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自然循环自动清洗式高效节能蒸发器的核心理论研究 总被引:1,自引:0,他引:1
严重影响现有蒸发器效益的焦点是高能耗的强制循环泵和加热面盐垢的周期性停车清洗。自然循环自动清洗式蒸发器能够满意地解决这两个问题 ,为企业创造相当可观的效益。以动力温度概念和不平衡汽化过程机理为基础的自然循环推动力理论研究 ,不仅得到有很大意义的计算模型 ,并且给出了自然循环推动力有效强化的思路 :设计较大截面、足够深度、出口部呈渐扩形的沸腾室来提高汽化的平衡度、降低出口动能损失 ;必须采用安装有像螺旋齿带那样能够低流速下自转、高效强化传热、较低流体阻力的自动清洗元件的短管加热室 ,以便增大动力温度 ,又使自然循环总阻力较低。按此动力学理论设计的自然循环自动清洗式蒸发器顺利地获得中试成功。 相似文献
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多家使用蒸发器表明,结垢尤其是蒸发器壳程管束结垢会导致蒸发器生产能力缓慢下降,用户难以发现。目前蒸发器壳程大多数没有留清洗口,用户难以查明原因,清洗壳程困难。壳程经过清洗后,生产能力恢复正常,表明壳程管柬外壁结垢阻碍传热,从而使蒸发器生产能力下降。 相似文献
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制盐蒸发器高速自然循环推动力模拟试验 总被引:1,自引:0,他引:1
自然循环自动清洗技术是解决制盐蒸发器垢问题最理想的方案,关键在于能否产生足够大的自然循环推动力。为此进行了自然循环推动力的冷模试验,由试验数据分析推算表明,蒸发循环液经过加热室后只要上升3℃以上,就可以形成1000pa以上的自然循环推动力,使加热管内的自然循环流速达到1.0m/s以上,满足带动塑料纽带自转清洗的要求。并且,蒸发压力愈高,自然循环取代强制循环的难度就愈小。 相似文献
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盐蒸发器加热管结晶盐自动清洗技术研究 总被引:18,自引:1,他引:17
文章论述了盐蒸发器加热管内结晶盐对能耗成本问题的重要性,对现有自动清洗技术作了简评。重点介绍了自转纽带自动清洗技术,其结构原理是直接利用蒸发溶液的循环流动能带动纽带旋转清洗,其清洗能力根据结晶动力学原理进行模拟考核,试验结果表明:自转纽带自动清洗技术能够满足蒸发器的自动清盐要求,可以在蒸发生产中广泛应用,达到长期连续生产的目的,具有显著的技术经济优势。 相似文献
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为了解决我车间蒸发器和其它管道结垢清洗问题,85年5月我们购置了一台CM—2型高压清洗泵,经过一段时间的使用证明,该设备对清洗蒸发器内的管道结垢和碱回收车间易产生结垢的黑液、绿液和白泥等管道有很好的效果。一、清洗蒸发器管道的情况 CM—2型清洗机,压力为300公斤/厘米~2,流量55升/秒,我们先后用这台泵清洗了两列五效长管升膜蒸发器管道各2次,其中两次是经酸洗后,再用清洗机清洗的,另两次是不经酸洗,直接用高压枪冲洗,两种清洗情况的效果都令人满意。经酸洗后进行高压水清洗,由于管垢与酸反应, 相似文献
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不同压力下的自然循环自动清洗蒸发器技术实验 总被引:1,自引:1,他引:1
自然循环自动清洗式蒸发器的综合效益相当高.其中的结晶垢自动清洗研究比较充分,技术也比较成熟,产生足够的自然循环推动力成为关键,并且与蒸发压力密切相关.为此研究它的蒸发压力适应性问题.得到的结果是,常压蒸发和加压蒸发中影响自然循环推动力大小的主要因素是汽化深度,分别在20℃、25℃以上的传热温差下,都可以达到带动长管加热室、光滑扭带自动清洗需要的11kPa以上,并且加压蒸发更有优势;真空蒸发中汽化深度和出口动能损失两者的影响都大,因此难以形成大的自然循环推动力,则需要采用旋流冲推齿形扭带自动清洗的短管加热室结构.该技术适用于国内普遍采用的0.6MPa加热蒸汽源的三效蒸发工艺. 相似文献
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In the studies of fouling and cleaning of heat exchange surfaces in dairy plants, whey protein deposits and heat induced whey protein gels (HIWPG) are considered as suitable model material to simulate the proteinaceous based type “A” milk fouling. Protein concentration of the fouling solution may significantly influence the formation of milk deposits on heat exchange surfaces, hence affecting the cleaning efficiency. In this study, a laboratory produced heat induced whey protein gels (HIWPG) and a pilot plant heat exchanger fouling/cleaning were used to investigate the effect of protein concentration on formation and cleaning of dairy fouling. Here, HIWPGs made from different protein concentrations were formed in capsules and then dissolved in aqueous sodium hydroxide (0.5 wt%). The dissolution rate calculation based on the UV spectrophotometer analysis. In the pilot-scale plant study, whey protein fouling deposits were formed by recirculating whey protein solutions with different concentrations through the heat exchange section in different runs, respectively. The deposit