The Birmingham age-herald., 1924-07-27
PuIuerized Coal 'ProUes
 It's Value In Industry

indications are that in the future pow derered coal will be available for the household heating furnace.
 Uses Culm
 A few years ago the Susquehanna Galleries company constructed 6,4OO kilowatt power plant at Lykens, Penn. This plant burned No. buck%heat coal until recently, when, after long test, the furnaces were altered to burn the culm, of which the colliery company possessed an immense store. The cost of grinding this waste into powder is 24 cents per ton and if the buckwheat be assumed to cost $224 per ton, the amount thus saved-203, ,6S1 tons being used last year-amoults to more than $4O0, GOO.
 Pulverized coal has been adopted for the super-pOwer plant at CahOkia, H., which provides the city of St. Louis with light and power. In this instance, Illinois coal, so low in grade as to be otherwise unsaleable, is burned with entire success.
 A Pioneer Installation
 One of the earliest power plant in- stallations, and one in which much pio- neer work was done, is that in the Oneida street plant of the Milwaukee Electric Railway and Light company. The result of S1 per cent net efficiency obtained on this installation and the de- cision of this company to use pulverized coal exclusively in it's Lakeside station gave considerable impetus to the adOp- tion of pulverized fuel for stationary boilers.
 The present total consumption of pull verized coal for all purposes in this country exceeds 2O,000,000 tons per year. This represents an increase of practically 100 per cent, in the last four years. When the plants now under con struction and contracted for are com. pleted and in operation, the total ton mage will have increased by apprOxi' mately 20 per cent.
 Firing System
 There are two general systems of fir ing pulverized coal, the unit system and the storage or multiple system.
 In the operation of the unit system raw coal of a size that will pass through 1 1-2 inch diameter ring is fed to the pulverizer through a simple, adjustable 1 feeding device. After the coal is reduced to the required fineness by the pulver- izing clements and thrOughly mixed with air this mixture of air and pulverized coal is blown into the furnace, where combustion takes place. Both the coal and the air supply are subject to in stant regulation to suit any variation of load conditions. No apparatus Is re- quired other than the motor-driven pull verizeF, and a pipe connection between the pulverizer and the furnace,
 In tine multiple system the coal Is PylveFized in a separate compartment of the boiler plant, then conveyed to storage bins above the boilers, From a bin the coal is fed by screw feeders to specially designed burners at the fur. mace. With this system from 10 to 2C per cent of the air required for com bustion is injected into the fuel at the feeder, the rest being drawn into the furnace by the stack draft.
 In The Home For the household furnace the tenta tive plan is to grind the fuel at a cen tral plant and to deliver it in tank wagons. The powdered fuel will be al lowed to flow from the wagon to 6 closed tank below ground level bu above the level of the boiler furnace. Il will be drawn into the burner by mo tor-driven fan. The speed of the mo tor will be regulated by room tempera ture and thereby control the amount o powdered coal blown into the furnace