NBR Nordic Beet Research foundation,
Borgeby Slottsväg 11, SE-237 91 Bjärred
AUTOMATED ACTIVE VENTILATION OF SUGAR BEET CLAMPS
JOAKIM EKELÖF1, WILLIAM ENGLISH1
1Nordic Beet Research Foundation, Borgeby Slottsväg 11, SE –237 91 Bjärred
A SYSTEM FOR GROWERS, AND TOUGH CONDITIONS
Long term storage of sugar beet in clamps can be challenging due to high accumulation
of degree days, frost, or excessive moisture. This may cause an increase in growth of
molds, spread of rots, and rates of respiration, which in turn leads to high sugar losses
during storage. With support from the agricultural European Innovation Partnership
(EIP-AGRI) anovel farm scale clamp ventilation system has been developed and tested.
The aim of this system is to reduce the amount of degree days and improve the storage
climate by pushing air through the clamp when the ambient temperature is lower than
the temperature inside of the clamp. The project has included the development of an
automatic control system based on wireless technologies, and a ventilation pipe that
can be inserted into an A-shaped pile.
Within the project a ventilation pipe that could easily be inserted and removed from
an existing A-shaped clamp was successfully developed. A fully automatic wireless and
online control system was also developed. The use of this active ventilation system
decreased the amount of degree-days (Cd) within the clamp with an average of 163 Cd
corresponding to approximately 35%. However, the effects on storage losses were
lower than expected even though the storage period was very long.On average the
losses were decreased by 2,1 percentage points, with a variation between 0,2- 3,8 pp.
Active ventilation of A-shaped sugar beet piles is unlikely to be profitable in Europe.
REDUCED DEGREE DAYS = REDUCE STORAGE LOSS: Temperature data (lines) and fan
activity (bars) from Borgeby 2021. In this clamp the fan decreased the amount of
degree days from 445 to 229 which resulted in a reduced sugar loss of 3,8 pp (22%).
The fan operated for 97 hours and consumed 232 kW. h .
UNDERSTANDING AIRFLOW WITH SMOKE & HEAT
Airflow dynamics were studied with both smoke and heat. Left: a smoke bomb has
been placed next to the air intake of the fan. Right: a gas heat element had been
placed at the intake, with the airflow in the clamp then evaluated with heat cameras.
GENERAL PROJECT INFORMATION
The project started in 2017 with design and development of the ventilation pipes
and software. During 2018 and 2019,hardware and software were fine-tuned.
Two sugar beet clamps at two different sites were ventilated in both 2020 and 2021.At
every site there was anon-ventilated reference pile. All piles contained approximately
100 tons of beet, were covered with Toptex®at harvest and protected with plastic
when serious frost events occurred. Typically the beets were harvested in mid
November and delivered in the beginning of February.
EVALUATION OF STORAGE LOSS
To evaluate storage loss, 12 samples were taken and analyzed at harvest from each
clamp.Additionally, net sacks were placed in the clamp to estimate weight loss.At
harvest, the net sacks and an additional 12 samples were analyzed from each clamp.
SCREW IT (IN)! The pipes were screwed into the clamps with a hydraulic drill mounted
on a wheel loader. The project was also, at times, challenging.
TOUGH CONDITIONS: Delivery day at Halmstadgården 5 Feb 2021, minus 9 degrees.
Effects of active ventilation on temperature and storage losses.
Acive ventilation Temperature Days Sugar content Cleanness Storage loss
Degree days in storage Pol Dirt tare Sugar
Explanation During storage After storage After storage During storage
Unit Cd days % % %
Reference Ädelholm 2020 497 90 17,11 83,96 14,2%
Ventilated Ädelholm 2020 367 90 17,20 84,79 12,7%
P_value 0,600 0,619 0,458
Reference Hamstadgården 2020 530 85 15,29 85,44 10,7%
Ventilated Hamstadgården 2020 357 85 15,53 86,77 7,9%
P_value <0.05 <0.05 <0.05
Reference Alfahill 2021 423 89 17,76 91,80 6,9%
Ventilated Alfahill 2021 290 89 17,89 91,93 6,7%
P_value 0,339 0,757 0,868
Reference Borgeby 2021 445 73 15,86 87,43 17,6%
Ventilated Borgeby 2021 229 73 16,46 89,01 13,8%
P_value <0.05 0,077 <0.05
Average all reference clamps 474 84 16,49 87,14 12,4%
Average all ventilated clamps 311 84 16,74 88,12 10,3%
P_value <0.05 0,084 <0.05
Scan for film
of system and