layers were then removed by recirculating aqueous sodium hydroxide (0.5 wt%) and the cleaning efficiency was monitored in the form of the recovery of heat transfer coefficient while both fluid electric conductivity and turbidity were monitored as indications of cleaning completion. It was found that increasing the protein concentration of the HIWPG significantly increased the gel hardness and the dissolution time. In addition, increasing the protein concentration significantly increased both, the amount of the fouling on the pilot-scale plant and the time required to clean the fouling deposit. 相似文献
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内循环流态化换热器的应用效益相当高,但是还不够完善,较长时期运行后可能发生流态化底室筛板部分筛孔堵塞和出口室沙子跑失的问题。中重点研讨了采用泡罩板取代筛板解决堵塞问题后出现的均匀性问题,多方案优化的结果是采用较大直径的泡罩,并且加装一块大孔均布板,以满足稳定运行的要求。研制成功的传热管管口档罩,不仅具有防止粒子跑失的功能,而且还具有一定的流速调匀作用和防止低流速管创新粒子倒流的稳定功能。 相似文献
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Fouling is the deposition of milk solids on heat transfer surfaces, particularly heat exchangers. It is a major industrial problem, which causes a decrease in heat transfer efficiency and shortens run times. The resultant effect is a decrease in process efficiency and economy. For studying and monitoring deposit formation, suitable fouling detectors or methods of measuring the deposit are required. This can be achieved through direct means, whereby the deposit is analyzed after a certain time, or indirectly through instrumentation for monitoring parameters such as temperature, pressure, flow rate, overall heat transfer coefficient, heat flux, and other physical properties. This article reviews the various reported fouling detection methods. 相似文献
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《Food Reviews International》2013,29(3):267-293
Fouling is the deposition of milk solids on heat transfer surfaces, particularly heat exchangers. It is a major industrial problem, which causes a decrease in heat transfer efficiency and shortens run times. The resultant effect is a decrease in process efficiency and economy. For studying and monitoring deposit formation, suitable fouling detectors or methods of measuring the deposit are required. This can be achieved through direct means, whereby the deposit is analyzed after a certain time, or indirectly through instrumentation for monitoring parameters such as temperature, pressure, flow rate, overall heat transfer coefficient, heat flux, and other physical properties. This article reviews the various reported fouling detection methods. 相似文献
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外螺旋塑料管自动清洗及其传热强化技术的研究 总被引:3,自引:0,他引:3
研究的外螺旋塑料管由自动清洗与传热强化需要的塑料外螺旋和刚性固定塑料外螺旋的塑料管组成,塑料管内可以填装液体或其它滚动体,使整体密度与管程液体相同,保持悬浮同心旋转,且利用其运动惯性提高自动清洗功效。组装在传热管内后,管程液体被导流成快速的螺旋线液流,螺旋线液流给外螺旋塑料管的反作用力使其自转清洗,且使管内的对流传热得到有效强化。通过理论计算研究,得到了外螺旋塑料管动力矩计算式,按此得到结构设计的基本原则。试验结果表明:自转动力矩比扭带增大141%,能够在04m/s以上的流速下实现自动清洗防垢;传热系数比光滑扭带平均提高50%左右;设备的流体阻力不大,在工程容许范围内。 相似文献
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