JPS6077153A - Fine particle material, particularly method of calcining cement clinker and apparatus for carrying out same - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is characterized in that the material in the preheating zone is thermally pretreated by dividing it into several parallel streams in separate preheating lines, and then in the clinker zone. The clinker was fired into tarinka, which was cooled in a cold zone, and the exhaust gas flow from the clinker zone was passed through one preheating line, and fuel and materials were injected into the other preheating line along with the hot exhaust gas from the cold zone. The present invention relates to a method and apparatus for calcining particulate material, in particular cement clinker, through which a flow of reactant gas is passed in a calcining zone.

Conventional technology Methods and devices such as those described above are known.

An overview of the corresponding equipment can be found in the magazine Tsement/For example.
/Gips (Zement-Kalk-Gips included 1)
Article on page 218 of the May 979 issue [Erflungen
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5atzbrennstoffen) J and FIG. This system utilizes two separate preheat lines of cooler exhaust and furnace exhaust gas. The calciner is connected to the back of the calciner line with four stages of cyclones,
Combustion air from the cooler is supplied to this calciner.

The parallel furnace lines (B) correspond to a conventional four-stage cyclone preheater. The powder is allocated to preheating lines of different sizes in proportion to the amount of sogas.

For example, the calciner line (A) is about 62% of the powder, and the furnace line (B) is about 38% of the powder.

In the calciner, the powder stream coming from the fourth stage of the furnace line and the powder stream coming from the third stage of the calciner line merge. At the bottom of the powder inlet, enough hot oil evaporates to deoxidize 90% of W.

The exhaust gas and the deoxidized powder are sucked out of the calciner and then guided into the fourth stage cyclone of the calciner line where they are separated.

The advantage of this arrangement is the separate guidance of the gases, which allows the two preheating lines to be regulated separately and to vary their capacity over a wider range.

However, the following disadvantages have been found in this case: That is, when dust circulation is taking place, dust-like material gets into the preheating line heated by the exhaust gas of the Talinka reactor. This material is already fully deoxidized. The part of the material guided into the calcination zone from this preheating line therefore has a higher degree of deoxidation than the part of the material leaving the other preheating lines. Therefore, in order to avoid repeated over-firing with the disadvantage of burning in the pre-calcining zone, the fuel supply in the calcining zone should be designed to remove as much of the preheat-treated material as possible in the pre-heating line, which is exposed to air from the cooler. You can't do as much as you need to acidify.

A similar situation where it is even more difficult to match the degree of deoxidation of two material streams can be achieved by increasing the capacity of a device that originally only had a military preheat line by adding a second preheat line with a precalciner. Occurs when one wants to. In such a case, the heat load on the sintering zone of the (unmodified) rotary kiln becomes a decisive limit to the capacity enhancement of the rotary kiln. Nevertheless, to the extent that it is desired to increase the charging capacity of the rotary kiln, the heat capacity must be removed by heat release before the rotary kiln inlet. In other words, the calcination work conventionally performed in the rotary kiln must be moved to a section of the apparatus in front of the rotary kiln entrance.

In theory, complete calcination of the entire material could be performed outside the rotary kiln. In the case of a second combustion portion of 60 percent of the total 'ff, capacity enhancement would be possible on average to 2.5 times that of the first.

In reality, in most cases very little capacity enhancement is achieved. Especially coarse powder crushing equipment, Tallinn power cooler,
This is because the individual functional elements of the overall device, such as other intermediate parts, and possibly also the sales market, do not permit an increase in production.

Increasing soil capacity would require major modifications to existing heat exchange equipment and coolers, which would also lead to long downtime.

As already mentioned, the problem when installing a second line preheating device either from the beginning or later is to match the precalcination ratios of both lines to the highest degree. The geometric structure is as follows. That is, one of the lines receives the furnace exhaust gas from the Talinka area, and the other line receives preheated air from the cooler, so-called tertiary air, so it is necessary to supply fuel to both lines for the purpose of pre-calcination. If you want to supply it, the calcined state that occurs in both lines will be different. That is, in the line through which the kiln exhaust gas flows, the residence time before entering the lowest separation cyclone is short and the C02/steam partial pressure is high.

In the O parallel line, the reaction distance is extended, the residence time becomes longer, and the C02/steam partial pressure becomes lower.

