Trolley type natural gas heat treatment furnace

Trolley type natural gas heat treatment furnace has the advantages of energy saving, low consumption and high economic benefit in many heat treatment equipment, which depends on the cooperative operation of various components. The trolley adopts anti-collision sealing brick, the furnace door adopts spring type pressing mechanism, and the trolley and the furnace door are sealed automatically. They are integrated and connected with rails. They can be used without foundation installation and placed on the horizontal ground. Furnace function: suitable for quenching, annealing and aging of high chromium, high manganese steel castings, nodular cast iron, roll, steel ball, 45 steel, stainless steel and other mechanical parts.

1. The natural gas trolley furnace uses various combustion gases as the medium and is heated by various burners with a higher temperature of 1200 ℃.

2. The framework of the furnace body is made of various large and medium-sized section steel by on-site combination welding. The shell sealing plate is color steel plate, and the high aluminum all fiber fire-resistant throwing carpet module is furnace lining. The sealing and energy-saving effect is obvious.

3. The trolley frame is composed of various large-scale I-beam, channel steel, angle steel and thick steel plate.

4. All wheels of the trolley are driving wheels, and the drive is reliable. The transmission system adopts the "three in one" motor reducer installation mode of shaft mounted, with compact structure, firm assembly, flexible access, simple operation and convenient maintenance.

5. The trolley fire-resistant masonry adopts high aluminum shaped brick structure, which has good sealing effect with the furnace body and high compressive strength. Put sizing block on the trolley surface for stacking workpieces. All the side plates of the trolley are poured to ensure that the car body is not deformed and durable. The sealing of furnace car and furnace lining adopts the automatic pressing structure of fire-resistant fiber sealing block electric push rod. The opening and closing of the side seal are interlocked with the in and out of the furnace car.

6. The furnace door adopts the combination frame structure of high aluminum all fiber fire-resistant throwing silk blanket and section steel, the electric hoist rises and falls, and the sealing mechanism of the furnace door adopts the long and short lever spring type automatic pressing cam mechanism and the soft edge sealing device. Ensure that there is no friction between the upper and lower parts, easy and free, safe and reliable.

7. The chimney is equipped with automatic furnace pressure control, butterfly valve, etc., which can adjust the cooling speed.

8. High speed burners are used for heating, with both sides evenly distributed. Continuously proportional combustion. The actuator regulates the air volume, and regulates the gas volume through the proportional valve to achieve the air-fuel proportional combustion. The gas and air volume are set with the lower limit limit. The gas pipe of each burner is equipped with a control solenoid valve. Each burner is equipped with an independent and complete combustion controller, with automatic ignition, flame detection, and automatic cut-off of fire alarm. This fully ensures the stability and safety of the combustion temperature control system.

9. Characteristics of burners

The high-speed burner is to realize the complete combustion of fuel and combustion supporting air in the combustion chamber. The high-temperature gas after combustion is ejected at the speed of 100m-150m / s, so as to strengthen the convective heat transfer, promote the air circulation in the furnace, achieve the purpose of uniform furnace temperature, and make the heat preservation uniform at ≤± 10 ℃.

a. Small volume of combustion chamber

b. High combustion gas outlet speed

c. Large proportion of burner adjustment, 1:10

d. Automatic ignition and flame monitoring

e. Failure alarm function of each burner

f. Low pressure protection of each combustion air

g. Safety control of large and small fire interlock of each burner

h. Combustion status display, fault alarm display

i. Design, modification, preservation and printing of temperature curve

j. Operation prompt

k. Combustion supporting fan control (switch), furnace door control (switch), air-fuel ratio control and process safety interlock control of trolley type natural gas furnace.

10. Preheater

GC type tubular heat exchanger is used to increase the preheating temperature of air. When the furnace temperature is 1000 ℃, the air temperature is preheated to 300-350 ℃.

Simultaneous interpreting heat transfer coefficient of GC type high efficiency inserting heat exchanger, the air side pressure loss is lower than the general insert heat transfer, and its value is about 1500Pa, thus reducing the power consumption.

