Heat recovery and flexibility - the new Recu system

Heat recovery and flexibility – upgrade of “old” spray dryer installations

Energy costs and flexibility to switch from one energy source to another has a high influence on the operating costs and efficiency of a spray drying plant.

SiccaDania has specialized in upgrades of existing spray dryer plants. Spray drying plants are among some of the most energy-consuming processes in the world. Many kilowatts are consumed to remove water from liquid to make powder by the means of hot air.

Old spray dryers in production today do not utilise the exhaust heat from the dryer. This means that these systems throw away a lot of energy which can be recovered.

By installing a recovery system or RECU system it is possible to utilise the many unused kilowatts thereby improving the process economy and reducing your production’s CO₂ footprint.

Additionally, if the process is running on gas, which today is a risky source of energy in some areas of the world, it can be a good idea to install flexible energy sources such as oil, electricity or steam which all can be a supplement for the natural gas supply.

Below please find an example of how fast a small investment into a RECU system will give a very high return rate.

The new system for recuperation of the hot exhaust gas is as follows:

Example:

A spray dryer which requires 95,000 kg of air per hour during the whole year with changing ambient temperatures will have the following scenario.

Design ambient temperature 10°C

Pre-heat with recuperated exhaust air to hot water to 46°C- saving 965 kWh/h

Winter ambient temperature -20°C

Pre-heat with recuperated exhaust air to hot water to 27°C- saving 1244 kWh/h

Summer ambient temperature 25°C

Pre-heat with recuperated exhaust air to hot water to 52°C – saving 751 kWh/h

Energy cost savings per year:

An annual saving over a year regarding an average ambient temperature:

Based on 7,500 hours of production will be 1000 kwh * 7500 h = 7,500,000 kWh

Based on price per kWh 0,34€/kwh= €2,550,000/year

The CAPEX for the installation will be paid back within 6 months.