All kinds of misunderstandings mentioned in this paper are not cases, for example, the brick stacks on the kiln and the gap between the kiln walls are serious over 5~6cm or more during the movement of the middle fire than the edge fire, which is the chronic disease of the handcraft kiln. Resulting in the loss of "excessive fire on the side of the central part of the kiln" and great loss. Mechanical yard blank is the only good medicine to solve this chronic disease. Pray for the colleagues to take care of them.
Misconception 1: after the ventilation gate of the tunnel kiln is adjusted, it is not allowed to touch. "Because the tunnel kiln and the wheel kiln are different, the rotary kiln is pulling the fire by the air lock, and the tunnel kiln is pushed forward by the trolley machine."
In fact, the air gate of tunnel kiln is just like the furnace door of coal-fired stove to control the wind pressure and air volume entering the kiln chamber. When you cook, you need a fire. When you open the stove door, you need a small fire when you boil it. The door must be kept a little smaller.
It is the same that the haufeng sluice of the tunnel kiln is the same. The bridge type sluice should be used when the residual moisture of the brick blank of the kiln is high.
Tunnel kiln does not work in vacuum, and the external environment, product specifications and varieties have a certain impact on the fire situation inside the kiln.
In summer, the air temperature is high, the temperature of the kiln itself is higher, and the temperature of the brick into the kiln is faster. Winter is the opposite.
In the rainy season, the relative humidity and air pressure of the air are relatively high. The flue gas and water vapor in the kiln are difficult to discharge.
When the fire direction and the wind direction coincide, the fire speed will increase, and the fire will decrease slightly, so we need to adjust the damper to make the basic balance.
The high temperature in the kiln needs to reduce the oxygen limitation, and the air brake should be reduced properly.
The abnormal high temperature of the roasting zone should increase the heat preservation gate of the moisture retaining and cooling belt, and restrict the air flow into the baking zone, so as to make the oxygen pressure and fire pressure of the roasting zone.
For roasting solid brick, the sintering time should be extended properly, the calcination zone at high temperature should be longer, and the thin wall hollow brick should be thin and weak, and the baking time at high temperature should not be too long.
When the tunnel kiln is limited in production, it is necessary to reduce oxygen and sluice.
It is known: the Kazakhstan is the main production tool of the kiln workers, "can not touch the wind gate" is the kiln worker to face the complex and changeable production conditions "Disarm surrender", how do the kiln workers "decide the work policy according to the specific circumstances"?
Misunderstanding two: tunnel kiln normal production can use inverted step gate.
3.2m wide 130m long two times code burning tunnel kiln, long use of inverted staircase, adding heat amount of 400kcal/kg raw materials, one day can only produce more than ten cars, "fire is burning not to go", the output is only half a little more than half of the design productivity. It is said that "tunnel kiln is this".
Among them, a group of two tunnel kilns in Ya'an, Sichuan, some people tried to change the inverted staircase sluice into a step sluice. Because of the rush, the "inverted ladder" was transferred into a "step ladder" at one time. As a result, the fire in the kiln was disorderly and the whole line was low at low temperature. The conclusion of the inverted staircase sluice.
It is correct to change to step gate, but the operation is improper.
Because of the long-term use of the inverted ladder gate, the fire of the inverted step gate has been turned into a "step by step".
A step-by-step adjustment plan has been worked out for this purpose.
(1) the lift range of the sluice is not more than 4cm;
2. At most, only two gates must be moved up and down.
3. Each adjustment interval is 1 to 2h, adjusted 12 times in place, 24h completed.
We must pay close attention to the fire and do not mutate, otherwise we should revise the plan.
And compiled a scheduling order for them. The list is as follows:
The next day was adjusted and the fire was completely normal.
A month later, it was learned that the raw material was reduced to 320kcal/kg, and the output doubled, and the quality was much better.
Misunderstanding three: the waste heat sluice is not used
A two code kiln tunnel kiln was blocked when it was put into production because it had no use.
There are no special waste heat gates in the rotary kiln, but each of them has two functions. To lift the pre tropical haufeng sluice, which is used for exhaust gas and water vapor, is the roasting sluice, and the haufeng sluice for lifting, discharging and cooling belt is used to pump out the heat in the kiln, is not the waste heat sluice?
