... 10 CO2 輸送系統(tǒng)物料衡算 ................................................................................................ 11 尿素合成塔物料衡算 .................................................................................................. 12 一段分解系統(tǒng)物料衡算 .............................................................................................. 14 二段分解系統(tǒng)物料衡算 .............................................................................................. 14 閃蒸槽物料衡算 .......................................................................................................... 15 一段蒸發(fā)器物料衡算 .................................................................................................. 16 二段蒸發(fā)器物料衡算 .................................................................................................. 17 熔融尿素輸送及造粒包裝物料衡算 .......................................................................... 18 一段蒸發(fā)冷凝器物料衡算 ........................................................................................ 19 二段蒸發(fā)冷凝器物料衡算 ........................................................................................ 20 熱量衡算 ......................................................................................................................... 22 閃蒸槽熱量衡算 .......................................................................................................... 22 一段蒸發(fā)器熱量衡算 .................................................................................................. 24 二段蒸發(fā)器熱量衡算 .................................................................................................. 28 第 5章 二段蒸發(fā)加熱器的設(shè)計 ........................................................................................30 加熱器設(shè)計相關(guān)數(shù)據(jù) ..................................................................................................... 30 試算并初選加熱器 ......................................................................................................... 30 加熱器試算 .................................................................................................................. 30 加熱器相關(guān)數(shù)據(jù)核算 .................................................................................................. 32 加熱部分尺寸計算選擇 ................................................................................................. 33 加熱器壁厚 .................................................................................................................. 33 加熱器封頭選擇 .......................................................................................................... 34 加熱器接管選擇 ..........................................................................................................