GB1561786A

GB1561786A - Heating vessles for molten metal

Info

Publication number: GB1561786A
Application number: GB5091575A
Authority: GB
Original assignee: Associated Engineering Ltd
Current assignee: Associated Engineering Ltd
Priority date: 1976-12-09
Filing date: 1976-12-09
Publication date: 1980-03-05

Description

(54) HEATING VESSELS FOR MOLTEN METAL (71) We, ASSOCIATED ENGINEERING LzMITaD, a British Company of Ince House, 60 Kenilworth Road, Leamington Spa, CV32 6JZ, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to heating vessels for molten metal and more particularly to furnaces for metals, such as baleout furnaces or melting and holding furnaces, as well as to ladles.

According to the present invention, a heating vessel for molten metal comprises a cover extending over at least part of the vessel and one or more radiant tube selfrecuperative burners disposed adjacent and extending at least partly across the underside of the cover and arranged when in operation to heat metal contained in the vessel by radiation, the or each burner having its outlet for combustion products outside the vessel.

By a self-recuperative burner is meant a burner in which heat from the products of combustion is used to pre-heat incoming combustible fuel and/or air.

Each of the burners may be an internal reverse flow combustion burner, for example, a gas burner.

The invention will now be further described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of one embodiment of furnace according to the invention, Fig. 2 is a cross-section on the line IT-II of Fig. 1, Figs. 3, 4 and 5 are respectively inverted plan, plan and end views, to a larger scale, of an embodiment of radiant tube selfrecuperative gas burner which may be employed in the invention, Fig. 6 is a plan view of a further embodiment of furnace, Fig. 7 is a cross-section on the line VII-VII of Fig. 6, Fig. 8 is a plan view of an embodiment of ladle, Fig. 9 is a cross-section on the line IX-IX of Fig. 8, Fig. 10 is a plan view of yet another embodiment of furnace, and Fig. 11 is a cross-section on the line XI-XI of Fig. 10.

Referring to Figs. 1 and 2, the furnace shown is a bale-out furnace and comprises a cylindrical vessel 10 surrounded by insulating heat-resisting bricks 11 housed in a casing 12. The vessel 10 is intended to be filled with molten metal, e.g. aluminium or aluminium alloy, up to the level indicated at 13.

A part-circular cover constituting a lid 14 is supported on the top of the casing 12 and has a cut-out portion 15 which provides an opening to allow access to the molten aluminium. Mounted as a parallel array adjacent the underside of the lid 14 is a plurality of radiant tube self-recuperative internal reverse flow gas burners 16. Each burner 16 has a fitting 17 outside the lid 14, which fitting is provided with a gas inlet 18 and an air inlet 19 (see Fig. 3), and an outlet flue 20.

At the end remote from the fitting 17 each burner 16 has a pin 21 which engages in a hole (not shown) in the lid 14.

The gas burners are shown in greater detail in Figs. 3 to 5. In operation, gas and air are supplied through the respective inlets 18, 19 and are burnt within the burners 16. Combustion gases travel down to the other end of the burner and back again with reverse flow so that the exhaust gases pass upwardly through the outlet flue 20 outside the furnace. The heat for melting the aluminium or other metal in the furnace is radiated from the body of each burner 16.

The embodiment shown in Figs. 6 and 7 is a bulk melting and holding furnace comprising a rectangular heat insulated vessel 22 and an arcuate lid 23 which covers the whole of the top of the vessel 22. A plurality of radiant tube self-recu native gas burners of the type shown in ig. 3 to 5 and shown diagrammatically at 24 is arranged along an arc beneath the lid parallel to each other and extending across the width of the vessel 22 along the greater part of its length.

The vessel 22 is provided with a door 25 in one end wall through which a charge of metal can be fed into the vessel. At the other end of the vessel adjacent the bottom there is a tap hok 26 through which molten metal can be tapped off.

Figs. 8 and 9 show a ladle for transporting molten metal comprising a cylindrical heat insulated vessel 27 which can be tilted about its trunnions 27a, and an arcuate lid 28 which covers the whole of the top of the vessel 27. A plurality of radiant tube self-recuperative gas burners shown diagrammatically at 24 is arranged beneath and fixed to the lid 28. The burners 24 extend parallel across the furnace and are arranged in a generally arcuate fashion under the lid. In using the ladle, the lid 28 is removed and the vessel 27 is tilted about its trunnions so that the metal can be poured out.

Figs. 10 and 11 show a rectangular furnace comprising a vessel 29 and an integral. cover 30 which extends over part of the vessel but leaving an open end 32.

The cover 30 comprises side walls 30a, 30b and 30c and a top 30d.

A plurality of radiant tube self'recnpera- tive gas burners 24 are disposed parallel to each other beneath the horizontal top 30d of the cover and extend across the width of the vessel 29.

This furnace may be employed as a baleout furnace in which case it is charged with metal via a door 31 provided in side wall 30a. Alternatively, the furnace may be used as a melting and/or holding furnace in which case the charge may be tipped in solid form into the open end 32 of the vessel.

As menlLioned above, the burners 24 in the embodiments of Figs. 6 to 11 are simi lar to that described with reference to Figs.

3 to 5. As will be apparent from the embodiments described, by having the outlet flues exterior to the vessel, the combustion gases are not released inside the vessel and so contamination of molten metal contained in the vessel is avoided.

