This Technical Note reviews the implementation, annual energy savings, payback period and estimated annual greenhouse gas reduction of the installation by CBA Associate Member Bernini Impianti. The technology comprised two groups of heavy oil burners where each group was equipped with 20 points of fire, divided on two zones with two thermo-regulators and two thermocouples.
Although there are not very many tunnel kilns firing with heavy furnace oil in South Africa, this project provided an ideal test for the hypothesis that new equipment incorporating recent technical advances can offer significant energy efficiency benefits.
- Heavy oil that did not burn properly and ended up under the brick packs and kiln car.
- A lot of time wasted on excessive maintenance and cleaning
- Presence of dark fumes delivered to the atmosphere
- High percentage of waste in the final product due to very poor pulverization of the oil and consequent bad combustion.
- Control of temperature inside the kiln not accurate.
Key findings of this Technology test
The post-implementation period recorded a 12.0% increase in the quantity of bricks packaged for sale. A portion of this came from an increased throughput of 4.6% but much can be attributed to the waste reduction of 6.1%. This waste reduction can be attributed to more even and effective burning of the fuel which serves to optimise the energy obtained from the fuel and minimise any negative effects such as flame impingement.
Despite the increased throughput, overall energy consumption dropped by 2.8% (estimated annual reduction of 1 220 283 kWh from baseline) which can be attributed to the 7.1% reduction in unit energy usage.
Simple payback could be achieved in <5 months.
The post-implementation period did not allow enough time to complete emissions monitoring. Nevertheless, the smoke plume from the stack has decreased significantly and the quantity of unburnt oil that was passing through the kiln car decks below the replaced burner banks has been eliminated.