EP1004822B1 - Sliding grate assembly for a solid fuel boiler or a similar installation - Google Patents

Abstract

A stepped grate (30) in a solid fuel boiler, combustion furnace or burner works with a rigid grate unit (3) and a movable grate unit (4), lowering in stages from the fuel intake (31) to the ash removal point (32). For a horizontal lift movement backwards and forwards the movable grate unit (4) is arranged on the rigid grate unit (3) or on a common baseplate.

Description

The invention relates to a step grating arrangement in the preamble of independent claim 1 specified Art.

Shear grate systems of incineration plants, especially step grate systems, tolerate a very wide range of one Fuel supply in terms of particle size, moisture content and flowability. To achieve a good burnout, can the layer height of the fuel on the grate in the course to some extent affected by combustion.

The object of the invention is to provide a step grating arrangement for a solid fuel boiler or the like, which is simple and which is nevertheless the Layer height of the fuel on the grate for an optimal Burnout can be finely influenced or fine-tuned.

The object on which the invention is based is achieved by a step grating arrangement with the features of claim 1.

The step grating arrangement or Sliding grate arrangement by the features of claims 2 to 13.

The essence of the invention is that the rigid and flexible Grate elements in cross-section have an angular shape and are perforation-free Large horizontal legs across the fuel delivery direction or to the ash discharge direction.

The grate elements according to the invention in angular form are special dimensionally stable and easy to manufacture preferably extruded, cut to length structural steel angle iron, the as rust elements in solid fuel boilers or the like be used for the first time. Through this execution can the vertical web is used as a heat sink for the grate element become (large surface). The combustion air of the (Primary air) sweeps past the vertical webs, cools the rust elements and thus protects them from thermal destruction. Heat is also exerted on the angle by the heat load Part of the grate elements directed into the cooling air space. Of Furthermore, the combustion air is preheated, which is positive affects the combustion.

The vertical legs of the angled grate elements are preferred at a base of the rigid or movable grate unit (loose) plug-in, which not only makes the grate elements can be easily installed and replaced, but with Advantage adjustable in height and possibly also laterally can be stored with little play. With the horizontal linear stroke movement a changed air gap can thus occur during operation can be achieved. This change in cross-section creates several Flow velocities of the primary feed Combustion air and ensures an even burnout and a clean rust surface.

US 5 069 146 A is a stepped grate arrangement known type. The well-known grate arrangement but has no angled grate elements according to the invention, whose vertical legs are plug-in, and therefore the aforementioned advantages of the invention and their developments are also not achievable.

Due to the movable and rigid grate unit of the Fuel entry to the ash discharge on the upper side in steps sloping step grate, which horizontal contact surfaces for the fuel, but also has vertical stop faces for the fuel, especially due to the grate element thickness the upper horizontal leg of a grate element and by leading edges angled downwards Direction ash discharge, is in the operation of a moving step grate after the direct fuel input practically one continuous movement of the ember bed like on a conveyor belt caused. Through the aforementioned vertical stop surfaces for the fuel or the level training the ember bed moves towards the ash discharge inevitably in the direction of ash discharge, i.e. not on the Place, as is often the case with known feed grates Case is. The ember bed thickness or layer height of the fuel can thus depending on the (if necessary adjustable) speed the movement of the movable grate elements and (if necessary adjustable) stroke length and / or by regulated Interval operation of the grate drive according to the invention very much can be finely regulated, which enables optimal unwinding becomes. The fuel material travels on the step grate different temperature zones. This is the fuel dried, degassed and finally completely burned. The combustion residues arrive at the end of the step grate in an ash pan with preferably automatic Ash removal through a rotating ash removal screw.

The combustion air (primary air) becomes the fuel from below supplied over a large area or through many slots. This Air flow according to the invention causes a good one Cooling the grate elements, on the other hand preheating the Combustion air, which has a positive effect on the combustion.

Another advantage of the invention is that it is very simple mechanical design of a maintenance-friendly feed grate, where cast links can be dispensed with. An easy one controllable electromotive single drive already on the order of e.g. 0.25 kW drive power ensures already for a reliable rust movement and rotary movement the ash removal screw for continuous operation or an intermittent operation during known designs use complex hydraulic drive technology in this regard have to. The simple drive technology of the invention additionally allows a further reduced construction weight.

