DE2458618A1 - SLEEVE HEATING TUBE - Google Patents

Description

BBC

BROWN, BOVERl & CLE - AKTIENGESELLSCHAFT

MANNHEIM BRÖWisTBOVERI

Mp.no. 680/74 Mannheim, December 9, 1974

ZFE / p / l-Kh / Hz

Jacketed radiant tube

The invention relates to a jacket radiant heating tube for gaseous or liquid fuels with a central, axially extending fuel supply pipe and a coaxially arranged one, the combustion air supply tube, both of which end in the burner head.

Such jacketed radiant tubes are then used for industrial furnaces, if in these for the heat treatment of the goods a prescribed atmosphere must be maintained that is not altered by the flue gases from open burners.

In the case of the known 'jacket radiant heating tubes, it has been closed so far always use a flame tube to discharge the breath gas to the burner head. Such a flame tube made of steel with DT-PS 1 811 155 can be found in the closed surface. Another flame tube, also made of metal DT-AS 1 074 802 shows a perforated jacket surface. Flame tubes with or without openings for the flue gas, the consist of a ceramic and consist of a variety of individual parts arranged one behind the other and next to one another Composing embodiments are previously known from DT-AS 1 551 762 and 2 314 118.

All of these jacketed radiant tubes have a poor degree of efficiency, because the flame hits the flame tube and that Jacketed pipe practically not directly from the hot flame

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is touched. The jacket pipe is therefore only exposed to thermal radiation of the flame tube is heated. At the same time, however, some of the heat rays are also caused by the already cooled leach gases, which are diverted from the radiant heating tube between the flame tube and the jacket tube, are also removed.

The invention is based on the object, the hot flame directly bring it up to the jacket pipe and at the same time also discharge the flue gas from the radiant tube ^

This object is achieved in that at the Inside of the jacket tube one or several evenly distributed on its circumference in their longitudinal extension: -, - ■

Inlet openings having and on

their ends open exhaust channels are arranged, the outlet nozzle to have.

According to the invention, however, the same task can also be achieved thereby be solved that one on the outside of the jacket tube or evenly distributed on its circumference several towards the furnace chamber Airtightly closed exhaust gas ducts are arranged, which in their longitudinal extension - '.- ■: das

Inlet openings penetrating the jacket tube and outlet nozzles at their ends protruding from the furnace.

Around the exhaust ducts located in the jet heater pipe in a simple way In order to be able to manufacture and secure in a reliable manner, the invention proposes that the exhaust gas ducts be formed by sections the inner surface of the jacket tube covering, in a row arranged one behind the other, sector-shaped ring sections are formed, which are received by arranged on the inner surface of the jacket tube webs.

If the exhaust ducts are arranged on the outside aa radiant heating tube, then wire recommended according to the invention that the exhaust ducts lay airtight on sections of the outer surface of the jacket pipe

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Gende, having closure plates at their ends on the oven side TJ-shaped profiles are formed.

Since the exhaust ducts are only over the smallest possible partial area of the jacket pipe should extend in order to heat it up directly by the flame or the absorbed heat To be able to deliver as evenly as possible, is according to the invention further proposed that the ring sections or the U-shaped parts Profiles have the shape of a polygon in their cross-section or are curved or executed in a combination of these shapes are.

Finally, according to a further advantageous embodiment of the invention, the ring sections made of a metal or a ceramic and the U-shaped profiles with their closure plates made of metal.

It is then according to the invention for reasons of manufacturing simplicity also possible that with several inside or outside of the jacket pipe attached exhaust ducts between these and one Outlet port inside or outside of the shell piece. Annular channel is provided.

The 'invention is described below with reference to the drawings, in which two exemplary embodiments are shown.

1 shows a radiant jacket heating tube provided with two internal exhaust gas ducts, which is partially cut lengthways is.

FIG. 2 is a section along the line II-II in FIG. 1, shown on a larger scale.

3 and 4, a radiant heating tube is shown in which two exhaust ducts are arranged on the outside of the casing tube.

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This is in the pig. 4 shows a section along the line IV - IV of FIG. 3 on an enlarged scale.

According to FIGS. 1 and 2, the radiant heating tube is enclosed by the jacket tube. At its free end this has a neck to support the radiant heating tube in the furnace. At the other end, a flange 3 connects to the jacket pipe 1 for airtight Attachment of the radiant heating tube to the furnace wall penetrates. The jacket piece 4 is arranged on the flange 3. This has the connection 5 for the fuel supply, a further connection 6 for the supply of the combustion air and the outlet connection 7 for the flue gas.

The centrally arranged, axially extending fuel supply pipe 8 is located in the jacket pipe 1. It is coaxial around this another tube 9 is provided. Through this and the fuel supply pipe 8, the annular channel 10 is used for the approach of the combustion air.

At the end of the fuel supply pipe 8 and the other pipe 9 is the burner head 11 is attached.

The two exhaust gas ducts 12, 13 are provided for discharging the flue gas from the radiant jacket. These are over an annular channel 23, which is not visible in the drawing and is therefore shown in a thin dashed line, which is located in the casing piece 4 is connected to the outlet port 7.

