DE3521043A1 - Furnace, in particular heating boiler - Google Patents

Abstract

The invention relates to a furnace, in particular heating boiler with an incandescent insert which is of tubular design and is made of ceramic. The incandescent insert consists of at least two pipe pieces which are in each case open at both ends and each pipe piece of which has a first end with a larger cross-section and a second end with a smaller cross-section. At least one pipe piece extends with its second end into the first end of a neighbouring pipe piece in such a manner that at least one ring-like gap is formed between the pipe pieces which overlap or engage in one another in this manner. At least on the second end of a pipe piece, which projects into a neighbouring pipe piece, the peripheral wall of this pipe piece is, in at least three regions which are offset around the longitudinal axis of the pipe piece, drawn inwards in such a manner that there are formed, on the outer surface of the peripheral wall of the pipe piece, ducts which are open towards this outer surface and the second ends, are approximately V-shaped in cross-section, extend in the longitudinal direction of the pipe piece and the depth of which increases towards the second end, and, on the inside of the pipe piece, noses, which project inwardly from the peripheral wall, with a height which increases towards the second end of the pipe piece.

Description

PATENT LAWYERS

Dipl.-Ing. A. Wasmeier

.. "£> ipl.-lng. H.Graf

Admitted to the European Patent Office · Professional Representatives before the European Patent Office

Patent Attorneys P.O. Box 382 8400 Regensburg 1 D-8400 REGENSBURG 1 To the GREFLINGER STRASSE 7 German Patent Office Telephone (0941) 54753 Zweibrückenstrasse 12 Telegram Begpatent Rgb. Telex 65709 repat d 8000 Munich 2

Your reference Your Ref.

Your message Your Letter

Our mark Our Ref.

W / p 11,919

Day date

May 29, 1985 gr / ly

Applicant:

Eduard Wandzel Hetzenbergstrasse 11 8491 Windischbergerdorf

Title:

Furnaces, especially heating boilers

fWIrtitsstnnri Renamthiirn

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Furnaces, especially heating boilers

The invention relates to a furnace, in particular a heating boiler according to the preamble of patent claim 1.

Furnaces, in particular also heating boilers for operating hot water heaters or for generating hot service water are known per se in numerous designs. In particular, ovens and heating boilers are also known where the fuel outlet is formed by the nozzle of a forced draft burner for liquid fuels and where in the combustion chamber is provided with a tubular glow insert penetrated by the flame of the forced draft burner. With With the help of the glow insert, the best possible combustion of the liquid fuel (oil) in the flame of the Fan burner can be achieved, in particular also by the fact that, above all, carried along at the outer edge of the flame, not or only incompletely burned components of the liquid fuel that are hot during operation of the furnace Evaporate the glow insert and in this state are returned to the flame for complete combustion (Afterburning). While it was previously proposed to make such annealing inserts from stainless steel, it was in Recently it has also been proposed to manufacture annealing inserts from ceramic, since these are made of stainless steel compared to those in particular have a longer service life.

The object of the present invention is to show a furnace or heating boiler that is simple and inexpensive constructive training in comparison to known ovens or heating boilers a significantly more favorable heat recovery especially with regard to the post-combustion processes within the combustion chamber.

A furnace, in particular a heating boiler, is used to solve this problem designed according to the characterizing part of claim 1.

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The annealing insert provided in the furnace according to the invention or its pipe sections can be relatively simple and therefore Above all, produce inexpensively from ceramics. The annealing insert of the furnace according to the invention makes an optimal one Combustion of a liquid, but also gaseous fuel and, above all, optimal afterburning of the not yet burned or inadequately burned part of this fuel is achieved, in particular by the inwardly drawn sections of the circumferential wall of the individual pipe sections, each at the ends of this Pipe pieces with a smaller diameter are formed, on the one hand between the pipe pieces at their points of overlap Openings or channels with a large cross section for recirculation of the air or gases within the combustion or Flame area are formed, as well as inwardly protruding noses or bridges are formed inside the pipe sections, which cause a division of the flame at least on its circumference or cause the flame to be attached to these lugs or builds up again behind it in the direction of the flame, so that an intensive "turbulence" also within the flame occurs through which (turbulence) the post-combustion processes are significantly improved.