Fig. 1

einen Festbrennstoff-Kessel schematisch in einem Vertikalschnitt gesehen von der Seite,

Fig. 2

den Festbrennstoff-Kessel nach Fig. 1 in einer horizontalen Teildraufsicht auf eine Schubrostanordnung nebst Antrieb und Entaschungsschnecke,

Fig. 3

den Antrieb nach Figur 2 in einer schematischen Seitenansicht,

Fig. 4

einen Horizontalschnitt durch die Schubrostanordnung nach Figur 2 nebst Antrieb und Entaschungsschnecke längs der Linie A-A der Figur 5,

Fig. 5

einen schematischen Teil-Vertikalschnitt nach Figur 1 zwecks Darstellung der Schubrostanordnung in größerer Einzelheit,

Fig. 6

einen Schnitt durch die Schubrostanordnung längs der Linie B-B der Figur 5, und

Fig. 7, 8, 9 und 10

perspektivische Teilansichten der Schubrostanordnung nach den Figuren 1 bis 6.

The invention is explained below using an exemplary embodiment with reference to the accompanying drawings; show it:

Fig. 1

a solid fuel boiler schematically seen in a vertical section from the side,

Fig. 2

1 in a horizontal partial plan view of a moving grate arrangement together with the drive and ash removal screw,

Fig. 3

2 in a schematic side view,

Fig. 4

3 shows a horizontal section through the sliding grate arrangement according to FIG. 2 together with the drive and ash removal screw along the line AA in FIG. 5,

Fig. 5

2 shows a schematic partial vertical section according to FIG. 1 in order to show the sliding grate arrangement in greater detail,

Fig. 6

a section through the sliding grate arrangement along the line BB of Figure 5, and

7, 8, 9 and 10

perspective partial views of the sliding grate arrangement according to FIGS. 1 to 6.

According to the drawing, a solid fuel boiler 40 is in shape a solid-fuel fan burner with automatic stoker screw-chip feed 37 over his entire inner Base area a moving grate arrangement in the form of a driven Step grate 30 with a drive motor 18 and a drive linkage 15, 16 outside the boiler 40.

The step grate 30 is designed as an interchangeable unit and on a common U-shaped in a side view Base plate 1 built, the boiler front leg in close proximity to the boiler fireclay lining 38 from the boiler base to just below the fuel supply 37 is sufficient and its shorter leg 39 behind the boiler also includes the ash discharge 32, in which a Ash removal screw 20 in the area of the height of the boiler base quererstreckt.

The ash removal screw 20 is driven by the drive motor 18, which also drives the step grate 30.

In particular, the step grate 30 has a rigid grate unit 3 and a movable grate unit 4, which in an arrangement in the boiler 40 from the fuel insert 31 to the ash discharge 32 drops in stages.

The movable grate unit 4 is on the rigid grate unit 3 for an essentially horizontal stroke movement arranged. The rigid grate unit 3 is in turn attached to the base plate 1.

The rigid grate unit 3 has rigid grate elements 5, such as also the movable grate unit 4 movable grate elements 6 has, wherein the fuel contacting from the fuel entry 31 rigid and movable to promote ash removal 32 Grate elements 5, 6 arranged in an alternating order and interlock in sloping steps.

All grate elements 5, 6 are of the same design and have in cross-section angular shape, with large, if necessary, roughened or corrugated horizontal legs 33 transverse to the fuel delivery direction R and vertical leg 34 are provided, which is the fuel entry side are facing.

The one facing the ash discharge side that runs transversely in the boiler Front edge 36 of the horizontal leg located at the top 33 of each grate element 5, 6 is inclined angled below, with a narrow grate element slot 35 for an air passage of primary combustion air L of the bottom of the boiler or the bottom of the broad boiler Fuel remains, which is on the horizontal legs of the Rust elements lies and is promoted.

The vertical legs 34 of the rigid and movable grate elements 5, 6 are in two lateral rigid or movable vertical plate-shaped combs are plugged into slots, then the grate elements 5, 6 together with the associated Holding combs, which by means of cross struts or guide rails 7, 8 are connected to each other, each rigid or form the movable grate unit 3 or 4.

On the base plate 1 or within the U-shaped base plate as already mentioned, the ash discharge 32 is also included, the lower end portion of the step grate 30 from Ash discharge 32 by a substantially vertically arranged Cross plate 2 is separated.

