US2835216A - Boilers - Google Patents

Description

May 20, 1958 w. H. SMITH 2,835,216

BOILERS Filed Jan. 25, 1955 2 Sheets-Sheet 1 Inventor l//LL//J 1 aJMW W. H. SMITH May 2o, 1958 BOILERS 2 SheetswSheet 2 Filed Jan. 25, 1955 Unid States Pater BOILERS William Herbert Smith, East Molesey, England Application January 2s, 195s, serial No. 483,919

Claims priority, applicationGreat Britain January 25, 1954 7 Claims. (Cl. 110--165) This invention relates to boilers for the supply of hot water or steam for industrial and domestic purposes. It is concerned particularly but not essentially with ,boilers having a gravity feed of fuel from a hopper to a tire bed and operating normally under a forced draught from a fan, power-operated means being providedy to eject clinker from the lire bed.

From one aspect, the invention provides a boiler having power operated means for ejecting clinker over the edge of the fire bars and crusher rolls below the tire bars which crush the clinker and deposit it outside the boiler.

From another aspect, a boiler according to the invention has power operated means for ejecting clinker from the fire bed into a chamber in which are mounted crusher rolls rotatable to crush the clinker, the bottom of the chamber being closed by a slide operable on rotation of the crusher rolls to allow the crushed clinker to fall from the chamber. The slide may be formed with a ramp which raises the slide as this is closed and effects sealing of the bottom of the chamber and the crusher rolls may be driven by a motor operated in synchronism with a motor operating the ejecting mechanism. According to another feature of the invention,` the re bars are spring supported to press the clinker ejecting ram against the boiler wall to seal the boiler against leakage of air thereinto.

Preferably there is incorporated in the boiler a fuel hopper to which fuel is supplied by a conveyor operated in accordance with the level of fuel in the hopper.

Other parts of the invention are embodied in the preferred form which will now be described with reference to the accompanying drawings in which Fig. 1 is a side view of the preferred form of the boiler,

Fig. 2 is a section through the boiler on the line lL-Il of Fig. 1.

This form is symmetrical about the centre line and in elfect comprises two boilers arranged back to back. A boiler of less capacity can in fact comprise one of these halves with the addition of a back plate.

In the form shown, the boiler comprises a casing 1 having water spaces 2 down each side and water spaces 3 extending inwardly from the sides and traversed by vertical re tubes 27. Between these water spaces 3 is a fuel hopper 4. Extending from front to rear of the boiler is a water space 5, the top surface 6 of which slopes downwardly from the centre to each side with the apex below the centre line of the hopper. The lower surface of the water space is similarly sloped downwardly from the centre to each side.

At each side of the boiler below the water space 5 are sets of iire bars 7. Associated with each set of fire bars 7 is a clinker ejecting ram 8 reciprocated along the fire bars by racks 9 engaged by quadrants 10 mounted on a cross shaft 11. The cross shaft 11 is operated by a crank 12 connecting rod 13 and crank 14 from a motor 15 which is operated periodically in accordance with the time for which the boiler has been operating under forced draught. A lost motion device is incorporated in the l'lce 2 connection from motor 15 to cross shaft 11 to facilitate adjustment of the timing operation. As shown, the rod 13 passes through the crank 14 and nuts 16 are threaded on rod 13 above and below the crank 14. A quick release device is also provided so that the shaft 11 may be released and operated manually.

The fire bars 7 are supported at their inner ends on channel members 17 extending from front to rear of the boiler and supported through adjustable bolts 18 from lugs 19 xed to the boiler casing. The outer ends of the re bars are spring supported. They rest on a channel member 20 supported on thrust members 21, the lower ends of which are pivoted to one arm of a bell crank lever 22 which is pivoted to the side of the boiler about the pin 23. The other arm of the lever 22 is connected to a pull rod 2S passing through the wall of the boiler.` A spring 26 pulls the rod 25 outwardly and thereby causes the members 21 to exert an upward thrust on the outer ends of the fire bars. The clinker ejecting ram 8 is pressed by the ends of the fire bars against the wall of the boiler and so limits the clearance for leakage of air from outside the boiler to above the re bars. The spring loading also permits expansion (due to heat) of the ejecting ram and other parts.

Fuel from the hopper 4 falls on to the top surface of the water space 5 and thence on to the re bars 7. The depth of the fuel bed is controlled to suit this type of fuel used by members 28 adjustable vertically on the walls of the hopper 4. The ends 29 of these members are bent inwardly so that at whatever level the members are fixed, the zone of unburnt fuel is kept well away from hot gases.

When the clinker ejecting rams 8 are operated, they push the clinker over the inner ends of the re bars so that it falls between Crusher rolls 30. There. are two rolls 30 provided with projecting picks -31 mounted on shafts 32 extending from front to rear of the boiler within a chamber 33. On the ends of the shafts `are pinions 34 in mesh with one another. The shafts are driven by a chain drive 35 from a motor 36 which is controlled to run and drive the Crusher rolls every time the motor 15 driving the clinker ejecting rams 8 is operated.