Because of the very intensive combustion and especially because of the intensive post-combustion processes, the contain Exhaust gases of the furnace or boiler according to the invention practically no more unburned residues, so that there is the furnace according to the invention is also possible to train this in its design as a heating boiler so that the combustion chamber is enclosed directly by the inner walls of the boiler receiving the heating or service water, with this embodiment of the heating boiler then the combustion gas (flue gas) to further increase the Efficiency is dissipated via a flue gas duct between a thermally insulated outer wall of the Heating boiler and the outer walls of the boiler is formed. The fuel outlet is in the invention preferably from a forced draft burner for liquid or

Formed gaseous fuel, V7obie under "gaseous fuel" in the broadest sense also an air-coal dust mixture is to be understood.

Further developments of the invention are the subject of the subclaims.

The invention is explained in more detail below with reference to the figures using an exemplary embodiment. Show it:

Fig. 1 in a schematic representation and in section an oven designed as a heating boiler, together with a Fan burner for liquid fuel as well as with a glow insert arranged in the combustion chamber, the is formed by three pieces of pipe or rings;

Fig. 2 in an enlarged view and in side view Annealing insert of the furnace according to FIG. 1;

3 is a plan view of the smaller cross-section end of one of the tube sections of the annealing insert;

4 shows a schematic representation to illustrate the distribution of the V-shaped channels around the axis of the Annealing insert when using several pieces of pipe for this annealing insert;

5 shows, in an enlarged detailed illustration, a longitudinal section of the annealing insert in the area of the overlap point two pieces of pipe;

6 shows a type of fastening of the pipe sections of the annealing insert in a further embodiment.

In the figures, the numeral "1" generally indicates a heating boiler designated with a combustion chamber or a combustion chamber 2. In the illustrated embodiment of the heating boiler 1, the combustion chamber 2 is on the side, i.e. on both of its vertical sides, above and preferably also below, as well as on the

Rear side through the boiler 3 receiving the heating or service water or through its inner walls 4, 5 and 6 directly limited, the outer surface of the wall 6, however, with an attachment made of foamed ceramic material is covered. In contrast to conventional heating boilers, in which an intermediate wall is arranged between the inner walls of the boiler and the combustion chamber, a Much improved efficiency because of the flame 7 of the fan burner 8 in the Combustion chamber 2 generated heat is transferred directly to the boiler 3 or its inner walls 4 and 5.

The aforementioned partition can be omitted in the boiler 1 because in the combustion chamber 2 one of the Flame 7 of the fan burner 8 penetrated glow insert 9 is provided, which will be explained in more detail below and which ensures almost complete combustion of the fuel (preferably oil) fed to the fan burner 8, so that the risk of unburned components or residues being deposited on the walls 4, 5 and 6 does not increase is feared.

The heating boiler 1 has outer walls 10, 11 and 12, which the interior of the heating boiler on the two vertical Sides, at the bottom, at the top as well as at the back limit to the outside, these, also with a thermal insulation provided walls are arranged so that between their inner surfaces and the outer Walls 13, 14 and 15 of the boiler 3 a flue gas or. Exhaust duct 16 is formed, which completely surrounds the boiler 3 and leads to a chimney connection 17 provided in the wall 12.

On the outer walls 13 and 14 of the boiler 3 are in this boiler and ribs 18 extending into the flue gas duct 16 are provided, which in FIG. 1 are only shown schematically are shown and also to a significant improvement in the transfer of the heat contained in the flue gas the water absorbed by the boiler 3 contribute.

On the front of the boiler, i.e. in the representation chosen for Fig. 1 on the left, is the Combustion chamber 2, the boiler 3 and the flue gas duct 16 receiving the interior of the heating boiler through a front wall 19 completed. The fan burner 8, which is connected to the burner nozzle, is also attached to this front wall having part 8 'extends through the front wall 19 into the combustion chamber 2. The arrangement is still like this taken that the inner surface of the front wall 19 at a distance from the front side delimiting the interior of the boiler 3 Wall sections 2 0 is so that the flue gas duct 16 between these wall sections 2 0 and the inner surface of the Front wall 19 continues into the combustion chamber 2 or in the area between the wall sections 2 0 and the inner surface of the Front wall 19 is in communication with the combustion chamber 2. The direction of flow of the inside and outside of the boiler 3 hot combustion gases is indicated by the arrows A in FIG.

The annealing insert 9 made of ceramic or ceramic material is shown in detail in FIGS. 2-5. In the embodiment shown, this annealing insert consists of three rings or pipe pieces made of ceramic 21a, 21b and 21c, which are each open at both ends and which are frustoconical on their peripheral wall 22, i. are designed such that each pipe section at one end has a substantially circular cross-section with the larger diameter D and at the other end has a maximum cross section with the smaller diameter d. the Information "D" and "d" each relate to the inner cross-section that differs from the associated outer cross-section differs in each case by the double wall thickness of the peripheral wall 22.

