摘要:
A calcining combustor for the suspension preheater of a rotary kiln cement manufacturing plant having a cooler for the clinker comprises an upright furnace vessel having an outwardly spiraling gas exhaust duct at its upper end leading to a preheater gas/meal separator and a mixing portion at its lower end; an inlet for hot combustion air from the cooler into the mixing portion; an inlet for cement meal from the preheater into the mixing portion downstream from the combustion air inlet to entrain the meal in the rising combustion air; and burners for injecting fuel into the air/meal stream downstream from the meal inlet to calcine the meal by heat released by burning of the fuel with the combustion air. The initial calcination temperature is a minimum because the combustion air atmosphere within the combustor is devoid of significant amounts of carbon dioxide and chlorine and alkali vapors typically present in kiln-off gases, and the endothermic calcination reaction absorbs heat energy to limit temperature rise within the combustor so that caking and formation of alkali and nitrogen oxide vapors is minimized. An alternative embodiment has an inlet for hot kiln-off gases into the furnace vessel at a point where substantial calcination has occurred so that both (a) calcining and (b) mixing of the calcined meal/air stream with the kiln-off gases to transfer heat energy thereto occur in a single vessel.
摘要:
Method and apparatus for the thermal treatment of finely divided material for the calcination of cement wherein the material is preheated in a multi-stage heat exchanger and later passed to a calcining furnace. The material is partly deacidified in a pre-calcination zone before entering the sintering furnace where further calcining and sintering of the material is completed. A portion of the feed material is treated with rapidly oxidizing fuel components in a pre-calcination zone in a first stage and with more slowly oxidizing fuel components in a second stage, the more slowly oxidizing fuel components being a mixture of relatively fine granulated fuel particles of substantially uniform size and larger particles of briquetted or coarsely broken fuel.
摘要:
Volatiles-rich dust and kiln gases are removed from a cement kiln by means of a special by-pass probe system located in the inlet end of the kiln. The probe system is designated to prevent the build-up of solidified volatiles-rich dust on the probe surfaces.
摘要:
The rotary combustion bed has a rotary drum with a permeable refractory lining through which air is blown during rotation of the drum and cascading of a charge of material in the drum. The air blown into the drum can be controlled to blow through various angular sections of the drum.
摘要:
In rotary tubes (1), an insert (4) which expands under the influence of heat can be moved in the radical direction in a cold outer casing (3) by means of an end plate (19) but is fixed in the axial direction, whereas other plates (20, 21) of the insert (4) have cogs (27) which are guided in sliding grooves (16) parallel to the axis due to the thermal expansion, each plate (20, 21) being provided with at least three cogs (24) and three sliding grooves (16) over its periphery.
摘要:
An apparatus for the thermal treatment of fine-grained material such as for the calcination of cement including a suspension type gas heat exchanger having a plurality of stages of progressively higher temperatures in the direction of material flow. A conduit connects the hottest stage of the heat exchanger with a rotary kiln. A combustion zone is provided within the conduit and rapidly oxidizing fuel components are introduced into this combustion zone. Slowly oxidizing fuel components are introduced into the rotary kiln in a second combustion zone.
摘要:
A method and apparatus for the production of cement clinker from a raw material containing sufficient moisture to be agglomerated wherein the raw material is dried and subsequently subjected to calcining in a series of steps including preheating, deacidification, sintering and cooling. The exhaust gases are passed from the calcining step into the drying step. The raw material exiting from the drying step is pulverized into a fine powder and then transferred directly into the preheating step without intermediate storage.
摘要:
Method and apparatus for heat treatment of comminuted raw material of the type used, for example, for the production of cement in which the material is preheated in a preheater by means of hot exhaust gases from a kiln, the material is separately calcined for the deacidification of a portion of the calcium carbonate present and is subsequently burnt to completion in the kiln. The specific improvement of the present invention involves utilizing undispersed coarse pieces of fuel for the separate calcination and conducting the separate calcination at the material inlet end to the kiln.
摘要:
A method and device for sintering materials and, in particular, limestone gravel, of very different granular size in the granular range of 5 to 50 mm, in a rotary shaft kiln with a shaft preheater and shaft cooler, are provided wherein the sintering charge of the original gravels are crushed into two or more granular fractions and are fed in a low band width to the furnace system periodically and alternately, and wherein the process gases flow through the filling or charge layers of the sintering materials. The filling layers are automatically changed in the shaft preheater and the shaft cooler in their thickness, so that the flow through resistance thereof remains constant.
摘要:
A method for the production of low alkali-cement clinker from alkali-containing raw material comprising a preheating step, a deacidification step and a sintering step utilizes a portion of the alkali-containing exhaust gases from the sintering step which are mixed with deacidified combustion gases from the deacidification step and reintroduced into the system in contact with the raw material to preheat and precalcity the raw material in a plurality of cyclones.