Our furnaces with a temperature range of 250°C are constructed with energy saving, insulated panels with an thickness of 150 mm. The panels are made of lacquered plate on the outside and aluminised steel plate on the inside fully filled with 150 mm Rockwool insulation. The panels are built together by special profiles for the connection to floor and fully isolated edge profiles for the connection of the separate walls. Due to the special panel construction a minimum of heat transit to the outside panel is guaranteed. In general, our ovens are made according to EN 746-1 and 746-2 This part of EN 746 specifies common safety requirements for industrial thermoprocessing equipment which meets the definition for machinery given in NEN-EN-ISO 12100 and specifies the appropriate preventative measures for reduction or elimination of hazards. The EN 746 is applicable to ageing ovens and heated by gaseous fuels and electricity and specifies the safety requirements for all live stages
The heating is generated by heater systems either operating by gas or electricity. In case of gas heated ovens, the combustion of the gas will take place in a combustion chamber made of heat resistant chrome-nickel-steel. The flue gasses will be mixed with the circulation air (direct heating) or passing a stainless steel heat exchanger and taken outside the oven (indirect heating).The modulating gas burner has a wide control range to assure a variable heat regulation with a minimum of temperature deviation. In case of electrical heating the heating elements can be regulated from 0-100% by means of thyristor regulation. Max temperature safety thermostat to protect oven against overheating.
Illustration: Inspection door, fan motors and gasburner
To assure equal and quick heating of the load, the ovens are equipped with an intense air circulation system. The air circulation is generated by high volume circulation fans. The ventilators are normally placed in the sidewall of the oven. The ventilators are direct driven and equipped with cool blades to cool the motor shaft to ensure a long lifetime of motor and bearings. The air is divided by an air duct system through the entire oven. This system is equipped with air grids with adjustable flow regulation. In this way a high air temperature accuracy of +/- 3°C in the entire oven can be guaranteed.
Illustration: Air flow in the oven
Our ageing ovens are normally equipped with vertical moving doors. The door(s) are insulated similarly to the oven casing and supported by a steel frame and operate by electrical driven. Airtight closing of the door(s) by a sealing construction with double ceramic rope seal. Safety locking and motor breaks secure a safe closing and opening. The oven will be provided inside with safety cables along both sides of the oven for emergency opening of the doors.
Middle doors gives the opportunity to create multiple chamber ovens in line. This makes bigger capacity possible because less space needed before and after the oven
Also this makes possible to handle longer profiles in case the middle door is in open position.
Illustration: Typical heating curves
Our ovens are provided with a platform for maintenance purposes. Access to the maintenance platform by means of access stairs or cage ladder according to NEN-EN-ISO 14122.