Water Lifted By Compressed Air
For Municipal, Manufacturing, Irrigation or Other Water Supply

pense whatever is incurred for pumping the water for condensing, as a part of that regularly handled by the plant can be passed through the condenser before it is pumped into the sei’vice mains. The total amount of water handled by such a plant is so great in proportion to the amount needed for condensing purposes that the increase in temperature is of trifling importance compared to the sav- ing in fuel effected. As an example, we cite a plant installed by this company in north Texas, consisting of a Corliss air compressor having both steam and air cylinders duplex cross compound. This is lifting water more than 300 feet vertically from three drilled wells. The additional lift into the standpipe by the piston pump is over 100 feet more. Still, under even these severe conditions, both the compressor and pump are run condensing, and the saving in fuel pays for the condenser every few months. The temperature of the water in the standpipe is raised so little that many citizens on being questioned stated that they had noticed no difference. It Pays to Pump Water Especially for Condensing Purposes. Let us look into this question a little further by using actual figures. We will assume in one case a 100 II. P. simple non-condens- ing engine, in first-class working order, so that it runs on a steam rate of 36 pounds per horse-power hour and supplied with steam from a first-class boiler plant giving an evaporation of 9 pounds of water per pound of coal, equal to 4 pounds coal per horse-power hour. To make a severe case, we will assume that this plant will run but 10 hours per day and 300 days, or 3,000 hours per year. This gives an annual coal consumption of 600 tons. The extra power required to operate an air compressor to pump condensing water for this plant, even lifting it as much as 75 feet vertically, would be under 10 II. P. ; but say 10. This makes a total horse power required of 110. But the reduction of the coal consump- tion by running condensing would be from 25 to 35 per cent. ; but say only 25 per cent., or to a coal rate of 3 pounds per horse-power hour. One hundred and ten II. P. at 3 pounds gives an annual coal consump- tion of 495 tons, or a saving per year, at the lowest estimate, of 105 tons. At $2 per ton this is 10 per cent, on $2,100—far more than the usual cost to make the change. If the above should be considered a case specially favoring the application of a condenser, we will take another case, already assumed to be a fairly economical plant, having a 500 H. P. compound non- condensing Corliss engine, or compressor, running only 3,000 hours 20