板式预热器在制盐工程中的应用

在我国制盐行业面临着整合和改革的背景下,制盐工程逐步向"自动化、智能化"方向发展.MVR热压制盐和多效真空制盐渐渐成为两种技术发展趋势,而卤水预热工艺是制盐工程中不可或缺的一环,占有重要位置.板式换热器是卤水预热流程的主要设备,其具有传热效率高、占地面积小等优点,在制盐行业中广泛应用.     

北大池盐湖卤水析盐规律的研究

文章以相图理论为依据,对北大池盐湖卤水常温蒸发及低温-5℃冷冻过程的析盐规律做了定性和定量分析,通过分析得到:北大池盐湖的湖表卤水综合利用工艺为先常温日晒制盐,制盐母液再自然冷冻提取水硝,而晶间卤水则应先自然冷冻提取水硝,再日晒制盐.其目的是为北大池盐湖卤水的综合开发利用,确定最佳的工艺流程和工艺参数提供理论基础.     

浅析一种岩盐卤水的处理工艺

文章提供了一个制盐行业卤水净化工艺.通过加入适量的絮凝剂与助凝剂两种药品来将卤水中带电荷的微小物质结合起来,帮助其快速沉降到道尔型沉降器底部.道尔型沉降器溢流出的清液中悬浮着极少量的不易沉降的微小颗粒,然后通过气浮装置将这些微小颗粒除去,为MVR制盐提供了优质的卤水,从根本上解决了无机杂质、有机物影响盐品质量、设备长周...     

真空制盐节能试验 卤水分效预热技术总结

为了进一步降低制盐能耗,达到或接近世界先进的制盐蒸发热经济(3.0)水平,我所在舒平盐厂3万吨/年真空制盐装置上,重点进行了卤水预热工艺、设备及防垢等工业性试验考察。     

"久大杯"第十六届全国井矿盐学术研讨会优秀学术论文评选结果

1.干式法双位加碘工艺在30万吨/年制盐生产上的研究应用万贞华2.高品位芒硝型卤水真空制盐工艺保证盐质的探讨李明星等3.旋转闪蒸干燥技术在盐化工生产中的应用栾昊4.制盐净化卤水的盐泥过滤技术探讨余少廷等5.蒸发罐设计及大型开发之我见黄健农6.卤水净化方案的优化曾琼等7.真空制盐工业压力容器材料改代综合分析法及应用华以进8.“杂项”光度法测定无水硝中SO42-含量张桂香等9.内热式流化床在设计制造中应注意的问题高暮春等10.我厂对延长Ⅲ效系统蒸发装置生产周期的改进陈菲11.制盐企业采用变频调速实现节能降耗的探讨与实践龚炳林12.金…     

制盐装置蒸发过程分析

采用白箱模型对１０万吨／年多效蒸发真空制盐装置的蒸发过程进行了分析。结果表明，损主要集中在加热室、卤水进蒸发罐时的混合过程以及卤水的沸腾。进料卤水与罐中卤水的混合损也不可忽视。     

卤水在不同温度下粘度的测定

卤水的物理参数如:沸点、比热、表面张力、粘度、导电率……是制盐工艺设计和科研、试验不可缺少的数据。对四川省自贡市长山盐矿人工岩盐卤水的粘度进行了测定,其卤水.浓度为:24.3~DBe',比重1.2025。其主要成份如表1所示。     

精心操作衬里蒸发罐延长刷罐周期

湖北省化工厂盐厂制盐车间第三组15万吨/年真空制盐装置于1988年4月试车投产。该装置Ⅰ、Ⅱ效为BFe30—1—1/A3衬里,Ⅲ、Ⅳ效为00Cr17Ni14M03/A衬里,复合层均厚2mm。原设计为净化卤水进罐,并安装有喷淋刷罐管线,刷罐周期为15天/次。由于卤水未经净化入罐,故制盐车间原有的第一组15万吨/年和第二组12万吨/年制盐装置的刷罐周期都是5天。     

制盐装置蒸发过程的Yong分析

采用白箱模型对１０万吨．年多效蒸发真空制盐装置的蒸发过程进行了Ｙｏｎｇ分析。结果表明，Ｙｏｎｇ损主要集中在加热室、卤水进蒸发罐时的混合过程以及卤水的沸腾，进料卤水罐中卤水的混合Ｙｏｎｇ损也不可忽视。     

多效改MVR制盐技术在四川久大舒平“煤改电”中应用浅谈

本文介绍了多效真空蒸发制盐改造为MVR蒸发制盐在四川久大制盐有限责任公司舒坪基地60万吨/年制盐装置MVR“煤改电”技改项目成功运用情况，同时全面对卤水成分、多效改造成MVR工艺、预热系统、蒸汽洗涤压缩等技术以及生产运行情况进行了介绍。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Chlorohydrins of bisphenol A diglycidyl ether (BADGE) and of bisphenol F diglycidyl ether (BFDGE) in canned foods and ready-to-drink coffees from the Japanese market

BADGE.2HCl and BFDGE.2HCl were determined in 28 samples of ready-to-drink canned coffee and 18 samples of canned vegetables (10 corn, 5 tomatoes and 3 others), all from the Japanese market. HPLC was used as the principal analytical method and GCMS for confirmation of relevant LC fractions. BADGE.2HCl was found to be present in one canned coffee and five samples of corn, BFDGE.2HCl in four samples of canned tomatoes and in one canned corn. No sample was found which exceeded the 1mg/kg limit of the EU for the BADGE chlorohydrins. However the highest concentration was found for the sum of BFDGE.2HCl and BFDGE.HCl.H₂O at a level of 1.5mg/kg. A Beilstein test confirmed that all cans containing foods contaminated with BADGE.2HCl or BFDGE.2HCl had at lest one part coated with a PVC organosol.     

European priorities for research to support legislation in the area of food contact materials and articles

A strong science base is required to underpin the planning and decision-making process involved in determining future European community legislation on materials and articles in contact with food. Significant progress has been made in the past 5 years in European funded work in this area, with many developments contributing to a much better understanding of the migration process, and better and simpler approaches to food control. In this paper this progress is reviewed against previously identified work-areas (identified in 1994) and conclusions are reached about future requirements for R&D to support legislation on food contact materials and articles over the next 5 or so years.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the