2003 Volume 82 Issue 8 Pages 588-593
A speady, simple and accurate method of characterizing Coal Water Paste (CWP) fluidity has been developed. Pressurized fluidized bed combustion (PFBC) technology has developed for utility applications to generate power. One of the problems concerned with the PFBC is stable feeding of coal to the pressur-ized fluidized bed. There are two types of feeding method, wet and dry.
The wet feeding method makes coal dryer system eliminated, promotes the reliability of feeding and attains a uniform temperature profile through the bed height because of the wide-spreaded dispersion of CWP in the fluidized bed.
The water content of CWP has to be as low as possible to have appreciable economics over dry feed-ing. A lower water content without addition of surfactant causes CWP to exhibit higher viscosity than CWM. Given this, main subjects of the wet feeding process are preparation of CWP with lower water content, pumping CWP without seperation of water from CWP.
In this study, torque in stirring CWP is measured using pin-type rotor. Accuracy of the proposed method has been obviously improved than the cylinder-type viscometer. Measurement error is within 5%. And this method gives simple way to evaluate the minimum water content and suitable size distribu-tion modulus of coal particles in CWP.