198 
The  Trials  of  Hop-Drying  Plant,  1909. 
The  plant  consists  of  a plain  cast-iron  cylindrical  vertical 
furnace,  fixed  on  the  floor  of  the  kiln.  The  hot  gases  from 
the  furnace  are  led  across  the  kiln  in  four  cast-iron  pipes, 
slightly  rising,  to  a distribution  box  fixed  on  the  opposite  wall. 
From  this  distribution  box  two  8 in.  pipes  branch,  one  right 
and  the  other  left,  encircling  the  inside  of  the  kiln,  and  then 
return  across  the  centre  of  the  kiln  to  the  back,  and  there 
deliver  into  a brick  chimney.  The  general  arrangement  is  seen 
from  the  accompanying  plan  and  section.  Fig.  1.  Openings  are 
provided  on  the  ground  level  around  all  sides  of  the  kiln  for 
the  access  of  air,  such  openings  being  regulated  by  dampers. 
The  furnace  is,  of  course,  also  provided  with  a damper  to 
regulate  the  fire,  and  it  was  found  to  be  quite  efficient  in 
operation. 
During  the  trials  for  the  first  week,  the  fuel  used  consisted 
of  coal  or  coke  in  equal  quantities,  after  which  coke  alone  was 
used  for  six  days,  and  the  last  two  days  wood  with  a little  coke. 
This  plant  has  no  fan  and  depends  entirely  on  natural 
draught. 
Sulphuring  is  effected  in  the  ordinary  way,  with  an  in- 
dependent sulphur  stove.  The  cost  of  this  plant  fixed  is 
quoted  at  161. 
On  August  9,  Mr.  Shew’s  plant  at  Bosbury,  near  Ledbury, 
was  the  first  to  be  examined.  Here  there  were  three  kilns, 
each  fitted  with  its  own  gill  furnace  and  radiating  pipes. 
The  special  feature  in  this  plant  is  the  arrangement  of  the 
radiating  pipes,  which  are  composed  of  a battery  of  twelve 
inclined  V pipes,  illustrated  in  plan  and  elevation  by  Fig.  2. 
The  object  of  this  arrangement  is  to  ensure  the  uniform 
distribution  of  the  heated  air  under  the  hair. 
The  air  is  blown  into  the  kilns  through  suitable  conduits  by 
two  fans,  one  fan  capable  of  delivering  9,000  cubic  feet  per 
minute  delivering  into  one  kiln  16  ft.  square,  the  other  larger 
fan  with  a capacity  of  25,000  cubic  feet  per  minute  delivering 
into  the  two  other  kilns,  each  15  ft.  square. 
The  fans  were  driven  by  a portable  steam  engine,  and 
when  running  maintained  an  air  pressure  in  the  lower  portion 
of  the  kiln  equal  to  about  one-tenth  of  an  inch  of  water.  For 
the  purposes  of  trial,  the  three  kilns  were  treated  collectively 
as  one. 
It  is  claimed  for  this  system  that  it  will  also  work  without 
the  aid  of  fans  by  natural  draught,  though  when  so  doing  the 
output  would  be  less  than  when  working  with  forced  draught. 
Two  oastings  were  made  in  this  way  in  one  of  the  kilns,  and 
although  the  air  inlets  were  not  arranged  for  efficient  working 
with  natural  draught,  the  result  proved  that  the  plant  would 
work  efficiently  without  forced  draught. 
