The APO850/13 rotary furnace was designed for burnout flasks in the process of jewelry production using the lost wax method. Equipped with two rotating tables with a diameter of 340 mm, it allows for heating 13 casting flasks with an external diameter of 100 mm and a maximum height of 300 mm simultaneously. The slowly rotating tables, during the entire heating process, ensure uniform temperature distribution and do not allow local overheating of the casting molds. In addition, full control over the rotary table allows you to "place" the currently cast tray under the door, facilitating its quick removal, which shortens the time of opening the furnace door to a minimum, and thus limits the cooling of the furnace and the flasks remaining in it. The design of the tables allows for the free flow of melted wax to a container located outside the furnace. The wax from the upper table is directed in a way that bypasses the flasks puted on the lower level.

FURNACE CHAMBER

The critical zones of the chamber, such as the ceiling or door frame, have been protected with profiles made of high-quality heat-resistant steel, which protects them from mechanical damage. The width of the furnace door opening has been reduced to the width of 217 mm and the height of 700 mm, which is necessary for ergonomic work. Thanks to this, when the furnace door is opened, heat loss has been reduced to an absolute minimum.

FLAP VENTILATION

The furnace can be optionally equipped with a chimney with mechanically controlled ventilation. The user can declare in each section of the program whether the ventilation should be closed or open. This allows the ventilation to be opened in the low temperature range, when the furnace burns large amounts of wax, and closed when it is no longer needed, so as not to cool the furnace, thus saving electricity.

FURNACE CONTROLLER

The furnace is controlled by a PLC controller with a built-in 7” touch panel. Its basic tasks include: temperature control, support for 33 casting program memories, table position control, recording the course of the casting process in the history, response to power failure and return after a failure, and control of the exhaust afterburner (as an additional option).

OVERHEATING CONTROL

The furnace can be optionally equipped with an additional temperature controller, electrically separated from the PLC controller, whose only task is to supervise the limit temperature that is safe for stones set on the wax tree. In the event of an unexpected failure of any of the elements responsible for heating the furnace, the independent controller will disconnect the supply voltage to the heater in emergency mode. This controller has its own independent thermocouple. The standard disconnection temperature is set to 770 oC, but it can be freely changed. The overheating control function is activated by a key from the operator panel. This option is absolutely essential when casting with diamonds.

EXHAUST GAS AFTER-BURNING

Another optional piece of equipment for the furnace is a process exhaust gas after-burner. In the first stages of heating, when the wax is melted, the temperature in the furnace chamber in the range of up to 400-500oC is too low to initiate and completely burn the wax fumes and other products of heating the casting mass. This generates large amounts of pollutants with a strong, unpleasant smell. For full combustion of exhaust gases, a device is used, which, in a controlled manner from the level of the casting program, switches on an additional heater placed on the furnace flue. Unpleasant and harmful fumes from the furnace chamber, flowing in a forced draft through a ceramic filter heated to a temperature of approx. 500-600 oC, are burned and discharged outside the furnace. The exhaust gas afterburner is a kind of second, independent furnace, with its own heater made of high-quality steel, resistant to aggressive exhaust gases, its own thermocouple and its own temperature regulator, as well as a mechanically forced exhaust system. The exhaust gas afterburner with its forced ventilation system and the APO850/13 furnace with its high installed power and maximum temperature of 850 oC allow for heating of polymer flasks, enabling rapid heating, ventilation of the furnace chamber and burning of unwanted ashes at the highest temperatures.