The chamber 33 housing the rolls 30 is closed at the bottom by a slide 37 which is supported on rollers 44 a-nd is withdrawn when the rolls 30 are rotated to allow the clinker crushed by the rolls to drop through the bottom of the chamber on to a bucket conveyor 6l) running from front to rear of the boiler.y This conveyor conveys the clinker and ash to a dump at any desired position away from the boiler.

The slide 37 is connected to a quadrant 38 engaged by a quadrant 39 which is oscillated by crank 40 connecting rod 41 and crank 42 mounted on the shaft 31 of one of the Crusher rolls Eil. The slide 37 is formed with ramps 43 at each end of the slide so that at the end of its closing movement the slide is raised into tight sealing contact with the bottom of the chamber 33.

Primary air is supplied by a fan d5 delivering air through an inlet 46 below the water space 5 and passes upwards through the fire bars and the lire bed, the gases passing upwardly through the fire tubes 27 into top flue spaces -fl7 from the rear of which the gases pass into an outlet flue 4S through a downwardly sloping section 49 shaped to improve the heat absorption of the water spaces. The bottom of the outlet flue 48 is shaped to direct ily ash and other deposits into a depositing chamber 50 the bottom of which is normally closed by a ilap 51. This flap 51 can be opened to allow the deposits to drop into the ash pit. It is arranged so that when it opens the depositing chamber 50, it closes the outlet from the fan 45 thereby cutting off primary air from the boiler and preventing blow-back of the ily-ash. A valve closing the inlet to the fan may be operated automatically when the clinker ejecting mechanism is operated for example by operating the valve from the cross shaft 11. This avoids the risk of ash and the like being blown back when the re is disturbed to remove the clinker. y

Secondary air is supplied through slots 52 at each side of the boiler above the top of the tire bed. These slots 52 are controlled by valve members 5.3 movable into or out of the slots 52 by eccentric cams 54 operated by `a handle 55.

Fuel is supplied to the hopper 4 by a conveyor (not shown) which is started and stopped by control means `in the hopper operated by the level of the fuel therein. A control vane S6 is pivoted at 57 and is lifted by the fuel to operate limit switches to stop the conveyor. When the fuel level falls the vane 56 drops and operates the limit switches to start the conveyor. The pivot "7 is protected from fuel falling on it by a ledge 58 extending from the sloping side of the hopper.

lt will be understood that the invention is not restricted to the details of the preferred form described which may be modified withoutfdeparture from the broad ideas underlying them.

I claim:

1. A boiler comprising a fire bed, a chamber below said re bed, said chamber having an outlet in the bottom thereof, crusher rolls mounted in said chamber, poweroperated means for intermittently ejecting clinker from said fire bed into said chamber, power-operated means for rotating said crusher rolls to crush the clinker whenever said clinker ejecting means are operated, a slide closing the outlet from said chamber, and means for operating said slide to open said outlet and allow the crushed clinker to fall from the chamber whenever said crusher rolls are rotated.

2. A boiler as claimed in claim 1 in which said means for operating said slide comprises a rack fixed to said slide, a toothed quadrant engaged by said rack and rotatable about a pivot, and crank and connecting rod mechanism connecting said quadrant to the shaft of one of said crusher rolls.

3. A boiler as claimed in claim 1 having parallel shafts on which said crusher rolls Nare mounted, and a pinion on each of said shafts, said p'inions interengaging one another.

4. A boiler as claimed in claim 1 comprising a conveyor beneath said slide to receive the clinker when said slide is opened.

5. A boiler according to claim 1 in which the slide is formed with a ramp which raises the slide as this is closed and effects sealing of the bottom of the chamber.

6. A boiler comprising re bars, means `for ejecting elinker intermittently over the edge of the re bars, crusher rolls below the fire bars in position to receive the clinker so ejected, means for rotating the crusher rolls to crush the clinker, means for operating said crusher roll rotating means when the clinker ejecting means are operated, and spring means supporting said lire bars to press said clinker ejecting means against the boiler wall to seal the boiler against leakage of air thereinto. l

7. A boiler according to claim 6 in which one end of the fire bars is supported on a member thrust upwardly by spring tension on a pull rod connected to one arm of a bell crank lever, the other arm of which is connected to a thrust bar engaging the supporting member.

References Cited in the tile of this patent UNTTED STATES PATENTS 1,808,479 Ritter June 2, 1931 2,013,680 Bennett Sept. 10, 1935 v2,029,285 Bennett Feb. 4, 1936 2,037,990 Martin Apr. 21, 1936 2,240,702 King May 6, 1941 2,277,879 Ness et al M'ar. 31, 1942 2,346,068 Foresman Apr. 4, 1944 2,367,558 Badenhausen Jan. 16, 1945 2,377,874 Fulton June 12, 1945 2,380,452 Kohout July 31, 1945 2,506,782 Fallon May 9, 1950 2,693,775 Berry Nov. 9, 1954 2,694,989 Klijzing et al. Nov. 23, 1954

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