As a result, especially in the case of slow-burning fuels such as charcoal, the conversion of heat to combustion and deoxidation in the preheating line with one precalciner is limited by the amount of ink flowing through the Talinka reactor exhaust gas. Much more effective than medium.

However, when feeding the Talinka reactor exhaust gas through-line with fuel to accomplish the necessary additional deoxidation work, the fuel is mostly It doesn't react and enters the cyclone on the lowest stage. This incompletely burned fuel can be decomposed without any residue in the upper stage cyclone, so some carbon monoxide (Co) can enter the electrical scum purification device and cause the worst accident there. . If dust circulation occurs in ., %, the tendency for overfiring will further increase, resulting in scorching that will impede operation.

Problems to be Solved by the Invention Therefore, the object of the present invention is to improve the method and apparatus as initially described, excluding the various drawbacks mentioned above, and to solve the problem of C.
As far as possible, a uniformly controlled desorption process is carried out before introducing the preheat-treated and precalcined material into the Tallinn force reactor in two parallel preheating lines without the risk of O evolution, oxidation, or scorching. It's about acidity. Furthermore, this goal must be achieved as uncomplicated as possible and with assembly parts that are simple and easy to install, especially when retrofitting a combustion device.

Means for Solving the Problem This task is achieved as in the case of the method described at the beginning. That is, the material stream preheated in the exhaust gas stream of the clinker zone is divided into two partial streams in the preheating zone, one of which is returned to the exhaust gas stream of the clinker zone and the other is introduced into the calcination zone of the parallel material stream. It is.

In this way, it is possible to omit the fuel supply for thickening the degree of deoxidation in the preheating line, through which the exhaust gas stream of the Talinka reactor flows, and, moreover, to divert the planned amount of material from the preheating zone. However, it can be supplied when transferred into the calcination zone of parallel material flow.

The kiln exhaust gas therefore impinges on the reduced powder and causes a stronger degree of deoxidation therein, while in the remainder of this line the entire volume of material flow remains intact for the regeneration of exhaust gas heat. A portion of the preheated material branched off from this line, together with the preheated material of the parallel line, is subjected to a second combustion in a calcination zone to be precalcined in its own form 9.

This is made all the more favorable by the favorable combustion and calcination conditions in the existing calcination zone, which is primarily driven by tertiary air. In this case, the pressure drop in the line through which the exhaust gas flows increases only slightly. This is because the additional material diversion lifting operation only has to be carried out via the lower part of the preheating line.

Effects An advantage of one embodiment of the process according to the invention is that one of the branched partial streams is combined in the calcination zone with the material stream preheated in the reactant gas stream, in which case they are mixed with each other in suspension and the fuel The material flow which is calcined or precalcined in the feed and reduced by a partial flow is calcined or precalcined to the same extent as y in the exhaust gas stream of the calcining zone. In that case, dawn is advantageously prevented.

Furthermore, in the case of stepwise heat exchange in the preheating zone, it is advantageous if the material stream preheated in the exhaust gas stream of the clinker zone is divided into substreams of a previous heat exchange stage.

A very important advantage of the method according to the invention is that, according to a further proposal, the quantity ratio of the partial streams is adjusted according to the fuel additive criteria in the calcination zone, so that the degree of deoxidation of the material streams in both preheating lines is the same. This can be obtained by setting

This control engineering measure has a very advantageous aspect of particular simplicity and visibility (Kl>F), in particular the ease of use of automatic control devices.

The achieved degree of deacidification of the lateral material streams or material/substreams is then determined in a simple manner by measuring the temperature at the material outlet of the preheating line according to known regulatory regimes.

This method further has the following configuration. That is, the atomized material precalcined in the exhaust gas stream of the clinker zone and the remaining material precalcined in the reaction gas stream of the calcination zone are separated from the gas stream and passed through separate channels to the clinker. are guided to the starting area of the area and mixed with each other in this area.

Some advantages that are quite special are that this method has an enhanced charge capacity due to the additional parallel arrangement of the second preheating line, and for calcination of particulate material into cement clinker, for which the preheating line was originally only one layer thicker. It can be obtained by applying it to the device.

For just such applications, it is simple to carefully match the precalcination degrees of the materials preheated and precalcined in two preheating lines of different equipment to each other in terms of their degree of deoxidation. It is extremely important to understand.