The movable grate unit 4 is slow in operation rotating) electric drive motor 18, a rotating Eccentric 17, a drive linkage 15, 16, a pivotable Crank 13, 14, 19 and a fixed with the movable Grate unit 4 connected carriers 11, 12 horizontally driven reciprocally, the drive motor 18th is electrically controlled and in particular an interval operation a lifting movement of the step grate 30 and / or one Rotational movement of the ash removal screw 20 enables.

The entire step grate 30 is a replaceable module in one Boiler or the like provided. But it can also Parts of the step grate, for example the movable grate unit, or parts of the movable grate unit designed as modules his.

The stroke of the movable grate unit 4 is by changing the effective lengths of the drive linkage 15, 16 or the rocker 3 adjustable or adjustable.

All grate elements 5, 6 are individual wear parts exchangeable with the retaining combs by loosening the plug connection.

The step grate 30 is provided for low-noise operation its front vertical leg of the base plate 1 a noise protection or insulation board 21.

The individual components are therefore on an interchangeable, U-shaped carrier plate constructed in the form of a base plate 1. Through the divider 2, the grate area becomes an ash pan separated. The two fixed holding combs are direct attached to the base plate 1 or the support plate. For stiffening and as a mounting support are the two side ones Struts 8 welded between the retaining combs. The two movable holding combs 4 are also a Bracing 9 and the driver elements 11, 12 braced. moreover are the two movable crests 4 as movable Grate unit via two guide strips 10 on the rigid grate unit suspended horizontally. With a horizontal shift the movable grate unit move the two guide strips 10 in two elongated holes 22 of the rigid Holding combs.

By intermittent movement of every second (movable) Rust element 6 becomes a temporarily continuous rearrangement of the ember bed. Thanks to the modular structure is a simple exchange of wear parts up to complete grate system possible.

Claims (13)

1. A stepped grate assembly comprising alternately disposed stationary and substantially horizontally reciprocally displaceable transverse grate elements (5 or 6) in stepped descending relationship to each other forming a downward slope toward the ash-discharging device, which grate elements form a stationary and a movable grate unit (3 and 4) respectively, wherein the stationary and movable grate elements (5, 6) are angular in cross-section, each having a vertical limb (34) and a horizontal limb (33) of unbroken large area.
2. A stepped grate assembly as defined in claim 1, wherein the vertical limb (34) of each grate element (5, 6) is plugged into a base element of said stationary and said movable grate unit (3, 4) respectively.
3. A stepped grate assembly as defined in claim 1 or claim 2, wherein the front edge of each grate element (5, 6) is bent downwardly in the direction of the ash-discharging device.
4. A stepped grate assembly as defined in claim 2 or claim 3, wherein the base element of the stationary or movable grate unit (3 or 4) is a stationary or movable plate-type retaining comb disposed in a vertical plane.
5. A stepped grate assembly as defined in any one of claims 1 to 4, characterized by a base plate which is U-shaped as viewed from the side, in which U-shaped base plate the ash-discharging device is installed or accommodated.
6. A stepped grate assembly as defined in any one of claims 1 to 5, wherein the lower end region of the stationary or movable grate unit (3 or 4) is separated from the ash-discharging device by a substantially vertically disposed transverse metal plate (2).
7. A stepped grate assembly as defined in any one of claims 1 to 6, wherein at least some of the stationary and movable grate elements (5, 6) are individually replaceable.
8. A stepped grate assembly as defined in any one of claims 1 to 7, wherein the entire stepped grate assembly optionally including the ash-discharging device forms a single unit or parts of the stepped grate assembly form replaceable single units.
9. A stepped grate assembly as defined in any one of claims 1 to 8, wherein at least one noise insulating panel (21) is provided.
10. A stepped grate assembly as defined in any one of claims 1 to 9, wherein the movable grate unit (4) can be reciprocated by means of a slow-speed electric driving motor (18) via at least one rotating excentric (17), a drive bar linkage (15, 16), a slewable crank (13, 14, 19), and an entrainer (11, 12) fixed to the movable grate unit (4).
11. A stepped grate assembly as defined in claim 10, wherein the driving motor (18) also serves to simultaneously drive a deashing screw (20) transversely located in the ash-discharging device.
12. A stepped grate assembly as defined in any one of claims 1 to 11, wherein the stroke length of the movable grate unit (4) can be adjusted or varied.
13. A stepped grate assembly as defined in any one of claims 10 to 12, wherein the drive motor (18) is electrically controlled and, in particular, makes it possible to effect intermittant operation of one reciprocal action of the movable grate unit (4) and/or one revolution of the deashing screw (20).

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