Pulverized fuel delivery system for a blast furnace

Abstract

A pulverized fuel delivery system for a blast furnace in which pulverized coal is delivered in dense phase fluidized form into the blast furnace from gas pressurized tanks that are placed in communication, one at a time, in cyclical sequence with a penumatic transport means. The tank gas pressure is regulated in accordance with the blast furnace wind rate to control the weight flow rate of pulverized coal into the furnace and the transport gas flow rate is regulated in accordance with the fuel weight flow rate to maintain a prescribed transport gas flow rate per pound of coal delivered to the furnace.

What is claimed is:  .[.1. A method of supplying pulverized fuel to a blast furnace which comprises introducing a quantity of pulverized fuel into a tank, pressurizing the tank with a gas, communicating the tank with the furnace to allow flow of pulverized fuel thereto under the influence of the gas pressure in the tank, and adjusting said gas pressure in accordance with a condition of the furnace to correspondingly regulate the flow rate of pulverized fuel thereto..]. .[.2. A method according to claim 1 wherein said tank gas pressure is adjusted in accordance with the flow rate of combustion air to the blast furnace..]. .[.3. A method according to claim 2 wherein said tank is communicated with the furnace through a conduit and including the step of introducing a carrier gas under pressure into said conduit to pneumatically convey said pulverized fuel 
     
        therethrough into the furnace..]. 4. .[.A method according to claim 3 including the step of.]. .Iadd.A method of supplying pulverized fuel to a blast furnace which comprises introducing a quantity of pulverized fuel into a tank, pressurizing the tank with an inert gas, communicating the tank with the furnace to allow flow of pulverized fuel thereto under the influence of the gas pressure in the tank, and adjusting said gas pressure in accordance with the flow rate of combustion air to the blast furnace to correspondingly regulate the flow rate of pulverized fuel thereto wherein said tank is communicated with the furnace through a conduit, introducing a carrier gas under pressure into said conduit to pneumatically convey said pulverized fuel therethrough into the furnace and .Iaddend.adjusting the flow rate of said carrier gas into the conduit in accordance with flow rate of pulverized fuel out of said tank to maintain a given carrier gas flow rate per weight unit of pulverized fuel delivered into the blast 
     
     
        furnace. 5. .[.A method according to claim 1 including the steps of.]. .Iadd.A method of supplying pulverized fuel to a blast furnace which comprises introducing a quantity of pulverized fuel into a tank, pressurizing the tank with an inert gas, communicating the tank with the furnace to allow flow of pulverized fuel thereto under the influence of the gas pressure in the tank, and adjusting said gas pressure in accordance with the flow rate of combustion air to the blast furnace to correspondingly the regulate flow rate of pulverized fuel thereto, .Iaddend.sensing the weight of said tank to determine the delivery rate of pulverized fuel into the furnace, converting raw fuel into pulverized fuel at a rate equal to said delivery rate, and storing the pulverized fuel resulting from such conversion for subsequent transfer into said tank to replenish the pulverized fuel supply thereof.  .[.6. In a method of supplying pulverized coal to a blast furnace having a plurality of pressurizable tanks for holding pulverized fuel, a conduit communicating with the blast furnace, and means for selectively communicating each of said tanks with said conduit, a method of supplying pulverized fuel to the blast furnace which comprises the steps of communicating said tanks, one at a time in a predetermined sequence, with said conduit, pressurizing with a gas the tank currently communicated with the conduit to effect flow of pulverized fuel from that tank into the conduit, introducing a carrier gas under pressure into said conduit to pneumatically convey said pulverized fuel therethrough into the blast furnace, and adjusting the gas pressure in said communicated tank in accordance with a condition of the furnace to correspondingly regulate the flow of pulverized fuel thereto..]. .[.7. A method according to claim 6 including the steps of pressurizing with a gas the next tank in said sequence to be communicated with said conduit and adjusting the gas pressure in said next tanks to maintain such gas pressure equal to that in the tank currently 
     
     
        communicated with the conduit..]. 8. .[.A method according to claim 6 including the step of.]. .Iadd.A method of supplying pulverized coal to a blast furnace having a plurality of pressurizable tanks for holding pulverized fuel, a conduit communicating with the blast furnace, and means for selectively communicating each of said tanks with said conduit, which comprises the steps of communicating said tanks, one at a time in a predetermined sequence, with said conduit, pressurizing with an inert gas the tank currently communicated with the conduit to effect flow of pulverized fuel from that tank into the conduit, introducing a carrier gas under pressure into said conduit to pneumatically convey said pulverized fuel therethrough into the blast furnace, and adjusting the gas pressure in said communicated tank in accordance with the flow rate of combustion air to the blast furnace to correspondingly regulate the flow of pulverized fuel thereto, .Iaddend.adjusting the flow rate of said carrier gas into the conduit in accordance with the flow rate of pulverized fuel out of said communicated tank to maintain a given carrier gas flow rate 
     
     
        per weight unit of pulverized fuel delivered into the blast furnace. 9. .[.A method according to claim 6 including the steps of.]. .Iadd.A method of supplying pulverized coal to a blast furnace having a plurality of pressurizable tanks for holding pulverized fuel, a conduit communicating with the blast furnace, and means for selectively communicating each of said tanks with said conduit, which comprises the steps of communicating said tanks, one at a time in a predetermined sequence, with said conduit, pressurizing with an inert gas the tank currently communicated with the conduit to effect flow of pulverized fuel from that tank into the conduit, introducing a carrier gas under pressure into said conduit to pneumatically convey said pulverized fuel therethrough into the blast furnace, and adjusting the gas pressure in said communicated tank in accordance with the flow rate of combustion air to the blast furnace to correspondingly regulate the flow of pulverized fuel thereto, .Iaddend.sensing the weight of said communicated tank to determine the delivery rate of pulverized fuel into the blast furnace, converting raw fuel into pulverized fuel at a rate equal to said delivery rate, accumulating the pulverized fuel resulting from such conversion, and introducing such accumulated pulverized fuel into one of said tanks other than the tank communicated with the conduit to continuously maintain within said tanks a supply of pulverized fuel available for delivery to the blast furnace.