JPS60246247A - Method and facilities for burning sinterable substance like cement clinker comprising lime stone, dolomite or like - 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 FJIJ of the present invention is used for firing sinterable materials such as cement clinker (8) consisting of minerals containing limestone, dolomite or similar raw materials. Method and equipment W,
It is related to. In that case, these raw materials in the form of raw meal are preheated in a preheating stage, calcined in a calcination stage, sintered into a clinker-like material in a calcination stage, and finally this is cooled in a cooling stage. K becomes.

[Prior art]

In order to protect against undesired oxidation phenomena, it is known, for example, to sinter the sinterable material under reducing conditions with as little ingress of oxygen as possible, and to protect it from ingress of oxygen also during cooling.

As an example of this, mention may be made in particular of the case of the production of white cement.

In one known process of the type mentioned above, the clinker leaving the furnace is sprayed with a reducing agent, for example oil, and subsequently quenched with water in order to cool it down (German Patent No. 117
No. 8769].

The disadvantage in this case is that the total heat of the clinker heated to about +450J is substantially lost.

(9) Another important disadvantage of this known method is that the water vapor generated from the cooling water enters the kiln, thereby reducing the flame temperature. For this reason, an auxiliary device is sometimes provided to suck out the water vapor.

However, this increases equipment costs and impairs energy balance. As a result, the steam in the rotary kiln increases the amount of energy required during firing and reduces the specific furnace throughput, forcing its size to increase accordingly.

All this works together to significantly reduce the economics of this known process and thus lead to an increase in the price of the final product.

Other known methods attempt to cool the fired clinker by continuously cutting off oxygen to prevent water vapor from entering the firing furnace; It is quickly removed from the aquarium using a scraping conveyor.

(10) In the case of 10, the moisture content of the clinker becomes 10 to 12 inches, which requires additional drying, which requires additional heat orgy, which is another drawback. Furthermore, such moisture causes a problem in that the strength value of cement made from such clinker is reduced. This is because some degree of hydration is unavoidable (UK patent 3315
84).

[Problem to be solved]

The basic problem of the invention is the development of a method and a device for the sintering of sinterable materials, such as cement clinker, from materials containing limestone, dolomite or similar raw materials, as described at the outset. This method is so advanced compared to known methods that it overcomes the drawbacks, difficulties and technical limitations mentioned above. In particular, the present invention prevents heat losses that are unavoidable when cooling the cage under oxygen exclusion by cold water quenching. The reduction in the efficiency of the firing stages due to the generation of steam is avoided at full pressure, on the one hand by the use of heated secondary combustion air, and on the other hand by the use of completely calcined raw materials, especially those heated above the calcination temperature. Significant increases in efficiency of the firing stage are achieved through the use of: maximally insulating the heat-treated material against the adverse effects of oxygen, preserving the best product quality and improving the economics of the process. In that case, partial energy savings of the order of approximately 30% compared to known methods are aimed.

[Action and Effect] Does clinker solve the set problem? This invention is realized in the method described at the beginning of the invention by adding coarse powder as a refrigerant in the cooling stage.

The invention also reliably eliminates the disadvantages which necessarily occur with the known production methods of, for example, white boatland cement.

In that case, for example, air-cooled clinker has a very low content of oxidizable metals and suffers from a significant disadvantage in terms of its brightness even with the use of carefully selected dielectric materials, or in the case of indirect cooling. The low values of heat transfer and mechanical problems (12) make the process uneconomical and therefore the product expensive, but very difficult to use when inert scum or organic reducing agents are used as refrigerants. The present invention eliminates this drawback, such as the diseconomies associated with quenching clinker in a water bath, whereas these devices also pose safety issues.

The process of this invention is uncomplicated and the coarse powder can be easily processed, making it economically advantageous and meaningful. Studies related to this invention based on thermoeconomic calculations show that this new method saves about 30% of the input partial energy compared to quenching the clinker in a water bath.

- In the example, this method is used for firing white cement.

From the above description it can be seen that it is particularly advantageous to use this new method in the production of white boatland cement, of which the production of white boatland cement is one advantageous example. On the other hand, this advantageous application example in no way limits the method to its application (15). For example, if suitable equipment is available, the method can in principle also be applied for the production of oxygen-sensitive sintered materials.

In one example, preheating and partial calcination of a portion of the coarse powder is performed in a cooling stage.

