10 Oct., 1917.] Evaporation of Apples. 589 



EVAPORATION OF APPLES.* 



//(/ ./. S. ('(lid well. Fvuil Jiy-l'roductn Specialist, State ('ollcge of 

 \Vusliin</ton Agrirulturnl K.fperiment Station. 



THE KILN EVAPORATOR. 



It may .be said in the outset that iii Western New York the kiln 

 eva])orator is universally used, haviiio: eoiajjletely di.^placed the various 

 types of tower or stack evaporators descrihod by Jiailey and Corbctt. 

 Among the reasims jijivcn by operators for the abandonment of towers 

 are that the fuel and labour cost per unit of output wei-e p^reater, as was 

 the initial cost of construction, and that the constant introduction of 

 fresh fruit retarded the drying of that already in the tower, lengthening 

 the process and permitting secondary changes in the fruit wliich resulted 

 in an inferior ])roduct largely devoid of flavour. Tiiey claim for the 

 kiln evaporator a lower cost of construction and operation and a decidedly 

 improved quality of the product. There can be no question that the first 

 of these claims is true, as the labour required to operate a kiln is consider- 

 ably less than is necessary for other driers of equal ca])acity. Also, the 

 quaility of tbe dry fruit is generally better and more uniform, but it must 

 be emphasized that the character of the jtroduct depends upon the watch- 

 fulness and skill of the operator at least as much as u|)on the type of 

 plant employed. 



In its essential features the actual drying room of tlu^ kiln evaporator 

 presents little that will be ■wiholily new to those familiar with tbe con- 

 struction of the hop kilns once so common in certain parts of the State. 

 The drying unit is two stories in height and in the smallest plants is 

 usually 20, much more rarely 18 or 22 feet square. In larger plants the 

 building is divided by walls continuous from ground to roof into a single 

 or double row of units of this size, each such unit constituting a kiln 

 whicli can be operated independently of the others. The ground floor 

 is usually 10 or 11 feet in height, and contains the stoves or heating 

 furnaces, one for each kiln, with space for the storage of fuel. The 

 second floor is usually only sufficiently high at tbe eaves to permit a man 

 to stand erect, and the ceiling is generally nailed to the lower side of the 

 rafters, this forming an inverted hopper or trough, which has a ventilat- 

 ing tower at its apex. The floor is made of nari-ow slats laid witJi an 

 interval of ^ or g inob between them, and the fruit to be dried is spread 

 in a uniform layer of 4 to 6 inches in depth upon this floor. For the 

 greater utilization and more uniform distribution of the heat supplied 

 by the furnace, the pipe collar is usually fitted with a T joint, or the 

 furnace may have two openings for pipe, and two lines of jiipe are 

 carried around the room one or more times, at a distance of about 2 feet 

 from floor and walls, before passing into tbe flue. 



Suoh a kiln will require eighteen to 24 hours to di-y a charge of sliced 

 apples spread to a depth of 5 or (5 inches. As regards capacity, a 



• This article cimsi^ts of an i-xtract from a liullrtin issuod by the State Collegi' of Wasliington 

 Agricultural ExpiTinn-nt Station. Thn prospect of a prolific si'asoii witli the stoppage of the overseas 

 fruit trade makes the nuesfion of the disposal of our surplus apple crop one of gri^at urgency. It is as a 

 suggestion to help to meet this emergency that we are printing this extract. Further\-xtraets from Mr. 

 Caldwell's article will tie published in subseqiu'nt issues. Perhaps it would be well to iiiviti- attention 

 to the article on Apple Dr\'iug by Mr. J. Farrcll Orchard Supervisor, which was printed in the Journal 

 of AgricitUure for April. 1016. 



