# US 8,784,097 B2 · Apparatus for the production of clinker from raw meal and relative process

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- Number: US 8,784,097 B2
- Document ID: US8784097B2
- Status: Granted
- Kind: B2
- Application number: 12/998,974
- Filed: 2009-12-17
- Published: 2011-12-22
- Granted: 2014-07-22
- Earliest claimed: 2008-12-23
- Assignees: Italcementi S.p.A.
- Applicants: Roberto Fedi; Antonio Clausi; Giovanni Cinti
- Inventors: Roberto Fedi; Antonio Clausi; Giovanni Cinti
- Web page: https://patentgrep.com/patent/US8784097B2

## CPC

- F27D 17/18: for preheating solid materials
- B01D 53/56: Nitrogen oxides (B01D53/60 takes precedence)
- B01D 53/8625: {Nitrogen oxides}
- C04B 7/364: {Avoiding environmental pollution during cement-manufacturing}
- C04B 7/38: Preparing or treating the raw materials individually or as batches {, e.g. mixing with fuel; (C04B7/362 takes precedence)}
- F26B 23/002: {recovered from dryer exhaust gases (F26B23/022 takes precedence)}
- F26B 25/005: {Treatment of dryer exhaust gases (incineration of volatiles F26B23/022)}
- F27B 7/2033: {with means for precalcining the raw material}
- B01D 2251/2062: Ammonia
- B01D 2258/0233: from cement factories
- Y02P 40/121: Energy efficiency measures, e.g. improving or optimising the production methods
- Y02P 70/10: Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working
- F27D: DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28)
- C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE
- F26B: DRYING SOLID MATERIALS OR OBJECTS BY REMOVING LIQUID THEREFROM (drying devices for combines A01D41/133; racks for drying fruit or vegetables A01F25/12; drying foodstuffs A23; drying hair A45D20/00; body-drying implements A47K10/00; drying household articles A47L; drying gases or vapours B01D; chemical or physical processes for dewatering or like separating liquids from solids B01D43/00; centrifugal apparatus B04; drying ceramics C04B33/30; drying yarns or fabrics in association with some other form of treatment D06C; drying frames for laundry without heating or positive air circulation, domestic laundry-or spin-driers, wringing or hot pressing laundry D06F; furnaces, kilns, ovens F27)
- F27B: FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present invention concerns an apparatus for the production of clinker from raw meal, comprising: a rotary kiln (8), optionally a precalciner; a multi-stage cyclone preheater (9) connected downstream of said rotary kiln (8) with respect to the direction of flow of the fumes (11) of a combustion taking place in said kiln (8); an electrofilter (10) connected downstream of said preheater (9) with respect to said direction of flow of the combustion fumes (11); characterized in that it comprises a first inlet (17) for feeding raw meal to said combustion fumes (11), said inlet (17) being arranged downstream of said preheater (9) and upstream of said electrofilter (10) with respect to said direction of flow of the combustion fumes (11), and in that it comprises a second inlet (18) for feeding partially preheated raw meal (14) from said electrofilter (10) to said preheater (9). The present invention also concerns an improved process for the production of clinker from raw meal.

## Claims

### Claim 1

Apparatus for the production of clinker from raw meal, comprising a rotary kiln (8);
(a) a multistage cyclone preheater (9) connected downstream of said rotary kiln (8) in relation to the direction of flow of the fumes (11) of a combustion taking place in said kiln (8);
(b) an electrofilter (10) connected downstream of said preheater (9) in relation to said direction of flow of the combustion fumes (11);
(c) characterised in that it comprises a first inlet (17) for the feeding of raw meal to said combustion fumes (11), said inlet (17) being placed downstream of said preheater (9) and upstream of said electrofilter (10) in relation to said direction of flow of the combustion fumes (11), and in that it comprises a second inlet (18) for the feeding of partially preheated raw meal (14) from said electrofilter (10) to said preheater (9) said apparatus further comprising apparatus for purifying the combustion fumes cleaned of dust exiting the electrofilter from further pollutants and/or apparatus for recovering their heat wherein the apparatus for purifying the combustion fumes cleaned of dust exiting the electrofilter comprise NOx lowering means and/or a sulphur lowering device.

