Heat Reduction, Recovery & Re-Use

A multi-national flexible packaging manufacturer had an existing Bobst Lemanic Rotogravue press producing cigarette cartons. The business needed a second line to meet growing demand.

However, there was a big concern that the fuel cost to operate the associated Thermal Oxidiser would be really high.

The original Bobst press had gas fired heating for the dryers and exhausted around 40,000 m3 /hr of solvent air to the Oxidiser. The oxidiser was sized at 80,000 m3 /hr. The cost for propane gas was UK GBP 1.78 pence per kW. The gas consumption was 10.8 million kW per year at a cost for UK £192,564 and with a CO2 emission of 2,326 tonnes of green house gases.

It was estimated that bringing in a second line would increase the gas consumption to 21.6 million kW per year at a cost of UK £385,128 and 4,652 tonnes of CO2 as a green house gases.

Operational designed a bespoke optimization and airflow control system and were able to reduce the exhaust airflow from the press from 40,000 m3 /hr to 16,000 m3 /hr.

Operational UK sent Electrical and Control Engineers during installation and Process Commissioning Engineers during final commissioning.

The overall result is that the oxidiser currently consumes 9.2 million kW of gas per year with 1.994 tonnes of CO2 green house gases emitted. LPG fuel consumption has been reduced by 12.4 m3 kW, CO2 green house gases reduced by 2,658 tonnes per year, an overall reduction of 57%. This provided a return on investment in 1 year based on original gas prices.

The Engineering Manager commented: “This was a great collaboration that worked really well.”

  • Benefits: Fuel Consumption reduced by 12.4million kW per year
  • Environmental Impact: Green House Gas reduced by 2,658 Tonnes per year
  • Cost savings: UK GBP £304,831 per year
  • Payback: 1 year