Reasonable selection, maintenance and energy saving of burner in asphalt mixing plant

Reasonable selection, maintenance and energy saving of burner in asphalt mixing plant
The research and development of automatic control burner has formed a series of products such as light oil engine, heavy oil engine, gas engine, oil and gas dual-purpose machine. Reasonable selection and maintenance of burners can save a lot of money and prolong the service life of the combustion system. With the change of fuel demand, the quality requirements of burners are becoming higher and higher. Good ignition performance, efficient combustion efficiency and wide adjustment ratio have been the goals pursued by all construction units. However, there are many manufacturers and different brands of burners. Only when properly selected can the above requirements be met.
1、 Selection of different types of burners:
1. According to the atomization mode, the burner is divided into pressure atomization, medium atomization and rotor atomization
(1) Pressure atomization is to transfer fuel to nozzle atomization through high-pressure pump, and then mix with oxygen for combustion. It has the characteristics of uniform atomization, simple operation, low consumption and low cost. At present, most highway construction machinery adopts this atomization mode.
(2) The medium atomization is premixed with fuel through 5~8kg compressed air or pressurized vapor pressure to the periphery of the nozzle and then burned. The characteristics are that the fuel requirements are not high (such as poor oil products such as residual oil), but there are many consumables and high costs. At present, the road construction machinery industry uses this type of machine less.
(3) Rotor atomization means that the fuel is separated from the atomization through the high-speed rotor plate (about 6000 rpm) and can burn high-viscosity residual oil. However, this model is expensive, and the rotor plate is easy to wear and needs to be adjusted. At present, the highway construction machinery industry basically does not adopt this mode.
2. Burner structure: automatic control burner can be divided into gas supply system, gas supply system, control system and combustion system.
(1) Air supply system: In order to make the fuel burn completely, sufficient oxygen must be provided. Different fuels have different requirements for air volume.
(2) Fuel supply system: fuel must have reasonable combustion space and mixing space to completely burn. The transportation mode of fuel is divided into high-pressure transportation and low-pressure transportation. The pressure-type atomizing burner adopts high-pressure delivery mode, and the pressure requirement is 15~28bar. The rotary cup atomization burner adopts low pressure delivery, and the required pressure is 5~8 bar. At present, the oil supply system of road construction machinery mostly adopts high-pressure transmission.
(3) Control system: due to the particularity of construction conditions, the road construction machinery industry chooses the burner with mechanical control and proportional adjustment.
(4) Combustion system: The shape and combustion of the flame are basically determined by the combustion system. The flame diameter of the burner is generally not more than 1.6m. It is better to adjust the width, which is generally set at 1:4~1:6. If the flame diameter is too large, it will cause serious carbon deposition on the furnace barrel. If the flame is too long, it will cause the exhaust gas temperature to exceed the standard and damage the dust removal bag. It will also scorch the material or make the material curtain covered with oil.
2、 Maintenance of burner
1. Check the fuel regulating valve. If the screw or nut surface is too dirty or rusty, the regulating valve needs to be repaired or replaced.
2. Oil pump: regularly check whether the pump is in good condition and the internal pressure is stable, and replace the damaged sealing device or leakage. When using hot oil, check whether all oil pipes are well insulated.
3. The filter installed between the oil tank and the oil pump must be cleaned regularly and checked for excessive wear, which can ensure the smooth arrival of fuel from the oil tank to the oil pump and reduce the possibility of potential component failure. The "Y" type filter on the burner should be cleaned frequently, especially when heavy oil or residual oil is used, to prevent the nozzle and valve from clogging. During operation, check the pressure gauge on the burner to see if it is within the normal range.  
4. For burners requiring compressed air, check whether the pressure device produces the required pressure in the burner, clean all filters on the supply pipeline, and check whether the pipeline leaks.
5. Check whether the inlet protection device of the combustion atomization air blower is installed correctly and whether the fan housing is free of damage or leakage. Observe the operation of the blades. When the noise is too large or vibration occurs, the blades can be adjusted to eliminate it. The bearing of belt drive blower shall be lubricated and fastened regularly to ensure that the blower can produce rated pressure. Clean and lubricate the air valve connector to see whether it works smoothly. If there is any obstacle in operation, replace the accessories. Check whether the air pressure meets the use requirements.
6. Clean the fuel injector regularly and check the spark gap of the ignition electrode (about 3mm).
7. Frequently clean the flame detector (electric eye) to determine whether the installation position is correct, the temperature is appropriate, the position is incorrect, and the temperature is too high, which will lead to the instability of the photoelectric signal, even the fire.
2、 Reasonable use of combustion oil
Combustion oil is divided into light and heavy according to its viscosity. Light oil can obtain good atomization effect without heating. Before using heavy oil or residual oil, heat it first to ensure that the viscosity of the oil is within the allowable range of the burner. The results can be measured with a viscometer to find out the best heating temperature of the fuel oil. The residue sample should be sent to the laboratory in advance to determine the heating value. After a period of use, check and adjust the burner for heavy oil or residual oil. When inspecting the dryer and bag-type dust remover, the combustion gas analyzer can be used to detect whether the fuel is fully burned and whether there is oil or oil smell to avoid fire and oil pollution blocking. Due to the change of oil, the accumulation of oil on the atomizer will increase, so regular cleaning is required. In addition, after the work is completed, first turn off the burner switch, and then turn off the heavy oil heating. When the machine is shut down for a long time or the weather is cold, switch the oil circuit valve and clean the oil circuit with light oil, otherwise the oil circuit is blocked or it is difficult to ignite.
With the rapid development of highway construction, the effective use of combustion system can not only extend the service life of mechanical equipment, but also reduce the engineering cost and save a lot of funds and energy.