When the flue gas temperature is 600 ℃, the comprehensive heat transfer coefficient is above 45W / m2 ℃, and when the flue gas temperature is ≥ 900 ℃, the comprehensive heat transfer coefficient is above 55W / m2 ℃.

The heat exchanger is designed with heat-resistant steel and stainless steel according to different temperatures, and the measures of temperature homogenization and thermal stress elimination are adopted in the arrangement.

11. Control system

The system mainly regulates and controls the flow of gas pipeline, the flow of flue gas and the dilution air volume of each furnace through the detection of furnace temperature and pressure, and is equipped with a quick cut-off device of natural gas main pipe.

The high and low furnace pressure has a great impact on the use effect of the heating furnace. When the furnace pressure is high, the furnace gas will rush out of the sealing gaps of the furnace body to form air flow erosion, which has a great impact on the compression of the furnace door and furnace bottom sealed with fiber materials. At the same time, the high temperature air flow will also have an impact on the surrounding environment and control devices of the furnace body. When the furnace pressure is low, the cold air is drawn in from the sealing gap, which not only increases the oxidation of the workpiece, but also causes the high temperature in the furnace to be rapidly drawn out by the negative pressure, resulting in fuel waste. Therefore, the flue gas duct is equipped with a furnace pressure measuring point to control the electric regulating flue gas valve, so as to keep the furnace pressure in a micro positive pressure state.

The furnace is controlled by zone furnace temperature, each zone is equipped with a thermocouple, and the measured temperature enters the multi-point recorder to track and record the temperature in the furnace.

12. Safety interlock system

The safety interlock between the trolley and the furnace door. When the furnace door is not opened to a certain position, the trolley will lock in and out, and when the sealing of the trolley is not opened, the trolley will lock in and out.

If the pressure of air, gas and compressed air fails to meet the specified requirements, the combustion of burner will not be started. If it is burning, it needs to be closed.

13. Main features of the equipment

1. The energy-saving effect of the trolley furnace is good: the lining of the furnace body is all made of high alumina refractory fiber. Compared with the refractory brick, the thermal conductivity is small and the heat capacity is small, so the thickness of the refractory layer is small and the heat absorption is greatly reduced.

The equipment adopts a high-speed temperature regulating burner system, with high spraying speed up to 100 m / s, which can effectively mix the furnace gas. The furnace temperature is uniform, and the burner system burns completely, making full use of the fuel. With the zero position control and full sealing technology of furnace pressure, the maximum joint surface (the sealing surface between the furnace car and the furnace body) is at the zero position furnace pressure, the furnace gas does not leak out, and the cooling gas does not seep in, so that the heat energy generated by combustion can be effectively used.

2. High degree of automation: the furnace door and furnace car are all electric, with operation console, and the operator can easily control the operation of the furnace door and furnace car. The furnace door and furnace car have stroke control, and can automatically stop running when reaching the limit position to ensure safety.

The combustion system has a complete set of ignition, large and small fire operation, detection, flameout alarm, flameout cut-off and re ignition functions, and each set of burner has an independent control box, which can be controlled separately. Each control box interface can be connected with the temperature controller between instruments, so that the whole system can be controlled automatically.

The pipeline parameters are controlled automatically. The pipeline pressure of combustion supporting air and fuel can be set and adjusted automatically, so that the combustion supporting air and fuel quantity can be controlled at a reasonable ratio, so as to ensure high combustion efficiency and eliminate black smoke.

Automatic control of furnace pressure: compare the furnace pressure signal with the set value through the pressure transmitter, transmit the signal to the actuator of the chimney, and automatically control the pressure in the furnace by changing the opening of the chimney.

The temperature control in the furnace adopts advanced intelligent digital display temperature controller, which forms a closed-loop control with temperature measuring elements and automatic burning nozzles. It has high precision, high flexibility, anti-interference and high reliability. The temperature control system can automatically calculate, operate, display and store the heat treatment production process curve to realize the whole process control.

The instrument cabinet is equipped with operation value display of temperature, furnace pressure, burner and pipeline parameters, abnormal alarm and emergency protection measures to ensure that the operation meets the operation specifications.