JP2819479B2 - U-type furnace boiler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention provides a boiler structure which is easy to assemble, easy to design and manufacture for a boiler corresponding to capacity, and easy to maintain and handle.

<Conventional technology and its problems> Conventional small-sized low-pressure boilers include a smoke tube boiler, a vertical boiler having a spiral evaporating tube, and a water tube boiler that forms a furnace with a series of tube walls including a front wall, a front wall, and a bottom tube. However, the diameter and length of the boiler drum are determined according to the amount of evaporation, and the inconvenience of having to design and manufacture each time the amount of evaporation and the pressure is different is inconvenient.

Further, there are various difficulties in the airtight structure for preventing gas leakage at the corners connecting the bent pipe surface and the left and right side wall surfaces. This is because when the wall forming the furnace enters operation, a crack occurs due to complicated movement and deformation due to the radiation of the heated boiler water and flame inside, and the plane of the two water pipe walls is orthogonal One of the causes is the presence of a corner (indicated by reference numerals a, b, and c in FIGS. 16 and 17). In addition, there is also a problem that the heat absorption at the corners is small and does not function effectively as a heat transfer surface.

<Object of the Invention> The present invention is carried out by changing the length of the side wall of the furnace wall without changing the dimensions of the drum when changing the capacity. The processing man-hour is small, the transportation can be easily divided, and the on-site assembly is easy and effective. An object of the present invention is to provide a structure of a U-type furnace boiler having a furnace with a U-type header to which heat is transferred.

<Summary of Means> In short, the present invention forms a U-shaped furnace by connecting a U-shaped upper header and a lower header consisting of an arc-shaped portion and a straight portion with a plurality of water pipes, and has a fuel supply means at a U-shaped opening thereof. A connecting piece for connecting a front wall, surrounding a rear water pipe wall with respect to the gas flow of the U-type furnace, providing a tertiary air supply chamber, and connecting water pipes constituting the enclosed water pipe wall to each other. A plurality of nozzles for supplying tertiary air are provided respectively, and a structure of a U-type furnace boiler in which a smoke tube type boiler drum is provided above the U-type furnace is disclosed.

<Embodiment 1> Figs. 1 to 3 show a first embodiment of the present invention. Fig. 1 is a side view of a partially cutaway, Fig. 2 is a sectional view taken along the line AA of Fig. 1, and Figs. FIG. 3 is a sectional view taken along the line BB of FIG. Reference numeral 1 is a fire tube boiler, 2 is a U-shaped furnace wall, 3 is a U-shaped upper header, 4 is a lower header, 5 is a plurality of water tubes constituting a furnace wall, 6 is a front wall, 7 is a stalker, and 8 is a descender. The pipe 9, 9 is a fuel supply means, and 10, 11 are risers. The fuel supply means is the fourth
As shown in FIG. 5 and FIG. 5, a burner structure for burning liquid fuel can be provided.

As shown in FIG. 3, the U-shaped upper and lower headers 3 and 4
And two straight portions 14, one steel pipe can be easily formed by heating and bending. By adopting such a shape, there is no occurrence of corners where the surfaces are orthogonal to each other, so that processing is easy without gas leakage from the corners (corners) as described above. The front wall 6 with the fuel supply means is connected to the U-shaped opening (opening of the furnace 15) of the U-shaped header. The combustion gas passes through the smoke tube 16 of the fire tube boiler, effectively absorbs heat in the smoke tube, and is then discharged through the gas outlet duct 17. The factory-built boiler can be divided into a fire tube boiler, a U-shaped furnace, and a front wall for distribution.
Small ones can be shipped as fully assembled boilers, significantly reducing the time of on-site installation.

As a tertiary air supply means, a tertiary air chamber 22 is formed by surrounding a water tube wall at the rear of the furnace with a plate-like cover indicated by reference numeral 22a in FIG. A connecting piece 24 for connecting the water pipes shown in FIG. 7 is provided on the water pipe wall covered with the plate-like cover, and the connecting piece has a plurality of nozzles 25 as shown in FIG.
Is provided. Tertiary air is supplied through the nozzle 25. The combustion gas flows along the arcuate surface at the rear of the furnace and mixes well with the tertiary air. The unburned portion burns, rises and reverses, flows into the smoke tube 16 of the smoke tube boiler from the left side of FIG. 1, and heats the boiler water in the can. After that, it flows into the chimney from the outlet duct 17.

