Thermal recovery or cleaning of sand

An apparatus for cleaning sand used at a foundry, comprising:

• a rotating oven which has means for adjusting an inclination and rotating speed of the oven;
• a feeding apparatus which has means for dosing the sand to be cleaned into the oven;
• a heating arrangement which has a least one or more temperature sensors and one or more heat sources;
• means for removing the cleaned sand from the oven at a second end of the oven, and
• a control unit for monitoring data conveyed by one or more sensors in the apparatus and for controlling one or more actuators by utilizing the monitored data conveyed by the one or more sensors,
• wherein the inclination and rotating speed of the oven is further adjustable to adjust an advancing speed of the sand in the oven based at least in part on the amount of sand fed in and/or the monitored oven temperature,
• the apparatus further comprising a screw conveyor to cool down the cleaned sand and to recover heat,
• wherein the screw conveyor includes a double casing, and wherein heat from hot sand from the oven is releasable into a liquid flowing inside the double casing.

An apparatus for cleaning sand used at a foundry, comprising:

• a rotating oven which has means for adjusting an inclination and rotating speed of the oven;
• a feeding apparatus which has means for dosing the sand to be cleaned into the oven;
• a heating arrangement which has a least one or more temperature sensors and one or more heat sources;
• means for removing the cleaned sand from the oven at a second end of the oven, and
• a control unit for monitoring data conveyed by one or more sensors in the apparatus and for controlling one or more actuators by utilizing the monitored data conveyed by the one or more sensors,
• wherein the inclination and rotating speed of the oven is further adjustable to adjust an advancing speed of the sand in the oven based at least in part on the amount of sand fed in and/or the monitored oven temperature,
• the apparatus further comprising a screw conveyor to cool down the cleaned sand and to recover heat,
• wherein the screw conveyor has an inclination that is adjustable between upper and lower limits such that a forward end of the screw conveyor is adjustable to be lower than a tail end of the screw conveyor, and
• wherein the controller is configured to adjust the inclination of the screw conveyor such that the hotter the sand from the oven is, the less the screw conveyor is inclined.