Since 2023, Sacmi has developed a number of projects for electrically-heated thermal machines. This report outlines the characteristics of gas-electric multichannel roller dryers, gas-electric vertical dryers, electric roller kilns and hybrid roller kilns.
Gas-electric multichannel roller dryers
The ECP and E7P dryers have one to seven roller decks and are equipped with electric heating elements alongside traditional gas generators. Although capable of fully electric operation, the presence of both heating systems means that the machines can be switched automatically to the most cost-effective energy source. This can be an advantage in the case of energy tariffs (especially in countries where electricity is cheaper) or if for example the ceramic producer has a surplus of self-generated electricity available at certain times of the day or periods of the year.
The electric generators consist of steel boxes housing a series of heating elements (coiled around ceramic tubes) that heat the air passing through them. The installed electrical power per Sacmi module (each 2.8 metres long) ranges from 80 to 300 kW, depending on the dryer’s width and number of decks.
This solution offers a number of advantages, including the option of partial electrification of the dryer thanks to its modular design. For example, in plants with heat recovery systems, hot air from the kiln’s cooling flue can be directed to modules operating at lower temperatures, while electrifying only those operating at higher temperatures. Here too, the machine automatically selects electric mode when it is more cost-effective, such as when self-produced electricity is available.
Another major advantage of this solution is that it can be quickly and easily retrofitted onto existing gas dryers.
One example is a project carried out in 2024 at a ceramic factory in Portugal, where Sacmi worked on a five-deck ECP dryer with a 2350 mm entrance width, 11.2 m length and a production capacity of around 5,500 kg/h of material with 6% incoming moisture content (equivalent to 300-320 litres/h needing to be removed). Each of the machine’s four modules was fitted with a 200 kW box, for a total installed power of 800 kW. In full electric mode, the machine’s energy consumption is 530 kW, which drops to 310 kW when kiln heat recovery is active. The dryer is connected to the facility’s rooftop photovoltaic installation and automatically operates in electric, gas or hybrid mode depending on energy availability. In the case of 990 hours/year of full electric operation (out of a total of 7,920 annual operating hours), CO2 emissions are reduced by around 100 tonnes/year.
If you want to know more, read the full article at: https://www.ceramicworldweb.com/index.php/en/technology/electric-kilns-and-dryers-towards-decarbonisation-ceramic-process
