Water & Wastewater Asia March/April 2024

IN THE FIELD
location and configuration for the volute
screw press, including access to power
and water. A 6m containerised unit —
constructed offsite — was placed inside
the existing processing plant containing
everything Pilgrim’s UK needed to start
processing the sludge. Hill added,
“With the screw press’ plug-and-play
capabilities, the team quickly adapted to
the technology, and after a five-day trial
period, it was decided to extend the trial
by directly renting the unit from WCSEE, to
further understand the ROI.”
POSITIVE ROI
The trial showed that the dewatered
sludge produced at the Spalding site had
a potential gas yield that could be used to
generate biogas electricity. Pilgrim’s UK
was able to send the dewatered sludge
to the nearest anaerobic digestion (AD)
plant which proved to have such a high gas
yield it was valuable feedstock for biogas
electricity generation.
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Since the installation of the screw press,
Pilgrim’s UK has seen more than an 80%
reduction in sludge volumes overall and is
now only sending dewatered sludge cake
from the AD plant once a week on average.
This process is now operating at zero cost
due to its high biogas electricity generation
value. The trial has provided an immediate
ROI for Pilgrim’s UK and resulted in the
three-month rental of the screw press
becoming a full purchase. Pete Cranney,
technical sales manager at WCSEE, said,
“The initial analytics service is offered at
no cost to the client, which allows site to
prove to themselves the suitability of the
technology, the potential cost savings of
the project, and the value of the volute
screw press as the most attractive ROI
option on the market.”
WATER AND ENERGY REDUCTIONS
The volute screw press offers thickening
and dewatering of DAF sludge with the
addition of a self-cleaning filter that
prevents clogging and enables constant
dewatering without using large volumes
of water. This delivers stable and constant
dewatering, achieving up to 99% efficiency
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savings against belt presses, and 92%
against conventional screw presses.
Operated automatically by a 24hr sensor
control if required, the volute screw press
also requires 70% of standard screw
presses footprint, and 5% of the power
usage of a comparable centrifuge.
Along with the direct sale of the screw
press, WCSEE has entered into an
ongoing relationship with Pilgrim’s UK,
which includes repair and maintenance
along with chemical support with
an optimised polymer used for the
dewatering process. Cranney said, “With
approximately 5,000 volute screw presses
already in operation across Europe,
WCSEE is seeing accelerated demand
in the UK due to tighter environmental
consents and sludge management
regulations, along with growing interest
for more sustainable processes in the
F&B sector. WCSEE [welcomes] Pilgrim’s
UK to our list of customers seeking a
simple-to-operate, simple-to-maintain,
and simple-to-service screw press that
cuts costs whilst delivering sustainability
goals.”
Images: WCSEE
Water & Wastewater Asia | March-April 2024 27