Evaporation.
HRS Heat Exchangers applies its heat exchanger technology for evaporation application. Both corrugated tube heat exchangers (K series) and scraped surface heat exchangers (Unicus series) have been used with great success for evaporation purposes.
The standard way of operating of our evaporators is with forced recirculation.
In this setup, a recirculation pump is used to pump the fluid through the evaporator (at many times the flow rate of the evaporator feed). This way the fluid velocity is maintained high and elevated heat transfer coefficients are obtained in the evaporator. The forced recirculation evaporator is of special interest for applications with viscous fluids. The higher the viscosity, the worse the heat transfer becomes. Therefore recirculating with higher flow rates (by using the recirculation pump) maintains heat transfer high and keeps the evaporator design relatively small.
Scraped surface evaporation.
For many environmental applications, standard evaporation technologies (falling film etc) often cannot deliver the desired performance. As the concentration of solids increase during the evaporation process, the risk of fouling substances depositing on the tube wall increases. A fouled evaporator will drop quickly in heat transfer. The result is underperformance and the unit will have to be put offline for cleaning. Repeated downtime is not beneficial to the plants economic balance.
The solution HRS Heat Exchangers proposes is the Unicus scraped surface evaporator. We have the capacity to supply evaporators up to 100 square meters (1080 square feet) of heat transfer area. This allows us to provide solutions for heavy fouling applications in evaporation with large evaporation capacity. No other company in the world can deliver this performance with a fouling free operation guaranteed.
Multi effect evaporation & integration with dryer plant.
With multi effect evaporation an optimal way of using the available energy for evaporation can be obtained. In multi effect evaporation, the evaporated water in the first effect is used as heating media in the second effect. This process can be repeated several times. This way of 1 kg of steam invested can evaporate several kg of steam from the product. HRS Heat Exchangers applies multi effect evaporation wherever possible. Combinations of multi effect evaporation and steam compression (mechanical vapor recompression or thermo compression) can be supplied as well for further energy optimization.
Another possibility of energy optimization is combining an evaporator plant with a dryer plant. These solution works well for cases where an (environmental) waste stream is separated in solid phase and a liquid phase by mechanical separation (centrifuge, decanter). The solid phase is sent directly to an indirect dryer. The liquid phase is send to the evaporators. As energy for the evaporators we take the evaporated water of the dryer plant. The concentrate from the evaporator is mixed with the solid phase prior to sending to the dryer. This way of operating reduces to a maximum the volume of the environmental waste in the most energy efficient way possible.
Applications.
Our applications:
Environmental:
Biomass and biofuels:
Food industry: