Changes in dust resistivity from optimum values to extreme values can change the collection efficiency of ESPs dramatically. Therefore ESP sizing and performance evaluation must always include resistivity as a primary factor. A typical dust resistivity analysis is shown on Figure 1. Resistivity plots of this type are used as a standard engineering design “tool” in the ESP industry.
Since resistivity is such an important factor in ESP design and performance evaluation, Lodge-Cottrell operates our own laboratory facility to measure resistivity. This laboratory equipment and test personnel have been in service for more than 30 years. Our equipment can handle one to four dust samples simultaneously, while varying gas temperature and moisture content. This gives us the capability to process a large number of dust samples in a relatively short period of time, as opposed to laboratory equipment that might test only one sample at a time.