A LOCOMOTIVE-BOILER COMPOUND.
The lines of a certain great R. R. traverse a country where the water is very hard and they are compelled to resort to some method of precipitating the lime that is held in solution. After many tests and experiments they have made a compound and use it as follows: in a barrel of water of a capacity of fifty gallons they put 21 lbs. of carbonate of soda, or best white soda ash of commerce, and 35 lbs. of white caustic soda. The cost, per gallon, is about 21⁄2 cents.
The compound is carried in this concentrated form, in calomine cans on the tender of each locomotive. A certain amount, according to the necessities of the case, is poured into the tender at the water tank at each filling. This amount is determined by analysis, and varies all the way from two to fifteen pints to two thousand gallons of water. The precipitating power of this compound may be taken roughly at 2⁄3 of a pound of the carbonate of lime, or equivalent amount of other material, per pint of the compound. On their western lines where they are dealing with alkali waters and those containing sulphates, the company use merely 60 pounds of soda ash to a barrel of water. When the water is pumped into the boiler the heat completes the precipitation and aggregation of the particles, and this does away with all trouble of the tenders or injector tubes clogging up.
The case is an interesting one to stationary engineers, because where the water is pumped into the boiler from tanks the same compound can be used, provided the water contains the proper constituents to be precipitated by it; and where the water is taken from city water mains, it would be a simple matter to devise an apparatus to admit the compound to the feed pipes.