How does ELODE compare to Thermal Dryers?
1. Thermal dryers require many additional pieces of equipment
Thermal dryers are neither stock nor standalone units. Thermal drying systems produce byproducts like heat, steam, odors, dust, and greenhouse gasses, therefore requiring additional equipment such as:
Exhaust stacks
Hot heat exchangers
Cyclone dust separators & respective cleaning/emptying
Odor treatment / scrubbers
Blower motors + assembly
Duct work
Pellet cooler at dryer exit
Steam condensers & respective huge water supply
Boilers and furnaces
Compressors
Dust filters, fins to clean
Fume/dust scrubber
Demister
Extra drain, piping, or electrical work
All these custom-fabricated moving parts and connections make thermal drying systems (1) complex to install, (2) less reliable, and (3) slower to operate, as seen in their lengthy start-up, shut-down, and maintenance procedures.
The additional equipment required dramatically increases a thermal drying system’s
Overall purchase costs
Footprint & space requirements
Installation & building costs
Energy usage
Frequency of repairs & downtime
Time to ROI
On the other hand, ELODE systems produce minimal heat, steam, and odors, as well as no dust or greenhouse gasses. This reduces the amount of additional equipment required by ELODE and enhances ELODE’s reliability.
ELODE systems are composed of stock units with small footprints, allowing them to be easily integrated into existing lines and facilities.
Because ELODE systems have low complexity and a fully automated design, they are easy to use and maintain.
2. Thermal dryers use energy inefficiently
Most of the sludge cakes we’ve tested have been 10-25% DS, meaning that 75-90% of the sludge cake is composed of water.
Thermal drying systems essentially try to boil the water in the sludge to steam.
At their best, 90% of thermal dryers’ input energy is used to overcome the latent heat of vaporization (turning liquid to steam) - a highly inefficient use of energy.
In practice, thermal dryers use almost double that ideal amount of energy due to (1) wasted heat from hot exhaust gas from burning fuel, (2) non-ideal heat transfer, (3) pre-heating, and (4) delayed exit of dried sludge.
To achieve greater efficiency, energy/cost savings, and a quicker ROI, sludge dryers must remove water from sludge without having to boil it away.
ELODE is a Non-Thermal Sludge Dryer
As a non-thermal dewatering system, ELODE does not use heat to remove water from sludge.
Instead, ELODE uses electro-osmosis: electricity to drive water out of sludge on a molecular level rather than heat energy to evaporate water away, consuming 9x less energy to dewater sludge.
Therefore, ELODE is much more energy efficient and consumes relatively low energy compared to thermal dryers, which waste the majority of their input energy as heat.
While the performance of an ELODE system may vary from application to application, it typically discharges cakes with solids contents of 40% or more. As a result, the cakes are generally drier and lighter than those produced by mechanical-based systems.
Due to their high water reduction rates, low energy consumption, and ease of use/maintenance, ELODE systems can offer considerable cost savings for sludge treatment, disposal, transportation, and storage operations. As a result, customers can quickly achieve full ROI.
Though ELODE may not be able to achieve the % DS figures that thermal dryers can, when it comes to sludge cake weight reduction, %DS vs. weight removal follows the law of diminishing returns.
For example, let’s say your sludge cake starts off at 15% DS, and ELODE dries it to 40% and a thermal drying system dries it to 90%:
15% —> 40% DS results in a 62% reduction in sludge weight
15% —> 90% DS results in a 83% reduction in sludge weight
Achieving an additional 21% weight reduction may not be worth a thermal drying system’s
Overall purchase costs
Footprint & space requirements
Installation & building costs
Energy usage
Frequency of repairs & downtime
Time to ROI
Summary
Thermal sludge drying systems are expensive, inefficient, and have a reputation of creating headaches for their operators.
ELODE is a non-thermal sludge dryer that drives water out of sludge efficiently with minimal additional equipment. ELODE allows customers to save on costs by reducing sludge cake weight optimally along the curve of diminishing returns. This enables customers to quickly achieve a full return on their investment.
