Polysilicon – is there anyone who does analysis work? Let’s exchange ideas.
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This post was last edited by wangli115 on 2011-11-9 at 08:11. Let’s exchange ideas regarding analysis – I work in online analysis; in various workshops such as distillation, reduction, thermal hydrogenation, and exhaust gas recovery, there are Siemens process gas chromatography instruments used to analyze the composition of the substances in various process pipelines. Personally, I think the analysis is quite accurate; the main issue is that maintenance is complicated. However, it’s much more accurate than manual sampling followed by gas chromatography analysis. When sampling manually using the drain valve, the material isn’t fully replaced, so the accuracy of the data is very low. Even though there are significant changes in the process, their analyses show no fluctuations at all, which makes it impossible to use such results as a reference for the process. The workers in our factory only need the data obtained from manual sampling and chromatographic analysis; we hardly rely on online chromatography at all. Moreover, only simple data analyses are carried out regularly, and there is very little communication among the technical department, the production workshop, and the quality analysis team. How can we improve the output and quality of our products? . . . .
Online process analysis: Generally, offline laboratory gas chromatographs are used for this purpose; samples have to be taken to the laboratory, which inevitably leads to contamination of the samples due to exposure to air. Moreover, long sampling intervals result in delays in the analysis results. Siemens process analyzers have extensive and reliable experience in the use of chlorosilanes, and they have developed a solution based on process gas chromatography, utilizing the MAXUM II online chromatograph along with a specific sample preprocessing system. Continuous sampling and continuous analysis are carried out within a sealed system; this eliminates the need to disconnect and reconnect the sampling cylinders. The samples are not exposed to the atmosphere, which prevents contamination risks and **increases the sampling frequency**. Siemens has installed over 100 sets of such systems for online chlorosilane analysis.
Turnkey measurement solution: This solution was developed based on years of experience in silane analysis. From sample extraction and sample preprocessing to the analyzer and mounting structure, all components form a closely integrated measurement system. Continuous measurement, unlike the intermittent sampling analysis in laboratories, is free from human interference, allowing the reproducibility and stability of analytical data to be maintained over long periods of time. Accurate, fast, and reliable measurements • A special sample preprocessing system that has been proven effective in countless installations around the world • All components that come into contact with the samples are made of non-corrosive materials • No valve stems, along with a highly sensitive detector, resulting in excellent analytical performance. Direct process control capability • Process optimization is achieved through closed-loop control • Automatic control of the sample preprocessing unit is possible via flow path switching and automatic calibration. On-site installation • The MAXUM II is certified for use in hazardous areas (ATEX, CSA, NEC, NEPSI) • The MAXUM II can operate within a temperature range of -18ºC to +50ºC. An analysis cabin without doors is not needed; a cabinet is sufficient. • The MAXUM II is installed near the sampling point: this reduces the length of the pipes, thereby lowering the installation costs ； The fast loop is short, so the analysis is quick. Advanced control and communication capabilities • Direct connection to DCS • Integration into communication networks (Modbus, Ethernet TCP/IP) • Remote access and maintenance • Easy networking with other analyzers via hubs and gateways • Compatible with SIMATIC Scalance components Customer benefits • Cost reduction and increased output through the use of process analyzers • Process control and optimization using data from online measurements • Effective improvement in operational efficiency and consistent product quality • Real-time monitoring of the process to ensure safe production
Do you also use it online for distillation? How much investment is needed?
Reply to 4# bluetear2008: It is indeed used. There are three units per distillation line, one each at the TCS and STC separation towers, as well as at the TCS purification tower and the STC purification tower; several sampling points are available at each of these locations to analyze the composition of the fluids within the respective pipes.