ION-SELECTIVE ELECTRODE ANALYZER FOR MONITORING GASEOUS HYDROGEN CHLORIDE

摘要

An analyzer system was developed to monitor HCl in off-gases from PVC pyrolysis and combustion in laboratory burn tests. Specific requirements to be met were as follows:1. Collect and present a representative sample and quantify rate and mass of HC1 emission.2. Monitor HC1 continuously with a response time adequate to follow changes in the off gas.3. Provide sensitivity for low emission and a wide dynamic range to meet large variability in the amount of emission.4. Provide direct comparison between samples for screening purposes.5. Be able to sample from a variety of test devices.6. Require minimal attention by test operator.A scrubber was developed which would extract HCl from the smoke and other gases and provide a suitable sample to the ion-selective electrode. A signal was generated, processed and recorded which was linearly proportional to the amount of HC1 emitted as a function of time during burning. The total amount of HCl was also determined. The lower limit of detection is less than 1 ppm. The system is able to run continuously without operator attention. Performance characteristics are given along with an example of application.