One of the at least two substantially parallel separate preheating lines is connected to the exhaust gas conduit of the tarinka unit, the other being equipped with a reaction unit for calcination of the heated material. A particulate material calciner suitable for the established method, which is connected to a conduit carrying the hot combustion air exiting the cooler unit, is equipped with a material flow branching unit in the preheating line connected to the exhaust gas conduit. It is characterized in that a first line leads from the unit into the exhaust gas line and a second line into the reaction unit.

A further advantageous configuration is the following combination. That is, in the case of the above-mentioned apparatus in which the calcining reaction unit is constructed as a reaction extension zone, the length of this apparatus is as follows. i.e. the length is such that a reaction residence time of at least 2 to 4 seconds is achieved in accordance with the intended flow rate of the gas/solid suspension flowing through it, and in the direction of flow in front of the material/partial flow inlet. At least one fuel supply device may also be provided at the rear of the vehicle and, if necessary, at the rear.

The relatively long residence times, especially in the case of additional combustion, using relatively slow-burning fuels, such as granular coal, ensure that heat is not converted to heat combustion or to deoxidation in the reaction unit without the risk of exhaustion. It is advantageous to have a very good effect on Therefore, the degree of deoxidation that can be achieved is relatively high, and there are no problems in regulating it.

After all, in the apparatus according to the present invention, one temperature measuring device is provided in each of the material pipes from preheating line A to the rotary kiln and from preheating line B to the rotary kiln.

This configuration, in combination with the inventive configuration of the double-line preheating device, is of fundamental advantage and importance. This makes it possible, without complications, to determine the respective degree of deoxidation according to temperature criteria through the measurement of the temperature of the material stream, and to reach a regulatory engineering effect with respect to setting the corresponding quantity ratios of the partial streams. This is because there is a possibility that it will be used until then.

Further details will be given with respect to the figures showing the apparatus for carrying out the method of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in the drawings, the apparatus for heat treatment of particulate materials consists of two floating gas heat exchange lines A and B arranged parallel to each other. A heat exchange line A connected to an exhaust gas pipe 1 of a rotary kiln 2 functioning as a firing furnace has four stages of cyclone separation devices 3, 4, 5.6. The top cyclone separator is configured as a double cyclone. Apparatus 7#'i is intended to supply rough material or coarse powder to the gas pipe 8 leading from the cyclone stages 4 to 3.

Heat exchange line B is cyclone separator stage 9゜10.11
, 12. The uppermost cyclone separator 9 is also a double cyclone separator.

The feed of raw material takes place by means of a material feeder 7' which is contained in a gas line 8 leading to the cyclone separator stages 1o to 9.

The lowermost cyclone separator 12 is connected upstream with a calcining castle in the form of a hairpin-shaped reaction extension zone 13 on the gas side. This reaction extension zone Fi is connected to the tertiary air gf15 at the inlet side end when viewed in the flow direction. A tertiary air line directs hot dust cooler exhaust from a material cooler, not shown in detail, into reaction extension zone 13. Clinker reactor 2
The gas economy of the preheating line B can be adapted to the supplied gas quantity via an additional connection 16 with the conduit 1 carrying exhaust gas from the preheating line B. Such gas flow regulation, especially on the suction side, is achieved by the 17 prongs of the exhaust machine at the outlet of the preheating line A or B;
This is done by appropriate adjustment of +7'.

At the beginning of the reaction extension zone 13 there is a separator cyclone stage 1.
The gas pipe 14 coming from 1 is included. A fuel supply device 19 is provided directly below this gas pipe.

In the configuration of the firing apparatus according to the present invention, there is a material direction changer 2o below the cyclone separation device at the stage immediately before the lowest stage. Two material pipes 21 and 22 branch off from this direction changer. These material pipes each receive a material fraction divided into partial streams from the material diverter 2o. The material pipe 21 directs one of the partial streams from the redirector 20 to the exhaust gas pipe 1.
Put it in. In the exhaust gas pipe 1, the material carried in is decomposed into flying seats by the once-through exhaust gas in a known manner, pre-calcined by direct heat exchange with the gas, and then returned to the gas flow in the cyclone separator 6 at the lowest stage. The material is separated from the rotary kiln 2 and carried into the inlet chamber 24 of the rotary kiln 2 through a material pipe 23.