### Claim 2 (depends on 1)

Apparatus according to claim 1 wherein the means for purifying the combustion fumes cleaned of dust exiting the electrofilter comprise NOx lowering means, preferably a selective catalytic reduction device operating with reducing additives.

### Claim 3 (depends on 1)

Apparatus according to claim 1 wherein the sulphur oxide lowering device comprises a device for injecting SO2, into the combustion fumes cleaned of dust of calcium oxide- and/or calcium hydroxide-based compounds.

### Claim 4 (depends on 1)

Apparatus according to claim 1 wherein the means for recovering the heat contained in the combustion fumes comprise a heat exchanger and/or a conditioning tower.

### Claim 5 (depends on 1)

Apparatus according to claim 1, wherein the second inlet (18) is provided in an intermediate point between two cyclones, preferably between the first and second cyclones.

### Claim 6 (depends on 1)

Apparatus according to claim 1 wherein the length of the path that connects the inlet (17) of the raw meal (22) in the combustion fumes (11) to the inlet (13) in the electrofilter (10) of the partially preheated raw meal (14) in suspension is such that the partially preheated raw meal (14) entering the preheater (9) has a temperature comprised in the 250-400° C.

### Claim 7 (depends on 1)

Apparatus according to claim 1 wherein the length of the path that connects the inlet (17) of the raw meal (22) in the combustion fumes (11) to the inlet (13) in the electrofilter (10) of the partially preheated raw meal (14) in suspension is such that the partially preheated raw meal (14) entering the preheater (9) has a temperature comprised in the 270-360° C. range.

### Claim 8 (depends on 1)

Apparatus according to claim 1 which includes a precalcinator.

### Claim 9

Improved process for the production of clinker from raw meal in an apparatus comprising a rotary kiln (8), a multistage cyclone preheater (9) and an electrofilter (10), said process comprising the following operating steps:
a) making the combustion fumes (11), from the rotary kiln (8), flow from bottom to top into the preheater (9);
b) mixing the raw meal (22) with the combustion fumes (11) exiting the preheater (9), with preheating of the raw meal (14) by contact with the combustion fumes (11), and formation of a gas flow containing a partially preheated raw meal (14) in suspension;
c) feeding the flow obtained in phase b) to the electrofilter (10) and separating the partially preheated raw meal (14) from a flow of combustion fumes cleaned of dust (15);
d) feeding the partially preheated raw meal (14) obtained in step c) to the preheater (9) and preheating the raw meal (14) by contact in counter-flow with the combustion fumes (11) that flow from bottom to top;
e) feeding the preheated raw meal (16) from phase d) to the rotary kiln (8) for the subsequent production of clinker and;
submitting the combustion fumes cleaned of dust (15) exiting the electrofilter (10) to further pollutant purification treatments and/or heat recovery treatments, wherein said further pollutant purification treatments comprise a NOx lowering treatment and/or a sulphur oxide lowering treatment.

### Claim 10 (depends on 9)

Process according to claim 9 wherein the partially preheated raw meal (14) which is fed to the preheater (9) in step d) has a temperature comprised in the 250-400° C. range.

### Claim 11 (depends on 10)

Process according to claim 10 wherein the partially preheated raw meal (14) which is fed to the preheater (9) in step d) has a temperature comprised in the 270-360° range.

### Claim 12 (depends on 11)

Process according to claim 11 wherein the NOx lowering treatment is a selective catalytic reduction process.

### Claim 13 (depends on 9)

Process according to claim 9 wherein step f) comprises a sulphur dioxide lowering treatment by means of injection in the combustion fumes cleaned of dust (15) calcium oxide- and/or calcium hydroxide-based compounds.

### Claim 14 (depends on 13)

A process according to claim 13 wherein step f) comprises a recovery treatment of the heat contained in the combustion fumes cleaned of dust (15) by means of at least one heat exchanger and/or one conditioning tower (21).

### Claim 15 (depends on 9)

Process according to claim 9 wherein the partially preheated raw meal (14) which is fed to the preheater (9) in step d) has a temperature comprised in the 270-360° C. range.

### Claim 16 (depends on 9)

Process according to claim 9 which includes a precalcinator.