Specification of John Ferguson : furnaces and fire-places.

  • Ferguson, John.
Date:
1854
Catalogue details

Licence: Public Domain Mark

Credit: Specification of John Ferguson : furnaces and fire-places. Source: Wellcome Collection.

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    Fergusons Improvements in Furnaces and Fire-places, §c. sumed gases is avoided. As adapted for an ordinary cylindrical boiler furnace with an external fire, a cold air supply pipe is let into the fur¬ nace seat or mounting on each side of the fire door at the front end. This pipe or flue runs horizontally into the seating, and passes in each case by a slight bend into a narrow horizontal flue formed in the 5 seating just beneath the level of the flame bed, beneath the boiler and behind the bridge. This flue runs along beneath the flame bed, only separated therefrom by a slight thin cover to the further end of the boiler; here it takes a bend outwards, and returns back to the front end in a line parallel to the first run of the flue, and at the same level. 10 In this way the cold air takes up considerable heat from the flame bed, and in this heated state it is passed amongst the gases as they proceed from the grate. For this purpose the extreme front end of the flue passes by a short bend or angle towards the line of the boiler’s centre, and here enters the outer end of a hollow or cellular bridge standing 15 up from the base of the seating at the back end of the grate bars. Precisely the same arrangement is followed out on each side of the boiler, and the hollow bridge has a central division across it to prevent the mingling of the two currents. At the back of the hollow bridge are a set of openings or jet passages, so that the heated air supplied to go the bridge chamber can thus escape in a diffused state on the side furthest from the grate bars. Here the air jets mingle with the gases passing over the front hollow fixed bridge, and the whole current of mixed heated air and gases then passes onwards and strikes against the front of a vertical hanging bridge of considerable depth. This bridge g5 stops the progress of the current, and enables the component matters thereof to become fully mixed. In this state the combined current descends and passes beneath the bottom edge of the hanging bridge, and rises up at the other side and over the top of a third bridge or flame spreader into the flame bed. Thus there are, as it were, two mixing 30 chambers for the air and gases, and the whole become well commingled, whilst an economical use is made of the flame bed heat in passing the cold air along the bottom flues. Although this arrangement has been specially mentioned in its application to a certain kind of steam boiler and fittings, yet it is equally applicable to all or most other varieties of 35