Similarly, the material pipe 22 branching off from the material diverter 20 instead enters the start 18 of the reaction extension zone 13 and, in particular, directly into the inlet of the material pipe 14 .

In this case, the material introduced into the reaction extension zone 13 by the material pipes 22 and 14 forms a vortex together with the fuel supplied from the fuel supply device 19 in the rising gas flow mainly carrying tertiary air.
It is made to react as a suspension. In that case 90
The heat liberated in the zero temperature range is converted into deoxidizing work.

Depending on the amount of fuel added, material introduction temperature, residence time, CO7/steam partial pressure criteria, for example
A reaction time of 4 seconds results in the corresponding degree of deacidification.

The functions of the method according to the invention performed by the device are as follows.

The coarse powder fed to the heat exchange line A with the material feed device 7 undergoes direct heat exchange with the convective exhaust gas from the rotary kiln 2 and is first heated in the uppermost stage 3 after the first heating for stepwise heating. separated and introduced into the gas line leading from the third stage cyclone separator 5 to the second stage 4, preheated there and during the separation step in the second stage to a second temperature level and subsequently the same The process is repeated with the next stage.

The coarse powder preheated in this way is separated from the gas stream in the third stage 5 and reaches the material diverter 20. There, the material stream is divided into two sub-streams of equal or different quantities depending on the position of the material diverter. Of this, -10,000 partial flow enters conduit 1. A stream of exhaust gas from a rotary kiln 2 flows through this line 1 . In that case, for example, the kiln exhaust gas with a temperature range of 10 mm or less will hit a relatively small amount of powder, and as a result of the temperature equilibrium set relatively high within it, the same amount of powder will occur. Achieves a relatively high degree of deoxidation. The thus precalcined material of the partial stream undergoes a final heat exchange and reaction process and is then significantly calcined in the riser tube up to the lowest stage 6 and, after being separated from the gas stream, is transferred to the kiln in the drop tube 26. It is carried into the entrance head 24. Due to the connection 161/C between the exhaust gas line 1 and the reaction extension 13, in which a regulatable gas velocity is set when the two exhaust exhaust pipes 7 and 17' are adjusted accordingly, harmful dust circulation occurs in this location. This effectively prevents Above this connection 16 with the conduit 22 emerging from the material diversion 12o, material preheated to a relatively low level of temperature, e.g. The dust passing through is avoided. The fuel supplied by the fuel supply device 19 mixes well with the combustion air, gases and materials at this location to form a homogeneous suspension), thus forming an ideal reaction system. According to the invention, further fuels can be metered into the reaction system at further downstream locations, for example at locations 25 and 26, as they flow further through the reaction extension zone 73.

As a result, the same reaction head is maintained over a wide portion of the reaction extension region 13.

In actual operation, it is surprising that when carrying out the invention, it is not necessary to refuel, for example, in conduit 1 of line A, and it is possible to supply the planned amount of powder to this heat exchanger from the bottom. It has been found that this is provided if a partial stream from the powder of the stage cyclone 5 is transferred to the reaction extension zone 13.

In that case, regulation of the device according to the method of the present invention is easily carried out as follows. That is, the following partial flow ratios are set in the material converter 2°, such that the partial flows introduced into the exhaust gas stream, when entering the kiln, have exactly the deoxidation degree as a whole that corresponds to the second combustion section. This is done by setting In that case, the degrees of deoxidation in the other two inions are set to the same value in terms of degree.

Overall, significant advantages are obtained with the method and apparatus of the present invention. Furthermore, the risk of overheating and burning in the reaction extension zone 13 is reliably prevented.

This invention avoids the addition of a fuel supply to line A without a reaction extension zone, which is especially true when expanding old one-line calciners to modern, high-capacity two-line units, so that the exhaust gas 9000 The risk of excess of minutes is prevented.

A further very important advantage then is the simplified regulation of the degree of deacidification required for each line, for which the necessary auxiliary means are adjustable material redirection with material tubes 21 and 22. Only the device 20 is included.

In any case, in almost all modern installations, when the measuring and regulating devices connected to the regulating unit are connected in a corresponding manner, by checking the material temperature which can be considered without difficulty to represent the corresponding degree of deoxidation. For example, material pipes 23 and 27
In this case, the possibility of setting a corresponding deoxidation degree by adjusting the material direction changer 20 easily arises.

