Prefabricated double-walled metal chimney

Claim 2

A prefabricated double-walled chimney section adapted to be connected to a similar section to form a chimney column, said section comprising: a cylindrical inner imperforate wall member having a radially extending flange at each end; a cylindrical outer imperforate wall member having a greater diameter than and spaced outwardly from said inner wall member, said outer wall member being shorter than said inner wall member so that at least one end edge is spaced above the end flange of said inner wall member; spacer connector means located between said inner and outer wall members near both ends, having an outer end portion fixed to the inside surface of said outer wall member and an axially extending inner end portion located adjacent to but unattached to the outer surface of said inner wall member an inner band means having a flange portion extending around said inner end portion of said spacer connector means and means on the opposite ends of said flange portion for drawing said inner band means tightly around said inner pipe member; and means near said end edge of said outer wall member for retaining a connectable outer band means adapted to extend circumferentially around said outer wall member.

Claim 3

The double-walled chimney section of claim 1 wherein said means for retaining said outer band means comprises a circumferential bead forming an annular recess spaced axially from said end edge of said outer wall member.

Claim 4

The double-walled chimney section of claim 1 wherein said spacer connector means comprises a plurality of separate spacer connector members located at circumferentially spaced apart intervals between said inner and outer wall members, said outer and inner end portions of said spacer connectors being interconnected by a web portion having a length such that said inner end portion of each connector is spaced outwardly a small but substantially uniform distance from and thereby avoiding actual contact with the outer surface of the inner wall member and minimizing the flow of heat therefrom to the outer wall member.

Claim 5

The double-walled chimney section of claim 1 wherein said inner band means has a central V-shaped portion which fits around the outer edges of adjoining end flanges on adjacent chimney sections to thereby hold them tightly together when the inner band means is tightened, and flange portions extending axially from the edges of said central V-shaped portion which extend around said inner end portion of said spacer connector means.

Claim 6

A prefabricated double-walled metal chimney comprised of a plurality of connected chimney sections, each section comprising: a cylindrical inner wall member having a radially extending flange at each end engaging a like flange of an axially aligned inner wall member of an adjoining chimney section; a cylindrical outer wall member for each section having a greater diameter than and spaced outwardly from said inner wall member, said outer member being shorter than said inner wall member for each said section so that its ends are spaced axially above and below the said end flanges of said inner wall member; spacer connector means located between said inner and outer wall members near both ends of each said section, said connector means having an outer portion fixed to said outer wall member and an axially extending inner portion located adjacent to but unattached to the outer surface of said inner wall member; an inner band extending around each pair of adjoining end flanges of adjacent connecting sections and also around said inner portion of said spacer connector means, and means for tightening said inner band to form a substantially gas tight joint between said end flanges; and an outer band extending around the outer wall members of adjoining sections for closing the gap betWeen adjoining sections.

Claim 7

A prefabricated double-walled metal chimney comprised of a plurality of connected chimney sections, each section comprising: a cylindrical inner wall member having a radially extending flange at each end engaging a like flange of an axially aligned inner wall member of an adjoining chimney section; a cylindrical outer wall member for each section having a greater diameter than and spaced outwardly from said inner wall member, said outer member being shorter than said inner wall member for each said section so that its ends are spaced axially above and below the said end flanges of said inner wall member; spacer connector means located between said inner and outer wall members near both ends of each said section, said connector means having an outer portion fixed to said outer wall member and an axially extending inner portion located adjacent to but unattached to the outer surface of said inner wall member; an inner band extending around each pair of adjoining end flanges of adjacent connecting sections and also around said inner portion of said spacer connector means, and means for tightening said inner band to form a substantially gas tight joint between said end flanges; and an outer band extending around the outer wall members of adjoining sections for closing the gap betWeen adjoining sections.

Claim 8

The chimney as described in claim 5 wherein each said spacer connector means comprises a plurality of connector members each having an outer end portion fixed to said outer wall member and an inner end portion located adjacent to the outer surface of said inner wall member, said inner end portions being engaged by and urged toward said inner wall member by said inner band.

Claim 9

The double-walled chimney section of claim 5 wherein said outer and inner end portions of said spacer connector means are interconnected by a web portion having a length such that said inner end portion of each connector means is spaced outwardly a small but substantially uniform distance and thereby avoiding actual contact with the outer surface of the inner wall member, thereby minimizing the conductive flow of heat therefrom to the outer wall member.

Claim 10

The double-walled chimney section of claim 5 wherein said inner band means has a central V-shaped portion with flange portions extending from its edges which fits around the outer edges of adjoining end flanges on adjacent chimney sections to thereby hold them tightly together when the inner band means is tightened.

Claim 11

The double-walled chimney section of claim 5 wherein said outer wall member on each said section has annular recesses spaced from its opposite end, said outer band comprising a web portion that fits flush against the outer surface of the outer wall members of adjoining sections with flange portions which extend radially inwardly into said annular recesses.

Claim 12

A double-walled metal conduit comprised of a series of prefabricated sections connected together in end to end alignment, said sections each comprising: a cylindrical inner imperforate wall member having a radially outwardly extending flange at each end, said flanges of adjoining sections being flush together and secured thereto; a cylindrical outer imperforate wall member having a greater diameter than and spaced outwardly from said inner wall member, said outer wall member being shorter than said inner wall member so that at least one end edge thereof is spaced above the end flange of its said inner wall member, said outer wall members of adjoining sections being spaced apart; a spacer connector means located at circumferentially spaced apart intervals between said inner and outer wall members at opposite ends of each said section, each said spacer connector means having an outer end portion fixed to the inside surface of said outer wall member and an axially extending inner end portion located adjacent the outer surface of said inner wall member and its said end flange; a circumferential recess located near said end edge of each said outer wall member; and a connectable outer band means retained in said recess and extending circumferentially around said outer wall members of adjacent aligned sections.

Claim 13

A double-walled metal conduit comprised of a series of prefabricated sections connected together in end to end alignment, said sections each comprising: a cylindrical inner imperforate wall member having a radially outwardly extending flange at each end, said flanges of adjoining sections being flush together and secured thereto; a cylindrical outer imperforate wall member having a greater diameter than and spaced outwardly from said inner wall member, said outer wall member being shorter than said inner wall member so that at least one end edge thereof is spaced above the end flange of its said inner wall member, said outer wall members of adjoining sections being spaced apart; a spacer connector means located at circumferentially spaced apart intervals between said inner and outer wall members at opposite ends of each said section, each said spacer connector means having an outer end portion fixed to the inside surface of said outer wall member and an axially extending inner end portion located adjacent the outer surface of said inner wall member and its said end flange; a circumferential recess located near said end edge of each said outer wall member; and a connectable outer band means retained in said recess and extending circumferentially around said outer wall members of adjacent aligned sections.

Claim 14

The double-walled conduit of claim 10 including an inner band means for each pair of adjoining sections having a flange portion extending around the inner end portions of said spacer connectors and means on the opposite ends of said flange portion for drawing said inner band means tightly around adjacent inner pipe members.

Claim 15

The double-walled conduit of claim 11 wherein said inner band means has a central V-shaped portion which fits around the outer edges of adjoining end flanges on adjacent chimney sections to thereby hold them tightly together when the inner band means is tightened and axially extending flange portions extending from the said central V-shaped portion which extend around and retain said inner end portion of said connector means.

Claim 16

The double-walled conduit of claim 10 including sealant means on the mating radially extending flanges of adjacent conduit sections, thereby assuring an air-tight inner passage in said conduit.

Claim 17

The double-walled conduit of claim 10 including weldments for permanently connecting the mating radially extending flanges of adjacent conduIt sections.