Particularly in the case of partial calcination of coarse powders, gases or vapors are advantageously liberated, for example to CO2 or H2O, which create at least a somewhat inert atmosphere in the cooling bath, which rejects oxygen by means of K. .

Furthermore, one cooling stage is divided into a preliminary cooling stage and a final cooling stage, and the coarse powder is used as a refrigerant in the preliminary cooling stage.

By said section of the cooling stage, the heat exchange between the clinker and the coarse powder ends at the temperature limit provided for this purpose, and the coarse powder heated to that limit temperature is withdrawn from the cooling stage and transferred to the calcination stage for subsequent heat treatment. We will take advantage of the simple method of putting it in.

Additionally, coarse powder is used as a refrigerant in the pre-cooling stage, and air is used as a refrigerant in the final cooling stage.

In the case of sintered materials, the cooling and crystallization steps are carried out to such a temperature range that the harmful effects of oxidation are no longer possible or occur so little that there is no danger of harmful alteration of the material. Air can advantageously be used as refrigerant. Air as refrigerant in this case has the advantage that this heat-carrying medium allows the heat-sensitive mass extracted from the clinker to enter the heating process again without any problems.

For example, heated air can be used as firing air in the calciner.

In a further aspect, a strong mixing movement is created between the coarse powder and the clinker to enhance the heat exchange between the clinker and the coarse powder.

Furthermore, it is proposed to use, as a cooling medium, a coarse component with a high loss on ignition, such as calcium carbonate, or to use it in addition to calcium carbonate. A surprisingly advantageous cooling effect is then obtained by exploiting the properties of calcium carbonate. In the case of this calcium carbonate, it is about 790
(15) After heating to ~900 υ, a temperature holding point is created before the material is heated further, where decomposition of the chemical compounds occurs and Co2 is liberated. The energy 1Fi required for this endothermic reaction is extremely high, approximately 500-600 kcalAcg (depending on the respective mineralogical conditions). On the other hand, the calorific value of coarse powder felt at 900υ is only about 210 kcal/&4).

Starting from this recognition, in one embodiment the clinker is cooled in the pre-cooling stage from the calcination temperature to about q o o tK? ! to reject. The large amount of energy required by the coarse powder during this deoxidation together with the strong mixing movements causes the clinker to cool very strongly and therefore quickly to the predetermined temperature limit of approximately 900 J.

For this reason, the use of components with a large loss on ignition of coarse powder, especially calcium carbonate, provides a highly effective refrigerant. Deoxidizing this material requires approximately 50 units more energy than a typical cement meal mixture. Furthermore, since calcium carbonate KFi has a low tendency for hot clinker granules to burn or clump (16), separating calcium carbonate from clinker is not a problem.

In yet another embodiment, a reducing atmosphere is created in the pre-cooling stage to effectively prevent clinker oxidation phenomena.

This can advantageously be achieved by admixing any form of fossil fuel to the coarse powder mixed into the refrigerant.

For example, coarse powder containing bituminous limestone can be used as a refrigerant. The setting of the reducing atmosphere during cooling is always necessary, for example if an inert gas atmosphere is insufficient for cooling without impairing the color of the clinker or if there is already partial oxidation to be removed by reduction. , can be done advantageously.

The fuel mixed according to the method proposed here requires oxygen, which can be obtained each time the temperature increases. In that case, the volatile parts of the fuel capable of low temperature values are driven off and, unless oxidized in the precooler, are transferred to the calcination stage and (also Fi) calcination stage for effective combustion. It will be done.

(17) The heating of the fuel, the expulsion of volatile components, and the cracking also consume further thermal energy released from the clinker.

As a result of this cooling energy consumption due to the endothermic reaction described above, 0 per kilogram of clinker as refrigerant
．． Addition of 2 to 0.5 kg, especially 0.3 kg of coarse powder will effectively cool the clinker. In that case, it is advantageous to determine the amount of addition so that temperature equilibrium is maintained within the calcination temperature range by balancing the calorific value of the clinker and the refrigerant.7 The advantage in this case is that the coarse powder as a refrigerant Significant deoxidation.

Furthermore, the precooled clinker and the heated coarse powder are separated after passing through the precooling stage, particularly by the separation effect in the waste stream, and the clinker is fed to the final cooling stage and the coarse powder to the calcination stage.

