(212b) L-Valve Operation Under High Temperature Conditions

The L-Valve as a solids flow control device has been used extensively in fluidized beds and circulating fluidized beds for solids recycling. Despite extensive research on the experimental characterization and correlative equations conducted under cold flow conditions, reports for the operation of the L-Valve under high temperature condition which are the normal practice in the industry are very rare. This paper presents an experimental study on the characterization of the L-Valve operation under high temperature condition. The tests were performed in a circulating fluidized bed system with various solids flow rates and temperatures. The relationships among the solids flow rate, aeration rate and pressure drop were investigated and compared with those under cold condition. It is found that a linear relationship between aeration gas flow rate and solids flow rate still holds with different coefficients than those under cold flow model. Some potential factors, such as agglomeration and sintering, which may cause the malfunction of the L-Valve under high temperature conditions, are also discussed.