COMBUSTION CHAMBER HOT FACE REFRACTORY LINING
The present application relates to a refractory lining in a combustion chamber operating in a reducing atmosphere, said lining comprising at least one or more Zirconia (Zr)-based refractory lining members comprising one or more Zr-based parts, wherein the Zr-based parts comprises at least 90 wt. %, preferably at least 95 wt. %, of monoclinic ZrO> 2 and/or partially stabilized ZrO> 2 and/or fully stabilized ZrO> 2 , wherein the total content of tetragonal and cubic ZrO> 2 amounts to at least 20 wt. %, preferably more than 35 wt. % as well as Zr based refractory lining members and methods for manufacturing said Zr based refractory lining members.
1 . Shaped and fired zirconia refractory material based on granular stabilized fused zirconia raw material low in silica for the inner lining of a combustion chamber in a vessel in which syngas comprising H 2 and CO is produced under reducing conditions essentially of crystalline zirconia, wherein the fired refractory material comprises a total content of tetragonal and cubic ZrO 2 measured by X-ray powder diffraction analysis of at least 20% by weight, wherein the Al 2 O 3 content is 0.05-6% by weight, and wherein the SiO 2 content of bonding phase of the material is below 1.5% by weight.
2 . Shaped and fired refractory zirconia material according to claim 1 , wherein the fused zirconia raw material is stabilized by Y 2 O 3 , MgO, CaO, CeO 2 or mixtures thereof.
3 . Shaped and fired zirconia refractory material according to the claim 1 , wherein the zirconia refractory material is shaped in form of a coating layer on an Al 2 O 3 -based refractory material.
4 . Shaped and fired zirconia refractory material according to claim 3 , wherein the coating layer has a thickness of at least 100 μm.
5 . Shaped and fired zirconia refractory material according to claim 3 , wherein the average grain size of the raw material is 2.5 μm to 50 μm.
6 . Shaped and fired zirconia refractory material according to claim 1 , wherein the refractory material is shaped in form of a brick.
7 . Shaped and fired zirconia refractory material according to claim 6 , wherein the brick has a bulk density of 3.80 g/cm 3 -5.40 g/cm 3 .
8 . Use of the shaped and fired zirconia refractory material according to claim 1 , for installing at least a part of an inner refractory lining of a combustion chamber of a vessel for producing H 2 and CO rich syngas under reducing atmosphere at temperatures above 1000° C. and pressures above 20 bar, wherein the outlet temperature of the vessel is below 1100° C.
9 . A combustion chamber operating in a reducing atmosphere comprising a refractory lining, wherein the refractory lining comprises a shaped and fired zirconia refractory material according to claim 1 .
10 . A combustion chamber operating in a reducing atmosphere according to claim 9 , wherein the shaped and fired zirconia refractory material has a thickness of 100 μm 250 mm.
11 . A combustion chamber operating in a reducing atmosphere, according to claim 9 , wherein the shaped and fired zirconia refractory material forms at least part of a combustion chamber refractory lining including at least part of the inner hot face wall lining and/or partition to downstream.
12 - 15 . (canceled)
16 . A method for manufacturing a shaped and fired zirconia refractory material comprising the steps of:
shaping a mixture based on granular stabilized fused zirconia raw material low in silica into a shape,
firing at temperature above 1400° C.,
thereby achieving a shaped and fired zirconia refractory material comprising a total content of tetragonal and cubic ZrO 2 measured by X-ray powder diffraction analysis of at least 20% by weight, and wherein the Al 2 O 3 content is 0.05-6% by weight, and the SiO 2 content of bonding phase of the material is below 1.5% by weight.
17 . (canceled)
18 . A method for producing a shaped and fired zirconia refractory material shaped in form of coating layer on an alumina based refractory material, the method comprising the steps of:
a) providing a shaped refractory of an Al 2 O 3 -based refractory material, optionally with a corresponding cleaning of the surface to be coated,
b) applying a powder dispersion comprising granular stabilized fused ZrO 2 raw material powder in form of a conditioned carrier fluid onto at least one surfaces of the shaped Al 2 O 3 based refractory material, and
c) drying the applied power dispersion followed by a thermal treatment at a temperature above 1200° C., thereby obtaining a bonded coating, the bonded coating layer comprises a total content of tetragonal and cubic ZrO 2 measured by X-ray powder diffraction analysis of at least 20% by weight, and wherein the Al 2 O 3 content is 0.05-6% by weight, and wherein the SiO 2 content of bonding phase of the material is below 1.5% by weight.
19 . (canceled)
20 . A method for producing shaped and fired zirconia refractory material in form of coating layer according to claim 18 , wherein the powder dispersion is applied by way of techniques within the group: spraying, painting, dipping and casting,
21 . The method of claim 18 , wherein the powder dispersion has a viscosity of 2000-6000 mPa's.
22 . The method according to claim 18 , wherein the powder dispersion comprising the stabilized fused ZrO2 raw material powder, presents an average grain size in the range of approximately 2.5 μm to 50 μm.
23 - 24 . (canceled)
25 . The method according to claim 9 , wherein the powder dispersion is applied one or more times resulting in a bonded coating having a thickness of at least 100 μm is obtained.
26 . Process for in situ formation of a shaped and fired zirconia refractory material in form of coating layer supported on at least one base refractory material, wherein the fired refractory material comprises a total content of tetragonal and cubic ZrO 2 measured by X-ray powder diffraction analysis of at least 20% by weight, wherein the Al 2 O 3 content is 0.05-6% by weight and wherein the SiO 2 content of bonding phase of the material is below 1.5% by weight, the method comprising the steps of,
applying one or more layers of a powder or powder mixture dispersion comprising a powder or a powder mixture based on stabilized fused ZrO 2 , optionally admixed powdered Al 2 O 3 , wherein the mineralogical composition of the powder or a powder mixture based on stabilized fused ZrO 2 is calculated in such a manner that, the mineralogical composition of the bonded coating is obtained after a thermal treatment,
in a first heating step, heating to a first temperature, at a first pressure thereby forming a adhered coating, and
in as second heating step, heating to a temperature above 1000° C. at a second pressure, thereby obtaining the bonded coating layer.
27 . The process of claim 18 , wherein the SiO 2 -content in the bonding phase of the coating layer is below 2.0 wt. %, and/or wherein the coating layer comprises 0.05-6 wt. % of Al 2 O 3 .
28 . The process according to claim 18 , wherein the at least one base refractory material comprises aluminum oxides and/or aluminum oxide based ceramic materials.
29 . The process according to claim 18 , wherein the first temperature is at least 200-300° C. and the first pressure is 1-20 bar.
30 . The process according to claim 18 , wherein the second pressure is at least 10 bar.
31 . The process according to claim 18 , wherein the atmosphere in the first heating step comprises an inert gas.
32 . The process according to claim 18 , wherein the atmosphere in the second heating step comprises hydrogen and carbon monoxide or a hydrocarbon containing gas or a hydrocarbon containing gas containing steam.
33 . The process according to claim 18 , wherein a refractory lining in a combustion chamber for producing H 2 and CO containing syngas is formed.