The amount of air required for drying bricks is greater than that required for sintering. The wind in the tunnel kiln comes in from the tail of the kiln, through the cooling belt, the heat preservation belt, the calcined belt, and the preheating dry belt. If all the wind moves forward in turn, the amount of wind in the calcined belt is "oversupply", and the cold wind burns the hot air to consume energy, so several pairs of heat insulation and cooling zones in the tunnel kiln are set up. In the waste heat sluice, the hot air which is heated by the heat of the cooling belt is brought in from the tail of the kiln and is directly sent to the drying pre tropics through the waste heat pipe. It not only guarantees the amount of air needed for baking, but also uses the remaining heat of cooling and insulation.
In fact, the use of heat recovery sluice installed in the heat preservation cooling zone will never stop this. If necessary, it will still be "life-saving brake".
When the calcination belt appears abnormal high temperature, high heat sluice is lifted, a large number of hot wind is removed, the waste heat path is directly entered into the waste heat and dry belt, and the amount of air entering the calcined belt is pressed to the lowest level, so that the calcined belt can not be burned up seriously, as if the door of the honeycomb coal stove is closed, the fire can not be burned up, and the high temperature also cooling itself.
Misunderstandings four: what's the use of the Bottom Sluice
A brick tunnel kiln has long been "a bit under fire" in the bottom one or two layers of the four sides, and the set of the Bottom Sluice "never used", because "there is no brick under the car".
It is necessary to know that in the work of the tunnel kiln, the fan is constantly pumping, and the kiln car's surface is all negative pressure. There is no wind under the kiln. It is atmospheric pressure. It is higher than the negative pressure on the surface of the kiln car. A large number of cold wind is coming up from the kiln.
In the operation of the tunnel kiln, it is hoped that the air pressure of the kiln car is zero (zero pressure point), the cold wind of the bottom of the kiln does not come, the fire on the surface of the kiln can not go down, neither the under fire brick nor the bearing of the kiln car will be burned out.
When the bottom brake is properly lifted, the bottom of the car is also pumping air, and the cold wind beneath the kiln car will not go up.
Misunderstanding five: "the fan opens the small point, saves the electricity"
In fact, no fan is more electricity saving, but it does not burn bricks.
A brick tunnel kiln, the fan frequency conversion often only open 25Hz, at this time the fan speed only half of its rated value, also said, "the fan is large, open half the wind is also enough", but "the fire is not moving."
It is necessary to know that when the tunnel kiln burns bricks, it not only needs enough air to promote coal combustion, but also must have enough wind pressure to press the wind from the tail of the kiln to the head of the kiln to enter the air, the wind is not enough, the wind is "running".
The characteristics of the fan are:
(1) the air volume is proportional to the speed. That is to say, the speed of the fan is reduced by half and the air volume is reduced by half.
(2) the wind pressure is proportional to the square of the speed, that is to say, the speed of the fan is halved, the wind pressure is only 1/4 of the original, of course, "the fire is not running".
(3) the shaft power of the fan is proportional to the cube of the speed, the speed is reduced by half, the power is only 1/8 of the original, and of course the electricity is saved.
Therefore, we must pay close attention to whether there is any negative pressure on the kiln tail when changing the speed of the inverter fan.
The way is: open up a newspaper, close to the end of the last kiln car brick stack, hand a loose newspaper can be sucked, "put on the brick" to show that the wind pressure of the fan enough.
Misunderstanding six: bake with a burning belt
Some brick and tile calciner furnace, immediately after the completion of the burning of bricks, the result is the kiln body cracking, air leakage, said, "the quality of the kiln is not good", and think that "the kiln is heating heating, brick or heating heating is the difference?"
When the kiln is built, a large amount of water is needed for brick, mud and sand slurry. Only red brick is used as an example, its water absorption rate is more than 20%. After a piece of brick water is soaked, water content is more than 0.5kg, a kiln of kiln, the water content of brick is more than 500t, and the sand slurry used in masonry is added to the natural water content in the fill, and the total water content of the newly built kiln is more astonishing. That's right. The water is heated to become vapour, which is more than 22.4 times the volume of the original water.
