New technique for electrostatic charge measurement in gas–solid fluidized beds

Electrostatic charge generation within gas–solid fluidized bed reactors has been a concern to industry for many years. Over the years, numerous methods for measuring this phenomenon within a fluidization column have been proposed. This paper focuses on the design of a new method that minimizes effects such as extra charging due to particle handling and bed hydrodynamic disruption due to the location of the measurement device. In addition, the new method provides the bulk charge of the bed particles rather than a local measurement. The device is flexible and can be adapted to a range of fluidization columns. The new method developed consisted of a Faraday cup placed within the windbox of a fluidization column. The distributor plate was designed in such a way that it can be automatically opened to drop the charged fluidizing particles into the Faraday cup below. The new measurement technique was validated by conducting fluidization experiments in a system consisting of a 0.10 m in diameter carbon steel column with glass beads as the fluidizing particles. The technique was proven to be suitable for measuring the total net electrostatic charges in gas–solid fluidized beds.