Guide: The chain grate boiler is a kind of layer-burning furnace with a high degree of mechanization. The structure is relatively simple, the manufacturing and installation process requirements are not high, and the grate does not leak coal. It is named because its grate is similar to a chain crawler. It is an industrial boiler A furnace type that is widely used in the middle. The operation of the chain is from the beginning to the heat collection and heat absorption zone. The heat released from the coal in the middle section basically does not help much. Therefore, the coal distribution, thickness, and chain speed are also very important. .Let’s talk about some of the faults and troubleshooting methods that often occur in the chain grate boiler body or auxiliary equipment.
The chain grate boiler is a kind of layer-burning furnace with a high degree of mechanization. The structure is relatively simple, the manufacturing and installation process requirements are not high, and the grate does not leak coal. It is named because its grate is similar to a chain crawler. It is an industrial boiler A furnace type that is widely used in the middle. The operation of the chain is from the beginning to the heat collection and heat absorption zone. The heat released from the coal in the middle section is basically not helpful to the benefit. Therefore, the coal distribution, thickness, and chain speed are also very important. .Let’s talk about some of the faults and troubleshooting methods that often occur in the chain grate boiler body or auxiliary equipment.
1 Common faults of chain grate boiler
1.1 The chain grate is stuck and stops rotating
The grate of a chain grate boiler is a rotating combustion equipment. Due to poor working conditions, it is very easy to jam and stop. In daily applications, the grate has many faults and large maintenance, which affects the normal use of the boiler. Failure occurs. The performance is as follows: the motor current suddenly increases, the safety spring of the grate is bounced or the safety clutch is activated, and an abnormal impact sound is issued. The quality of the boiler material manufacturing is an important reason for the failure of the grate. The chain adjustment screws on both sides of the chain grate are adjusted Improperly, the length of the chain on the left and right sides is different. The flatness of the front and rear shafts of the grate affects the resistance of the grate and the uniformity of the stress, which is easy to cause the grate to deviate and fragment. The grate piece is broken, and one end is exposed on the grate surface. The point of the slag baffle is sometimes blocked by the tip of the slag baffle, and sometimes the grate piece falls off entirely. When the slag baffle is reached, the tip of the slag baffle sinks to support the grate. It hinders the normal operation of the grate, and in serious cases Will jam or pull off the grate.
1.2 chain grate boiler combustion chamber furnace wall and hanger are damaged
The common faults of the furnace wall include coking, cracks, tilt, loose bricks, partial fall off, the furnace tube is stuck by a hard object through the wall, and the sealed asbestos rope is burned out. When the chain grate boiler is working normally, if outside air occurs, Entering the furnace, the carbon dioxide content in the flue gas is reduced, the oxygen content is increased, the combustion chamber becomes positive pressure, the boiler bracket or wall skin heats up or even burns, which indicates that the furnace wall has more cracks and serious air leakage. The wall lining bricks are cracked or partially peeled off, which may damage the furnace wall and the hanging scroll of the combustion chamber. The reasons are: improper oven after repair, incorrect heating or shutdown method, poor quality of refractories, poor construction quality, design Unreasonable, the furnace wall hinders the normal expansion of the heated parts, or the thermal intensity is too high, the hanging fan is not cooled enough, the furnace wall is severely worn, and its wear thickness exceeds 1/3 of the original thickness, causing the boiler to often operate under positive pressure, and the furnace temperature It is too high, or the furnace wall is severely coked, and water is sprayed on the furnace wall during coking.
1.3 Uneven combustion on the grate surface of the chain grate boiler
During the operation of the chain grate boiler, the large coal at the coal gate is blocked, the speed of the coal feeder and the grate is adjusted too frequently, the opening height ratio of the coal gate is the same, or the wind on both sides is uneven, one side is large and the other is small. Less coal seams are unevenly distributed, coal feeders are not properly adjusted, coal seam control is unreasonable, air supply adjustment performance in the air chamber is poor, the main combustion area is not hot, the wind on both sides is large, red coal runs in the middle, and the coal seam on the grate appears slope , The grate is on the fire bed. There is fire on one side and no fire on the other. It is in a triangular shape. The coal particles on both sides are large and the wind is also large. The fire is early, and the slag on both sides of the wall hinders the movement of coal as soon as possible. , The length of the flame is uneven. There is a pile of coal in front of the arch, and the coal under the arch is coking.