As FIG. 1 shows in particular, the annealing insert 9 consisting of the three pipe sections 21a, 21b and 21c is of this type arranged in the combustion chamber 2 so that all the pipe sections are coaxially and axially aligned with the flame 7 in their axes

and are also arranged such that the end with the larger diameter D dem for each pipe section Fan burner 8 or its nozzle is closer than the end with the smaller diameter d.

As FIG. 2 shows in particular, the pipe sections 21a, 21b and 21c are furthermore arranged relative to one another in such a way that that the fan burner 8 closest to the pipe section 21a with its end with the diameter d in the end with the larger diameter D of the pipe section 21b extends, which with increasing distance from the forced draft burner 8 on the Pipe section 21a follows. Furthermore, the pipe section 21b extends with its end with a smaller diameter d into the end larger diameter D of the pipe section 21c, which is at a greater distance from the fan burner 8 on the pipe section 21b follows. It goes without saying that if necessary (depending on the expansion of the flame 7 or depending on the thermal Power of the fan burner 8 and thus of the heating boiler 1 in the direction of the longitudinal extension of the flame 7 and depending on the spray angle of the nozzle of the fan burner) also more than three or less than three pieces of pipe interlocking in the manner described could be.

The diameter D and d of the pipe sections 21a, 21b and 21c are coordinated so that where the pipe section 21a extends into the pipe section 21b and the pipe section 21b into the pipe section 21c, between the respective interlocking Pieces of pipe ring column 2 3 are formed by the combustion gases at high pressure from inside the Annealing insert 9 can emerge, as is indicated by arrow B in FIG. In order to prevent that with the emerging combustion gases of high pressure (arrow B) unburned or insufficiently burned quantities or Droplets of liquid fuel (oil) are taken along, at least the pipe sections 21a and 21b are at least in Area of the annular gaps 2 3 provided with an inwardly reaching flange 24 (Fig. 5), which is used as a "stripping edge" for any. entrained on the outer area of the flame 7, not burned

35210A3

or insufficiently burned parts (droplets) of the liquid fuel, i.e. these unburned or Retains not completely burned parts of the liquid fuel and the combustion process (afterburning) feeds.

As FIG. 3 also shows in particular, the circumferential wall 22 of at least the pipe sections 21a and 21b is shaped or drawn inward in partial areas in such a way that they are three evenly around the longitudinal axis L of the annealing insert on their outer surface 9 staggered, in the direction of the longitudinal axis L extending and in cross section approximately V-shaped channels, which are open to the outer surface of the peripheral wall 2 2 and to the end with the smaller diameter d. These channels 25, whose extension in the direction of the longitudinal axis L is greater than half the length of the respective pipe section in this Axial direction, preferably about four fifths of the length of the respective pipe section, have a depth t, which increases with decreasing distance from the end with the smaller diameter d.

Through the channels 25 or through the inwardly drawn subregions 22 'of the peripheral wall 22 which form these channels (Partial areas) can also be referred to as bridges, there are three inside the pipe section in question, around the longitudinal axis L evenly distributed noses are formed, the height of which extends radially to the longitudinal axis L with decreasing distance from the smaller diameter end d increases. The height of these noses is of course equal to the depth t plus the thickness of the peripheral wall 2 2 or of the section 22 '.

In a preferred embodiment of the invention, the maximum height of the noses formed by the channels 25 is approximately Range from 1/4 d to 1/6 d.

The channels 2 5 formed by the inwardly drawn regions or bridges 2 2 'also result in openings relatively large diameter between the nested

BAD ORJGINAL

telten pipe sections 21a and 21b or 21b and 21c for one Recirculation flow, as indicated by the arrow C in FIG. 2.

The noses generated by the bridges 22 and reaching into the interior of the pipe sections result in a division of the Flame 7 generated at least in its edge area, with a corresponding offset of the bridges 22 ' formed lugs around the longitudinal axis L from pipe section to pipe section at the same time a multiple deflection of the Flame 7 on its outer areas and thus a certain turbulence in the flame forced v / ground, which is also to a significant improvement of the combustion process, especially that of the surfaces during operation hot pipe sections 21a, 21b and 21c impinging and there evaporated, originally not or insufficiently burned components of the liquid fuel leads. Precisely because of this deflection or turbulence effect the pipe section 21c also preferably has the noses formed by the bridges 22 ', in which case also on this pipe section the flanges or flange sections 24 are provided at least in the area between the three bridges 22 '.

