Time：2022-09-26 Hit：

            The trolley type fuel fired roasting furnace is an industrial heating equipment that uses fuel as a heat source and is equipped with a movable trolley (used to carry workpieces). It is mainly used for high-temperature roasting, heat treatment, or sintering of workpieces such as metals, ceramics, refractory materials, etc. It is widely used in industries such as mechanical manufacturing, metallurgy, and building materials. The following is a detailed introduction about the device:
1、 Working principle
The core of the trolley type fuel fired roasting furnace is to generate high-temperature heat energy through fuel combustion, uniformly heating the workpieces on the trolley to achieve the process goal of roasting (such as removing moisture, organic matter, solidifying or phase changing materials). The specific process is as follows:
Loading and furnace feeding: Arrange the workpieces to be fired (such as shells, castings, ceramic bodies, etc.) neatly on a movable trolley, push the trolley into the furnace through the track, close the furnace door and seal it.
Fuel combustion heating: Fuel is atomized and mixed with air through a burner (such as a diesel or heavy oil burner), ignited and burned in the furnace, producing high-temperature flue gas (temperature can reach 800-1600 ℃, adjusted according to process requirements).
Heat transfer and temperature control: High temperature flue gas transfers heat to the workpiece through heat exchange (radiation, convection) in the furnace, gradually raising the temperature of the workpiece to the set roasting temperature. The furnace is equipped with temperature measuring elements such as thermocouples to monitor temperature in real time. The fuel supply and air ratio of the burner are adjusted by the control system to ensure stable temperature within the process range.
Insulation and cooling: After the workpiece is kept at the set temperature for a certain period of time (to complete the internal structural transformation), it is cooled according to the process requirements (natural cooling or forced cooling). After the cooling is completed, the trolley is removed and the workpiece is taken out.
2、 Structural composition
The structure of the trolley type fuel roasting furnace is designed around "uniform heating, convenient loading and unloading, and safe temperature control", mainly including:
Furnace body:
Furnace: Built with high-temperature resistant materials (such as fire-resistant bricks and refractory castables) to form a closed heating space, with insulation layer (such as aluminum silicate fiber) laid on the inner side to reduce heat loss, and steel structure shell on the outer side.
Furnace door: It is manually, electrically or hydraulically driven, and the contact area with the furnace body is equipped with a sealing device (such as refractory fiber sealing strip) to prevent heat leakage.
Car:
Frame: Made of welded steel sections, with wheels installed at the bottom, it can enter and exit the furnace body along the track, with a load-bearing capacity ranging from a few tons to tens of tons (depending on the model).
Tabletop: Lay refractory materials (such as heat-resistant steel grating or refractory bricks) to avoid direct contact between the workpiece and the trolley steel structure, while uniformly transferring heat.
Sealing mechanism: The junction between the trolley and the furnace body is equipped with a sand seal or air seal device to prevent cold air from entering the furnace or hot air from leaking out.
Combustion system:
Burner: The core component, including fuel pump, atomizer, ignition device, fan, etc., atomizes fuel and mixes it with air in proportion before combustion. It can automatically adjust the firepower according to temperature requirements.
Combustion chamber/nozzle: Some furnace bodies are equipped with independent combustion chambers to fully burn the fuel before introducing the flue gas into the furnace, avoiding direct contact of the flame with the workpiece and causing local overheating.
Flue and chimney: used to discharge the flue gas after combustion, some equipment is equipped with waste heat recovery devices (such as heat exchangers), which use the waste heat of the flue gas to preheat the combustion air and improve thermal efficiency.
Control system:
Temperature control system: composed of thermocouples and temperature control instruments (or PLC), it can set the temperature rise curve (such as step heating) and insulation time, achieve automatic temperature control, and the accuracy can reach ± 5 ℃.
Operation panel: Integrated temperature display, start stop button, fault alarm and other functions, some devices support remote monitoring.
safety system:
Overtemperature alarm: When the furnace temperature exceeds the set upper limit, the burner will be automatically cut off and an alarm will be triggered.
Flameout protection: When the burner stalls, immediately turn off the fuel supply to prevent fuel leakage.
Trolley interlock: When the trolley has not fully entered the furnace or the furnace door is not closed, the combustion system cannot be started to avoid heat leakage.
3、 Equipment features
Convenient loading and unloading: The trolley can be removed from the furnace as a whole, and the workpiece can be assembled and disassembled outside the furnace, reducing operational risks in high-temperature environments and suitable for batch processing of large and heavy workpieces.
Good heating uniformity: The furnace is equipped with guide plates or circulating fans (some models) to evenly distribute high-temperature flue gas. Combined with refractory materials on the trolley platform, the temperature difference between different parts of the workpiece is small (generally ≤± 10 ℃).
Wide temperature range: Depending on the type of fuel and the performance of refractory materials in the furnace, the maximum working temperature can reach 1600 ℃, which can meet the roasting needs of different materials (such as metal annealing, ceramic sintering, and shell roasting).
Strong adaptability: The furnace size and trolley carrying capacity can be customized according to the size of the workpiece, and the compatibility with the shape of the workpiece (regular or irregular) is high.
Moderate operating costs: Fuel (such as diesel and heavy oil) is relatively easy to obtain, with a thermal efficiency higher than coal stoves (about 60% -75%) but lower than gas stoves, making it suitable for areas without natural gas supply.