With this simple regulation method, this device, especially the rotary kiln 2, the side heat exchange line A, and the BVi can be used to the fullest capacity.

Moreover, when it is added to an existing firing device, the time it takes to stand still is extremely short.

As mentioned above, the method and device according to the invention ideally solve the problem mentioned at the beginning.

[Brief explanation of the drawing]

The accompanying drawings are schematic representations of the apparatus used to carry out the method of the invention. 1... Exhaust gas pipe 13... Reaction unit 20. 1 unit 21. 22... Conduit A, B... Heat exchange line agent Mitsuyoshi Ezaki agent Mitsufumi Ezaki

Claims (1)

[Claims] (Li) The material in the preheating zone is divided into several parallel streams and is thermally pretreated in separate preheating lines, and then fired in the clinker zone to form a talin force. This is cooled in the cold zone, and the exhaust gas flow from the clinker zone is passed through one line of the preheating line.
Another preheating line contains the fuel and material along with the hot exhaust air of the cold zone, and the reactant gas stream of the calcination zone is passed through the particulate material;
In the method of firing tK cement tarlinker, the gas stream preheated in the exhaust gas stream of the clinker zone is divided into two partial streams in the preheating zone, one of which is returned to the exhaust gas stream of the clinker zone, and the other is fed into the parallel material. A method characterized by introducing the fluid into a calcining zone. (2) 10,000 branched partial streams are combined in a calcination zone with a material stream preheated in a reactant gas stream, mixed in suspension in the reactant gas stream and supplied with fuel for calcination; The precalcined and partially reduced material stream is calcined or precalcined to the same extent in a heterogeneous manner in the exhaust gas stream of the calcination zone (
1) The method described. (3) In the case of stepwise heat exchange in the preheating zone, the material stream preheated in the exhaust gas stream of the clinker zone is divided into partial streams in the previous heat exchange stage (or (2)). (4) The quantity ratio of the partial streams is set according to the proportion of the fuel supply in the calcination zone so that the degree of deoxidation of the material streams in both preheating lines is the same. Range (Su~(3)
The method described in any of -. (5) Separate the thermally pretreated material fraction from the gas stream, on the one hand, in the exhaust gas stream of the clinker zone and, on the other hand, in the reaction gas stream of the calcination zone; and mixed therein, claims (1) to
The method according to any one of (4). (6) The charging capacity was strengthened by adding a second preheating line in parallel; at first there was only one preheating line;
A method according to any one of claims (5) to 1 (7) which is applied to an apparatus for firing particulate material into cement clinker. The streams are divided into separate preheating lines for preheating treatment, then calcined in the clinker zone, turned into a tarliner, and cooled in the total cooling zone, passing the exhaust gas stream from the clinker zone through one preheating line, and passing through the other preheating line. The reactant gas stream in the calcination zone containing the fuel and materials is passed inhomogeneously along with the hot exhaust air in the cold zone, the gas preheated in the exhaust gas stream in the clinker zone in order to calcinate particulate materials, especially cement clinker. A device for carrying out a method in which the flow is divided into two partial streams in the preheating zone, one of which is returned to the exhaust gas stream of the clinker zone, and the other is introduced into the calcination zone in a parallel material flow, where It has at least two separate preheating lines, one of which is connected to the exhaust gas pipe of the tarinka unit, and the other is equipped with a reaction unit for calcining the preheated material and for cooling. In equipment connected to the conduit for hot combustion air leaving the unit, the preheating line (A) connected to the exhaust gas conduit
A unit (20) is arranged for dividing the material flow into the area from which a first conduit (21) leads to the exhaust gas pipe (22) and a second conduit (22) leads to the reaction unit (20). 1
3) A device characterized by being guided inside. (8) the length of the reaction extension zone (13) is determined so that the reaction residence time is at least 2 to 4 seconds depending on the expected flow rate ratio of the gas/solid suspension flowing through; In the flow direction, at least one fuel supply device (19, 25,
26) The apparatus according to claim (7), wherein the reaction unit for calcining, which is FC arranged, is configured as a supporting region. (9) There is no leakage in the material pipe (23) that communicates from the preheating line (A) to the rotary kiln (2), and in the material pipe (27) that communicates from the preheating line (Bl) to the rotary kiln (2). Device according to claim 7 or 8, characterized in that it is provided with a temperature measuring device (28, 29).