4 shows the staggered arrangement of the noses of all the pipe sections 21a, 21b and 21c formed by the bridges 22 '.

All pipe pieces have the same number of noses or bridges 22 'and are these bridges in all pipe pieces about the longitudinal axis L offset from one another by the same angular amount or with the same pitch T, so are the individual pipe sections 21a, 21b and 21c arranged offset from one another in such a way that each with increasing distance from the forced draft burner 8 on a pipe section following pipe section opposite the first-mentioned pipe section by the angular amount a - · T / n is arranged offset or rotated about the longitudinal axis L, where η is the number of pipe sections used. at In the illustrated embodiment, the angle a is thus 40 °,

since three pipe pieces 21a, 21b and 21c are provided and the Pitch T on each pipe section with three noses or bridges 22 'is 120 °.

In a preferred embodiment of the invention, the diameter D and d of the pipe sections are chosen so that the Annular gaps 2 3 in the direction radial to the longitudinal axis L have a width of approximately 9 mm. In addition, the pipe sections 21a, 21b and 21c formed in terms of their diameter D and d according to the following table, so that the mean cross section of the glow insert from the end facing the fan burner 8 to that of the fan burner 8 facing away from the end remains the same.

Tabel 21a 9 mm 21b 5 rnm 21c 1 mm 146, 2 mm 157 7th mm 168, 4th mm D. 129 139 150 d 4th 6th 6th N

In the illustrated embodiment of the annealing insert 9, however, it is also advantageous that the individual pipe sections 21a, 21b and 21c in a different manner or order than shown in Fig. 2, are attached to one another can, or that more than three or less than three pieces of pipe are connected to the annealing insert depending on the performance, the size and design of the combustion chamber, and the pump pressure for the liquid fuel and the spray angle of the nozzle of the forced draft burner 8. The annular gap can also be dependent on of the aforementioned influencing variables may be larger or smaller than specified, with the larger annular gap also the Increasing diameter D, so that with increasing distance from the fan burner a larger and more effective Cross-section for the annealing insert results. The number (N) of

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Bridges 22 'can also be different for the individual pipe sections as indicated in row N of the table above.

The individual pipe sections 21a, 21b and 21c are connected to one another or held to one another that on the Outer surface of the circumferential wall 2 2 of these pipe pieces angle element made of corrosion and heat-resistant material (e.g. stainless steel) are attached with one leg and the other Leg has a bore. Through these holes of the angle elements 2 6 threaded rods are passed, the Carry nuts 28, each angle element 26 or its protruding from the circumferential surface of the pipe section in question Leg is tightly clamped between two nuts 28. This is not only a particularly simple and effective one Attachment of the pipe sections 21a, 21b and 21c achieved, but also the possibility of a precise position adjustment of the given individual pieces of pipe relative to each other.

Fig. 6 shows a different from Figure 2 type of Attachment for the pipe sections 21a, 21b and 21c to one another. In this embodiment, the pipe pieces are at their each having the larger diameter D end with one over the outer circumferential surface radially outward protruding flange 2 9 provided. An approximately Z-shaped bent strip 30 made of corrosion-resistant material is used for fastening Material: stainless steel). One leg (30 '.) Rests against the inner surface of the pipe section in question. Of the Flange 2 9 is encompassed on the outside by a U-shaped bracket 31 made of corrosion-resistant flat material (stainless steel), one leg of which is connected to the middle section 30 ″ of the strip 30 with the aid of a screw 32, so that the pipe section in the region of the flange 2 9 between the leg 3 0 'and the bracket 31 is held. The other Leg of the strip 30 is held with the help of a screw 33 on a perforated plate 34, on which several similar Fastening devices of the type described above for everyone three pipe pieces 21a, 21b and 21c are attached. It goes without saying that, offset around the longitudinal axis L, several fastening

facilities (each consisting of the perforated plate 34, the strip 30 and the bracket 31) are provided. The single ones Perforated sheets 34, each with their longitudinal extension in the direction of the axis L, are crossed by several or Transverse webs (not shown) that run perpendicular to this axis are connected to one another to form a frame or cage. By using the perforated metal sheets 34, each of which has a plurality of holes for the screws in the longitudinal direction 3 3, it is possible to change the arrangement of the individual pipe sections 21a, 21b and 21c to one another according to the respective To be chosen according to requirements. In principle, it is also possible to make each perforated plate 34 from several sections 34 ' assemble, which then each overlap in the area of the screw 3 3 and are connected to each other there.

