CS269481B1 - Method of cement clinker and similar substances firing and equipment for realization of this method - Google Patents

Abstract

The essence of the method is that in a dropout part of the aggregate in which the calcined is separated flue gas raw material, se this feedstock is introduced continuously fluidizing air to the fluidized bed - dispersion state and de-mechanical underburn in solid residues burning solid fuel. For implementation this method can be carried out by dropping part of the cyclone separator as fluidized the chamber or may be a fluid chamber abutment either the lower part of the preheater the raw material or the outlet part of the calciner. The fluid chamber has a fluidized bed connected with fluidizing air supply and is connected by the feed of the feedstock to the rotary kiln.

Description

EN 269 401 B1 1

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for firing cement clinker and solids, and to a method for carrying out this process comprising a calcining step in which fuel is combusted, typically less valuable. In the firing of cement clinker, the predominant technology today is the firing system with precalcinations of the raw material. In the calcining stage, preferably less valuable and less solid fuels of lower calorific value and higher ash content can be burned. However, the combustion of these fuels has a higher demand on the combustion aggregate solution and requires a longer combustion time. Therefore, when calcining plants originally intended for liquid or gaseous fuels are used, fuel is often completely burned out. The feedstock then contains, at the end of the calcining path, unburned portions of fuel, which cause problems with the flowability of the feedstock in the tapered firing portions of the aggregate, or increased formation of stickers in the inlet portion of the rotary kiln. Therefore, the calcination stage is mainly adapted to use solid and less valuable fuels to prolong the combustion time, for example by molding the actual calciner chamber, extending the calcining channel, or installing a special self-contained chamber to complete combustion. However, these treatments do not usually bring about substantial improvements and increased combustion efficiency, as they increase the complexity and ruggedness of the baking agent. The above mentioned drawbacks are eliminated by the method of firing cement clinker and the like according to the invention, the principle being that in the discharge part of the aggregate in which the calcined feedstock is separated from the flue gases, the feedstock is fed continuously through the fluidizing air into the fluid-dispersion state and dispersing mechanical impurities in solid residues resulting from solid fuel combustion.

According to the invention, the essence of the first method for firing cement clinker and the like is that the discharge portion of the cyclone separator is formed by a fluidized-bed fluidized-bed chamber provided with a fluidizing air inlet, the fluid chamber being connected to the rotary kiln by a feedstock line .

The second device for carrying out the method according to the invention is based on the fact that the lower part of the raw material preheater is provided with a fluidized bed fluidized bed fluidized air supply, the outlet being connected to the rotary kiln through the feedstock.

The third device for carrying out the process according to the invention is based on the fact that the outlet part of the calcining plant is provided with a fluidized-bed fluidized bed chamber equipped with a fluidizing air supply, the fluid chamber being connected by a feedstock to a rotary kiln. An advantage of the method and the device according to the invention is that the overall efficiency of the solid fuel combustion in the calcining stage of the kiln line is increased. A suitably designed fluidized bed forms a compact discharge part of the respective aggregate, where the processed raw material is separated from the gases, which reduces the device's layout and pressure loss. The physical properties of the calcined raw material are also substantially improved in terms of flowability and sticking, which contributes to increasing the reliability of the kiln line.

The invention will be further elucidated with reference to Figures 1, 2 and 3, where three exemplary embodiments of the apparatus for carrying out the process of the invention are shown.

The furnace line of the apparatus of FIG. 1 consists of a rotary kiln 15 of a calciner X with a cyclone separator and a raw material preheater. These aggregates are interconnected for the passage of raw materials and gases. The flue gases from the rotary blower 2 are fed through the pipe 10 to the calciner 1, where the preheated feedstock is also fed through the feedstock 14 from the feed preheater 2. In the calciner 2, the solid, preferably less valuable, fuel supplied by the feed 2 is combusted. In addition, preheated air from the clinker cooler can be introduced into the calciner 7 via the preheated air, and hot gas can also be fed as fuel. using less valuable solid fuel in a fluidized bed furnace prior to calciner 2 »

Claims (4)

