PATHAK ELECTRICAL WORKS
Manufacturers of Scientific & Laboratory Instruments
SPECIAL OVENS
PEW-250F, PEW-250FS
Construction
Cabinet; Double-walled cabinet with an outer wall made of mild steel, and inner chamber can be of mild steel or stainless steel as required.
Insulation: Glass wool filled between the walls to a minimum thickness of 2 inches.
Door: The door is fitted with heavy chrome plated brass hinges, and it contains a 'spring and roller' type latch.
Element Cover: In PEW-250FS, the element cover is without perforations and it covers the heaters completely.
Finish: The outer side is painted with enamel paint. The inner side (in case of mild steel) is painted with heat-resistive aluminum paint.
Heating and Control
Heating: Heating is carried out by a specially designed low-rating heater.
Control: The temperature is controlled by a specially fabricated thermostat. For better accuracy and safety of the oven, Digital Temperature Controller (PEW-202) can be provided at an extra cost.
Temp. Range5OC above the ambient temperature to 250OC maximum. (up to 300OC can be provided, at an extra cost)
Accuracy: Better than ± 2OC below 80OC and Better than ± 1OC above 80OC.
Heat Transfer in 250F
In PEW-250F, hot air enters directly into the working chamber from the bottom of the oven, with the help of a motorized blower. The air is exhausted from the top ventilator. The airflow is as shown in the adjacent figure
In PEW-250FS, the hot air enters into the working chamber from the perforations made on the false side-walls. The hot air is exhausted from the top ventilator. The airflow is as shown in the adjacent figure
In this model of Special Oven, the blower is provided at the top of the oven. The heaters are mounted on the false side-walls of the inner chamber. This mechanism minimizes the heat loss and the temperature gradient. The airflow is as shown in the adjacent figure.
In this model of Special Oven, a fan (no blower) is provided on the backside of the inner chamber to obtain a horizontal re-circulation. The airflow is as shown in the adjacent figure.