1.4 Common faults of soot blower
The soot blower is a device that purges the heating surface of the boiler to collect soot and keeps the heating surface clean to improve the heat transfer effect, ensure the thermal efficiency of the boiler, and prevent the heating surface from coking. The soot blower is a device to prevent ash and coking on the heated surface of the boiler, and avoid the tail The secondary combustion of the flue and the air preheater plays a very important role in improving the heat transfer efficiency and ensuring the safe and economic operation of the boiler unit. Common faults include: boiler fire extinguishing, coking, soot blower pipe burned and smashed or jammed The slag machine and the air preheater are blocked or stuck. During the boiler startup, shutdown and low-load operation, the furnace flame combustion is unstable, and the air volume and pressure are not adjusted in time, which may cause the boiler to extinguish the fire. The soot blower tube cannot be caused by failure. After exiting and being burned, it will fall directly into the slag crusher at the lower part of the cold ash hopper, jam or smash the slag crusher, causing the boiler to fail to discharge slag normally.
2 How to repair chain grate boiler
2.1 Dealing with grate stuck fault
When the chain grate is stuck and stops rotating, you should immediately cut off the power supply, stop the operation, find out the cause, and eliminate it. Use a special wrench to reverse the grate for a certain distance (generally reverse 2 to 3 groups of grate), and continue to run if there is no abnormality If the chain is still stuck after starting, you can check the tightness of the safety spring of the grate, if necessary, tighten it appropriately, and then start again, if the starting does not get stuck, you can continue to run. Repeated two or three times and can not start The furnace should be stopped immediately for maintenance. If a large piece of coke slag is accumulated at the slag baffle and jams the grate, you can put a fire crowbar at the fire door to break the coke slag or lift the tip of the ash baffle to let it burn. The slag falls into the ash hopper. If the operation cannot be resumed in this way, the furnace should be shut down for maintenance. If the fault time is long and the superheated steam temperature cannot be maintained, the main steam valve should be closed. The dust accumulation in the air chamber is timely removed to facilitate the normal air supply, and the furnace beam can be Cooling. If the falling coal ash is not removed in time, it will burn due to the high temperature in the furnace and burn the furnace beam track. In addition to the correct and timely operation of the boiler operator, the rocker or tie rod should be labor-saving and reliable. The friction surface is polished, and the effect of thermal deformation is fully considered. The grate stops due to the failure of the grate gearbox, and the furnace should be shut down for repair.
2.2 Dealing with the damage of furnace wall and hanging scroll
When the boiler steel frame, hollow beams are burning red, and the furnace wall is in danger of collapsing, the furnace should be stopped urgently, and manual repairs should be organized. For example, the damage area of the furnace wall or hanging snail is not large, and the degree of damage is not serious. Coefficient, reduce the combustion temperature or reduce the evaporation capacity to maintain a short-term operation.If the furnace wall has a large damaged area, which causes the surface temperature of the furnace wall to rise above 200°C, the furnace should be stopped immediately and repaired or rebuilt.
2.3 Treatment of uneven combustion on the grate surface of the chain grate boiler
Remove the large coal, use the fire hook to evenly mix the coal on the grate, adjust the speed of the coal feeder and the grate, adjust the coal gate or reduce the wind speed of the air inlet, so that the large particles of the coal bucket roll to the sides, and the herringbone can be added. If the baffle or more coal is placed, the side wall should be sloped to the outside to avoid slagging to prevent coal.
3 Preventive measures for common failures of chain grate boilers
Improve the operation level of operation and maintenance personnel, prevent misoperation, and avoid boiler overpressure. Improve the quality of maintenance personnel, strictly implement the maintenance process, strengthen spot inspections, regularly clean and check the leakage detection device of the furnace tube, and regularly add bearings and gearboxes Lubricants and greases. Develop emergency plans, find problems in time and deal with them in time.
The chain grate can control the thickness of the coal seam and the structural characteristics of self-cooling. The boiler has stable combustion conditions, high thermal efficiency, convenient operation and operation, low labor intensity, and low smoke emission concentration. It should be strengthened during use and timely Find the problem and deal with it in time. This article analyzes the causes of the chain grate stuck and stalls, the combustion chamber wall and hanging snails are damaged, and the burning on the grate surface is uneven, and specific repair methods are proposed.
In short, there are many reasons for chain grate boiler equipment accidents. Corresponding countermeasures should be formulated for each reason and gradually solved to avoid various accidents and unsafe phenomena caused by this. The operation of equipment should be strengthened. Maintenance and management to ensure the safe and economic operation of boiler equipment.