间歇式煤气工业炉窑的设计

本文介绍一种简单间歇室式煤气工业炉窑的结构特点及其参数的确定，其炉膛温度为６００－８００℃。     

Vaporisation coulometric Karl Fischer titration: A perfect tool for water content determination of difficult matrix reference materials

Volumetric Karl Fischer titration (V-KFT) is the reference method to determine the water content in a whole range of organic and inorganic matrices. The method has several important drawbacks e.g. a high solvent consumption and a rather large measurement uncertainty when determining the water content in reference and candidate reference materials containing starch (e.g. maize, toasted bread, etc.). It is also labour intensive for routine measurements. In order to overcome these disadvantages, a relatively new method of coulometric Karl Fischer titration, equipped with a fully automated oven system, has been established and optimised.     

Study on pentaerythritol–zinc as a novel thermal stabilizer for rigid poly(vinyl chloride)

Pentaerythritol–zinc (penzinc) was prepared by a solid‐phase reaction technique. The principal volatile products of the reaction between pentaerythritol and ZnO were analyzed with a coupled thermogravimetry—mass spectrometery system. The results indicated that a large amount of water was formed at the reaction temperature. Scanning electron microscopy (SEM) results showed the appearance of penzinc as flaky particles. Accordingly, the penzinc obtained through the dehydration between pentaerythritol and ZnO is likely to be a monopentaerythritol complex, such as zinc monoglycerolate. The thermal stability of poly(vinyl chloride) (PVC) with penzinc as a thermal stabilizer was investigated by a Congo Red test, Oven aging test and thermal gravimetric analysis (TGA). The Congo Red test showed the thermal stability time of PVC with penzinc was 38 min, longer than those with commercial thermal stabilizers. TGA indicated that the penzinc had little impact on the thermal degradation of PVC, but could increase the mass of residues. Oven aging test showed that the penzinc could significantly retard the discoloration during the long‐term decomposition of PVC. Meanwhile, no “zinc burning” was observed in the PVC with penzinc. These results indicate that the penzinc is an excellent thermal stabilizer for rigid PVC. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Effects of Drying Methods on the Release Kinetics of Vitamin B12 in Calcium Alginate Beads

The aim of this article was to investigate the morphology, swelling properties, and respective drug release kinetics of vitamin B₁₂–loaded calcium alginate beads prepared by oven (air), vacuum, and freeze drying. The initial particle size was 1 mm. The mean bead sizes of dried Ca-alginate beads were 0.7, 0.8, and 0.9 mm for oven-, vacuum-, and freeze-dried beads, respectively. The surface morphology of the dried beads was affected by the different drying methods applied. Oven- and vacuum-dried beads shrank in size, and more cracks appeared on the surface of oven-dried beads. Freeze-dried beads almost retained the same size prior to drying; however, the surface was rougher and highly porous. The swelling profiles were also affected by the drying methods, whereby freeze-dried beads showed the fastest solvent uptake at the start of the experiment. The release data of the dried Ca-alginate beads were treated with first-order, Higuchi, Korsmeyer, and Peppas kinetic models. The data for oven and vacuum seemed to follow a combination of diffusion and swelling controlled release, whereas data from freeze-dried beads seemed to follow more diffusion-dominated controlled release.     

Can the water content of dairy products be determined accurately by microwave drying?

 Oven drying is the most frequently used moisture determination method. To obtain results faster than heating by convection in classic drying ovens, more rapid heating techniques are used. One of these is drying by microwaves. The result of all drying methods is mass loss under the conditions applied. Only in a few cases does the mass lost correspond exactly to the water content. Mass loss is caused by the evaporation of all volatile matter during the drying process, i.e. not only by the loss of water. Foodstuffs in particular risk decomposition reactions and the formation of volatile substances at higher temperatures. The results of drying processes depend on the drying parameters and are variable, whereas the water content is a specific property of the sample. If the water content is to be determined accurately by a drying process, the drying parameters must be adjusted in a way that the results equal those obtained by a specific method, e.g. the Karl Fischer titration. The dependence on the drying parameters varies for different products. In many cases the levels of a set of parameters can be determined so that the mass lost equals the analysed water content; in other situations a differing but reproducible result can be multiplied by a constant factor to give the reference value. This study shows that, for some dairy products, the water contents found by microwave drying are very close to those determined by Karl Fischer titration. Received: 26 May 1998     

推焦车定位和推焦数据管理

提出基于推焦车的炉号识别技术和无线通讯技术,结合昆钢焦化厂实际的生产水平和操作计划,实现对推焦数据的操作管理。     

马钢新区7.63m 焦炉配套干熄焦存在的问题及其对策

干法熄焦的焦炭质量指标优于湿法熄焦的焦炭,通过增建干熄焦,提高焦炭干熄率对实现马钢新区大高炉稳定生产意义重大,且具有明显的经济和环保效益。     

Influence of the correction for moisture/water content on the quality of the certification of cadmium,copper and lead mass fractions in rice

The moisture/water content of rice sample was determined by means of three different methods: oven drying, Karl Fischer titration and thermogravimetry. These results were applied for the certification of the Cd, Cu and Pb mass fractions by isotope dilution mass spectrometry, IDMS, in this rice material.     

多功能烧烤微波炉

介绍了多功能烧烤微波炉的硬软件结构及其工作原理     

焦炉长结焦时间状态下的管理与维护

在焦炉不能维持正常生产时,一般采用延长结焦时间的方法降低生产能力.介绍了焦炉在长结焦时间状态下,从规范出炉操作入手,做好炉温调控、压力调控、炉体维护等工作.分析了焦炉长结焦时间状态下的控制措施与控制经验,对K均、K安、炼焦耗热量等工艺指标及炭化室高向加热等问题提出了建议.