An outer peripheral edge part of the air-fuel mixture permeable member is connected to a portion away outward by a predetermined distance from an inner peripheral edge of the burner frame. Between the burner frame and the air-fuel mixture permeable member a clearance reaching the inner peripheral edge of the burner frame is secured at a position inward of the outer peripheral part of the air-fuel mixture permeable member. Preferably, a bent edge part formed on an inner peripheral edge of the burner frame, in a manner to be bent toward the air-fuel mixture permeable member. The amount of the air-fuel mixture to flow into the clearance is limited to a smaller amount.

Liner device, adapted to be mounted between a burner box and a tube interface plate of a furnace. The liner device includes a base section, one or more tube sections, and one or more angle fasteners. The base section includes a shielding layer formed from a first flexible mesh of flame-resistant fibers, the shielding layer defining a first surface that is configured to face the burner box, a second surface opposite to the first surface, and a medial region with a through-hole forming a passageway through the shielding layer. The tube section is composed essentially of a second flexible mesh of flame-resistant fibers formed into a tubular shape that defines an internal channel around a nominal axis. A proximal end of the tube section is positioned at the base section, such that the channel opens into the through-hole and that the tube section projects from the second surface and in a direction faced by the second surface. The angle fastener has a base portion that is positioned along and fixed to the second surface of the shielding layer. The angle fastener further has a leg portion that projects towards the second direction and is positioned along and fixed to an outer surface of the tube section at or near the proximal end thereof.

A burner assembly according to aspects of the disclosure includes a burner surface carried by a burner, the burner surface extending outward from a front side of the burner, a housing coupled to the burner on a side opposite the front side of the burner, a gasket disposed between the burner and the housing, a thermally anisotropic protective covering located on the front side of the burner and surrounding a perimeter of the burner surface, and an igniter positioned adjacent to the burner surface.

A burner assembly according to aspects of the disclosure includes a burner surface carried by a burner, the burner surface extending outward from a front side of the burner, a housing coupled to the burner on a side opposite the front side of the burner, a gasket disposed between the burner and the housing, a thermally anisotropic protective covering located on the front side of the burner and surrounding a perimeter of the burner surface, and an igniter positioned adjacent to the burner surface.

The purpose of the present invention is to provide a smoke tube boiler which can prevent leakage of mixed gas and exhaust gas through a gap between a mix chamber and an ignition bar assembly. To this end, the smoke tube boiler according to the present invention comprises: a mix chamber having a mixing space, in which a combustion gas and air are mixed, and a flat plate type burner, the mix chamber being disposed on the upper side of a combustion chamber; an ignition bar assembly assembled to pass through one side of the mix chamber and extending across the upper portion of the combustion chamber to the lower side of the flat plate type burner; and a sealing means for preventing the mixed gas in the mixing space and an exhaust gas in the combustion chamber from leaking to the outside through a gap between the mix chamber and the ignition bar assembly.

A burner assembly according to aspects of the disclosure includes a burner surface carried by a burner, the burner surface extending outward from a front side of the burner, a housing coupled to the burner on a side opposite the front side of the burner, a gasket disposed between the burner and the housing, a thermally anisotropic protective covering located on the front side of the burner and surrounding a perimeter of the burner surface, and an igniter positioned adjacent to the burner surface.

The air-fuel mixture permeable member is disposed to overlap that surface of the burner frame which lies opposite to the burner body. The fixing frame is disposed so as to be fixed to the inner peripheral portion of the enclosing frame part of the burner frame by pinching the air-fuel mixture permeable member between the inner peripheral portion and the fixing frame. The air-fuel mixture permeable member has an extended part protruding outward beyond the fixing frame so as to cover by this extended part an outer peripheral portion of the enclosing frame part.

An outer peripheral edge part of the air-fuel mixture permeable member is connected to a portion away outward by a predetermined distance from an inner peripheral edge of the burner frame. Between the burner frame and the air-fuel mixture permeable member a clearance reaching the inner peripheral edge of the burner frame is secured at a position inward of the outer peripheral part of the air-fuel mixture permeable member. Preferably, a bent edge part formed on an inner peripheral edge of the burner frame, in a manner to be bent toward the air-fuel mixture permeable member. The amount of the air-fuel mixture to flow into the clearance is limited to a smaller amount.

Liner device, adapted to be mounted between a burner box and a tube interface plate of a furnace. The liner device includes a base section, one or more tube sections, and one or more angle fasteners. The base section includes a shielding layer formed from a first flexible mesh of flame-resistant fibers, the shielding layer defining a first surface that is configured to face the burner box, a second surface opposite to the first surface, and a medial region with a through-hole forming a passageway through the shielding layer. The tube section is composed essentially of a second flexible mesh of flame-resistant fibers formed into a tubular shape that defines an internal channel around a nominal axis. A proximal end of the tube section is positioned at the base section, such that the channel opens into the through-hole and that the tube section projects from the second surface and in a direction faced by the second surface. The angle fastener has a base portion that is positioned along and fixed to the second surface of the shielding layer. The angle fastener further has a leg portion that projects towards the second direction and is positioned along and fixed to an outer surface of the tube section at or near the proximal end thereof.

A gas-fired, powered infrared burner unit comprising a perforate distribution plate configured as a tray and a porous foam metal burner element carried in the tray, the combination overlying the open top of a plenum box and sealingly fastened to an edge flange of said box by a retainer having a surrounding flange fastened to the plenum box flange by welding, staking or other means so as to eliminate the need for a gasket. The foam metal medium is constructed of a foam metal alloy to have a pore size of 1000 micros±5%, and produce, along with the perforations in the distribution tray, a port loading of between about 850 and 1,000 BTU/in.sup.2.