EP0272579A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Refractory shields for curved and straight superheater tubes
Assignee: Saint Gobain Abrasives Inc
•
Filing: 1987-12-14
•
Granted: —
•
Expires: 2007-12-14
Abstract
Abstract Straight and arcuately curved superheater tube shields of refractory material comprising of pair of elongated half shields (12; 32) of identical interchangeable interfitting and interlocking size and shape, each half shield having a semicircular sidewall (14; 34) of corresponding straight or arcuate shape of predetermined radius of curvature extending between opposite ends and to inner diametrically opposite inner sides lying in a central plane and the plane of curvature. A number of mating camming portions (20; 40) with inclined camming surfaces (22, 24; 42, 44) are precisely spaced adjacent each of the inner sides so that one of the half shields may be turned end for end relative to and assembled to the other about a correspondingly shaped superheater tube by a relatively short axial movement and engagement of the inclined camming surfaces whereby the half shields are pulled together to close the joints therebetween and interlocked about the superheater tube. A refractory cement may be applied to attach the half shields to the tubes.
Inventors
- 👤 Roger W. Woodruff
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 20:23
CPC Classifications
F; F22; F22G; F22G3/00; F16; F16L; F16L3/00; F16L3/08; F16L3/12; F16L3/1226; F22B; F22B37/00; F22B37/02; F22B37/10; F22B37/107; F27; F27D; F27D1/00; F27D1/12
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
400 words
A refractory shield for protecting correspondingly shaped sections of straight and curved superheater tubes against attack by the products of combustion characterized by: a pair of elongated refractory half shields (12;32) of identical interchangeable, interfitting, interlocking size and shape adapted when one half shield is turned longitudinally end for end relative to the other half shield to fit laterally together, to be shifted longitudinally a short distance relative to one another, to be cammed and interlocked together to close diametrically opposite joints between the half shields and thereby to cover and protect a section of a superheater tube of corresponding shape, each half shield having an elongated sidewall portion (14;34) of predetermined thickness and longitudinal length between opposite ends thereof, extending circumferentially between and to diametrically opposite inner sides (16) lying in a central plane (cp); a plurality of identical mating camming portions (20;40) spaced longitudinally between the opposite ends of and along the sidewall adjacent each of the diametrically opposite inner sides of the sidewall, each camming portion having a central junction (J) lying in a radial plane at its center and located substantially the same predetermined distance from an adjacent one of the opposite ends as is the central junction of another camming portion situated adjacent the same one of the diametrically opposite inner sides is from the other adjacent one of the opposite ends, a raised inclined cam (22;42) of predetermined identical size, shape, and inclination on one and the same side of the central junction and the central plane of the half shield, and an overhanging recessed inclined cam receiving portion (24;44) of predetermined identical mating size, shape and inclination projecting from the sidewall portion and situated on the opposite and same side of the central junction (J) and the central plane, inclined opposite to the raised camd, adapted to laterally enter a space of greater width adjacent each of the camming portions of the other half shield and moved longitudinally a relatively small distance to matingly engage the raised inclined cams (22;42) of the other identical half shield turned end for end relative to the other of the pair of identical half shields, whereby the overhanging recessed inclined cam receiving portions and the raised inclined cams of each of the pair of identical half shields slidably engage one another and simultaneously pull and lock the pair of half shields together and close the joints therebetween.
