A METHOD AND APPARATUS FOR TREATING A BED OF PARTICULATE MATERIAL

摘要

A description is made of a method as well as an apparatus for treating a bed (2) of particulate material which is supported by a gas distribution bottom (1) comprising a number of sections (1a), utilizing a treatment gas which via ducts (3) is conducted in sectionalized manner to and directed up through the gas distribution bottom (1) and the bed (2) of material from one or several underlying compartments (4), the flow of the treatment gas through each duct (3) being regulated by means of a flow regulator (5) provided in each duct in order to compensate, at least in part, for a changing pressure drop through the bed, each flow regulator (5) being automatically movable in direct response to the gas flow rate in the respective duct (3), where the regulation is effected continuously variably within a operational range about a datum flow rate, the regulator (5) reducing the gas passage area in the duct (3) when the flow begins to rise, and vice versa. The method and apparatus is peculiar in that an adjustable flow of treatment gas from the respective underlying compartment (4) in a section (1a) during operation of the apparatus is allowed to bypass the gas flow regulation taking place in the respective duct (3). Hereby it is obtained, that the flow rates through the respective sections of the gas distribution bottom can be changed during operation of the apparatus. This is due to the fact that the resultant flow of treatment gas to the respective section of the gas distribution bottom, besides from minor leakage gas and idle gas, consists of the sum of the treatment gas flowing through the flow regulator and the adjustable flow of treatment gas being bypassed the flow regulation. Thus, by having the opportunity during operation of the apparatus to adjust the flow of treatment gas being bypassed the flow regulation the resultant flow of treatment gas to the respective section of the gas distribution bottom can be adjusted and fine tuned during operation of the apparatus for obtaining optimum operation in terms of total pressure loss, heat recuperation etc..