DE10316207A1 - Clinker production unit, comprises sinter furnace, bypass system with heating unit, spray unit and separator for the removal of solidified droplets - Google Patents

Abstract

An installation for producing clinker, comprises a sinter furnace (2) for firing pre warmed raw material, and a by-pass system for part of the dust laden exhaust gases. The bypass has a heating unit (8) for heating the dust laden exhaust gas to the dust melting point, and a spray unit (10) for spraying the melt in droplet form. A separator (12) is used to separate out the solidified droplets. The installation has a cyclone pre-heater (1) and a cooler.

Description

The The invention relates to a system and a method for manufacturing from clinker with a sintering furnace for firing preheated raw material and a bypass system for branching off part of the in the sintering furnace resulting exhaust gases containing dust.

raw materials and fuels for cement production mostly contains chlorides, Alkalis (sodium-potassium compounds) and sulfur compounds, especially sulphates, which are easy at relatively high treatment temperatures volatile become. While of the firing process in the sintering furnace evaporate the aforementioned volatile Components or connections to a large extent, so that they with the Combustion or treatment gases transported in the sintering furnace be and in colder Can condense areas of the sintering furnace, a calcining zone and a preheater, wherein the raw material to be burned largely serves as a condensate surface. These condensed components (compounds) come together with the raw flour to be burned again in the sintering zone. The process the evaporation and condensation of the constituents mentioned away, so that there is between hotter areas such as the sintering furnace and colder Areas, like the preheater, a cycle of volatile Ingredients, especially from the chloride, alkali and sulfur compounds expands that swell considerably can.

Especially it becomes critical when pollutant concentrations are reached, where the raw material is poorly or no longer flowable at all and caking and constipation occur.

Around To break this pollutant cycle are so-called Bypass systems are provided that contain part of the dust-containing exhaust gases of the sintering furnace. The bypass hot gas is then usually cools down by means of air or water until the pollutants condense the dust particles. Here is the dust concentration of the bypass hot gas too small, there are problems with the approach. To increase the dust concentration for example, you work with an additional flour curtain in the oven inlet housing.

In a bypass filter, the dust particles of the Bypass flow separated. If there is too much dust in the bypass flow elevated thus the proportion of the bypass filter dust.

There, where the separated bypass dust is relatively low If quantities are involved, he can add them to a cement mill or to others mineral binders can be used. For larger quantities of bypass dust, as is the case in many countries, such as the United States, the case, the bypass dust is a waste product, which often has to be deposited at correspondingly high costs.

From the DE-A 196 27 660 it is therefore known to supply the bypass flow to a separation device in which at least the largest proportion of the volatile constituents is separated from the bypass flow by quenching or condensing. The remaining partial gas stream is then fed to a dust separation device, so that the dust contained therein can be separated off, which is then fed to a dust combustion reactor. Then the fired dust material can be cooled together with the clinker fired in the sintering furnace in the cooling zone. The required quenching and the intermediate storage of the dust are, however, relatively complex.

The The invention is therefore based on the object of a simpler method to specify the conversion of the bypass dust.

According to the invention Task solved by the features of claims 1 and 5, respectively.

The Plant according to the invention for the production of clinker has a sintering furnace for burning preheated Raw material and a bypass system for branching off part of the Dust-containing exhaust gases arising in the sintering furnace, whereby the bypass system a device for heating the dust-containing exhaust gases until melting of the dust contained in the exhaust gas, a device for spraying the resulting melt to drops and a device for separation the drop provides.

At the method according to the invention for the production of clinker by firing preheated raw material part of the resulting dust-containing exhaust gases becomes Bypass system branched off, where the dust-containing exhaust gases heated up so far until the dust contained in the exhaust gas becomes molten, the resulting melt is sprayed into drops using a fluid, who cool, solidify and form clinker and finally be separated.

The Plant according to the invention and the process converts the bypass dust directly without quenches and intermediate storage of the dusts, into clinker.

Further Embodiments of the invention are the subject of the dependent claims.

In becomes a preferred embodiment as a spray medium Air and / or water used. The separation of the solidified drops expediently takes place in a cyclone.

Further Advantages and refinements of the invention are described below the description of an embodiment explained in more detail.

The Drawing shows a schematic representation of a system according to the invention with bypass system.

The plant for the production of clinker shown in the drawing essentially consists of a multi-stage cyclone preheater 1 , a sintering furnace designed as a rotary kiln 2 as well as a cooler 3 , The raw materials are at 4 the cyclone preheater and then come in the individual stages of the cyclone preheater with the hot exhaust gases from the sintering furnace 2 in contact. The preheated raw materials are then fired in the sintering furnace and finally cooled in the cooler. The exhaust gases from the preheater are in one facility 5 , cooled and then in a filter 6 dusted.

Part of the dust-containing exhaust gases from the sintering furnace 2 is via a bypass line 7 a device designed as a melting cyclone 8th supplied to heat the exhaust gases containing dust. The melting cyclone also has agents 9 for supplying fuel and combustion air. In this melting cyclone, the exhaust gases containing dust are heated until the dust contained in the exhaust gas becomes molten.

The resulting melt is led downwards out of the melting cyclone and into a facility 10 to spray the melt into drops. This institution has funds 11 for supplying a spray medium, for example air and / or water. The drops get into a device together with the spray medium 12 to separate the solidified drops.

The drops, which are also cooled at the same time, pass through a line 13 into the main clinker stream after the cooler or are fed directly to a cement mill.

That in the separator 12 heated spray medium can be piped 14 as combustion air in the facility 8th can be used to heat the exhaust gases containing dust. The facility's exhaust gases 8th can for example in a cogeneration unit 15 used or simply quenched and in a filter 16 be dusted.

The The method described above is characterized by a minimal Share of waste materials (salts).

Claims (10)

Plant for the production of clinker with a sintering furnace ( 2 ) for firing preheated raw material and a bypass system for branching off part of the dust-containing exhaust gases generated in the sintering furnace, characterized in that the bypass system has a device ( 8th ) for heating the dust-containing exhaust gases until the dust contained in the exhaust gas melts, a device ( 10 ) for spraying the resulting melt into drops and a device ( 12 ) for separating the solidified drops. System according to claim 1, characterized in that the device ( 8th ) for melting agent ( 9 ) for supplying fuel. Installation according to claim 1, characterized in that the device for spraying ( 10 ) of the resulting melt ( 11 ) for supplying a spray medium, such as air and / or water. System according to claim 1, characterized in that the device ( 12 ) to separate the solidified drops by a cyclone. Process for the production of clinker by firing of preheated Raw material, with some of the resulting dusty Exhaust gases is branched into a bypass system, characterized in that that the dust-containing exhaust gases in the bypass system are heated so far until the dust contained in the exhaust gas becomes molten, the resulting melt is sprayed into drops by means of a fluid and finally the solidified drops can be separated. A method according to claim 5, characterized in that to spray air and or water is used in the melt. A method according to claim 5, characterized in that when spraying the melt air is used, which is then used as combustion air Melting is used. A method according to claim 5, characterized in that the exhaust gases generated during melting are dedusted. A method according to claim 5, characterized in that the exhaust gases formed during melting prior to dedusting to gain energy be used. A method according to claim 5, characterized in that fuel and combustion air are supplied to melt the dust.