Vol. XIV. No. 312. 



THE AGRICULTURAL NEWS. 



179 



beating coils and calandrias, and from vacuum pan and 

 evaporator condensers, as well as securing overflows from 

 water tanks which will take the ex ■ back into the general 

 water supply. 



A certain unavoidable loss o1 water will always exist, 

 due to escape of excess steam from boiRlr safety valves ami 

 blowoffs, arid from tin' reliei valve on the exhaust steam 

 recipient, while washing of filtei cloths, general cleaning up 

 and water used for boiling out pans and evaporators will 

 remove another portion from the stock, ami in addition to 

 (ibis arc the losses dm- t.. evaporation from water tanks, flash 

 Lag from steam traps, ami I i >n and wind entrainmeiit 



from the cooling tower. 



In evaporating jniee from 18 degrees to 95 degrees 

 Brix, to take an average ease in Cuba, there will lie a product 

 of water amounting to si per cent, of the weight of original 

 juice. Assuming that the mill is extracting the low yield 

 of 75 per cent, juice on cane weight, this will be a quantity 

 of 60 tb. water 100 lb. of cane; or per thousand Spanish 

 tons (2,500 lb.), a volume of about 180,000 gallons daily in 

 a house grinding the tonnage named. 



The disappearance of water from stock in the factory 



should not exc I a total of (.", per cent, of tin' amount 



received from the cane, and will lie distributed about as 

 follows: — 



Steam leaks, boiler blowoff and excess 



exhaust from escape 5 per cent. 



Accident, overflows, sugar in water, etc. 10 „ „ 



Washing machine, general cleaning 15 ,, „ 



Rvaporation leakage ami wind losses 



at cooling tower 13 ,, ,, 



43 per cent. 



Leaving.")? per coin, of the water received in excess over 

 the consumption ami loss in the factory, or an available 

 quantity of about 102,000 gallons. 



About one-third of this total excess water can 

 be regarded as wasted, as i> passes into the circulation 

 water of the cooling tower by way of the condensers, and the 

 circulation supply cannot be safely used for general sugar mill 

 purposes. This one-third disappears as overflow from the 

 cooling tower basin. 



There are then left about 68,000 gallons of pure water 

 which, if care is taken in the factory in the ways indicated 

 earlier, will overflow from the boiler feed tanks and can be 

 saved and retained in quantity for all emergencies and uses, 

 among which is the important one of holding a supply large 

 enough to change the entire contents of the cooling tow^er 

 basin and circuit at frequent intervals, to keep it fresh and 

 avert corrosion of piping due to acidity of this water caused 

 by the small trace of sugar which it will always carry under 

 the best of conditions, and which forms various acids under 

 fermentation and other changes. 



It is the usual practice to add to the condensed water in 

 the boiler feed tanks a -mall ami continuous feed of natural 

 water, in order to prevent the harmful action which pure 

 distilled water has on boiler tubes and plates. This addition 

 of outside water can be omitted if thin lime milk is arranged 

 to drip into the feed-water tanks so that a quantity of dry 

 lime equal to about 1 tt>. per 5,000 gallons of water 

 will be maintained. Acidity will not occur, and the water 

 will acquire a safe degree "t hardness without forming too 

 much scale. 



In a factory handling 1,000 tons cane daily, a fair 



allowance of water for the ling tower and the filled 



circulation would be about 150,000 gallons. With proper 

 precautious taken to keep the condensation free of sugar and 



oil, and to save ill leakage that can l»- prevented, and 



bringing to the fee. I water tanks all of it that can be 



the overflow from bhi se t inks ''an be diverted into a concrete 



basin, or main reservoir, ind held there in ready condition 

 tor all of tie factorj service where water is not wanted 



actually hot, the latter being taken direct fr the 



water \>\ ;i special service pump. 



Such a reservoir should !"■ located near to the cooling 



tower basin, hut not where spray from the latter will be blown 



into it. It should carry a 1 .out twice as much as the volume 



in circulation and in the basin, or, say, 250,1 to 300,000 



gallons, with its bottom about the same level as the bottom of 

 the cooling tower basin, and with walls twice the height of 

 those of the basin. Tin* will permit of emptying out the 

 basin once or twice a week, and refilling it from the reservoir 

 by a 10-inch or 12-inch connecting pipe, without stopping 

 the mill or interfering with the work in any way, if the basin 

 outlet is opened and the contents run oft' to a minimum 

 working level, anil the pipe from the reservoir then opened 

 full while the drainage from the basin is closed. 



The general supply of water for the factory will be 

 drawn from the main reservoir and will be always plentiful 

 and cool enough for all purposes. All condensation lines 

 leading to the boiler feed tanks arc to be provided with 

 means for turning out water if it becomes charged with 

 sugar, until the trouble is corrected, and should be brought 

 to some single point where the stream from each of these 

 lines will be in plain sight and easy of access for examination. 



It is not the intention of this article to go into the 

 question of what sort of cooling tower is best to use. There 

 are several types of cooling apparatus, and any one is good 

 which will expose enough water surface to the air for a long 

 enough time, and which has a catch basin wide enough to 

 pi event excessive wind loss of the cooled water. (Louisiana 

 Planter, April 24. 1915.) 



Radio-Active Manures. — The Journd of the 



Bo'ird of Agriculture (England) for April 1915, gives the 

 following summary of United States Department of Agricul- 

 ture Bulletin No. 149, which deals with radio-active sub- 

 stances as fertilizers : — 



'The properties of radio-elements and the influence of 

 radio-active rays on plants are discussed. The experiments 

 in England by Hedworth Foulkes, on the Continent by 

 Malpeaux, Berthault and Bretigniere (see this Journal, 

 July 1913, p. 324), and in Australia by Ewart, are reviewed 

 and reference is made to the question of catalytic manures. 



'The conclusion is reached that it seems incredible 

 that radium or any of its products can have any economical 

 application as a fertilizer in general farming; and still less 

 credible that the so-called radio-active manure has any value, 

 as far as its radio activity is concerned, since the radium 

 already present, on an average, in an acre-foot of soil, is 

 about 100 times greater than is contained in the quantity 

 of radio-active manure commonly recommended for applica- 

 tion to an acre. 



'It is thought, however, that radio elements may prove 

 oi considerable value, justifying the expense involved in 

 botanical research, and possibly also in greenhouse work. 



'Evidence is given to show that the action of uranium 

 on plants is due to its chemical properties rather than to its 

 property of being radioactive, and that the conflicting results 

 obtained with radio-active manure from different sources is to 

 be explained largely by Hie presence of uranium, and of such 

 non radio-active constituents as soluble salts and free acids.' 