This is a particular advantage in the case of aluminium and aluminium alloys where contamination of the molten metal or alloy by products of combustion is a substantial problem.

Although the furnaces in Figs; 6 and 7, and Figs. 10 and 11 have burners 24 extending across the width of the vessels 22, 29, the burners 24 may alternatively extend lengthwise of the vessels.

Instead of gas burners, oil burners may be used.

It will also be appreciated that the heating is achieved primarily by radiation.

WHAT WE CLAIM IS:- 1. A heating vessel for molten metal comprising a cover extending over at least part of the vessel and one or more radiant tube self-recuperative burners as hereinbefore defined disposed adjacent and extending at least partly across the underside of the cover and arranged when in operation to heat metal contained in the vessel by radiation, the or each burner having its outlet for combustion products outside the vessel.

2. A vessel as claimed in claim 1, in which the cover extends over only part of the top of the vessel and thereby leaves an opening affording access to the interior of the vessel.

3. A vessel as claimed in claim 2 which forms a bale-out furnace.

4. A vessel as claimed in claim 1 in which the cover constitutes a removable lid which extends over the whole of the top of the vessel.

5. A vessel as claimed in claim 4, in the form of a ladle for pouring molten metal.

6. A vessel as claimed in any preceding claim, in which each of the burners is an internal reverse flow combustion burner.

7. A vessel as claimed in any preceding claim, in which the burners are gas burners.

8. A vessel for molten metal substantially as hereinbefore described with reference to Figs. 1 and 2, or Figs. 6 and 7, or Figs. 8 and 9, or Figs. 10 and it of the accompanying drawings.

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Claims

**WARNING** start of CLMS field may overlap end of DESC **.

each burner 16.

The embodiment shown in Figs. 6 and 7 is a bulk melting and holding furnace comprising a rectangular heat insulated vessel 22 and an arcuate lid 23 which covers the whole of the top of the vessel 22. A plurality of radiant tube self-recu native gas burners of the type shown in ig. 3 to 5 and shown diagrammatically at 24 is arranged along an arc beneath the lid parallel to each other and extending across the width of the vessel 22 along the greater part of its length.

The vessel 22 is provided with a door 25 in one end wall through which a charge of metal can be fed into the vessel. At the other end of the vessel adjacent the bottom there is a tap hok 26 through which molten metal can be tapped off.

Figs. 8 and 9 show a ladle for transporting molten metal comprising a cylindrical heat insulated vessel 27 which can be tilted about its trunnions 27a, and an arcuate lid 28 which covers the whole of the top of the vessel 27. A plurality of radiant tube self-recuperative gas burners shown diagrammatically at 24 is arranged beneath and fixed to the lid 28. The burners 24 extend parallel across the furnace and are arranged in a generally arcuate fashion under the lid. In using the ladle, the lid 28 is removed and the vessel 27 is tilted about its trunnions so that the metal can be poured out.

Figs. 10 and 11 show a rectangular furnace comprising a vessel 29 and an integral. cover 30 which extends over part of the vessel but leaving an open end 32.

The cover 30 comprises side walls 30a, 30b and 30c and a top 30d.

A plurality of radiant tube self'recnpera- tive gas burners 24 are disposed parallel to each other beneath the horizontal top 30d of the cover and extend across the width of the vessel 29.

This furnace may be employed as a baleout furnace in which case it is charged with metal via a door 31 provided in side wall 30a. Alternatively, the furnace may be used as a melting and/or holding furnace in which case the charge may be tipped in solid form into the open end 32 of the vessel.

As menlLioned above, the burners 24 in the embodiments of Figs. 6 to 11 are simi lar to that described with reference to Figs.

3 to 5. As will be apparent from the embodiments described, by having the outlet flues exterior to the vessel, the combustion gases are not released inside the vessel and so contamination of molten metal contained in the vessel is avoided.

This is a particular advantage in the case of aluminium and aluminium alloys where contamination of the molten metal or alloy by products of combustion is a substantial problem.

Although the furnaces in Figs; 6 and 7, and Figs. 10 and 11 have burners 24 extending across the width of the vessels 22, 29, the burners 24 may alternatively extend lengthwise of the vessels.

Instead of gas burners, oil burners may be used.

It will also be appreciated that the heating is achieved primarily by radiation.

WHAT WE CLAIM IS:- 1. A heating vessel for molten metal comprising a cover extending over at least part of the vessel and one or more radiant tube self-recuperative burners as hereinbefore defined disposed adjacent and extending at least partly across the underside of the cover and arranged when in operation to heat metal contained in the vessel by radiation, the or each burner having its outlet for combustion products outside the vessel.
2. A vessel as claimed in claim 1, in which the cover extends over only part of the top of the vessel and thereby leaves an opening affording access to the interior of the vessel.
3. A vessel as claimed in claim 2 which forms a bale-out furnace.
4. A vessel as claimed in claim 1 in which the cover constitutes a removable lid which extends over the whole of the top of the vessel.
5. A vessel as claimed in claim 4, in the form of a ladle for pouring molten metal.
6. A vessel as claimed in any preceding claim, in which each of the burners is an internal reverse flow combustion burner.
7. A vessel as claimed in any preceding claim, in which the burners are gas burners.
8. A vessel for molten metal substantially as hereinbefore described with reference to Figs. 1 and 2, or Figs. 6 and 7, or Figs. 8 and 9, or Figs. 10 and it of the accompanying drawings.