Coal pulverizer inerting and fire extinguishing system

Claim 1

In a bowl mill having a substantially closed separator body, a rotatable grinding surface mounted for rotation in a first direction within the separator body and upon which pulverization of material is effected, material supply means supported within the separator body for supplying material to be pulverized to the grinding surface and having a first portion projecting outwardly of the separator body, outlet means supported on the separator body for discharging from the bowl mill material that has been pulverized therewithin, and air inlet means for supplying air to the interior of the separator body for transporting material that has been pulverized on the grinding surface therefrom to the outlet means for discharging from the bowl mill, the improvement of a combination inerting and fire extinguishing system comprising: (a) an inerting subsystem operative for establishing an inert atmosphere within the separator body as well as for clearing material from the bowl mill, said inerting subsystem including inerting inlet means connected to the air inlet means for supplying an inerting medium through the air inlet means to the interior of the bowl mill, a primary inerting medium supply means connected in fluid flow relation to said inerting inlet means and operative for supplying a primary inerting medium to said inerting inlet means and therefrom to the air inlet means and therethrough into the interior of the bowl mill, a backup inerting medium supply means connected in fluid flow relation to said inerting inlet means and operative for supplying a backup inerting medium to said inerting inlet means and therefrom to the air inlet means and therethrough into the interior of the bowl mill, a no material flow detection means suitably mounted on the first portion of the material supply means so as to be located externally of the separator body of the bowl mill, said no material flow detection means being operative when the bowl mill is in operation to detect the absence of material flow in the material supply means and to provide a signal indication of such a lack of material flow in the material supply means, a receiving means connected in circuit relation with said no material flow detection means for receiving the signal generated thereby, said receiving means being operative upon receiving a signal from said no material flow detection means to provide an indication of the receipt thereof and a control means connected to said receiving means for receiving the signal therefrom, said control means further being connected in fluid flow relation with said primary inerting medium supply means so as to be operative upon receipt of the signal from said receiving means for initiating the flow of the primary inerting medium to said inerting inlet means and therefrom to the air inlet means and therethrough to the interior of the bowl mill when a lack of material flow in the material supply means is detected by said no material flow detection means, said control means further being connected in fluid flow relation with said backup inerting medium supply means so as to be operative upon receiving the signal from said receiving means for initiating the flow of the backup inerting medium to said inerting inlet means and therefrom to the air inlet means and therethrough to the interior of the bowl mill when said primary inerting medium supply is inoperative; and (b) a fire extinguishing subsystem operative for effectuating a reduction in temperature within the interior of the bowl mill.