南京科臣节能设备有限公司

氧化铝分解槽

分级降温的节能设备

NJKC-101型风冷水冷一体式热管换热器

氧化铝生产企业，氧化铝分解槽的分级降温，多年来一直采用宽流道不锈钢板式换热器，配备渣浆泵送料浆进入板式换热器，经与循环冷却水对流换热实现降温，一条生产线安装六台套，方可解决料浆降温要求。夏季气温偏高时，冷却循环水温随之升高，降温效果仍难满足生产工艺要求。

新装板式换热器初期运行换热降温效果较好，运行中由于板片逐步产生结疤、堵塞，每年需停用5-6次进行专业清洗，换热降温效果仍逐步下降，且易磨损洞穿、维护、维修费用大，5-6年即行报废。与之配套的渣浆泵极易磨损，每年维修费用几近一台新泵费用。渣浆泵运行功率132KW/台套，单条生产线6台套，按载荷90%计算，每小时耗电能约700度，每天16800度，每年6132000度。

综上所述，板式换热器+渣浆泵作为分解槽分级降温设备，运行耗能大，易结疤堵塞，易损坏，维护保养频繁，维修费用高。一直是困扰氧化铝生产企业的一道难题。

南京科臣节能设备有限公司经多方实验，研制成功NJKC-101型风冷水冷一体式热管换热器（发明名称：氧化铝分解槽降温热管换热器，专利号：ZL201110210358.3），应用于氧化铝分解槽分级降温生产工艺流程中，新型热管换热器运行中不用渣浆泵，无电力损耗，只需供给循环冷却水，水压0.3Pa～0.4Pa即可，降温效果优异，运行可靠，无需维修，维护保养简易，使用寿命在6-8年以上。与板式换热器相比较，节省渣浆泵电力100%。

采用新型热管换热器为氧化铝分解槽分级降温，可为氧化铝生产企业节省大量电能和维修费用，大幅提升生产效率和经济效益。

热管换热器是通过以下技术方案来实现的：

在分解槽顶部切割长方孔，将适当数量安装支架放入，焊牢于顶部承重构架之上。在框架上安装热管换热器，热管换热器的冷却段安装循

环冷却水进水接口和出水接口。热管换热器的受热段伸入到分解槽内的料浆中，吸收热量，通过热管换热器内的工作介质蒸发上下循环将热量传导至热管换热器上部冷却段，再经与循环冷却水热交换，将热量带走排放，即实现了为分解槽内的料浆降温，通过增减冷却水流量即可控制降温幅度，达到实际工艺要求。见图1：热管受热段吸收热量，并将热量传给工质（液态），工质吸热后以沸腾与蒸发的形式转变为蒸汽，蒸汽在压差作用下上升至放热段，同时凝结成液体放出汽化潜热，热量传给放热段的冷流体（循环冷却水），冷凝液依靠重力回流到受热段。由于热管内腔抽成高度真空，所以工质极易沸腾蒸发，起动迅速热传输效率高，热管单根独立工作，无需借助外部动力，所以热管运行无动力损耗。

图2 热管换热器安装及供排水示意图

图3 热管换热器在氧化铝分解槽顶板上的安装分布

按此图可布置热管换热器210件，根据各级分解槽降温要求不同，决定安装数量（各级分解槽的安装数量在140件以上，210件以下）。

氧化铝分解槽安装应用热管换热器正常运行必备条件和维护保养要求：

1、槽顶供水主管道必须安装一台袋式滤清器，出水口安装两侧分控闸阀。定期清洗更换滤袋，可保证热管上部冷却水通道不瘀堵，冷却水畅通无阻。

2、循环冷却水蓄水池补水管道必须（前置）安装一台软水处理器（软水处理器设备投资约5万元，每小时可将30吨井水或自来水转化成软水，每天运行损耗费用约30元），可杜绝冷却水通道内产生水垢和结疤，免清洗。

3、正常给水运行时，必须每槽每班交替停供冷却水30分钟。另每槽每隔15天（错日、错时）交替停供冷却水24小时。照此操作办理，可彻底解决热管受热段（伸入料浆部分）会产生结疤的难题，可保证热管换热器长期高效运行，无需停槽清洗结疤，免维修。

南京科臣节能设备有限公司多年来专业生产热管及热管换热器节能产品及设备，积累了各行业应用热管及热管换热器产品节能降耗的丰富经验。公司可为客户设计、制造、指导安装、调试。

欢迎氧化铝企业安装试用，验证实效，缓付货款。科臣公司该产品寻求合作单位共同开发、生产经营。

Energy-saving Equipment -- Stepped Cooling Equipment for Decomposition Tank of Alumina Refinery

NJKC-101 Air-cooling and Water-cooling Integrated Heat Pipe Exchanger

Alumina refineries have always been adopting broad-flow stainless steel plate heat exchanger for many years for stepped cooling of decomposition tank, with slurry pump equipped for delivering slurry into plate heat exchanger, so as to realize cooling by heat convection with circulating cooling water. Each production line is equipped with 6 sets.

Service rating of slurry pump is 132KW per set. Each production line is equipped with 6 sets, and the consumption of electric energy is about 700 degrees per hour, 16800 degrees per day and 6132000 degrees per year as per calculation of 90% load.

As traditional cooling equipment, plate heat exchanger and slurry pump consume high energy, and are easily subjected to scab, jam and damage as well. Thus, it requires frequent maintenance and high maintenance costs.

Through many experiments, Nanjing Kechen Energy Saving Equipment Co., Ltd has successfully developed NJKC-101 Air-cooling and Water-cooling Integrated Heat Pipe Exchanger (title of invention: Cooling Heat Pipe Exchanger for Alumina Refinery Decomposition Tank, patent number: ZL201110210358.3), which is applied in production process of stepped cooling of decomposition. This new type of heat exchanger requires no slurry pump without power loss during running. It only needs circulating cooling water with hydraulic pressure of 0.3Pa～0.4Pa, then bringing you the outstanding cooling effect, reliable operation and zero maintenance. It is easy to conduct maintenance and the life span of this heat pipe exchanger is more than

6 to 8 years. Compared with plate heat exchanger, it can save 100% slurry pump electric power. As shown in figure 1, heat pipe absorbs heat by hot arc and delivers heat to working fluid (liquid). After working medium has absorbed heat, it will transform into vapor in the form of boiling and evaporation. Under the effect of differential pressure, vapor goes up to cold side and coagulates into liquid, releasing latent heat of vaporization. Then heat passes on to the cold fluid (circulating cooling water) in cold side. Condensed fluid back flows to hot side by gravity. Since the lumen of heat pipe has been pumped to high vacuum, working fluid is rather liable to boil and evaporate. With quick starting,

high-efficient heat transport and independent work of heat pipe, the running of heat pipe has no power loss without virtue of external power.

Figure 2: Diagram of Heat Pipe Exchanger Installation and Water Supply and Drainage

Figure 3: Installation of Heat Pipe Exchanger on the Top Plate of Decomposition Tank

As shown in this figure, 210 sets of heat pipe exchangers can be installed. Installation amount is decided according to different cooling requirement of all levels of decomposers (the installation amount for decomposers at all levers is more than 140 pieces but less than 210 pieces).

Heat pipe exchanger for decomposition tank in normal production operation can reach the result of being free from clean, maintenance, incrustation and scab.