高分子精密微孔过滤技术（Polymer Microporous Precise Filtration Technology）

      摘要：亚刚性高分子精密微孔过滤技术从硬件到软件是我们自主创新研发出来的一种液固精密过滤技术，从开始研发至今已有四十三年多，在工业生产上推广应用也已有三十年。本文简要介绍了该技术硬件与软件中的主要概况，并简单罗列了曾成功应用的几个生产领域，也介绍了某些主要计算及实验数据。

      Abstract: The sub-rigid polymer precise microporous filtration technology is high-performance liquid-solid precise filtration technology which is researched and developed independently by us from hardware to software. It has been more than forty-three years since the beginning of research， and it has also been applied in industrial production for thirty years. This article briefly introduces the main profile of hardware and software of the technology， and simply lists some production areass which have been successfully applied. It also introduces the main calculation and the experimental data.

      关键词：亚刚性、精密微孔过滤、滤饼过滤、澄清过滤

      Keywords: sub-rigid， precise microporous filtration， cake filtration， clarification filtration

      1. 概述（1. Overview） 廿世纪发展起来的膜过滤技术是zui重要的发明之一，它能明显地提高产品质量，收率与劳动生产率，能减少能耗、物耗与生产成本，能减少废物与废水排放，因而获得愈来愈广泛应用。廿一世纪是膜过滤技术进一步向深度与广度发展的世纪，对世界经济必将产生不可估量的影响。

      The development of membrane filtration technology which is developed in twentieth-century is one of the most important inventions. It can obviously improves the product quality， yield and labour-productivity. It can reduce energy consumption， material and production costs， and can reduce waste and wastewater discharge. So it has been widely applied. Membrane filtration technology has been further developed at the depth and width in the twenty-first century， and it will lead to an immeasurable affection on the world economy.

      膜过滤可分为均相膜过滤与非均相膜过滤两种。反渗透、纳滤与大部份超滤属均相膜过滤，微孔膜与部份超滤属非均相膜过滤。非均相膜过滤又可分为两大分支，一是其过滤介质为柔性薄膜，另一是其过滤介质为刚性或亚刚性微孔管。柔性薄膜的厚度一般只有几十微米，原料成本较少，制造难度相对较低，因此发展快，应用范围广，但其抗拉强度较差，不能用简单的物理方法（即高压气体反吹法）卸除滤饼与再生，难以应用到能得到较干滤饼的精密滤饼过滤，目前绝大部份微孔膜仅用于含固量很少的液体精密澄清过滤，只有很少部份用于无滤层的动态增稠过滤。刚性或亚刚性的微孔管，其壁厚一般不小于2至3毫米，抗拉与抗压强度相对较高，可用物理方法反吹排渣与再生，不仅可大规模用于含固量很少的液体精密澄清过滤，用于无滤层或薄层的动态增稠过滤，还大量用于含固量多，能排出较干滤饼的液体精密滤饼过滤。

      Membrane filtration can be divided into two types of homogeneous membrane filtration and non-homogeneous membrane filtration. Reverse osmosis， nanofiltration and most of ultrafiltration are homogeneous membrane filtration. Microporous membrane and some ultrafiltration are non-homogeneous membrane filtration. Non-homogeneous membrane filtration can be divided into two branches. One of its is that filter medium is flexible thin membrane， and the other is that its filter medium is rigid or sub-rigid microporous media. The thickness of flexible thin membrane is only a few dozen microns. The cost of raw materials is less， and the difficulty of manufacturing is relatively lower. So it develops rapidly and it be applied widely. But its tensile strength is poor， and we can not use simple physical method （method of high pressure gas backblowing） for cake discharging and regeneration. It is difficult to be applied for precise cake filtration which can get dry cake. The vast majority microporous membrane is only used for liquid-solid precise clarification filtration containing small quantities of solid particles， and only a few used for the dynamic thickening filtration with non-cake layer. The thickness of rigid or sub-rigid microporous tubes is generally not less than 2-3 mm. The tensile strength and compressive strength are relatively high. It can be used for cake discharging and regeneration by physical methods. It can be not only used for liquid precise clarification filtration with a little volume of solid and non-cake layer or thin-cake layer dynamic thickening filtration， but also be used for liquid precise cake filtration which has substantial amount of solid content and can discharge dry cake on a large scale.

