Solids to Gas
An alternative solution to high-temperature bulk solids heat transfer
For more than 30 years, Solex has championed the advancement of indirect heat transfer technology for heating and cooling bulk solids. Currently active within more than 600 installations worldwide across a broad range of industries, the technology is focused on bulk solids moving slowly by gravity between stainless-steel plates, while water, steam or thermal oil flow counter-currently within the the plates.
Heat transfer involving bulk solids and gas, however, requires a different solution: cooling a high-temperature product with a lower temperature gas, or using a high-temperature gas to heat a product. In many cases, the need is driven by the opportunity for energy recovery — converting an energy-rich waste stream into an energy stream that can be used elsewhere in the process or converted to power.
Vertical tube exchange technology
Solex has developed vertical tube exchange technology capable of cooling bulk solids in excess of 1,000°C, with the heat then captured into a process gas stream. This advanced technology is also able to operate as a bulk solids heater, in which case a process gas is introduced on the shell side of the exchanger.
Based on the vertical shell and tube concept, a solid material passes through the tubes while gas flows through the shell side of the exchanger. Design work includes:
- Modeling the heat transfer to guarantee performance
- Careful selection of tube geometry to ensure mass flow of the bulk solid
- Thermal expansion analysis of different components and allowance in the design for relative movement
- Control of gas velocity on the shell side to optimize thermal efficiency
- Configuration of the top tube sheet to ensure uniform product distribution
- Mass flow cone discharge to ensure uniform velocity of product through the tubes
- Material selection considering corrosion as well as high temperature mechanical properties
The Solex benefits
Our vertical tube heat exchange technology provides numerous benefits when compared to fluid bed, rotary air coolers or other direct bulk solid-to-air heat exchange solution:
- There is no contact or cross-contamination between the gas and the solids, thereby eliminating or minimizing gas-treatment processes.
- Operating temperatures in excess of 1,000°C
- Efficient design, suitable for large flow rates in a single unit
- Virtually no moving parts to minimize maintenance costs and downtime
- Small footprint, even for large flow rates
- Advanced thermal modeling guarantees performance
Vertical tube heat exchange technology can uniquely recover heat from a high-temperature product stream due to:
- The ability to operate at temperatures in excess of 1,000°C with heat exchange between a bulk solid and a gas, while eliminating the temperature constraint of fluid-based systems such as thermal oil or water.
- Using multiple passes on the gas side creates counter-current flow between the solid and fluid streams
- Low pressure drop on the fluid (gas) side, minimizes parasitic losses
We’ve got the team and the technology to solve your toughest energy challenges
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