Additional heat recovery on Dryers

Fouling and corrosion problems limit heat recovery. Polymer economisers and air preheaters are corrosion resistant and have in-line cleaning.

Improve dryer efficiency up to 20%

Avoid fouling

Prevent corrosion

Your Dryer has additional heat recovery potential

Improve Dryer efficiency

Dryer efficiency can be improved with up to 20%, by using a polymer air preheater or economiser.

Lower CO2 emissions

Every 1% efficiency increase in your Dryer, results in 1% CO2 emission reduction.

Decrease fuel costs

The additional heat that is recovered is applied to heat up air entering the Dryer or heating up process water. 

Heat recovery on Dryers is limited by fouling or corrosion

Fouling

Heat recovery from the exhaust air stream from a drying process is difficult due to the fouling behavior of dust and product contaminants present. It is a challenge to keep the exchangers clean and to prevent  condensate flowing back to the dryer.

Corrosion

The moisture in the exhaust air in combination with corrosiveness of the dried material can create corrosion problems. Carbon steel and even stainless steel will quite often not provide the required corrosion resistance. In food applications the minimum standard is stainless steel.

How to recover more heat from your Dryer exhaust air

Use flue gas heat to warm up fresh drying air

The most important question is what to do with the recovered heat from the Dryer. The simplest and most economic solution is direct integration of the heat which means preheating the fresh air that enters the Dryer. The simultaneous presence of waste heat and need for heat in combination with short distances makes this the ideal solution. To prevent corrosion and deal with fouling, a polymer Air PreHeater which is corrosion resistant and has good anti-fouling properties is applied.

Use condensation heat to warm up process water

Other heat users could also be present on your site, like process water, cleaning water or building heating. To prevent corrosion and deal with fouling, a polymer Economiser which is corrosion resistant and has good anti-fouling properties is applied.

In-line cleaning

All HeatMatrix heat exchangers can be equipped with an in-line cleaning system. This prevents blocking of your heat recovery system. Condensate and washing liquids are collected separately and can not flow back to your drying process.

Heat recovery systems for Dryers

Polymer Air PreHeater

Warm up drying air by extracting heat from the exhaust air or flue gas. The air preheater is corrosion resistant & anti-fouling and easy to maintain and clean.

Stainless steel or Polymer Economiser

Warm up process water with waste heat from exhaust air or flue gas. The economiser is corrosion resistant & anti-fouling and is easy to maintain and clean.

Industries with waste heat recovery potential

CPVC producer Lubrizol

8% energy consumption reduction

Lubrizol is committed to enabling a sustainable world. To reduce their energy consumption on a drying process of CPVC, they wanted to recover heat from the outgoing drying air.

Before no heat was recovered from the drying air, because of the high hydrochloric acid content in it. When cooled down, through the water and acid dew point, hydrochloric acid is formed and corrosion occurs. 

A HeatMatrix polymer Air PreHeater was selected, because of its ability to handle corrosive exhaust air. Incoming cold air was heated from 10 to 56 °C, resulting in an energy saving of 169 kW. No corrosion issues were observed.

Technical Assessment of heat recovery on your Dryer

Our process engineers assess the technical feasibility of additional heat recovery on your Dryer. The potential reduction in CO2 emissions, energy consumption and costs is determined.