Let's begin our lesson on the basics of electrically heated rotary ovens!
An electrically heated rotary oven is a device that uses various energy sources to heat the combustion chamber, and then sends hot air into the furnace through a heat exchanger and a fan to bake the items inside. It is suitable for food factories, bakeries, and individual businesses for large-scale baking of bread, cakes, mooncakes, chicken, duck, meat, fish, and other foods. It can also be used for drying food. Hot air tunnel ovens are available in various models based on their heating methods, including electric hot air rotary ovens, gas-fired hot air rotary ovens, diesel-fired hot air rotary ovens, coal-fired hot air rotary ovens, and dual-purpose hot air rotary ovens.
The electrically heated rotary furnace body employs a gear transmission structure. A flange is welded to the center of the furnace body's bottom, and this flange is bolted to a flange on the rotating shaft. The rotating shaft is mounted on a central base via upper and lower bearings, forming the furnace body's rotation center. A motor, reducer, and gear transmission constitute the power source for the furnace body's rotation. When the motor is turned on, it transmits power to the transmission shaft at a specific speed ratio through the reducer. A gear is mounted on the upper end of the transmission shaft, directly engaging with a pinion gear at the bottom of the furnace shell to form a gear transmission. When the power source drives the gear to rotate, the furnace shell rotates around the central base at the bottom. At this time, the guide wheels supporting the bottom of the furnace shell act as pulleys, causing the furnace shell to rotate under a small torque. By designing specific transmission ratios for each transmission section, a certain rotation speed of the furnace shell is ensured. Simultaneously, the required motor speed is selected by adjusting the motor speed using a frequency converter.
The safety protection system consists of a burner controller and a main gas solenoid valve. Since this kiln uses liquefied petroleum gas as fuel and requires a low calcination temperature, sufficient attention should be paid to the safety of the gas used. To address this, we have installed a flame detection/automatic ignition device before each burner. If a burner experiences flameout, the system will issue an alarm signal and simultaneously switch to automatic ignition operation. If ignition fails within the specified time, the gas solenoid valve before the burner will automatically close, cutting off the gas supply and alerting personnel for assistance. The main gas pipeline is equipped with high and low pressure switches and an emergency shut-off solenoid valve. In case of excessively high or low gas pressure or a sudden power outage, the gas supply can be immediately shut off to ensure kiln safety. The rotary drum speed and feeder speed are controlled manually using a variable frequency speed control motor. All control systems are centrally controlled by two control cabinets, each equipped with a touchscreen processor.