Claim 2
Dependent Claim
400 words
A refractory shield for protecting correspondingly shaped sections of straight and curved superheater tubes against attack by the products of combustion characterized by: a pair of elongated refractory half shields (12;32) of identical interchangeable, interfitting, interlocking size and shape adapted when one half shield is turned longitudinally end for end relative to the other half shield to fit laterally together, to be shifted longitudinally a short distance relative to one another, to be cammed and interlocked together to close diametrically opposite joints between the half shields and thereby to cover and protect a section of a superheater tube of corresponding shape, each half shield having an elongated sidewall portion (14;34) of predetermined thickness and longitudinal length between opposite ends thereof, extending circumferentially between and to diametrically opposite inner sides (16) lying in a central plane (cp); a plurality of identical mating camming portions (20;40) spaced longitudinally between the opposite ends of and along the sidewall adjacent each of the diametrically opposite inner sides of the sidewall, each camming portion having a central junction (J) lying in a radial plane at its center and located substantially the same predetermined distance from an adjacent one of the opposite ends as is the central junction of another camming portion situated adjacent the same one of the diametrically opposite inner sides is from the other adjacent one of the opposite ends, a raised inclined cam (22;42) of predetermined identical size, shape, and inclination on one and the same side of the central junction and the central plane of the half shield, and an overhanging recessed inclined cam receiving portion (24;44) of predetermined identical mating size, shape and inclination projecting from the sidewall portion and situated on the opposite and same side of the central junction (J) and the central plane, inclined opposite to the raised camd, adapted to laterally enter a space of greater width adjacent each of the camming portions of the other half shield and moved longitudinally a relatively small distance to matingly engage the raised inclined cams (22;42) of the other identical half shield turned end for end relative to the other of the pair of identical half shields, whereby the overhanging recessed inclined cam receiving portions and the raised inclined cams of each of the pair of identical half shields slidably engage one another and simultaneously pull and lock the pair of half shields together and close the joints therebetween.
Claim 3
Dependent Claim
21 words
A refractory shield according to claim 1, wherein each of the identical half shields has a sidewall (14;34) of semi-circular cross-section.
Claim 4
Dependent Claim
78 words
A refractory shield according to claim 1 or 2, wherein the raised inclined cams (22) and overhanging recessed inclined cam receiving portions (24) each have mating inclined shoulder surfaces of predetermined height above the sidewall, inclined relative to the diametrically opposite inner sides and the central plane of the sidewall from opposite smaller ends to larger ends of the raised inclined cams and overhanging recessed inclined cam receiving portions situated at the central junction and the radial plane.
Claim 5
Dependent Claim
54 words
A refractory shield according to claim 1 or 2, wherein the raised inclined cams and the overhanging recessed inclined cam receiving portions have mating inclined camming surfaces extending upwardly at the same inclination from opposite sides of the camming portions to a higher point located at the central junction and the radial plane therebetween.
Claim 6
Dependent Claim
58 words
A refractory shield according to claim 4, wherein the mating inclined camming surfaces of both the raised inclined cams and the overhanging recessed inclined cam receiving portions are arcuately curved downwardly at a predetermined same radius and in opposite directions away from a higher inclined edge of the inner sides of the sidewall lying in the central plane.
Claim 7
Dependent Claim
69 words
A refractory shield according to any one of the preceding claims, wherein each of the pair of identical half shields (12) is of arcuate shape and comprises: an elongated sidewall (14) extending arcuately between the opposite ends and circumferentially to diametrically opposite arcuately curved upper and lower inner sides each of a different predetermined radius of curvature and arcuate length lying in the central plane and plane of curvature.
Claim 8
Dependent Claim
21 words
A refractory shield according to claim 1, wherein each of the identical half shields has a sidewall (14;34) of semi-circular cross-section.
Claim 9
Dependent Claim
78 words
A refractory shield according to claim 1 or 2, wherein the raised inclined cams (22) and overhanging recessed inclined cam receiving portions (24) each have mating inclined should surfaces of predetermined height above the sidewall, inclined relative to the diametrically opposite inner sides and the central plane of the sidewall from opposite smaller ends to larger ends of the raised inclined cams and overhanging recessed inclined cam receiving portions situated at the central junction and the radial plane.
Claim 10
Dependent Claim
54 words
A refractory shield according to claim 1 or 2, wherein the raised inclined cams and the overhanging recessed inclined cam receiving portions have mating inclined camming surfaces extending upwardly at the same inclination from opposite sides of the camming portions to a higher point located at the central junction and the radial plane therebetween.
