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 burners have formed a series of products such as light oil machines, heavy oil machines, gas machines, and oil-gas dual-use machines. Reasonable selection and maintenance of burners can save a lot of money and prolong the service life of the combustion system. With the change in fuel demand, the quality requirements of burners are getting higher and higher. Good ignition performance, efficient combustion efficiency, and wide regulation ratio have always been the goals pursued by all construction units. However, there are many manufacturers of burners with different brands, and only a proper selection can meet the above requirements.

First: 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 deliver fuel to the nozzle through a high-pressure pump for atomization, and then mixing with oxygen for combustion. It has the characteristics of uniform atomization, simple operation, fewer consumables, and low cost. Now, most highway construction machinery uses this atomization mode.

(2) The medium atomization is to premix and burn the fuel with 5-8KG compressed air or pressurized vapor pressure to the periphery of the nozzle. It is characterized by low fuel requirements (such as poor oil products such as residual oil). However, there are more consumables and higher costs. At present, the road construction machinery industry uses fewer such models.

(3) Rotor atomization refers to that the fuel is separated from the atomization through the high-speed rotor tray (about 6000 RPM) and can burn high viscosity residual oil. However, the price of this model is expensive, and the rotor is easy to wear, so it needs to be adjusted. At present, the road construction machinery industry basically does not adopt this mode.

2. Burner structure: the automatic control burner can be divided into the gas supply system, gas supply system, control system, and combustion system.
(1) Air supply system: in order to completely burn the fuel, sufficient oxygen must be provided. Different fuels have different requirements for air volume.

(2) Fuel supply system: the fuel must have a reasonable combustion space and mixing space before it can be completely combusted. The transportation mode of fuel is divided into high-pressure transportation and low-pressure transportation. Among them, the pressure atomizing burner adopts the high-pressure conveying mode, and the pressure requirement is 15 ~ 28bar. The rotary cup atomizing burner adopts low-pressure transmission, and the required pressure is 5 ~ 8bar. 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 selects burners with mechanical control and proportional regulation.

(4) Combustion system: the shape of flame and combustion is basically determined by the combustion system. The flame diameter of the burner is generally not more than 1.6m, and it is better to adjust the width, which is generally set at about 1:4 ~ 1:6. When 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 cloth bag. It will also scorch the material or make the material curtain stained with oil.

Second: Burner maintenance
1. Check the fuel regulating valve. If the screw or nut surface is too dirty or rusty, repair or replaces the regulating valve.

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, so as to ensure that the fuel can reach the oil pump smoothly from the oil tank 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 being blocked. During operation, check the pressure gauge on the burner to see if it is within the normal range.

4. For the burner requiring compressed air, check whether the pressure device generates 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 casing is damaged or leaked. Observe the operation of the blade, and adjust the blade to eliminate excessive noise or vibration. The bearings of the belt drive blower shall be lubricated and tightened regularly to ensure that the blower can produce rated pressure. Clean and lubricate the air valve connector to see if 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 injection nozzle 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, whether the temperature is appropriate, whether the position is incorrect, and whether the temperature is too high will lead to instability of the photoelectric signal or even fire break.

Third: Rational use of combustion oil
Combustion oil can be divided into light and heavy according to its viscosity. Light oil can obtain a good atomization effect without heating. Before using heavy oil or residual oil, it should be heated 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 fuel oil. Residue samples should be sent to the laboratory in advance to determine the heating value. After using for a period of time, the burner of heavy oil or residual oil shall be checked and adjusted. When inspecting the dryer and bag-type dust collector, the combustion gas analyzer can be used to detect whether the fuel is fully combusted and whether there is an oil or oil smell to avoid fire and oil blockage. Due to the change of oil, the accumulation of oil on the atomizer will increase, so it needs to be cleaned regularly. In addition, after the work is finished, turn off the burner switch first, and then turn off the heavy oil heating. When the machine is shut down for a long time or it is cold, switch the oil circuit valve and clean the oil circuit with light oil, otherwise, the oil circuit will be blocked or it will be difficult to ignite.

With the rapid development of highway construction, the effective utilization of combustion systems can not only prolong the service life of mechanical equipment but also reduce engineering costs and save a lot of funds and energy.