Method and arrangement for burning lime mud

Patent metadata

Field	Value
Publication number	US-2017291851-A1
Application number	US-201715590740-A
Country	US
Kind code	A1
Filing date	May 9, 2017
Priority date	Feb 28, 2011
Publication date	Oct 12, 2017
Grant date	—

Abstract

An arrangement for burning lime mud into lime in a lime kiln. The lime mud flows counter-currently to flue gases from a feed end to a firing end and the fuel used is flue gas that is produced by gasifying a fuel in the presence of combustion air in a gasifier. The combustion air for gasification is preheated with heat generated in lime mud combustion. The arrangement is provided with a conduit between the lime kiln and the gasifier for leading air from the lime kiln into the gasifier as combustion air. At least a portion of the combustion air for gasification is preheated with heat generated in the lime mud combustion so that air is led into cooling of lime obtained in the combustion and further into the kiln, from or through the firing end of which air is taken into the gasification.

First claim

1 . A lime mud combustion plant comprising:
a lime kiln having a rotary drum with a feed end and a firing end; a lime kiln burner aligned with the firing end of the rotary drum; a gasifier configured to produce fuel gas using combustion air; a fuel gas conduit coupled to the gasifier and forming a passage for fuel gas produced by the gasifier flowing to the lime kiln burner, and at least one conduit coupled to the lime kiln and the gasifier, wherein the at least one air conduit forms a passage providing the combustion air to the gasifier, wherein an air inlet to the at least one air conduit is configured to receive air from or through the firing end of the lime kiln.

2 . The lime mud combustion plant according to claim 1 , wherein the air inlet to the at least one air conduit extends into an interior of the lime kiln at least to the depth of a dam of the kiln.

3 . The lime mud combustion plant according to claim 1 , further comprising a cooling conduit adjacent a cooler section of the lime kiln and the cooling conduit is coupled to the at least one air conduit such that air passes through the cooling conduit into the at least one air conduit.

4 . The lime mud combustion plant according to claim 1 , wherein the at least one air conduit includes a second air conduit providing an air passage for air flowing to the gasifier, wherein the second air conduit has an air inlet coupled to a hood and the hood at least partially surrounds the lime kiln.

5 . The lime mud combustion plant according to claim 1 , further comprising an inlet conduit configured to allow ambient air to enter the at least one air conduit.

6 . The lime mud combustion plant according to claim 1 , further comprising an air regulation device connected to the at least one air conduit, wherein the air regulation device includes an air valve and the air valve is adjustable to regulate the combustion air flowing to the gasifier.

7 . The lime mud combustion plant according to claim 1 , wherein the feed end is at an opposite end of the rotary drum to the firing end.

8 . A lime mud combustion plant comprising:
a lime kiln having a rotary drum with a feed end and a firing end opposite to the feed end; a lime kiln burner at the firing end of the rotary drum; a gasifier configured to produce fuel gas using combustion air; a fuel gas conduit coupled to the gasifier and forming a passage extending from the gasifier to the lime kiln burner, wherein the fuel gas conduit is configured to convey fuel gas produced by the gasifier to flow to the lime kiln burner, and an air conduit extending from the lime kiln to a combustion air inlet the gasifier, wherein the air conduit includes an air inlet positioned to receive air from or flowing through the firing end of the lime kiln and an air outlet coupled to the gasifier.

9 . The lime mud combustion plant according to claim 8 , wherein the air inlet to the air conduit extends into an interior of the rotary drum.

10 . The lime mud combustion plant according to claim 9 wherein the air inlet to the air conduit extends at least to the depth of a dam of the rotary drum.

11 . The lime mud combustion plant according to claim 8 , further comprising a cooling conduit adjacent a cooler section of the lime kiln and the cooling conduit is coupled to the air conduit such that air passes through the cooling conduit into the air conduit.

12 . The lime mud combustion plant according to claim 8 , wherein the air conduit includes a second air conduit including an air inlet coupled to a hood and the hood at least partially surrounds the lime kiln.

13 . The lime mud combustion plant according to claim 8 , further comprising an ambient inlet conduit configured to duct ambient air into the air conduit.

14 . The lime mud combustion plant according to claim 8 , further comprising an air regulation device connected to the air conduit, wherein the air regulation device includes an air valve and the air valve is adjustable to regulate the combustion air flowing to the gasifier.

15 . The lime mud combustion plant according to claim 8 , wherein the feed end of the rotary drum is at an opposite end of the rotary drum to the firing end.

Assignees

• Andritz Oy

Inventors

• Vehmaan-Kreula Juhani

Classifications

• C10J2300/1869

  with one stream being air, oxygen or ozone · CPC title

• F27B7/20

  Details, accessories or equipment specially adapted for rotary-drum furnaces · CPC title

• F27B7/36

  Arrangements of air or gas supply devices · CPC title

• C04B2/10

  Preheating, burning calcining or cooling (decarbonation during burning of cement raw materials C04B7/43; {obtaining CaO or MgO otherwise than by thermal decomposition of the corresponding carbonates C01F11/02, C01F5/02}) · CPC title

• Y02P20/129

  Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines · CPC title