Apparatus and method for accurately metering and conveying dry powder or granular materials to a blender in a substantially closed system

An apparatus for accurately metering and conveying a dry powder or granular material comprising:

• means for storing the dry powder or granular material;
• means for metering the dry powder or granular material out of the storing means at a substantially uniform density;
• and
• means for supplying the metering means with the dry powder or granular material at a bulk rate that exceeds the rate at which the metering means conveys the dry powder or granular material and in a substantially enclosed environment.

A method of accurately metering and conveying a dry powder or granular material comprising the steps of:

• storing the dry powder or granular material in a storage tank;
• metering dry powder or granular material out of the storage tank at a substantially uniform density with a metering feeder;
• and
• supplying the metering feeder with dry powder or granular material at a bulk rate that exceeds the rate at which the metering feeder conveys the dry powder or granular material and in a substantially enclosed environment.