This separation of clinker and preheated or deoxidized coarse powder
After leaving the precooling stage, the mixture is placed into the hot cooler exhaust stream that rises after exiting the final cooling stage;
Separation can advantageously be achieved with K due to the separation effect that occurs in that case. In this way, advantageously effective separation is achieved without special separation equipment.

Separation of the mixture of powder and clinker into the primary components by sieving in the waste stream is therefore advantageous since experience has shown that clinker has a particle size distribution that overlaps only slightly with that of the coarse powder. It is.

Further, the preheated and partially trap-calcined powder streams consisting of a preheating stage and a precooling stage are combined in a calcination stage. Thereby, the heat of the cooled clinker transferred to the refrigerant is obtained virtually without loss from the thermal system of the sintering process.

In the calciner, the following several material streams merge:

i.e. the preheated combustion air leaving the final cooling stage, the largely deoxidized coarse powder, inert gas, separated from the clinker contained therein and partially cooled by the sieving effect. and (19) as the case may be, the fuel components coming out of the pre-cooling stage, the fuel required for calcination of the remaining sintered material, the exhaust gas of the combustion stage in the case of a single-line configuration of the coarse powder pre-heating stage, and the exhaust gas. Combustion air obtained by indirect heat exchange and optionally added.

In the application of the method according to the invention to the production of white Boatland cement, the tendency of coarse powder with a small melt layer to scorch is lower than for other types of cement at temperatures above calcination.

Therefore, in another aspect, it is possible to perform a complete calcination in the calcination stage and also to heat the material above the calcination temperature without any danger due to the easy implementation of the method.

In the case of a double-line configuration of the preheating stage, in which the exhaust gases of the sintering stage and the exhaust gas of the calcination stage are respectively introduced for heat transfer to the coarse powder by separate parallel preheater lines, the method is further adapted as follows. One advantage arises. That is, the excess heat content of the exhaust gas can be utilized, in particular by indirect heat exchange, (20) for the recuperative production of hot secondary combustion air for the calcination stage, and that the regulation of the gas mass flow can be used in the pre-cooling stage. Pressure on both sides can be carried out without any problem in a way that produces pressures of approximately the same strength.

By setting the pressure balance on both sides of the precooling stage, it is ensured in the simplest way that, for example, contaminated air cannot enter the precooling stage as an oxygen carrier.

Setting this pressure balance can be carried out most simply by adjusting the pressure ratio of the mutually independent gas flow using an exhaust gas blower.

Furthermore, the number of cyclone heat exchanger stages in the mutually independent preheater lines of the preheating stages can be advantageously varied;
Therefore, the coarse distribution in both lines can maximize the measurable heat content of the calciner stage, while creating hot secondary combustion air for the fuel in the waste stream of the calciner line. There remains a sufficient amount of excess heat at a temperature high enough to allow

Apparatus for calcining sinterable materials such as semenodo clinker consisting of minerals including limestone, dolomite and similar coarse materials, in particular coarse powder preheaters, (21) especially calciners with one material outlet Claim 1 having one or more lines of cyclone heat exchanger leading to
In the apparatus for carrying out the method according to item 17 to 17, the material outlet of the calciner is connected to the firing apparatus, and the material outlet of the calciner is connected to the cooling apparatus, in which case the cooling apparatus is used for pre-cooling. and a final cooler spatially separated from the precooler.

Sudden in pre-cooling stage? '? It is advantageous for the precooler to be a rotary tube cooler in order to generate the necessary intensive external mixing movements between the coarse powder and clinker.

In a further embodiment, the precooler has a device for meterable supply of cold coarse powder, and the coarse powder supply device optionally has an additional device for meterable mixing of fuel into the coarse powder. Has equipment.

In order to easily and advantageously satisfy the regulation engineering requirement of equalizing the pressure at the inlet and the outlet of the precooler, in one embodiment the precooler measures the pressure difference between the inlet and the outlet. We have equipment for this purpose. The precooler can furthermore have a temperature measuring device in the area of the outlet.

In a further important feature of the invention, the secondary cooler located below the precooler has a particularly vertically extending exhaust duct. The dumping end of the precooler leads into the exhaust duct.

Furthermore, an adjustable diaphragm is provided in the region of this inlet. By means of this aperture, the magnitude of the sieving effect can be advantageously controlled and the separation boundary between coarse powder and tarinka can be adjusted.