The invention was described above using an exemplary embodiment. It goes without saying that changes as well as modifications are possible without thereby departing from the inventive concept on which the invention is based.

For example, in the type of fastening shown in FIG. 6, it is also possible not to use the element 31 as a U-shaped bracket, but to be designed as a Z-shaped element, in which the leg then resting on section 30 ″ points upwards, as indicated in FIG. 6 at 31 'with broken lines. This will make the attachment with the help of the screw 32, since then in the element 31 made of corrosion-resistant material no threaded hole, which is difficult to manufacture, is required, but only a simple hole. The screw 32 is held in place by a threaded nut in this case.

In the embodiments shown in the figures, close the inner surfaces of the pipe sections 21a, 21b and 21c with the longitudinal axis L an angle of about 12.5 °, the Pipe sections are frustoconical over their entire length on the inner surface. In contrast to this is however, it is also possible to have the pipe sections in the region of their ends with the larger diameter D on the inner surface

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to provide a short cylindrical or circular section, as shown in Fig. 5 with the broken line 22 '' is indicated. This embodiment has the advantage that there is then a larger diameter in the area of the ends greater thickness for the peripheral wall 2 2 and thus greater strength results, which is particularly the case with the one in FIG. 6 The type of fastening shown can be important. Furthermore results from the cylindrical or circular ring-shaped Sections 22 have the advantage that each in the lower part of the annealing insert on the inlet side Pipe section results in a horizontal collecting surface for such unburned fuel that is still on the glow insert could not evaporate. This collecting surface will allow fuel to drip down from the glow insert effectively avoided.

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Claims (7)

Claims 1. Furnace, in particular heating boiler, with a combustion chamber, with a fuel outlet at the combustion chamber for Formation of a flame as well as with a tubular and made of ceramic penetrated by the flame of the forced draft burner produced annealing insert in the combustion chamber, characterized in that the annealing insert (9) from at least two pipe pieces (21a, 21b, 21c) that are open at both ends, each pipe piece on its peripheral wall (22) is frustoconical and a first End with a larger cross-section (D) and a second end with a smaller cross-section (d), of each of which the first end of the fuel outlet (8) is closer than the second end that at least one Pipe piece (21a, 21b) with its second end into the first end of an adjacent pipe piece (21b, 21c) in such a way extends in that between the in this way overlapping or interlocking pipe pieces (21a, 21b; 21b, 21c) at least one annular gap (23) is formed, and that at least in an adjacent one Pipe section (21b, 21c) protruding second end of a pipe section (21a, 21b) the peripheral wall (22) of this pipe section at least three regions (22 ') offset around the longitudinal axis (L) of the pipe section in such a way inward is drawn that on the outer surface of the peripheral wall (22) of the pipe section to this outer surface and to the second Ends open towards and in cross-section approximately V-shaped channels (25), which extend in the longitudinal direction of the pipe section extend and the depth of which increases towards the second end, as well as inside the pipe section from the peripheral wall inwardly protruding lugs are formed with the height to be added towards the second end of the pipe section. 2. Furnace according to claim 1, characterized in that all the pipe sections (21a, 21b, 21c) of the annealing insert (9) their second end have the inwardly drawn regions (22 '). BATH ORIGINAL 3. Oven according to claim 1 or 2, characterized in that the inwardly drawn regions (22 ') of two adjacent Pipe sections (21a, 21b, 21c) each by a certain angular amount (a) around the longitudinal axis (L) of the annealing insert (9) are offset from one another. 4. Oven according to one of claims 1 to 3, characterized in that the pipe sections (21a, 21b, 21c) with the help of continuous, rod-like elements (27) are attached to one another. 5. Oven according to one of claims 1 to 4, characterized in that the pipe sections (21a, 21b, 21c) at their second end each at least between the inwardly drawn regions (22 ') a radially inwardly extending one Have splash or flange portion (24). 6. Furnace according to one of claims 1 to 5, characterized in that the combustion chamber (2) directly from the inner walls (4, 5, 6) of the boiler (3) serving for receiving heating or industrial water is limited. 7. Oven according to claim 6, characterized in that between the outer walls (13, 14, 15) of the boiler (3) and outer walls (10, 11, 12) of the furnace or boiler a flue gas duct leading to a chimney connection (17) (16) is formed on the front of the boiler with the fan burner (8) having Combustion chamber (2) is in communication. BATH