<Embodiment 2> The front wall 6 with the fuel supply means has a structure of a refractory wall containing a steel frame as shown in FIG. 3 and a burner 12 using a liquid liquid material shown in FIGS. 4 and 5. It can be provided on the water pipe wall so as to close the opening of the U-type water-cooled furnace, but it is preferable to provide a metal fitting 21 (FIG. 5) so as to prevent gas leakage from the furnace.
Inspection nipples indicated by reference numeral 20 in FIG. 5 are used for inspecting the inside of the header by cutting off the ends thereof during a periodic inspection.

If the pressure is relatively low, use a flange type as shown in the figure instead of the inspection nipple. Can be shortened. At the time of inspection and cleaning, a fiber scope or an electric wire brush can be easily inserted from the inspection nipple.

<Example 3> The water tube wall surrounding the furnace can be formed as a membrane panel, and the front wall can also be formed as a membrane panel as shown in FIG. The tertiary air nozzle is similarly provided on a connecting piece (lug) connecting the water pipe.

FIG. 6 shows a state in which a tertiary air chamber 22 is provided in the arc portion at the rear of the furnace. FIG. 7 shows a partial cross-sectional view of the state. The water pipe forms a membrane which is welded from the furnace side with a connecting plate 24 and is surrounded by a plate-like cover 22a separated from the membrane surface to form a tertiary air chamber 22. The connection plate 24 is provided with a plurality of nozzles 25 at the arc-shaped portion of the membrane panel in consideration of the number of holes and the pitch (nozzle density on the panel surface) so that post-combustion is suitably performed.

The use of triangular fillet welding as shown in the figure prevents distortion and deformation of the membrane panel surface. If necessary, when the connection plate is provided so as to be located in the virtual plane including the axis of the water pipe, an effect of preventing deformation of the panel due to welding distortion is exerted.

<Embodiment 4> FIG. 8 is a side view of an apparatus showing a fourth embodiment of the present invention,
FIG. 9 is a sectional view taken along the line CC of FIG. This device has means for switching the flow path of the combustion gas at a low load. The damper 26 on the front wall side is closed during normal operation, the damper 27 on the rear side of the furnace is open, and the combustion gas is inverted from the furnace rear wall side and enters the smoke tube from the front wall side of the smoke tube boiler and exit duct 17
Is sent by

When the load is low, the damper 27 is closed to reduce the gas flow to the rear of the furnace and reduce the amount of heat transferred from the furnace wall.The damper 26 on the front wall is open, so the combustion gas flows into the smoke tube boiler through the opening where the damper 26 is located. I do. Thereby, low load operation can be performed. The dampers 26 and 27 are driven by an air cylinder (not shown).

<Embodiment 5> Figs. 10, 11, and 12 show the apparatus of the fifth embodiment, Fig. 10 is a side view, Fig. 11 is a DD view of Fig. 10,
FIG. 12 is an EE view of FIG. In this example,
A steam separator 28 is provided in place of the smoke tube boiler, and the lower header is connected to the lower header by the downcomer pipe 30 and the upper header is connected to the upper header by the riser pipe 31, and the combustion gas is sent out from the furnace ceiling to the chimney by the outlet duct 29. With this structure, it is possible to reduce the cost of the apparatus by adopting a simple steam-water separator instead of a smoke tube boiler. Also, it can be used as a garbage incinerator, and can also be used as a hot water generator when the customer does not need steam.

<Embodiment 6> Figs. 13 and 14 are drawings of an apparatus showing a sixth embodiment.
FIG. 14 is a partially cutaway side view, and FIG. 14 is a FF view of FIG. As shown by the arrow, the combustion gas flows from the rear partition chamber 32 of the drum to the inverted flow chamber 33 at the front of the drum through the lower half tube group 34 of about half of the smoke tube group, and then reverses and flows through the upper half tube group 35. It flows to the outlet duct 36. Thereby, since the temperature of the boiler water in the can is higher in the lower half than in the upper half, the circulation of the can water can be improved, and the heat transfer effect in the smoke tube boiler can be enhanced.