Yet another important feature of the invention is that the exhaust duct leads directly into the calciner. This advantageously produces a very simple and easily controllable flow condition with the lowest possible construction costs.

A further advantageous configuration is as follows. That is, in the case of a coarse powder preheater having two parallel cyclone heat exchanger lines, one line is connected to the calciner and the other line is connected to the calciner.

And the latter requires more cyclone heat exchange (two It has a pseudomembrane.

The last configuration described is as follows.

That is, the heat exchanger line connected to the calciner has a recuperator for producing hot secondary combustion air with hot air conduits, said hot air conduits being connected to the combustor side of the calciner with one and optionally a partial stream. It is also connected to the calcination machine.

Example A further detailed description will be given based on the drawings showing one embodiment.

The equipment shown in FIG. 1 includes a preheating stage A1, a calcination stage B1, a firing stage 0, and a cooling stage. In the preheating stage A, there are two parallel preheating lines 1 and 1', and there is a recuperator 2 in the exhaust gas 28 of the preheating line 1. This recuperator serves to heat the fresh air 27 and thus to utilize the excess heat of the exhaust gas stream 28 for processing the hot secondary air 8 which is also used for the calcination stage C. There is a calcination device 7 in the calcination stage B. Two streams 26 and 26' of preheated coarse powder are connected to this calciner from the preheating line 1.1'. The calcining device 7 further includes a fuel supply bag (24) and a holder 25. The fuel supply system also includes tertiary air 20 carrying hot powder and optionally precooler exhaust gas 24 carrying powder and fuel.

An exhaust gas stream 6 exits the calciner 7 and enters the preheating line 1 . From the calcination device 7, the coarse powder 10 that has been further calcined and heated above the calcination temperature in some cases is carried out and put into the sintering device 5 of the sintering stage C. In convection with it, fuel 9, hot secondary air 8, and possibly fuel-carrying exhaust gas 16 are carried into the sintering device 5 from the cooling stage.

The essential structure of the method of the present invention is that the cooling stage is divided into a preliminary cooling stage 12 having a preliminary cooling device 13 and a final cooling stage 12' having a final cooling device 14. The tarinka 11 carried out from the firing stage C is first transferred to the preliminary cooling device 1.
3, in which it is intensively mixed with the cooled coarse powder as a refrigerant by the coarse powder supply device 15. Additional fuel supply device 1
5' allows fuel or other reducing agents to be added to this mixture (25) if desired. The tarinka, coarse powder and optionally additional fuel are agitated into phase q in the precooler 15, causing a strong mixing movement and a forced heat exchange. The hot tarinka is then rapidly cooled, and the coarse powder, which is then used as a direct refrigerant, is heated and calcined. Most of the added fuel volatilizes and cracks.

The energy required for the endothermic reaction in the case of coarse powder and fuel (the energy required for deoxidation j'il It: 1
, 500-600 depending on the mineralogical conditions at the time.
kcal/kg. ) causes an unexpectedly rapid cooling of the hot cement clinker or cricker/meal mixture in the temperature range of the calcination reaction. A clinker/powder/fuel mixture 18 is discharged from the precooling device 13 and a tertiary air stream is introduced into the hot air stream 20 rising from the final cooling device 14 . In this case, the sieve fraction that has formed is effectively separated from the hot coarse powder from the precooled talinka. By means of a particularly adjustable throttle 19 of the tertiary air stream 20, the effect of this sieving can be adjusted, so that the separation cross-section of the granular clinker and the finely divided heated powder is uncanny. The heated powder is conveyed to the calcination device 7 by a heated powder carrying tertiary air stream 20, while the screened clinker 21 enters the secondary cooling device 14. Among them, this clinker is #r fresh air 22
The heat is transferred to the tertiary air stream 24 in the usual manner.

The completely cooled clinker 23 is carried out as a product.

Since according to the invention no gas must flow through the precooling stage 12, this is advantageously achieved with the same pressure on both sides of the precooling device 15. That is preheating line 1
and 1' can be realized in a very simple manner by adjusting the exhaust gas flows 28 and 28' led off.

Furthermore, an additional amount of coarse powder is transferred to both preheating lines 1 and 1' by means of a coarse powder supply device 5 provided in preheating stage A, so that as much heat as possible of waste stream 4 of calcining stage C is transferred to the coarse powder. The amount of heat in the waste stream 6 of the calciner 7 can be divided into two parts to produce hot secondary air 8 in the waste stream 28 in the preheating (27) line 1. The coarse powder is fed so that there is sufficient heat.

