Page 66 - AJWEP-22-5

Darlami, et al.

Mahmoud et al. applied thermal-mechanical
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assisted dewatering (TMAD) to alfalfa biomass
using a two-factor central composite experimental
design. At 80°C and pressure conditions ranging
from 300 kPa to 3000 kPa, the method removed up to
83% of inherent water, compared to only 43% using
mechanical dewatering alone. A regression model with
R > 88% was used to predict final dry solid content. The
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optimized process required <150 kWh/m , reducing
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energy consumption by over 30% and achieving up to
87% total solids after thermal drying.
Marcel et al. developed an integrated milling-
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Figure 5. Moisture content of digestate after sieving-dewatering system for grain slurry, which
dewatering improved extraction efficiency and reduced moisture
Abbreviations: TMAD: Thermal-mechanical assisted content. The system achieved a moisture content of
dewatering; VDSC: Vertical double-squeeze cassava; 25.35% with a specific energy consumption of 183 kJ/kg
WATDM: Water-absorption-trough dewatering machine.
under optimal conditions: 70 L/h water feed, 10 rpm
operating speeds using a variable frequency drive. It was sieving speed, and 90 kPa vacuum pressure. This
identified that 8 rpm was the optimal speed for system represented reductions in moisture content of 19.64%
operation. At this speed, the system demonstrated its and energy consumption of 19.13% compared to the
highest efficiency, achieving a liquid yield of 92.02% original design settings.
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and an extraction efficiency of 73.12%. The results Afeni et al. fabricated a manually operated fuel-
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highlighted the importance of precise speed control free dewatering machine designed for blasthole water
in optimizing performance, maximizing resource removal in mining. It achieved an average discharge
recovery, and enhancing overall system effectiveness in rate of 0.27 L/s and a mechanical efficiency of 76%,
the dewatering process. offering an environmentally friendly and cost-saving
Olusegun and Ajiboye developed a vertical double- solution. Annual dewatering cost savings exceeded
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squeeze cassava pulp dewatering machine to handle 90%, and the device can operate on solar power,
200 kg of cassava pulp. The machine featured acme- making it a sustainable alternative in remote areas.
threaded screws operating at a principal stress of The performance assessment of various dewatering
100 N/mm and a torque of 1,182 kN/mm, powered by machines implemented for different materials is
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a 7.5-horsepower single-phase motor with an efficiency illustrated in Table 1 and Figure 5.
of 40%. It effectively reduced the moisture content of Among the technologies assessed, TMAD
fine cassava pulp from 80% to 29.85% in 33.72 min, achieved the lowest final moisture content (13%),
which was approximately seven times faster than the showcasing the significant enhancement that thermal
International Institute of Tropical Agriculture manual input provides. The vertical double-squeeze cassava
batch-type machine. The machine also achieved machine also performed well, reducing moisture to
10 – 20% greater removal of toxic water and enhanced around 29.85%, outperforming traditional manual or
gari production by a factor of seven. batch-type equipment. The milling-sieving-dewatering
Mudryk et al. utilized the EDZ 20 strength machine system reduced the moisture content of starch slurry
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with replaceable screens of 0.1 – 0.3 mm to dewater to 25.35%, while EDZ 20, operating under mechanical
digestate under varying pressures (0.58 – 2.91 MPa). pressure without thermal aid, achieved a modest 7.4%
The highest rate of moisture loss occurred at 1.74 MPa moisture reduction, resulting in higher final moisture
(30 kN), although additional increases in pressure content (>70%). The manual fuel-free machine
yielded diminishing returns. Using a 0.3 mm screen, the offers sustainability benefits but is primarily used for
maximum reduction in moisture content was <7.4%, with water pumping, not fine particulate dewatering. The
only 2.5% additional mass loss when pressure increased water-absorption-trough dewatering machine method
from 2.32 MPa to 2.91 MPa, indicating a performance indirectly improves moisture-related estimations and is
threshold for mechanical pressure-based dewatering. not a direct dewatering method.

Volume 22 Issue 5 (2025) 60 doi: 10.36922/AJWEP025130093