Sintered brick in the tunnel kiln output and quality can meet the requirements of design standards, in the process of production, often met down billet, above the fire, poor primer, squat down fire, crack, retuned, black foot brick, embossing, bread, lime burst phenomenon such as restricted the production and quality standards, lead to waste is difficult to deal with. The author according to the relevant manufacturers know situation and treatment way to say it, reference for sintered brick relevant manufacturer, is conducive to a similar situation occurred in the process of production control.
A collapsed, the kiln car setting several situation analysis
1, good code kiln car has not yet entered the preheating zone and collapsed, the reasons are as follows: one is careless operation, unstable code car; Second leg of the kang body strength is too low, can't bear the weight of the stress of slab buttress. Encounter this kind of situation, calcining zone to squat down the fire in time, the timely processing of the collapse of the kiln car, cannot make the collapse of the kiln car into the preheating zone and calcining zone.
2, collapsed in preheating zone, the main reason is that residual water into the kiln body is too high, plus the preheating zone gas relative humidity is bigger, encounter cold billet occurred condensation, make body softened and collapsed.
Solution: shorten preheating zone, by relatively centralized opened smoke to relatively scattered release of smoke, to reduce flue gas relative humidity, reduce the water body into the kiln.
Yards at a time tunnel kiln burning, when code good kiln car entering the kiln drying with several car after it collapsed, the reason is due to high water body into the kiln stove caused by high relative humidity. The solution is to strictly control the water body into the kiln, relatively decentralized instead of relatively concentrated moisture removal for moisture removal, improve the moisture removal right temperature.
3, in the calcining zone collapsed, causing reason is the temperature control, high diesel blending and uneven, to soften local bricks burnt down. This kind of circumstance commonly occur in the setting of the part.
Solution: occurrence situation, general let it continue to burn in the past, but you have to shorten the shop every time, even into the car in a row, in order to shorten the calcining zone, can also be burnt belt and pitch and coal holes or heat gate open "fire". In addition, must be timely and reasonable adjustment of the internal combustion content and its uniformity, are necessary measures.
Second, the fire, bottom go on
Cause stove fire up, bottom go bad reasons: one is exhaust equipment take power shortage, kang lower leg form, fuel ash content is too big, too much coal, at the bottom of the ash clogging under fire, make legs, poor ventilation, cause bad primer and above the fire. Second sometimes associated with the song of sealing of kiln car, the leak is serious also can make poor primer above the fire. Three yards kiln is not appropriate, kang leg too high too thin, short, cause excessive ventilation, cooling with lower cooling too quickly, after the early fire is out.
Settlement way: first of all, to find out the reason reasonably adjust the belt length, change the code method leg kang, timely adjust YanZhi gate opening, appropriate increase nearly brake reduce brake.
Above, several measures to comprehensively consider only one measures, often to no avail.
Third, squat down fire
When the equipment accident, tile is in short supply or power failure, kiln crouch fire. Squat down the fire, the first to shut down the tail door and blower, close brake, close brake also need to be very small. Such as power failure to open the wicket into car end, open the calcining zone and preheating zone between coal hole cover. Coal feeding, less frequently, try to reduce the fire line speed, even to where he was roasting.
Four, product defect elimination
Sintered brick no matter how good the firing in the kiln, if improper operation will produce all kinds of defects.
1, crack: bricks in the process of kiln firing, prone to fracture or reticular crack, there is a thin crack called hair crack. Fracture were a nalyzed and reticular crack, low body strength, preheating temperature, rapid, billet temperature vary widely in vivo and in vitro, billet evaporation speed vary widely in vivo and in vitro, inevitably destroyed the body structure, commonly known as "burst".
Solution: to extend the time of preheating, the appropriate gate, especially the lock cannot be too high, avoiding the car end temperature is too high, in addition, the residual moisture into the kiln bricks to control within 6%, to prevent the occurrence of fracture and the reticular crack is extremely important. Hair crack is caused by rapid cooled in the roasting, mainly to extend the time of heat preservation.
2, retuned: the main reason is the wet billet preheating, rapid heating up, without fully dry crack forming. Already dry bricks or stored in a humid atmosphere by furnace flue gas in the process of the tropical moisture regain adverse effects occur. Winter adobe, containing water, alternative action by frozen soluble and burnt products, cooling speed and rapid cooling, etc., are the cause of retuned sintered brick. Only eliminate the abnormal operation, can eliminate the above defects.
3, black leg brick: kang leg brick was not burning of coal and slag heap, formed surface wave blue, black stripes, commonly known as "black leg brick", in view of the fuel ash, choose high kang leg code method, the appropriate increase nearly brake (near the calcining zone), strengthen the primer, such as plus coal, should be to add add less frequently, make the fuel burn adequately. Improve tile internal combustion method, can also be taken to reduce the black leg brick.
4, embossing: the so-called embossing, brick and tile stack yards (surface) is blue or cyan embossed, as internal combustion brick, embossing phenomenon more and more common, brick and tile overlap in due to lack of fuel combustion in the absorption of oxygen, and in reducing atmosphere, reduction of the clay iron oxide of FeO or Fe3O4, is embossed in blue or green. And because of the low iron oxide, the clay has a strong role in combustion, so when roasting, quantity of liquid in stamping place than other parts, causing the area after roasting contraction deformation also is big, this is the embossed appears concave depression because of the pit. To eliminate or reduce the embossing phenomenon is the main approach to solve: should choose the appropriate code method or a change in body shape. Make a face, at the top of the overlapping area as far as possible to a minimum, extend firing cycle, make the fuel burn completely, as much as possible and to ensure that sufficient oxidizing atmosphere.
5, "bread brick" : as the adobe heating up fast, sharp vitrified tile surface, tile surface becomes solid dense, but the reaction of body produce gas is not over, a gas cannot escape through the high viscosity of the melt, lead to a significant expansion inside body, make the brick deformation, and become "bread brick". At this time should be reduced with the amount of fuel, to control the combustion rate, the excess air coefficient of appropriate, can effectively prevent "bread brick". , of course, can also increase rate of the hollow brick, but also avoid "bread brick" the reliable way to produce.
6, "lime burst" exists in sintering brick, lime particles under the action of water vapour and carbon dioxide in the atmosphere in the digestion and expansion, to make the surface of the brick happen spalling, this phenomenon is called "lime burst". Containing limestone Jiang stone material, easy to generate "lime burst". Screening and finely is effective to remove more than 1 mm diameter Jiang stone particles, using sufficient heat and heat preservation time fully, and reducing atmosphere, can make in adobe Jiang stone particles sintering and not harmful.
