Writer： admin Time：2021-04-16 00:00 Browse：℃
1 Reasonable selection of burners for asphalt mixing plant 1.1 The burner is divided into pressure atomization, medium atomization, and rotary cup atomization according to the atomization method (1) Pressure atomization is a highpressure pump that delivers fuel to the nozzle for atomization and then mixes and burns with oxygen. It is characterized by uniform atomization, simple work, fewer consumables, and lower cost. At present, most road construction machinery All use this type of atomization model. (2) The atomization of the medium is through the compressed air of 58kg or pressurized vapor pressure to the periphery of the nozzle and the fuel for premixing after combustion. The characteristic is that the fuel requirements are not high (such as residual oil and other poor oil products), but There are more consumables and higher costs. At present, the road construction machinery industry uses fewer models of this type. (3) Rotary cup atomization is to remove the fuel from the atomization through a highspeed rotating cup disk (about 6000 rpm). It can burn poor oils, such as highviscosity residual oil. However, the model is expensive, and the turntable is easy to wear, which requires high debugging. At present, this type of machine is basically not used in the road construction machinery industry. 1.2 The burner can be divided into an integrated gun type and a split gun type according to the machine structure (1) Allinone gun machine is a combination of fan motor, oil pump, chassis and other control components. It is characterized by small size, small adjustment ratio, generally 1:2.5, and highvoltage electronic ignition system is mostly used, which is lower in cost, but High requirements for fuel quality and environment. Equipment with a discharge below 120t/h and using diesel as fuel can choose this model, such as the German Weishaupt. (2) The split gun machine divides the main engine, fan, oil pump unit, and control components into four independent mechanisms. It is characterized by large volume, high output power, gas ignition system is mostly used, and the adjustment is relatively large, generally 1:4~1:6, even up to 1:10, low noise, low fuel quality and environmental requirements. The road construction industry at home and abroad mostly uses this type of model, such as British Parker, Japanese Tanaka, and Italian ABS. 1.3 The structure of the burner Automatic control burners can be divided into air supply system, fuel supply system, control system, and combustion system. (1) The air supply system must provide sufficient oxygen to completely burn the fuel. Different fuels have different air volume requirements. For example, 15.7m3/h of air must be distributed for each kilogram of oil to be completely burned under the standard pressure of No. 0 diesel. To completely burn heavy oil with a calorific value of 9550Kcal/Kg, 15m3/h of air must be distributed. (2) The fuel supply system must provide reasonable combustion space and mixing space for complete combustion of fuel. Fuel delivery methods can be divided into highpressure delivery and lowpressure delivery. Among them, the pressure atomization burner adopts the highpressure conveying method, and the pressure requirement is 1528bar. Rotary cup atomizing burner adopts low pressure conveying mode, and the pressure requirement is 5～8bar. At present, the fuel supply system of the road construction machinery industry mostly adopts the highpressure conveying method. (3) Control System The road construction machinery industry uses burners with mechanical control and proportional adjustment due to the particularity of its operating conditions. (4) Combustion system The flame shape and combustion completely depend on the combustion system. The flame diameter of the burner is generally required to be no more than 1.6m, and the adjustment is better, generally set to about 1:4 to 1:6. If the flame diameter is too large, serious carbon deposits will be formed on the furnace barrel. A too long flame will cause the exhaust gas temperature to exceed the standard and damage the dust collection bag. It will also scorch the material or make the material curtain full of oil. Take the 2000 type mixing station of our unit as an example: the diameter of the drying cylinder is 2.2m and the length is 7.7m. The maximum flame diameter cannot be greater than 1.5m, and the flame length is preferably adjustable within 2.5~4.5m. 2 Maintenance of burner (1) Pressure regulating valve Regularly check the fuel pressure regulating valve or pressure reducing valve to determine whether the surface of the lock nut on the adjustable bolt is clean and can be disassembled. If the surface of the screw or nut is dirty or rusted, the regulating valve needs to be repaired or replaced. (2) Check the oil pump regularly to determine whether the sealing device is intact and the internal pressure is stable, and replace the damaged or leaking sealing device. When using hot oil, check that 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 that the fuel reaches the oil pump smoothly from the oil tank and reduce the possibility of potential component failure. The Ytype filter on the burner should be cleaned frequently, especially when heavy oil or residual oil is used, to prevent the fuel injection nozzle and valve from clogging. When working, check the pressure gauge on the burner to see if it is within the normal range. (4) For burners that require compressed air, check the pressure device to see if the required pressure is generated in the burner, clean all filters on the supply line, and check for leaks in the line. (5) Check whether the inlet protection device on the combustion and atomizing air blower is correctly installed, and whether the blower casing is not damaged or leaking. Observe the operation of the blades. When the noise is too large or vibration, the blades can be adjusted to eliminate them. For the blower driven by the belt pulley, the bearings should be lubricated regularly and the belt should be tightened to make sure that the blower can generate the rated pressure. Clean and lubricate the air valve connection to see if the operation is smooth, and replace the accessories when there is an obstacle in the operation. Determine whether the wind pressure meets the working requirements. If the wind pressure is too low, it will cause backfire and cause the guide plate at the front of the drum and the material plate in the combustion zone to overheat. If the wind pressure is too high, the current will be too high, and the bag temperature will be too high or even burnt.
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