<Effects> By implementing the present invention, the following effects can be obtained.

(1) Since the header is U-shaped, there is no corner part (corner part) due to surface connection, manufacturing is easy, effective heat absorption is performed with good heat transfer efficiency, and there is no gas leakage accident.

(2) There is an impact nipple (including a flange type) at the end of the header, which makes it easy to inspect and clean the inside of the U-shaped header. The inspection nipple of the front wall header can be easily assembled by adopting the structure shown in FIG.

(3) Since the tertiary air chamber and the nozzle are located at the rear of the furnace, good combustion can be achieved and combustion efficiency can be improved.

(4) Ordinary D-type furnace (shown in Fig. 16 and Fig. 17) (a furnace in which a water pipe is formed into a D-shape with a ceiling, a side, and a floor and connected to a drum) In contrast, in the present invention, the width, depth, and height of the furnace can be freely selected and designed independently of the drum. Therefore, according to the present invention, a vertical furnace and a horizontal furnace can be freely selected.

(5) The evaporator is a smoke tube and maintenance is easy.

(6) In the present invention, the water tube wall may have only a part of the rear portion with a membrane structure, or if necessary, the entire water tube wall may have a membrane structure.

(7) A U-type furnace without a fire tube boiler can be adopted.

(8) The drum can be supported by the U-type furnace, and a drum base is not required.

(9) Incinerator boiler (fixed bed, stoker-fired, fluidized bed furnace as vertical furnace including pressurized type) It can be used in general heavy oil, gas and stoker-fired boilers.

(10) The drum can have a vertical structure.

(11) When used for incineration of ash-rich materials as incinerators for general waste and factory waste, configure the furnace as a horizontal furnace with a short water pipe length, and incinerate polymer-based materials with little ash. In this method, a vertical furnace having a high furnace height can be constructed, a free design can be performed, and a suitable incineration can be performed.

[Brief description of the drawings]

FIG. 1 is a side view of a partial cutout according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG.
B sectional view, FIG. 4 is a perspective view of a front wall with a burner for liquid fuel, FIG. 5 is a partial view showing the connection between the front wall of FIG. 4 and a header of a U-type furnace, and FIG. Plan view showing the air chamber,
FIG. 7 is a partially cutaway enlarged view showing the connection plate 24 and the nozzle 25, FIG. 8 is a side view of a device showing the combustion gas flow path switching damper, FIG. 9 is a sectional view taken along the line CC of FIG. FIG. 10 is a side view of a device with a steam separator, FIG. 11 is a DD view of FIG. 10, FIG. 12 is a view of EE of FIG. 10, and FIG. FIG. 14 is a side view of an apparatus having a reverse flow of combustion gas, and FIG.
FIG. 13 is a sectional view taken along line FF of FIG. 13, FIG. 15 is a partial sectional view of an impact nipple at an end of a header of a front wall, FIG. 16 is a side sectional view of a water tube boiler having a conventional D-type furnace, FIG. 17 is a cross sectional view thereof. 1 ... fire tube boiler 2 ... U-shaped furnace wall 3 ... upper head 4 ... lower head 5 ... water pipe 6 ... front wall 7 ... stoker 8 ... downcomer 9 ... fuel supply device 10 ... ascending Pipe 11 ... Ascending pipe 12 ... Burner 22 ... Tertiary air chamber 24 ... Connection plate 25 ... Nozzle 26, 27 ... Damper 28 ... Steam separator 29 ... Outlet duct 32 ... Drum rear partition Chamber 33 ... all inverted flow chamber

────────────────────────────────────────────────── (5) References JP-A-50-148701 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F22B 21/04 F22B 31/00

Claims (1)

(57) [Claims] 1. A U-shaped furnace is formed by connecting a U-shaped upper and lower header comprising an arcuate portion and a straight portion with a plurality of water pipes, and a front wall with fuel supply means is connected to the U-shaped opening thereof. A tertiary air supply chamber is provided surrounding the rear water tube wall for the gas flow of the U-type furnace, and a plurality of tertiary air supply members are connected to connecting pieces of water tubes forming the enclosed water tube wall. U-type furnace boiler, wherein a nozzle for the boiler is provided, and a smoke tube type boiler drum is provided above the U-type furnace.