An apparatus for carrying out the method shown in FIG. 1 is shown in FIG. The preheating stage A has a preheating line 1 with a four-stage cyclone heat exchanger, while the preheating line 1' has a three-stage cyclone preheater.

5 and 3' are respective coarse powder supply devices. Preheating stage A
K further includes a recuperator 2 in the form of a rotating gas/air indirect heat exchanger. After passing through the recuperator 2 with 28 waste gas pipes, the waste gas enters an exhaust gas blower 52tlC, while the waste gas pipe 28' of the preheating line 1 is connected to a separate waste gas blower 52'. A secondary air pipe 34 leads from the recuperator 2 to the rotary kiln 5 of the firing stage C. The fuel 9 and the secondary air 54 create a flame 5' which provides the energy required for clinker firing at 1400-1500 m.p.m.

From the rotary kiln 5, heated combustion gas enters the preheating line 1 via the conduit 4. At the same time, the coarse powder, which has been calcined and in some cases heated above the calcining temperature (28), enters the rotary kiln 5 from the calciner 7 through the conduit 34, where it forms a convection with the flame 5' and becomes clinker.
After passing through the rotary kiln 5, it passes through the entire tariff drop duct 29 and is dropped into the precooler 13. This falling duct 29 leads to a coarse powder supply device +5, which optionally has an additional device 15' for adding fuel to the coarse powder.

In this invention, the preliminary cooler is a 16-tube cooler. This is because a strong mixing movement is required in order to cause a sufficiently strong heat transfer in the meal/clinker/fuel/mixture.

A rotary tube cooler is ideal for this purpose and is a very economical cooling unit.

Cooling Stage The present invention has two cooling devices spatially separated from each other, namely a precooler 13 and a final cooler 14. This final cooler is especially equipped with several cold air blowers 35. The final cooler has an air extraction duct in the region of its feed end 36. The inlet end of the precooler 13 communicates with this duct at 31 (29). In the region of this inlet 51 there is a particularly adjustable restrictor #) 19, which adjusts the predetermined flow rate and thus a predetermined sieve for separating the coarse powder/clinker mixture introduced into said duct. Useful for adjusting minute effects. In a further embodiment of the installation according to the invention, the heated air line 36 extends vertically in a straight line as a tertiary air line and passes into the calciner 7 without changing its cross-sectional area.

If the pressure on both sides of the precooler 13 is the same, gases will flow through this precooler.

As a result, in the precooler 13, gases produced by thermal effects may flow out on both sides.

Volatile fuel, for example in the form of fuel-containing waste 16 (FIG. 1), is then forced back into the rotary kiln 5 from the precooler 13.

For example, a measuring device 17 is provided for pressure monitoring, and a temperature measuring device is provided at the end of the precooler 13 for temperature monitoring.

Points that are unclear from the above description of FIGS. 1 and 2 regarding the function of the equipment shown in FIG. 2 will be described below. In this case, the steps in the preheating stage A and the calcination stage BK are known.

As already stated, the essence of the structure of this invention is the following point.
Ill. That is, in the precooler 13, the tarinka and the coarse powder used as the refrigerant are brought into contact with each other in a deep mixing motion to facilitate heat transfer from one medium to another.

The actual amount of heat absorbed during the calcination reaction of the coarse powder that takes place here rapidly draws out most of the heat from the tarinka.

For example, the tarinka, which is introduced into the precooler 13 after about 1450 to 1500 mm, comes into contact with the coarse powder and is very rapidly cooled down to about 900 j'VC, kl. At this temperature, for example, the calcium carbonate contained in the coarse powder decomposes, and the
00-600 kcal/1q) (depending on the mineralogical conditions at the time) are consumed. Therefore 79o~900
A temperature holding point in the range r is obtained. At the same time, they were expelled k=
The carbon oxide gas provides effective inerting of the cooling bed during precooling. Protection against incoming oxygen-containing gas components, such as secondary air or combustion air, is prevented in the following way by K on its upper side (31). That is, by adjusting the waste flow in the preheating stage A or the two parallel preheater lines 1 and I/, the same intensity of pressure is set on both sides of the precooler 13. This effectively prevents gas from flowing through the precooler 13. For example, the pressure equilibrium state is measured through the precooler 13 using a measuring device known per se, such as a U-shaped tube 17 with a measuring liquid;
It can be used as an adjustment value for adjustment.