These water vapor can only be squeezed out of the bricks in the kiln.
Misunderstanding seven: all of the fire holes on the top of the kiln on the top of the tunnel kiln are all open after the ignition of the tunnel kiln.
All the fire holes are negative pressure, and the air suction into the kiln is closer to the entrance of the kiln. The greater the suction, the less the suction.
The tunnel kiln in normal operation should only have an inlet, that is, the kiln room above the surface of the truck, so that the fan is pumped through the air vent (tide), and the air is pumped into the air through the cooling belt, the heat preservation belt, the calcined belt, the pre tropical Zone, and the dry belt into the air vent, the flue, the fan and the fan. Now the top of the kiln is all the entrance to the air, and the wind is just a short cut, so the closer the suction force is, the more the fan has been full, which can take care of the end of the end of the kiln?
In this regard, first from the entrance to the entrance of the kiln to close the top of the "row of the tide", and in order a row of rows of places to cover a good fire, each time seal a row of tide or cover a row of fire, each time 0.5 to 1H, after a day and night, "fire go forward".
Misunderstanding eight: "one day to burn 68 sets of kiln car bearings, the quality of the bearing is too poor."
After investigation, the retaining walls on both sides of the kiln were completely broken, and there was not a grain of sand in the sand sealed trough. Before the kiln enters the kiln, "someone specially pumps oil for the bearings, but the kiln car oil is dried up", and the bearings are all blue and purple. From the sides of the kiln to the kiln, the sides of the car are all flare in the baking zone.
In tunnel kiln, the retaining wall of sand seal trough on both sides of the kiln not only holds the sand in the sand seal trough not to be lost and the sand layer should be thickness, but also forms a zigzag seal with the sand seal plate on both sides of the kiln car. During operation, the sand seal plate on both sides of the kiln is inserted into the sand layer 50 ~ 80mm to separate the air of the kiln car surface and the bottom of the kiln, so that the cold wind of the car bottom can not go up, the hot wind on the car will not come down, in order to keep the sand often enough, the "Gaza steel pipe" is also set on both sides of the kiln wall, and the dry sand without mud and water is injected.
Now these facilities are no longer, even if the full negative pressure roasting "hot wind does not go down" roasted the heat produced by high temperature above 1000 degrees centigrade, roast the oil in the bearing. The bearing is also baked into blue purple (the coal gangue brick of the kiln is sintered at a temperature greater than 1020 degrees Celsius). Therefore, in operation, it is essential to keep the sand seal plate, the sand sealing groove and the sand thickness enough.
Misunderstanding nine: the protection of the heavy kiln and the maintenance of the light kiln car
The result is:
(1) the kiln car "kiln shaft", when running on the track, the body swings less and less 6, 7mm, and more than 10 mm, hang both sides of the kiln wall, hanging sand seal plate, sand seal groove, kiln wall, even "the top car can not move on top".
(2) the surface of the car is uneven, and the tiles around the kiln cars are all in disorder.
The result is that the bottom of the brick is not fractured or deformation, the slime on, a kiln will be dried and shedding, the kiln on both sides of the earth slag is filled into the car "can not move".
Note: the surface of the kiln car is the flat surface of the tunnel kiln, or the tunnel kiln. The ground is not flat, and the tables and chairs are not stable. Can the brick be broken, broken and poured?
The brick is more than a dozen yards on the kiln car. "Grab a kiln ash and lay it flat". Is it still flat? The brick layer on the side of the kiln car is unavoidable to collide with the left and right sides.
It should be, a bad brick face brick, change a good car face brick and should be leveled, fill a solid, less a block of brick layer, the loss will be ten or more of the cushion and finished bricks.
In addition, the kiln surface is not only the kiln bottom to hold up the brick stably, but also endure the severe test of high temperature when roasting, and it must have enough heat insulation and heat insulation function to make the car face as little as possible down the bottom of the car, so as to avoid burning the bearing. Otherwise, not only can not protect the bearing, a lot of heat run away from the bottom of the car, can the coal consumption of the brick be not high?