# US 2018/0320897 A1 · Waste heat recovery

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- Number: US 2018/0320897 A1
- Document ID: US20180320897A1
- Status: Published application
- Kind: A1
- Application number: 15/773,309
- Filed: 2016-11-04
- Published: 2018-11-08
- Earliest claimed: 2015-11-04
- Assignees: Linde Aktiengesellschaft
- Applicants: Linde Aktiengesellschaft
- Inventors: Stephen Carney; Sebastian Ulmer; Rene' Quist
- Web page: https://patentgrep.com/patent/US20180320897A1

## CPC

- F23G 5/46: Recuperation of heat
- F28D 7/12: the surrounding tube being closed at one end, e.g. return type (F28D7/14 takes precedence)
- F28D 7/1615: {the conduits being inside a casing and extending at an angle to the longitudinal axis of the casing; the conduits crossing the conduit for the other heat exchange medium}
- F28D 15/02: in which the medium condenses and evaporates, e.g. heat pipes {(heat pipes used in solar heat collectors F24S10/95; in radiators F28D1/0226; in nuclear reactors G21C15/257)}
- F28D 15/0208: {using moving tubes}
- F23G 2206/00: Waste heat recuperation
- F28F 2280/10: Movable elements, e.g. being pivotable
- Y02P 80/15: On-site combined power, heat or cool generation or distribution, e.g. combined heat and power [CHP] supply
- F23G: CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F28D: HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT (fluid heaters having heat generating means and heat transferring means F24H; furnaces F27; details of heat-exchange apparatus of general)
- F28F: DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION (water and air traps, air venting F16)
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

There is provided a method for pre-heating a fluid (140, 240, 340) by heat transfer from combustion gases (101) flowing through an exhaust duct (100) of a furnace, wherein the fluid (140, 240, 340) is supplied to a heat transfer device (120, 200, 300) which is in heat transfer contact with the combustion gases (101). At least a portion of the heat transfer device (120, 200, 300) is movably arranged relative to the exhaust duct (100) such that it can be moved into and out of the exhaust duct.

## Claims

### Claim at position 1

1-12. (canceled)

### Claim 13

In a method for pro-heating a fluid (140, 240, 340) by heat transfer from combustion gases (101) flowing through an exhaust duct (100) of a furnace, wherein the fluid (140, 240, 340) is supplied to a heat transfer device (120, 200, 300) in heat transfer contact with the combustion gases (101), the improvement comprising:
the heat transfer device (120, 200, 300) comprising a double pipe (200) having an inner pipe (201, 301) and an outer pipe (202, 302);
passing the fluid (240) first through the inner pipe (201) and subsequently through the outer pipe (202); and
arranging at least a portion of the heat transfer device (120, 200, 300) relative to the exhaust duct (100) for moving that at least a portion of the heat transfer device into and out of the exhaust duct (100).

### Claim 14 (depends on 13)

The method of claim 13, wherein the fluid (140, 240, 340) comprises a substance selected from the group consisting of an oxygen-containing gas, an oxygen-containing gas comprising at least 90% by volume oxygen, a fuel, and a gaseous fuel.

### Claim 15 (depends on 13)

The method of claim 13, wherein the furnace comprises a glass furnace.

### Claim 16

In a furnace having an exhaust duct (100) to exhaust combustion gases (101) from the furnace, and a heat transfer device (120, 200, 300) for pre-heating a fluid (140, 240, 340) by heat transfer from the combustion gases (101), the heat transfer device (120, 200, 300) including an inlet (204, 304) for the fluid (140, 240, 340) to be pre-heated and an outlet (206) for pre-heated fluid, the improvement comprising:
the heat transfer device (200, 300) comprising at least one double pipe (200, 300), and at least a portion of the heat transfer device (120, 200, 300) is arranged relative to the exhaust duct (100) and movable for movement into and out of the exhaust duct (100).

### Claim 17 (depends on 16)

The furnace of claim 16, further comprising an automated retraction system for moving at least a portion of the heat transfer device (120, 200, 300) into and out of the exhaust duct (100).

### Claim 18 (depends on 16)

The furnace of claim 16, further comprising the heat transfer device (120, 200) being oriented vertically with respect to the exhaust duct (100).

### Claim 19 (depends on 16)

The furnace of claim 16, wherein a portion of the double pipe (200, 300) movable into the exhaust duct (100) has a length selected from the group consisting of at least 0.25 m, at least 1.0 m, and at least 1.5 m.

### Claim 20 (depends on 16)

The furnace of claim 16, wherein a portion of the double pipe (200, 300) movable into the exhaust duct (100) has a maximum length selected from the group consisting of a maximum of 1.0 m, a maximum of 1.5 m, and a maximum of 2.0 m.

### Claim 21 (depends on 16)

The furnace of claim 16, wherein the double pipe (200, 300) comprises:
an inner pipe (201, 301); and
an outer pipe (202, 302) closed at one end (303),
wherein the inner pipe (301) is reset with respect to the closed end (303) of the outer pipe (302).

### Claim 22 (depends on 16)

The furnace of claim 16, further comprising an inert gas supply line (245) connected to the heat transfer device (120, 200, 300).

### Claim 23 (depends on 16)

The furnace of claim 16, further comprising at least one additional heat transfer device (120, 200, 300), and at least one burner, wherein the outlet of each of the heat transfer devices (120, 200, 300) is connected to a corresponding same one of the at least one burner.

### Claim 24 (depends on 23)

The furnace of claim 23, wherein the at least one additional heat transfer device (100, 200, 300) is an amount selected from the group consisting of between 1 and 30 heat transfer devices per burner, and less than 20 heat transfer devices per burner.

### Claim 25 (depends on 16)

The furnace of claim 16, further comprising the heat transfer device (120, 200, 300) being located upstream of other waste heat recovery devices and emission control devices of the furnace.