A mixture of precooled tarinka and heated or partially calcined hot powder 18 exits the precooler 3 and is fed into a hot air stream 19 rising from the final cooling stage 14 . In this case, a sieving action takes place in the gas stream, which separates the heated coarse powder and the talin powder. The heated powder conveying tertiary air stream 2o flows from the bottom upwards into the calciner 7, while the talinka 21 flows into the final cooling stage 14.
be carried inside. Among them, this (32) tarinka is brought to a predetermined final temperature by means of fresh air 22 in a manner known per se. '? rejected, product 2
It will be carried out as 6. During the corresponding addition of fuel, precooler exhaust gas 24 carrying powder and fuel can escape from the precooler 13, possibly also to the calciner. The components of the volatile fuel which have not yet been oxidized are then effectively burned in the calciner 7. Therefore, the following material flows merge in the calcination device 7. That is, preheated combustion air (tertiary air) 2o exiting from the final cooling device 14
1 the partially deoxidized or deoxidized powder contained therein, the inert gas and the optionally volatile residual fuel components 24 exiting the precooler 13, the preheating line 1 of the preheating stage A.
Preheated coarse powder 26, 26' emerging from 1', fuel 2 required for complete calcination and possibly heating above the calcination temperature.
It is 5.25'.

The calcined material 1o reaches the calciner #5, in which it is calcined in a manner known per se to form a tarinka, while the calcined waste 6f'i for preheating the coarse powder (35) in the preheating line 1 used in

In particular, the coarse powder used in the production of white cement is poor in molten phase acid components and rich in components that have a high loss on ignition.
Coarse powder has a very weak tendency to burn at temperatures above calcination. However, if, for example, there is an increase in the formation of a melt of the recycled material, which results in scorching, this phenomenon can be treated in a known manner by partial removal (bypass) or partial removal of the calcined powder. to prevent it.

For trouble-free operation in the calcination device 7, an excess amount of fuel 25' can therefore be used without danger for rapid stationary heating of the material after calcination. This shortens the heating range of the firing device 5, saving energy and correspondingly reducing investment costs. Furthermore, the calciner 5 and the recuperator 2 are controlled by an adjustable front fuel addition device 25'.
operation is the best. This is because the gas flows 28 and 27 are adjusted in the original sense (secondary air temperature).

! In particular, in the case of the combustion device 5, the preheated combustion air is initially depleted, since a part of the heat is transferred to the coarse powder and not to the combustion air. In comparison, preheating stage A receives too much waste with respect to the heat capacity of the coarse powder component fed thereto. In order to achieve an economical exhaust gas temperature and at the same time to provide the necessary secondary combustion air, according to the invention a recuperator 2 is provided in the preheating stage A after the preheating line 1, in which Heated secondary air 8 is produced from the fresh air 27, in particular by indirect gas/air heat exchange.

The two-line configuration of the preheating stage A results in important advantages for KVi% if the waste stream 4 is fed exclusively to the preheating line 1', the waste from the two preheating lines 1 and 1' not merging. This is because the requirement to achieve a pressure equilibrium on both sides of the precooler 150 can thereby be met in a simple manner by independent regulation of the exhaust gas flows 28 and 28'.

Therefore, K is the two parallel preheater lines 1 and (35) It is advantageous to have different heat conduction characteristics of 1'.

That is, in the preheating line 1', the heat in the waste gas stream 4 is utilized to the maximum, while the heat in the waste gas stream 6 is still sufficiently transferred to the waste gas stream 28 by reducing the capacity of the heat exchange stage and the coarse powder feeder 3. Secondary air 8 heats the remaining fresh air 27 with a certain amount of heat and temperature level.
The temperature should be selected so that the temperature is raised to .

As mentioned above, this new method has the following basic idea of the invention. That is, in the case of suitably sensitive sinterable materials, rapid cooling can be achieved by strictly avoiding any air ingress after calcination and by using coarse powder as a refrigerant, which will later be sintered into clinker. It is particularly advantageous that just a portion of the powder can be used, while the cooling stage still functions as a coarse powder preheater.

This surprisingly simple solution is achieved in particular by utilizing the special properties of cement meal in the method according to the invention.

