Acetone Recovery Plant :
Whilst the Nitration Hills and the Cordite Milling Houses have a fairly obvious function, the enigmatic tall
buildings of the Acetone Recovery Plant remain as a challenge to interpretation. Fortunately, the writer had access to
the website on RNCF Holton Heath, an illustration of a Stoving Room for cordite being the first step on a path that has
led to full interpretation. The assistance of Malcolm Bowditch and Les Hayward is acknowledged with thanks.
The function of Acetone Recovery was to gently heat the finished cordite and to drive off as much as possible of the
acetone used to stabilise the Nitroglycerine during transportation, gelatinisation with Nitrocellulose and milling
into cordite. At the same time, the process removed any unbonded Nitroglycerine and any water vapour. Recovered acetone
was purified by distillation and returned to the Acetone Storage Plant, whilst water vapour was vented and any
Nitroglycerine vapour was condensed and returned for purification to the Nitration Hills.
Unit 1 and Unit 2 have different locations and layouts for the Acetone Recovery Plant. Unit 2 had a more linear layout,
with a northerly alignment from Nitration to Wet Mix to Cordite Milling, then Acetone Recovery, followed by Drying
and Blending. Unit 1 by contrast was confined by a narrower site, so the flow was north and west from Nitration to Wet Mix,
then south and east to Cordite Milling, then southwest and west to Acetone Recovery and north again for Drying and Blending.
This arrangement emerged after examining the clusters of buildings on a map and then checking their processes. It is ironic
that the more haphazard arrangement in Unit 1 has survived whilst most of the alignment in Unit 2 has been demolished.
Archaeological Evidence for the Acetone Recovery Houses :
From a map survey it was self-evident that there were originally two full-size and one half-size hall in each of the
two production Units. The full-size halls in Unit 2 were clearly flanked by two buildings that turned out to be Stoving
Houses, from reliable internal photography of facilities at ROF Holton Heath. The half-size hall was beside just the one
Stoving House. For more details go to the Acetone Recovery Houses page.
The Stoving Houses are long one-storey structures similar in appearance to Narrow Cordite Milling Houses and to the
Drying and Blending Houses, but differing internally in layout and surviving equipment. For more details go to
the Stoving Houses page.
Summary of the Stoving Operation :
Cordite laid out on racks in the Stoving Rooms was gently heated by the radiators on the walls of the Stoving Rooms
until acetone was driven off. It was then extracted through pipes to the Acetone Recovery Houses, together with any
vaporised Nitroglycerine. As Nitroglycerine is less volatile than acetone, the explosive may have condensed at an early
stage. According the Malcolm Bowditch, it tended to accumulate in expansion joints, which were sections of pipe like U-bends
with a tap in their lowest point. At RNPF Holton Heath, a man with a leather bucket would collect this condensate every
week, then take it to the Nitration Hills for addition to the product Wash Columns.
The Acetone Recovery Houses took the vapour and chilled it, to separate any remaining Nitroglycerine and then the Acetone,
which was freed of any remaining water vapour by distillation. The purified acetone will have been stored, sampled for
purity, then returned to the main Acetone Plant. There are the bases of a possible acetone storage tank on a ridge in
Unit 1, almost in a direct line between the Acetone Recovery Plant and the Acetone Storage Plant.
A Modern Ecological Lesson :
The Acetone Recovery Plant's technology and scale are copied today in miniaturised Acetone Recovery Stills now used by
industry to recover this relatively cheap but surprisingly versatile solvent. By recycling solvents such as acetone,
businesses can save thousands of pounds a year in purchase and disposal costs, whilst at the same time avoiding the risk
of polluting watercourses and grounwater that may be needed for the drinking water supply. Thus, the technology evolved
to use scarce resources to produce wartime explosives, is of equal and greater value for fighting for peace and the planet.
The Acetone Recovery Plant has at last been recognised from a forgotten ruin and its importance as a wartime means of
economic explosives production has been established. Many aspects of its operation - notably in the Acetone Recovery
Houses - still need to be worked out. Site visitors are invited to send any information they have to