A method for firing cement clinker and the like, wherein the treated layer is gradually preheated, calcined, and sintered, wherein a valuable fuel is burned in the calcining stage, characterized in that in the discharge portion of the aggregate in which the calcined raw material from flue gases, is this raw material introduced continuously using CS 26? 481 81 3 of the fluidizing air supplied to the fluid-dispersion state and deprives the mechanical non-doping in solid residues resulting from the combustion of the solid fuel. 2. Apparatus for carrying out the process according to claim 1, comprising a calciner with a separator, a rotary kiln and a raw material preheater, characterized in that the discharge cyclone (2) is designed as a fluidized bed fluid chamber (5). ) provided with a fluidizing air inlet (6), the fluid chamber (5) being connected by a feedstock line (8) to a rotary kiln (3). 2 CS 269 481 81 not shown in the diagram. The heat released by the fuel burn is used to calculate the feedstock. The calcined feedstock, together with the unburned portions of the fuel, is entrained by the gas through the interconnecting conduit 11 to the cyclone separator 2. Here, the material is separated from the gases and compressed in the lower outlet portion formed by the fluid chamber 5. The gases are passed through line 12 of the preheater 2. The fluid chamber 2 is provided with a fluidized bed 11 through which fluidized air is fed from the connected inlet 6. The amount of fluidizing air is such that a fluid-dispersed layer of separated material is formed and the non-combusted fuel is combusted. Due to the fineness of the material being processed, the fluidization rate is low, up to 0.5m.s ”1. The amount of air required is therefore not large, so that even in the case of cold air, the heat loss is negligible. In the formed fluid-dispersion layer, an intense burn-out of unburned fuel takes place and the released heat is used to further calcination. The technologically processed material with minimal residues of the underfloor is discharged from the fluid chamber 5 through the feedstock to the rotary kiln 3 for further processing. This material, due to the minimal content of flammable residues and also because it is perfectly aerated, has improved flowability and low tendency to stick. An alternative embodiment of the device according to the invention is shown in FIG. 2. The furnace furnace line is again formed by the rotary furnace 2> the calciner 3 by the raw material preheater 4. The calciner 2 is equipped with a fuel inlet 2 or a preheated air line 15, respectively. The flue gases coming from the rotary kiln 2 enter it via line 10. In this case, the gas outlet duct 13 entraining the calcined raw material and the unburned portions of the fuel is introduced into the bottom or bottom stage of the feed preheater. In this part of the preheater 4, the material is separated from the gases and collected in the fluid bed 2 which forms the outlet of the lower part of the preheater 4. The arrangement and function of this fluid chamber 2 is similar to that of FIG. 1. The technologically processed material with minimal residues of the ash is discharged from the fluid chamber 3 by means of a divider 16, partly led via the feedstock 14 to the calciner 23 partly via line 2. the feedstock to the rotary kiln 2 for further processing. A further alternative embodiment of the device according to the invention is shown in Fig. 3. The furnace line is formed by a rotary kiln 2 with a calciner 2 directly connected to the preheater shaft. The calciner 2 is provided with a fuel inlet 2 and is connected via a gas line 10 with a rotary device 2 or a preheated air line 15 with a clinker cooler. The calcined feedstock, together with the non-burnt fuel residues, is trapped in the fluidized bed 2 forming the discharge part of the calciner 2. Its functions and arrangements are also the same as in FIG. 1. The material processed with minimal residue of non-doping is discharged from the fluid chamber. 2 through the feed line 8 to the rotary kiln 2 for further processing. SUBJECT MATTER 3. Apparatus for carrying out the method of claim 1, comprising a calciner coupled to a lower portion of the feed preheater through a gas supply and calcined feedstock, and a rotary apparatus, characterized in that the outlet of the feedstock preheater (4) is provided with a fluidized bed fluid chamber (5) (7) provided with a fluidizing air inlet (6), the outlet being connected by a feedstock line (8) to the rotary kiln (3). 4. Apparatus for carrying out the method according to claim 1, comprising a calciner directly connected to a preheater shaft and a rotary kiln, characterized in that the discharge part of the calciner (1) is provided with a fluid chamber (5) with a fluidized bed (7) provided with a fluid (6) the air chamber, the fluid chamber (5) being connected by a feed line (8) to a rotary bake (3). 3 drawings