Surface World August 2019 Surface World August 2019 | Page 64

PRE-TREATMENT, SURFACE PREPARATION, DEGREASING & CLEANING
Five-fold increase in cleaning effi ciency
The arrival of a front-
loading, aqueous washing
and rinsing system from
Turbex at the Hampshire
production facility
of leading UK pump
manufacturer Selwood
(www.selwood.co.uk) has
improved dramatically
the effi ciency with which
machined castings are
washed in preparation for
assembly. Two rotating-
drum machines, also
aqueous and supplied by
Turbex (www.turbex.co.uk)
20 years ago to supplant a
trichloroethylene cleaning
process, have been replaced
by a new AC-1.7-2 twin-stage
machine from the Alton
supplier.
Keith Wright, Section
Leader at Selwood’s
Hampshire production
facility, pushing a batch
of cast iron pump
components into the
Turbex aqueous cleaning
machine for processing.
The second table on its
rail-mounted carriage
with clean parts for
offl oading can be seen
in the background.
The old equipment had served well,
but its effectiveness was diminishing through
age and an inability to maintain water
temperature sufficiently high to activate the
detergent adequately. A batch of 12 to 15
castings for the assembly of one pump used
to take 40 minutes to clean and sometimes
they would have to go back in if they were
still soiled.
The new Turbex industrial washing machine
can process five such loads placed in four
rectangular stainless steel stillages in 45
minutes, representing a five-fold cleaning
efficiency uplift. Valuable pump build hours
in the six production bays are no longer lost
and delivery lead-times have consequently improved. around 75°C via spray arms that are rotated around the load in the
sealed, 1.4-metre-cube process chamber.
With Selwood’s reputation for reliable and robust pumps, it is
important that its castings are clean before assembly to ensure
correct functioning of the products. The fine swarf generated when
machining cast iron, together with coolant residue and grease, must
be removed completely such that none is visible or detectable by
touch. The AC-1.7-2 achieves this level of cleanliness in a fast cycle
time due to efficient penetration of a mix of water and detergent at To minimise delay between the end of a cycle and loading of the next
batch for cleaning, there is a shuttle arrangement at the front of the
machine comprising two rail-mounted carriages, each carrying a
table capable of supporting two tonnes. While one batch is being
processed, components are set up on the other table, which is ready
to be pushed by the operator into the chamber as soon as the clean
parts exit the machine via the automatic door.
Close-up of pump castings
in a stainless steel stillage
for cleaning.
CONTINUED ON PAGE 64
62
AUGUST 2019
read online: www.surfaceworld.com