Tech Topics By Paul Smith, HF Press+LipidTech
Innovation for Increased Capacity and Yield
Global demand for rendered products is increasing,
leading rendering companies to examine the latest state-of-
the-art technologies available to maximize opportunities
and markets in the most efficient ways. Factors such as a
global focus on sustainability, a growing interest in tallow as
a feedstock for renewable diesel, and a worldwide increase in
pet ownership, and thus pet foods, brought on by COVID-19
lockdowns are resulting in unprecedented demand for
rendered products.
To implement any facility expansion with the goal of
ensuring the greatest return on investment, the starting point
should be the primary equipment within the rendering process
to ensure the optimum key performance indicators are suitable
for the business plan. Given that rendering is the separation
of fats from the solids, the screw press is a key element in all
rendering plants.
Screw presses are designed to mechanically separate
solids and liquids. In rendering, this applies to separating
the fats/lipids (liquids) from the protein meal (solids). As
the material is fed into the press and moves along, there is
a reduction in volume between the screw shaft/flights and a
strainer cage that causes an increase in pressure on the solids.
This forces the liquids through the gaps in the strainer cage
before being collected in the base of the screw press and
transported via a collecting screw. The remaining solids are
then discharged out the end of the press cage.
If a screw press is not configured correctly (e.g., the
geometries of the screw outfit and the spacing of the gaps
and scrapers within the cage lining), there is a high possibility
of fat losses within the protein meal since the residual fat
will remain in the meal and not be recovered. Various factors
around the raw material received can affect the efficiency of
the fat extraction (i.e., moisture, temperature, solids content);
however, in general, anything above 12 percent residual fat
would be considered high within the industry.
New Direction for Increased Demand
Until recently, the best solution to increasing plant
throughput was to add extra screw presses. The models that
have been around for the past 30 to 40 years were rated at
around 8 to 10 metric tons (17,637 to 22,046 pounds) per hour.
By utilizing more than 150 years of experience in mechanical
engineering and screw-pressing applications, and calling on
the know-how from supplying more than 1,000 presses across
all applications, HF Press+LipidTech has developed the new
SP280R screw press that offers renderers the opportunity
to process up to 50 percent greater throughput on a single
machine. This creates an optimized solution from both capital
and operating cost analyses with the added benefit of a lower
overall footprint.
TBN Zweckverband Tierkörperbeseitigung Nordbayern in
Walsdorf, Germany, installed a SP280R screw press to replace
a machine in operation since 1988 as part of an expansion and
optimization project. The older machine had been a major
bottleneck for the company’s goals; however, using the same
raw material always processed, the company managed to
achieve the following results with the new screw press:
• an increase in throughput of 50 percent of semi-dried
product from the dryer
• a reduction in residual fat/tallow of more than 2
percent in the meat and bone meal
• an overall tallow yield increase of more than 60
percent
• a project payback measured in months rather than
years
• annual maintenance costs down by 30 percent,
on average, combined with a reduced load on the
maintenance team
Robert Schuster, operations and technical manager at
TBN Zweckverband Tierkörperbeseitigung Nordbayern, said,
“The SP280R has helped us increase our yield and profitability,
alongside the durability that we require from our machines to
keep up with our demand. It has been instrumental in helping
us stay one step ahead of the competition.”
Benefitting from the same robust design principles as
the previous model, the SP280R rendering press is capable
of pressing up to 17 metric tons (37,480 pounds) per hour
of raw rendering material, which can equate to 6.5 metric
tons (14,330 pounds) of dried semi-finished product. This
is achieved with a footprint only 50 percent greater than
traditional models, with operating costs significantly lower per
ton. In addition, the SP280R also offers features and benefits
that are key to HF Press+LipidTech technical solutions to screw
presses, such as various screw configurations to maximize fat
output from any animal by-product mix; pressing components
fixed around a single, rotating shaft; self-centering, free-floating
shaft; and 360-degree access points for inspection
and maintenance.
Be Proactive, Be Preventative
The old saying, “If you don’t schedule your maintenance,
it will schedule it for you,” does not ring truer than in the
rendering industry. With high solids content in most raw
material, what starts as a small amount of wear can soon
escalate into an inefficient, or even worse, unusable screw
press. Therefore, it is important to have a robust, regular
inspection schedule backed by a reliable supply chain so
production can keep up with demand.
Given that animal proteins and fats demand is forecast to
increase year over year for the foreseeable future, forward-thinking
renderers need to consider all options on how to
stay at the forefront of their customers’ minds. By combining
the development mindset that is part of HF Press+LipidTech’s
fabric with the engineering know-how, the SP280R screw press
continues to be a valued and key component for ambitious
renderers. R
26 June 2021 Render www.rendermagazine.com
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