Claim 11
Dependent Claim
58 words
A refractory shield according to claim 4, wherein the mating inclined camming surfaces of both the raised inclined cams and the overhanging recessed inclined cam receiving ortions are arcuately curved downwardly at a predetermined same radius and in opposite directions away from a higher inclined edge of the inner sides of the sidewall lying in the central plane.
Claim 12
Dependent Claim
69 words
A refractory shield according to any one of the preceding claims, wherein each of the pair of identical half shields (12) is of arcuate shape and comprises: an elongated sidewall (14) extending arcuately between the opposite ends and circumferentially to diametrically opposite arcuately curved upper and lower inner sides each of a different predetermined radius of curvature and arcuate length lying in the central plane and plane of curvature.
Claim 13
Dependent Claim
42 words
A refractory shiedld according to claim 6, wherein the mating camming portions are spaced longitudinally between the opposite ends in radially aligned pairs along and adjacent each of the diametrically opposite arcuately curved inner sides of the elongated and arcuately extending sidewall.
Claim 14
Dependent Claim
48 words
A refractory shield according to claim 7, wherein each of the raised inclined cams and overhanging recessed inclined cam receiving portions extend from opposite sides of each camming portion to a central junction thereof situated in a radial plane passing through a center of the radius of curvature.
Claim 15
Dependent Claim
83 words
A refractory shield according to claim 8, wherein the mating camming portions including the raised and overhanging recessed cam receiving portions along each of the diametrically opposite arcuately curved inner sides are of the same arcuate length and radius of curvature and the mating camming portions along and adjacent one of the diametrically opposite arcuately curved inner sides have a greater outer radius of curvature and arcuate length than the camming portions spaced along adjacent the other diametrically opposite arcuately curved inner side.
Claim 16
Dependent Claim
88 words
A refractory shield according to claim 9, wherein the raised inclined cams and overhanging recessed inclined cam receiving portions of each of the identical mating camming portions are of equal arcuate length from the central junction and the radial plane therebetween and the central junction of each of the camming portions spaced along each of the diametrically opposite arcuately curved inner sides and situated adjacent and closer to each of the opposite ends are located the same arcuate distance from the adjacent opposite ends of the elongated sidewall.
Claim 17
Dependent Claim
57 words
A refractory shield according to any one of claims 1-6, wherein each of the pair of identical half shields is of straight elongated shape and comprises: an elongated straight sidewall extending longitudinally between and to opposite ends thereof and circumferentially to diametrically opposite straight inner sides of the same longitudinal length and lying in the central plane.
Claim 18
Dependent Claim
50 words
A refractory shield according to claim 11, wherein the mating camming portions are of the same size and shape, spaced longitudinally between the opposite ends in radially aligned pairs along and adjacent each of the diametrically opposite straight inner sides of the straight elongated sidewall portion of each half shield.
Claim 19
Dependent Claim
90 words
A refractory shield according to claim 12, wherein the raised inclined cams and overhanging recessed inclined cam receiving portion of each of the identical mating camming portions are of equal width from the central junction and the radial plane therebetween and the central junction of each of the camming portions along and adjacent each of the diametrically opposite straight inner sides and situated adjacent to and closer to each of the opposite ends are located the same axial distance from the adjacent opposite ends of the straight elongated sidewall portion.
Claim 20
Dependent Claim
51 words
A refractory shield according to any one of the preceding claims, which includes a layer of refractory cement on inner surfaces of each half shield for attachment to a section of a superheater tube and containing a refractory material which is silicon carbide, alumina, zirconia, magnesia, chromia, or a mixture thereof.
Claim 21
Dependent Claim
18 words
A refractory shield according to claim 14, wherein the layer of refractory cement contains calcium aluminate bond material.
Claim 22
Dependent Claim
43 words
A refractory shield according to any one of the preceding claims, characterized by the fact that each of the half shields is made of a refractory composition containing a refractory material which is silicon carbide, alumina, zirconia, magnesia, chromia, or a mixture thereof.
Claim 23
Dependent Claim
20 words
A refractory shield according to any one of claims 1-15, wherein the half shields are made of nitride-bonded silicon carbide.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.