ABSTRACT
This chapter discusses the methods for measurements of powder flow rate by classifying them into six groups: weighing method, flowmeters based on mechanics, differential pressure method, electrical method, statistical method, and others. It also discusses two types of powder flow. One is bulk solids flow, and the other is suspension flow as in the pneumatic transport of pulverized coal. The weighing method is the most reliable and accurate for measurement of the powder flow rate in bulk solids flow. The differential pressure method has the advantage that the electric parts of the flowmeter can be isolated from the main process. The electrical phenomena utilized in the measurement of powder flow rate are electrostatic charging, piezoelectric effect, the electric capacitance increase by particles, and microwave resonance. The statistical method is truly obstructionless and is preferable for the process instrumentation. Flow detector is the powder flowmeter, which only gives data on whether or not the powder flows.