The cement meal can consume a large amount of energy (56) as a result of the endothermic reactions that occur there after heating to a temperature in the calcination region.

This recognition reaches a practical method. That is 14
The material to be sintered at a temperature of about 0.00 to 1500 m
A relatively small amount of coarse powder (approximately 0.3 kg7
9 clinker) is sufficient.

Theoretically, even less coarse powder could be used, but a certain excess amount of refrigerant is required to be able to cool the chestnut quickly and reliably.

Since the powder bed is a thermally insulating layer in a static state as a powder bed, other important features of the method of the present invention are as follows. That is, to provide an intensive mixing section of the material bed for improved heat exchange.

Therefore, in the case of equipment for this purpose, a tubular cooler is used as a preliminary cooler. Due to its special agitation feed trap, this tubular cooler has a relatively small diameter compared to conventional ones, and the length to diameter ratio can be large. It is also advantageous to determine the rotational speed relatively high.

(37) A further important feature of the invention is to place the precooler under the same pressure on both sides, thereby inertizing the free cooler capacity with an inert gas such as CO2 liberated from the deoxidation. What you do will work fine. Another advantage arises in the precooler with the addition of fuel, together with the reflux effect.

This is possible because the gas flow does not pass through the precooler. As mentioned above, this fuel requires all available oxygen at the temperature mentioned, so that if necessary it is also possible to resuppress the oxidation phenomena that took place before the precooling. The low-temperature carbonization components of the volatile fuel are then completely eliminated. Components that have been carbonized at a low temperature and are not used as subsequent components are effectively combusted in the precooler as long as they are not oxidized after being carried out and reach the rotary kiln and calciner.

Another advantage is that the precooler opens vertically from the final cooler into the tertiary air duct that passes into the calciner.
arise. Its vertical arrangement results in a straight conduit line that is short and easy to manufacture, and thus a very simple construction of the installation with low flow losses.

This method and the corresponding equipment thus solve the above-mentioned setting problem in a simple, economical and uncomplicated manner in terms of adjustment engineering.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the basic structure of the method of the present invention, and FIG. 2 is a pure schematic diagram of equipment for carrying out the method of the present invention. Code D in the figure...Cooling device 13...Pre-cooler 14...Final chiller agent Mitsuyoshi Ezaki agent Mitsufumi Esaki (39) - 291-9-shi\-sticky-- door (-[hama-2,2 book (ka style)
1M1 sum 1ρp+z month/8F+ Commissioner of the Japan Patent Office Manabu Shiga 1, case indication 1989 patent application No. 22ρ82 4 Agent

Claims (1)

