Page 174 - Demo

PRECAST CONCRETE ELEMENTS172 CPI %u2013 Concrete Plant International %u2013 4 | 2025 www.cpi-worldwide.coma standalone electrical evaporator which operates at atmospheric pressure and is available in several outputs. The system can be easily retrofitted into virtually any existing curing system which utilises some form of air circulation system. This system increases the relative humidity within the chamber by introducing steam through eight large diffusers directly into the main warm air supply duct. Water-misting based humidity addition systems with micro nozzles are still very much commonplace in the market. The AutoFog steam system offers a number of notable benefits over misting systems, including all equipment being centralized for ease of maintenance, steam is more readily dispersed into the environment, and the use of contaminant-sensitive micro nozzles is not required, making the unit more reliable and lower in maintenance. Delivering humidity in this manner, ensures that the airflow can carry the steam into the main chamber for further distribution into the curing environment. Very consistent humidity dispersion can be achieved in this way, preventing unwanted condensation in ducting and water pooling on the chamber floor. Because there are no nozzles in the chamber itself, and the nozzles installed within the duct are maintenance-free, all service work to the AutoFog can be carried out safely from outside of the curing chamber, and without disruption to production or heating and circulation within the chamber. This particular AutoFog has a large steaming capacity of 100kg per hour, ensuring a minimum relative humidity of 80% at 40 degrees Celsius can be achieved. Various size units can be supplied depending on the project. A comprehensive reverse osmosis water treatment system was supplied by Kraft to prevent scale build up within the boiling vessel. An intelligent internal control system within the AutoFog provides regular and automatic cylinder flushing to not only remove sludge build-up but also eradicate any potential risk of exposure to Legionella if the AutoFog unit is out of use for an extended period. The heart of the Kraft curing system is the Convect-Air, air-heating and circulation unit. The Convect-Air is specifically designed for this application, carousel curing chambers for the precast industry. Powerful inboard radial ventilators provide circulation within the curing chamber. The materials used in its manufacture allow for a long, reliable service life, even in high-humidity environments. In order to meet the relatively large hourly heat requirement, which includes four to six incoming steel pallets per hour along with a generous concrete load, a 500 kW heating system was calculated to be sufficient. To take advantage of a locally available, sustainably generated electricity source, Explore Manufacturing opted for an electrical resistance heating solution, including a multi-step heater control cabinet. Although this particular system is heated using an electrical resistance heating bank, the Convect-Air system is available with a number of potential heat sources including %u2013 multiple gas types, multiple Left: KC 500 Convect-Air air heating and circulation unit connected to the original ducting.Right: Electrical load cabinet which provides multi-step control of the 500 kW electrical resistance heater, designed to provide a minimum curing temperature of 40 degrees Celsius year-round.