離心機(jī)主要應(yīng)用于無機(jī)化工、有機(jī)化工、石油、制藥及藥品中間體、化學(xué)肥料、農(nóng)藥、染料、食品及添加劑等行業(yè)。通過強(qiáng)大的過濾壓力--離心力,實(shí)現(xiàn)固液混合物的分離,同時(shí)可實(shí)現(xiàn)對分離產(chǎn)品的提純(洗滌),因此,在諸多行業(yè)中得到了廣泛的應(yīng)用。
離心機(jī)適用性選擇因素:
1)所分離的類型:液、固(介質(zhì)腐蝕特性、防爆特性)
2)顆粒尺寸(粒徑分布)、形狀和密度
3)固相密度、料液的相對密度
4)沉降速度
5)流量
6)粘度
7)溫度
8)PH值
9)產(chǎn)量
10)洗滌要求
11)GMP要求
...
固相顆粒大小、沉降速度和混合物濃度是主要的適用性衡量指標(biāo)。除了上述的物料理化特性,還有諸如洗滌要求、液相含固率指標(biāo)、濾餅含濕率指標(biāo)等也是在選擇應(yīng)用時(shí)需要考慮的因素。
在選擇分離工藝時(shí),首先是從過濾、沉降或沉降+過濾方式中選擇最適宜的技術(shù)。通常,沉降方法比過濾方法更為經(jīng)濟(jì),特別是那些涉及大處理量、連續(xù)液體流的情形,沉降分離更為適宜。
Selection technologyof centrifuge
The centrifuge is mainly applied in field of nonorganic chemical, organic chemical, petroleum,pharmaceutical and intermediates, chemical fertilizer, farm chemical,dye, food and additives. With its centrifugal force, the powerful filtering pressure, the centrifuge is applicable for separation of solid/liquid mixture and purifying(rinsing)products out of the separation process and therefore widely applied in many industries.
Whether a centrifuge is applicable is determined by following factors:
1) Type of separation to be undertaken, liquid or solid(medium corrosive or explosion-proof?)
2) Size, shape and density of particles(size distribution)
3) Density of the solid content and relative density of the liquid content
4) Sedimentation rate
5) Sedimentation rate
6) Dynamic viscosity
7) Temperature
8) PH value
9) Throughput
10) Washing requirement
11) GMP requirement
...
Among which,size of solid particle,sedimentation rate and concentration of the mixture are three major index for determining applicability/serviceability of the unit.In addition to physical and chemical properties abovementioned,factors/index including washing requirement, solid content rate of the Iiquid phase, moisture content of the filtering cake and other factors also need to be considered while determining application/serviceability of the unit.
To define a most applicable separation process, the most suitable technoIogy to be applied shall be selected from three options, i.e.filtration, sedimentation or sedimentation plus filtration. Sedimentation option is more economic than the filtration option and it’s especially suitable in case of bulk amount of treatment and continuous flow of liquid.
濾布選用
過濾過程中,由其表面或內(nèi)部留住固體粒子的任何有滲透性的材料,稱為過濾介質(zhì)。過濾介質(zhì)對過濾的效率、有效性往往起著決定性的作用。
過濾介質(zhì)的主要作用是用最少的能量消耗將固體微粒從流動(dòng)的液體中分離出來。
成功的過濾過程很大程度上取決于選擇合適的過濾介質(zhì)。通過研究與經(jīng)驗(yàn)積累,在過濾介質(zhì)的性能和選擇方面有大量的技術(shù)信息可以參考,但過濾介質(zhì)的選擇還是在依靠對固液混合物的一些實(shí)驗(yàn)來選擇,這些實(shí)驗(yàn)操作要非常仔細(xì),實(shí)驗(yàn)工藝中很小的變化可能對結(jié)果產(chǎn)生很大的影響。
由于過濾介質(zhì)的多樣性造成選擇過濾介質(zhì)的工作很困難,僅依靠粒徑測定和分布很難確定哪一種過濾介質(zhì)最適合該分離操作。顆粒濃度和形狀的改變也會(huì)給實(shí)際應(yīng)用帶來困難。
聚合材料制造的編織濾布和非編織建布:聚丙烯、聚乙烯、聚醋、聚酰胺、聚氯乙烯等。
單絲雙層復(fù)合濾布:過濾介質(zhì)是雙面的,緞紋織法織出用于過濾的光滑表面,表面可經(jīng)砑光處理得到進(jìn)一步改善,較粗的單絲編織的下層有較好的強(qiáng)度起到支撐的作用并有助于排液,微粒在穿透過濾面后不會(huì)被濾布截留而是順著支撐層內(nèi)部的漏斗狀孔道流出,而不至于卡在濾布中形成堵塞,也有助于濾布再生。
對于大顆粒固相,可選用金屬燒結(jié)網(wǎng)或席形網(wǎng)作為過濾介質(zhì),以達(dá)到更高的過濾效率。
Selection of filtering
Filtration medium, which could be any permeable material that retains solid particle on its surface or inside of it in filtration process, determines effectiveness and validity of filtration process.
Main function of the filtration medium is to separate the solid particles out from the flowing Iiquid by consuming minimum energy.
Effective filtration, to a Iarge extent,depends on proper selection of applicable filtration medium, the customer may refer to those technical specification and information as results of research efforts and experience of the industry concerning performance and selection of filtration medium, however, to select the filtration medium, relevant experiments and tests shall be conducted to the solid and liquid mixture to be separated extremely carefully as a tiny change in process of experiments/tests might bring major impact to the results.
Diversity of the fiItration medium makes it a hard job to select the proper applicable one, you can hardly define which filtration medium is the most applicable for the specific separation operation simply by referring to its particle size and size distribution, in fact, change of partiele coneentration and shapes will make your decision of filtration medium harder.
Woven filter cloth and non一woven filter cloth made of polymeric material: Polypropylene,polyethylene, polyester, polyamide, polyvinyl chloride and others.
Single wire double-layer composite filter eloth:It’s a double-layer filtering medium, with satin weave texture on smooth surface of the top layer,such smooth surface may bo subject to matting treatment for improvement. The bottom Iayer is made of single wire woven cloth of higher strength which is supportive and helpful for discharging. Particles penetrating or passing through the top layer would not be retained there resulting in clogging, instead, it will flow down along the funnel in between the top Iayer and bottom supportive layer, which is good for regeneration of filtering cloth.
Metal net or mat sheet could be selected as filtering medium for large particle solid to achieve higher filtering efficiency.