[Claims] (1) A method for sintering sinterable materials such as limestone, dolomite, or cement clinker made of minerals containing solid raw materials, by preheating these raw materials in the form of raw meal. It is preheated in the calcination stage, calcined in the calcination stage, fired into a sintered material such as clinker in the calcination stage, and then cooled in the cooling stage. A method characterized by using raw meal as a medium for silkworm eggs. (2) The method according to the first paragraph Vc of claims, which is used for producing white boat rad cement clinker. f5) The method according to claim 1, wherein a part of the raw meal is preheated and partially calcined in the cooling stage. (4) The method according to any one of claims 1 to 3, wherein the cooling stage is divided into a preliminary cooling stage and a final cooling stage, and in the preliminary cooling stage, raw meal is used as a cooling medium. (5) The method according to any one of claims 1 to 4, wherein raw meal is used as a cooling medium in the preliminary cooling stage and air is used as a cooling medium in the final cooling stage. (6) The method according to any one of claims 1 to 5, wherein intensive and sufficient mixing movement is performed between raw meal and clinker in order to intensively exchange heat. (7) As a cooling medium, use a low-meal component such as calcium carbonate that has a high degree of loss on ignition, or
The method according to any one of claims 1 to 4, which is added to this. (8) At the pre-cooling stage, from the firing temperature, approximately 900t1
Claims 1 to 7 featuring a clinker up to
The method described in any of the preceding paragraphs. (9) The method according to any one of claims 1 to 8, wherein a reducing atmosphere is introduced in the pre-cooling stage to avoid the oxidation phenomenon. (10) The method according to any one of claims 1 to 9, wherein an inert atmosphere is introduced at least partially in the final cooling step in order to avoid oxidation phenomena. (+1) Clear Moisture 9 to 0.2 to 0.5 per kg
, %K 0.5 right raw meal is added as a cooling medium, and in that case, the addition it is selected so that a temperature balance occurs in the range of the calcination temperature by compensating the chestnut force and the heat amount of the cooling medium. The method according to any one of items 1 to 10 in the range of . (12) Pre-cooled chestnuts and heated raw meal are separated after passing through the pre-cooling stage, and the chestnuts and raw meal are sent to the final cooling stage and the raw meal to the calcination stage. The method according to any one of (5) to (5) above. (15) The method according to any one of claims 1 to 12, wherein a stream of preheated and partially calcined meal is collected from a preheating stage and a precooling stage of the calcination stage. (14) Complete calcination is carried out in the calcination stage, and in particular, the substance is further characterized at a temperature above the calcination temperature.
The method described in any of Items 3 to 3. (15) Passing the exhaust gas from the condensation stage and the waste from the calcination stage through separate and parallel preheater lines in the preheating stage, such that substantially equal pressures are generated on both sides of the precooling stage. 15. A method according to any one of claims 1 to 14, characterized in that the gas flows through the gas flow. (16) In order to generate heated secondary combustion support air for the combustion phase in a recuperative manner, the excess external heat content of the exhaust gases is characterized in particular by indirect heat exchange. (17) When the preheating stage consists of two or more lines, the distribution of the feed amount to each line of raw meal is as follows:
A considerable amount of heat from the waste gas from the calcination stage is transferred to the raw meal, whereas a sufficient amount of residual heat from the waste gas from the calcination stage is sufficient to generate heated secondary combustion support air in a recuperative manner. 17. The method according to any one of claims 1 to 16, which is carried out so as to be transmitted to a raw meal. (18) For firing sinterable materials such as cementite made of minerals containing limestone, dolomite or similar raw materials, these raw materials are preheated in the preheating stage in the form of raw meal and calcined. A method is implemented in which raw meal is added as a cooling medium to the sintered material during the cooling stage, in which the sintered material is calcined in several stages, then fired into a sintered material of various levels in the firing stage, and finally cooled in the cooling stage. A preheater for low-meal use, in particular for carrying sinterable materials such as cement clay/power (5) made of minerals containing limestone, dolomite) or similar raw materials. , has a cyclone heat exchanger consisting of one or several lines, the material outlet of which is in the calcination device, and the material outlet of the calcination device is in the calcination device, In this device in which the material outlet of the firing device is located in the cooling device, it is noted that the cooling device (D) has a precooler (13) and a final cooler (14) spatially separated therefrom. Featured device. (19) The device according to claim 18, wherein the precooler (13) is a rotating tube cooler. (20) Device according to any of claims 18 or 19, characterized in that the precooler (13) has a device (15) for metering and dispensing cold raw meal. (21) The device according to any one of claims 18 to 20, wherein the raw meal delivery device (+5) has an additional device (15) for metering and mixing fuel into the raw meal. (22) The device according to any one of claims 18 to 21, wherein the precooler (16) includes a device (17) for measuring the differential pressure between the inlet and the outlet. 23) The precooler (13) has a temperature measuring device (55) in the area of its discharge end.
The device according to any one of items 8 to 22. (24) A final cooler (14) arranged below the precooler (13) is provided, in particular in a vertically extending exhaust duct (50).
24. Device according to any one of the claims 18 to 23, characterized in that the duct has a drop-end of the precooler (13). (25) Connection of precooler (13) (exhaust duct in the range of 5) (3o) Internal pressure, in particular adjustable throttle (19)
) are arranged in claims 18 to 24.
The device according to any one of the preceding paragraphs. (26) The device according to any one of claims 18 to 25, wherein the exhaust duct (3o) enters directly into the calciner (7). (27) When equipping the low meal preheater (A) with two cyclone heat exchanger lines (1, 1') '1r,
One of the lines (1') connects to the calciner (7), the other (
1) is connected to the rotary kiln (5), and the latter (
27. Apparatus according to any one of claims 18 to 26, wherein the latter has more cyclone heat exchanger stages than the former (1'). (28) Calciner (7) K connected heat exchanger line (
1') has a recuperator (2) for generating secondary combustion support air heated in a hot air pipe (34) connected to the burner side of the rotary kiln (5). The device according to any one of Items 1 to 27.