Oxyfuel clinker production with special oxygen addition

Patent metadata

Field	Value
Publication number	US-2021198142-A1
Application number	US-201917051087-A
Country	US
Kind code	A1
Filing date	Apr 26, 2019
Priority date	Apr 30, 2018
Publication date	Jul 1, 2021
Grant date	—

Abstract

Processes and plants for producing cement clinker, in which an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen is conveyed from a first section of the cooler directly adjoining the top of the furnace into the rotary furnace and is optionally additionally conveyed to the calciner, and where the total gas streams fed in to the combustion processes consist to an extent of more than 50% by volume (preferably more than 85% by volume) of oxygen.

First claim

1 .- 14 . (canceled)

15 . A method for producing cement clinker, comprising:
preheating a starting material to a calcination temperature, performing calcination of the preheated starting material in a calciner, firing, in a rotary furnace, the calcined starting material to form cement clinker, cooling the cement clinker in a cooler, and feeding an oxygen-containing gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen into a first section of the cooler, the first section of the cooler directly adjoining a top portion of the rotary furnace, and from the first section of the cooler into the rotary furnace, wherein the total gas streams fed to the combustion processes consist of more than 50% by volume of oxygen, and wherein the introduction of the oxygen-containing gas is set so that there is an excess of oxygen at a main burner and residual amounts of the oxygen-containing gas are permitted to enter the calciner for combustion.

16 . The method of claim 15 wherein said feeding further comprises feeding of the oxygen-containing gas into the calciner.

17 . The method of claim 15 wherein an exhaust gas is supplied to said preheating of starting material step at a ratio wherein the starting material is greater than 1.0 kg of starting material per 1 kg of gas and wherein at least one cyclone preheater is used for preheating.

18 . The method of claim 17 wherein the ratio of starting material fed in to the exhaust gas in said performing step is greater than 1.0 kg of starting material per 1 kg of exhaust gas, wherein the calciner is an entrained flow calciner.

19 . The method of claim 15 wherein coarse fuels having an edge length of 70 mm or more are introduced into the calciner, which includes a nonvertical section, so that hot gases flow over the coarse fuels in the calciner.

20 . The method of claim 15 wherein a gas substream from an inlet of the rotary furnace or downstream of the calciner is recirculated to a top of the rotary furnace for combustion.

21 . The method of claim 15 wherein hot exhaust air from the clinker cooler is fed at least partly to said preheating step, or at least partly to a drying and milling operation, or at least partly to said preheating step and subsequently to said drying and milling operation, while avoiding mixing with exhaust gas from the calcination and firing steps.

22 . The method of claim 15 wherein oxygen-rich gas taken off from a rotary inlet region is, after having been depleted in at least sulfur and chlorine, recirculated to the rotary furnace.

23 . The method of claim 15 wherein the oxygen-containing gas contains one or both of 75% by volume or more of oxygen or contains 10% by volume or less of nitrogen.

24 . The method of claim 15 wherein the amounts of oxygen-containing gas and a fuel fed in are regulated as a function of combustion temperature and gas volume flows.

25 . The method of claim 15 wherein introduction of the oxygen-containing gas is set so that the oxygen fed in is sufficient for complete combustion at a main burner and in the calciner.

26 . The method of claim 15 wherein introduction of the oxygen-containing gas is carried out exclusively on the side of a gas separation device which is arranged in the cooler and directly adjoins a top of the furnace, wherein the gas separation device is one or both of a mechanical gas separation device or a system based on supply of a barrier gas.

27 . A plant for producing cement clinker, comprising:
a preheater, a calciner, a rotary furnace, and a clinker cooler, wherein the plant has, at a section of the cooler directly adjoining a top of the rotary furnace, a device for feeding gas from the cooler to the rotary furnace, the device configured to feed a gas having a proportion of 15% by volume or less of nitrogen and a proportion of 50% by volume or more of oxygen, and wherein the plant is configured for feeding gas streams which in total consist to an extent of more than 50% by volume of oxygen to combustion processes wherein the introduction of gas is set so that there is an excess of oxygen at a main burner and residual amounts of the oxygen are conveyed into the calciner.

28 . The plant of claim 27 further comprising a device for feeding the gas into the calciner.

Assignees

• Thyssenkrupp Ind Solutions Ag
• Thyssenkrupp Intellectual Property Gmbh

Inventors

• Lemke Jost
• Willms Eike

Classifications

• C04B7/475

  using the waste heat, e.g. of the cooled clinker, in an other way than by simple heat exchange in the cement production line, e.g. for generating steam · CPC title

• F27B7/36

  Arrangements of air or gas supply devices · CPC title

• F27B7/3205

  Charging · CPC title

• C04B7/4407

  Treatment or selection of the fuel therefor, e.g. use of hazardous waste as secondary fuel (fuels in general C10L); Use of particular energy sources, e.g. waste hot gases from other processes · CPC title

• C04B7/4476 Primary

  Selection of the kiln atmosphere · CPC title