Patent EA-000229-B1 (EA)
Title: Method and apparatus for treating a bed of particulate material
Inventor: FONS MOGENS JUHL
IPC: F26B3/08
Filed: 1996-07-05
Abstract: 1. A method for treating a bed (6; 78) of particulate material which is supported by a gas distribution bottom (9; 75), utilizing a treatment gas which via ducts (19; 35; 77) is conducted in sectionalized manner to and directed up through the gas distribution bottom and the bed of material from one or several underlying compartments (15; 76); the flow of the treatment gas through each duct (19; 35; 77) being regulated by means of a flow regulator (21) provided in each duct in order to compensate, at least in part, for a changing pressure drop through the bed; and each flow regulator being automatically movable in direct response to the gas flow rate in the respective duct; characterised in that the regulation is effected continuously variably within an operational range about a datum flow rate; the regulator reducing the gas passage area in the duct when the gas flow begins to rise, and vice versa. 2. A method according to Claim 1, wherein the gas flow through each duct (19; 35; 77) is regulated so that within an operational range, the gas flow does not decrease or increase as the pressure drops across the superjacent part of the bed increases or decreases, respectively. 3. A method according to Claim 1, wherein the gas flow through each duct (19; 35; 77) is regulated so that it increases or decreases as the pressure drop across the superjacent part of the bed increases or decreases, respectively. 4. A method according to Claim 1, wherein the gas flow through each duct (19; 35; 77) is regulated so that it is maintained substantially constant at any pressure drop occurring across the superjacent part of the bed. 5. A method according to any one of the preceding Claims, wherein a datum setting of each flow regulator (21) is adjusted in order to achieve the desired flow characteristics. 6. A method according to Claim 5, wherein the datum setting of the flow regulators is automatically adjusted by means of measuring and monitoring equipment (23) which is connected to a control unit (25). 7. An apparatus (1; 71) for treating a bed (6; 78) of particulate material, the apparatus (1; 71) comprising a gas distribution bottom (9; 75) for supporting the bed to be treated and provided with a number of ducts (19; 35; 77) for sectionalised supplying of treatment gas from one or several underlying compartments (15; 76); each duct (19; 35; 77) having a respective flow regulator (21) which is automatically movable in direct response to the gas flow rate in the respective duct; characterised in that the flow regulator provides a continuously variable regulation of the gas flow within an operational range; the regulator being arranged to reduce the gas passage area in the duct when the gas flow begins to rise, and vice versa. 8. An apparatus according to Claim 7, wherein each flow regulator (21) comprises one or several venturi-like nozzle means (45), each of which is connected through a connecting means (46) to a variable restriction means (44), of which the total nozzle opening area is variable. 9. An apparatus according to Claim 7, wherein each flow regulator (21) comprises one or several variable orifice-like nozzle means (90), of which the total orifice area is variable. 10. An apparatus according to Claim 9, wherein each nozzle-means (90) comprises at least two flow restriction overlapping plates (91, 92) which, in conjunction, define at least one nozzle opening (93) and in that at least one of the plates (91, 92) is movable over the other(s) and is connected to means (94, 95) for generating this displacement in response to the gas flow condition. 11. An apparatus according to Claim 10, wherein on one side of each movable plate there prevails the pressure P1 upstream of the nozzle opening and on the other side of there prevails the pressure P2 downstream of the nozzle opening (93), and the movable plate (94) is directly or indirectly connected to a characteristic controlling means (95). 12. An apparatus according to Claim 11, wherein the flow restriction means (91; 92) are configured so that the total nozzle opening area for any pressure difference prevailing across the nozzle within a specific operating range precisely result in the desired gas flow through the duct (19; 35; 77). 13. An apparatus according to any one of Claims 7 to 12, wherein each flow regulator (21) comprises means (51, 52) for adjusting its datum setting. 14. An apparatus according to Claim 13, which comprises measuring and monitoring equipment (23) which via a control unit is connected to the adjusting means (51; 52) of each flow regulator. 15. An apparatus according to any one of Claims 7 to 14, which is a grate cooler (1) for cooling hot particulate material (6), such as cement clinker being discharged from a cement kiln (3). 16. An apparatus according to any one Claims 7 to 14, which is a fluidized bed kiln (71).