更换分子筛的具体操作步骤是什么？

 更换分子筛的具体操作步骤是什么？塑料除湿干燥机

# Specific Operation Steps for Molecular Sieve Replacement ## 中英双语完整操作流程 ## English Version ### Step 1 Safety Shutdown & Cooling 1. Stop feeding PET pellets, run the dryer for 30 minutes to exhaust materials inside the hopper. 2. Turn off heating system, keep circulation and regeneration fans running for 1 hour to cool hot air inside pipelines. 3. Cut off the main power supply of the whole machine, lock power switch to prevent accidental startup. 4. Close compressed air inlet valve, open pressure relief valve of adsorption towers to release residual gas pressure. 5. Wait 2 hours until tower shell temperature drops below 40℃, avoid scalding. 6. Wear dust mask, protective gloves and safety goggles. Prepare vacuum cleaner, brush, new 3A molecular sieve, new flange gaskets, filter screens, wrench. ### Step 2 Discharge Old Failed Molecular Sieve 1. Loosen all flange bolts of one adsorption tower diagonally, separate the tower top cover. 2. Take out the top pressing plate and filter screen. 3. Remove the discharge port cover at the bottom of tower, completely discharge all aged, pulverized, contaminated molecular sieve. 4. Use industrial vacuum cleaner to suck all powder, carbon deposits and residue from tower inner wall, partition, air distribution plate and bottom mesh. 5. Scrub stubborn oil stains and plastic volatile sediment with dry brush; wipe clean the whole tower cavity. 6. Check the bottom supporting filter screen, replace it if broken or perforated. 7. Repeat the above steps to empty the second adsorption tower. ### Step 3 Fill New 3A Molecular Sieve 1. Confirm the filling volume standard according to equipment model, prepare enough food-grade 3A molecular sieve (4A is forbidden for PET drying). 2. Pour molecular sieve evenly into the tower little by little, tap tower wall gently while filling to eliminate hollow gaps inside the material layer. 3. Stop filling when reaching the standard liquid level, reserve 3–5cm expansion space to avoid blockage during high-temperature regeneration. 4. Lay new filter screen and pressing plate on the top of molecular sieve layer, fix tightly to prevent powder leakage into air duct. ### Step 4 Assemble & Seal Adsorption Tower 1. Replace the old rubber flange gasket with a brand-new one; remove residual dust on flange contact surface. 2. Align tower body and top cover, place the gasket flat without offset or distortion. 3. Tighten flange bolts in diagonal cross order with uniform force to prevent air leakage caused by uneven compression. 4. Install bottom discharge cover and lock all screws. ### Step 5 Air Tightness Test (No Heating Mode) 1. Restore compressed air pipeline, open air inlet valve. 2. Switch on main power, start dryer in cold running mode (close heating function). 3. Dip soap water on all flange joints, pipe connections and discharge ports. If bubbles appear, retighten bolts until no air leakage. 4. Run cold circulation for 30 minutes, check no abnormal powder overflow or tower vibration. ### Step 6 Pre-Regeneration Aging of New Molecular Sieve 1. Turn on heating system, set standard regeneration temperature. 2. Operate the machine continuously for 2–3 full adsorption-regeneration cycles without feeding materials. This removes surface adsorbed moisture of new molecular sieve. 3. Real-time monitor dew point value on touch screen. Only proceed to mass production when dew point stably reaches -40℃ ~ -50℃ for more than 1 hour. ### Step 7 Formal Production Startup 1. Feed PET raw materials into drying hopper, set drying temperature 160–175℃. 2. Observe dew point, heating temperature and fan operation within the first 2 hours; record equipment operation data for maintenance file. --- ## 中文对照 更换分子筛详细操作步骤 ### 步骤1 **停机、充分降温 1. 停止上料，设备空载运行30分钟，排空料斗内残留PET原料； 2. 关闭加热系统，保持循环风机、再生风机持续运转1小时，带走风道内热空气； 3. 切断整机总电源，上锁断电开关，防止他人误启动； 4. 关闭前端压缩空气进气阀，打开吸附塔泄压阀，释放塔内残余气压； 5. 静置冷却2小时，待塔体外壁温度降至40℃以下，杜绝高温**； 6. 穿戴防尘口罩、防护手套、护目镜；备好工业吸尘器、毛刷、全新3A分子筛、法兰密封垫、滤网、扳手等配件工具。 ### 步骤2 排出旧失效分子筛 1. 对角松开单座吸附塔全部法兰螺栓，分离塔顶盖板； 2. 取出顶部压板与滤网； 3. 打开塔底出料口盖板，完全倾倒出老化、粉化、污染的旧分子筛； 4. 用吸尘器彻底吸净塔内壁、隔板、布风板、底部滤网处全部粉末、积碳残渣； 5. 干毛刷清理顽固油污与塑料挥发沉淀物，擦拭干净整个塔腔； 6. 检查底部支撑滤网，出现破损、穿孔必须更换； 7. 另一座吸附塔重复以上操作，全部清空。 ### 步骤3 装填全新3A分子筛 1. 对照设备型号确认标准装填量，准备塑胶干燥专用食品级3A分子筛，严禁使用4A分子筛； 2. 少量分次均匀倒入分子筛，装填过程轻敲塔壁，消除料层内部中空缝隙； 3. 装填至标准液位停止，预留3–5cm膨胀空隙，防止高温再生时分子筛膨胀堵塔； 4. 在分子筛顶层铺设全新滤网、压紧压板，固定牢固，避免粉末窜入循环风道。 ### 步骤4 吸附塔装配密封 1. 法兰接触面清理干净，旧橡胶密封垫直接换新； 2. 对齐塔体与顶盖，放平密封垫，无偏移、无挤压变形； 3. 采用对角交叉顺序均匀锁紧法兰螺栓，受力一致，避免单边密封不严漏风； 4. 装回底部出料盖板，锁紧全部螺丝。 ### 步骤5 不开加热，气密性检漏 1. 复原压缩空气管路，打开进气阀； 2. 接通总电源，开启设备冷风运行模式，关闭加热功能； 3. 肥皂水涂抹所有法兰接缝、管路接头、出料口，出现气泡代表漏风，重新紧固螺栓直至无漏气； 4. 冷风循环运行30分钟，观察无异常喷粉、塔体剧烈震动现象。 ### 步骤6 新分子筛预再生烘干 1. 开启加热系统，设置标准再生温度； 2. 不上料空载连续运行2～3组完整吸附-再生循环，脱除新分子筛表面吸附的空气中水分； 3. 实时监控触摸屏露点数值，露点稳定维持在-40℃~-50℃并持续1小时以上，才可投入生产。 ### 步骤7 正式开机生产 1. 向干燥料斗投入PET原料，设定烘干温度160–175℃； 2. 开机前2小时持续观察露点、加热温度、风机运行状态，记录运行数据存入设备维保档案。