      刚性或亚刚性微孔过滤管有金属类烧结微孔管，无机类烧结微孔管与高分子类烧结微孔管等三大类。金属类与无机类的诞生与工业上推广应用已有七十至一百多年；高分子类的诞生只有四十多年，工业化应用只有三十多年。从过滤精度，机械强度，再加工性能，抗堵塞性能，抗腐蚀性能，耐热性能及价格等几方面全面对比，三类微孔过滤管各有优劣。金属类耐热性能与机械强度相当理想，但价格与抗腐蚀性能是其劣势；无机类的耐热与抗腐蚀是优势，但机械强度与再加工性能是其劣势；高分子类的耐热性能是其劣势，目前工业生产上广泛应用的还不能超过120℃，但由于加工较易，价格较低，机械性能不差，耐腐蚀性能非常突出，虽然开发时间zui短，自上世纪六十年代末在我国试制成功，技术上愈来愈趋成熟，应用领域与应用规模愈来愈大，目前在中国，已超过金属类与无机类。

      The rigid or sub-rigid microporous filter tubes contain sintered microporous metal tubes， sintered microporous inorganic tube and sintered microporous polymer tube. From birth and industrial application of metal and inorganic， it has history of 70-100 years. From birth of polymer type there is only 40 years， and the industrial application is for only 30 years. According to comprehensive comparison of several aspects， such as filtration accuracy， mechanical strength， re-processing performance， anti-clogging performance， corrosion resistance， heat resistance and price， three types of microporous filter tubes have their own advantages and disadvantages. The heat resistance and mechanical strength of metal is quite good， but the price and corrosion resistance are its disadvantages. The heat and corrosion resistance of inorganic are its advantages， but the mechanical strength and re-processing performance are its disadvantages. The heat resistance of polymer type is its shortcoming， and at present the temperature at which it can be widely used for the industrial production can not exceed 120 ℃. Because of easier processing， lower price， not bad mechanical properties and very prominent corrosion resistance， though the development time is the shortest， it has been becoming increasingly technically grown up since the end of the sixties of the last century. The application areas and the application scale are larger and larger， and it is more than metal and inorganic types at present in China.

      为了提高过滤精度，为了能过滤更细小的微粒，又要减少过滤过程中的能耗，无论无机类、金属类或高分子类，都在研制与开发多层微孔管，这类过滤管的表层的毛细孔径很小，基层的毛细孔径较大，基层与表层紧密粘结，表层可承受高压气体反吹。多层无机类的无机膜技术国外发展很快，国内也广泛进行很有成效开发，金属类与高分子类的多层微孔管的研制较晚，但进展也很快，都已开发出可在工业生产上成功应用的产品。

      In order to improve filtration accuracy， to catch smaller particles efficiently， and to reduce energy consumption in the process of filtration， the inorganic， metal and polymer type have been researching and developing multi-layer microporous tube. The surface pore diameter of such filtering tube is very small and the pore diameter of the base body is larger. The base level is bonding closely with the surface， and the surface can withstand the backblowing of high-pressure gas. The multilayer inorganic membrane technology has been developed rapidly abroad， and domestic multilayer inorganic membrane technology is also highly successful in extensive development. The multi-layer microporous tube of metal and polymer type is developed late， but the progress is also very fast. All of them have developed the products which have successful application in industrial production.

      作者从1966年初开始在国内从事高分子类精密微孔过滤技术的研制，在多种高分子烧结微孔过滤管及各种结构过滤机研制成功的基础上，对该技术的硬件与软件进行了连续四十三年的系统研制、开发与推广应用。限于篇幅，本文仅介绍该技术某些主要概况。

      The author has started to engage in the development of polymer precise microporous filtration technology since early 1966 in domestic. Based on a variety of polymer sintered microporous filter tubes and many structures of filters which have been successfully developed， the hardware and software of the technology have achieved system development， popularization and application for consecutive 43 years. Due to space limitations， this article only introduces some of the main overviews of the technology.

      （作者单位：上海东瓯微孔过滤技术研究所）