Each exhaust duct 12 or 13 is in a row one behind the other arranged sector-shaped ring sections 14 of polygonal cross-sectional shape formed. The ring sections are held by the webs 15 arranged on the inner surface of the jacket tube 1.

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On the one hand, a flame that extends over the length of the jacket tube 1 and burns as evenly and calmly as possible to obtain and on the other hand, the flue gas in the desired amount and correct distribution from the radiant jacket to be able to discharge, the open ends at their free ends Ring sections 14 in an appropriate arrangement in their longitudinal extension - a number of inlet openings 16 for the flue gas.

The ring sections 14 can also have a different cross-sectional shape and be made of metal or a ceramic.

The shape of the ring sections will always be chosen so that that only the smallest possible part of the inner surface of the jacket pipe 1 is required to form the exhaust gas ducts 12 or 13, in order to achieve as uniformly strong heating as possible of the jacket tube 1 by the flame.

In the jacket radiant heating tube according to FIGS. 3 and 4, the same parts as in FIGS. 1 and 2 are available the same reference numerals are used.

To form the external exhaust ducts 17, 18 are on the Jacket tube IT-shaped profiles 19 made of metal welded on. These are hermetically sealed at their free ends with respect to the furnace space by metal plates 20.

On the other side, the exhaust ducts 17, 18 go into outlet stubs 21 over, both of which protrude from the casing piece 4.

In order to be able to discharge the flue gas from the jacket pipe 1, are in this in the area of the exhaust gas ducts 17,18 at a certain distance inlet openings 22 are provided in such a size, which is necessary to let the flame burn out stably in the desired length in the jacket pipe.

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Of course, in this embodiment, the U-shaped profiles 19 will be given a cross-sectional shape such that The exhaust gas ducts 17, 18 can be formed with the smallest possible part of the outer surface of the jacket tube 1.

When using the exhaust gas ducts 17, 18 located on the outside, it is particularly advantageous that the flame is applied directly to the entire inner surface of the jacket pipe 1 arrives and this is thereby heated evenly and strongly.

It is, of course, also possible, e.g. with a large-sized radiant heating pipe on the inside and / or outside of the jacket pipe, with exhaust ducts 12, 13 or 17, 18 to be provided in any arrangement at the same time and this directly or via one or more ring channels to connect to the outlet port.

The advantages achieved by the invention are in particular that by heating the largest part or the entire inner surface directly by a flame of the same power, the jacket pipe is heated higher than before and thereby Of course, the temperature in the furnace also increases significantly.

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Claims (7)

680 / 74_ - 7 - claims: 1. Jacketed radiant tube for gaseous or liquid fuel « with a central, axially extending fuel supply pipe and a coaxial with this, the combustion air supply serving tube, both of which end in the burner head, characterized in that on the Inside of the jacket tube (1) one or several evenly distributed on its circumference in their longitudinal extent Exhaust gas ducts (12, 13) having inlet openings (16) and open at their ends are arranged are, the outlet port (7) have. 2. Jacketed radiant heating tube for gaseous or liquid fuels with a central, axially extending fuel supply tube and a pipe which is arranged coaxially therewith and serves to supply the combustion air, both of which end in the burner head characterized in that one on the outside of the jacket pipe (1) or evenly distributed on its circumference a plurality of exhaust gas ducts (17, 18) which are hermetically sealed towards the furnace chamber and which in their longitudinal extent - - the jacket tube (1) penetrating inlet openings (22) and at their out of the Furnace protruding ends have outlet nozzles (21). 3. jacket radiant heating tube for gaseous or liquid fuel «according to claim 1, characterized in that the exhaust ducts (12,13) by sections of the inner surface of the jacket tube (l) covering, arranged in a row one behind the other, sector-shaped ring sections (14) are formed, which are received by webs (15) arranged on the inner surface of the casing tube (1). - 8 609825/0501 680/74 4. Jacketed radiant tube for gaseous or liquid fuels according to claim 2, characterized in that the exhaust gas ducts (17118) through on sections of the outer surface of the jacket pipe (l) U-shaped profiles lying airtight and having closure plates (20) at their ends on the furnace side (19) are formed. 5. Jacketed radiant tube for gaseous or liquid fuels according to claim 1 to 4, characterized in that the ring sections (14) or the U-shaped profiles (19) have the shape of a polygon or are curved in their cross-section or in a combination of these forms. 6. Jacketed radiant tube for gaseous or liquid fuels according to claim 1 to 5, characterized in that the ring sections (14) are made of a metal or a ceramic and the U-shaped profiles (19) with their closure plates (20) are made of metal. 7. Jacketed radiant tube for gaseous or liquid fuel «according to the preceding claims, characterized in that that in the case of a plurality of exhaust gas ducts (12, 13 or 17, 18) mounted on the inside or outside of the jacket pipe (1) between them and an outlet connection (7 or 21) inside or outside of the jacket piece (4) an annular channel (23) is provided. 609825/0501 Blank