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A further consequence of forced draught is the tendency for the 

 products of the burning brimstone to be forced from the kiln 

 throughout the oast, making the place untenable for the men 

 engaged in " pressing," etc.; this is aggravated when sufficient 

 outlets, mentioned above, are wanting. Very careful ceiling of 

 the partitions between the cooling floor of the oast and the kilns 

 is therefore necessary. 



When the fans are electrically driven they can be fixed in any 

 desired place and this is generally in the roof of the kiln some 

 few feet (6 or 8) above the level of the hops so lhat the suction 

 may not create a greater draught through the hops near the fan 

 than elsewhere. In this position it is essential that the remain- 

 der of the roof area shall be very perfectly ceiled since otherwise 

 any leakage of air through the roof will lessen the efficiency of 

 the draught through the hops. By such an arrangement of the 

 fan the difficulties associated with the interference of work by 

 the fumes of the brimstone are. of course, obviated and it is 

 generally found that drying is more uniform over the drying 

 floor. 



If the fans are used in association with open fires suction 

 draught is the only form which can be applied, whereas with the 

 closed stove it is immaterial whether forced or suction draught is 

 utilised. 



Source of Power. — There can be no question when a reliable 

 source of electric power, as from an electric power company, is 

 available that this will prove both most reliable and most 

 economical. Where this is not the case either a portable steam 

 engine or a fixed oil engine can be utilised to drive fans below the 

 hops through a belt transmission. In some cases even it may 

 be desirable where power is largely required for other farm pur- 

 poses to drive the fans electrically from a fixed oil engine in 

 some central position on the farm. Each case will need to be 

 considered on its merits with the help of competent engineering 

 advice. 



Modifications in Drying Practice when Fan- Draught is Used. 



+— Loading. — Generally when fan-draught is used, and provided 

 the fan power and area of fireplace are sufficient, the load can 

 be doubled and when hops are ripe the depth may amount to 

 18 in. to 22 in. Greater depths may be loaded and dried success- 

 fully but no useful purpose is served because the rate of drying 

 is slow and the kilns cannot complete the drying of two loadings 

 in 2-1 hours. When hops are unripe the load should be reduced 



