DE20696C - Innovations to grates and furnaces for steam generators - Google Patents

Description

IMPERIAL

PATENT OFFICE.

The present innovations relate to the furnace and the grate for one Articulated boiler constructed by Babcock and Wilcox, and that from a steam collector and a set of inclined boiler pipes lying under it, which the latter attach to both ends are connected to the steam collector again to ensure free circulation and which are higher in front than in the back.

In the accompanying drawing is:

Fig. Ι a vertical longitudinal section of the furnace and the grate of a Babcock-Wilcox boiler, who is shown in view,

Fig. 2 shows the same section through the main part of the furnace on an enlarged scale,

Fig. 3 is partly a front view, partly a vertical section of Fig. 2, after the same enlarged scale.

A is a steam collector, a horizontal iron cylinder 50 centimeters and more in diameter. Depending on the size of the plant, several such boilers A are usually arranged next to one another. B is a set of inclined boiler tubes about 10 cm in diameter that are lower in the back than in the front. C and D are compounds that keep water circulating from A through D down and through B and C up and back into A. E is the sludge collector that runs across under the boiler, to which it is connected by a sufficient number of nozzles. G is a pipe about 15 cm in diameter lying in the transverse wall R , which is kept filled with water by the pipe g ^x connected to the rear end of the boiler, while it is in connection with the steam collector A through the pipe ^ · ^2. The step grate used consists of two systems of flat, horizontal bars that are perpendicular to the boiler axis. In each system the bars are arranged in groups that alternate with the groups in the other system. Thus, Fig. 1 and 2, starting from above, show first five movable rods ^ then five fixed rods of the system /, then again five of /, then five of / etc. The rods / are fixed to the masonry by bolts or in some other way Firing connected, while the rods J are connected in groups by means of strong frames J ¹ and can be moved a small distance forwards and backwards through these frames. This is made possible by the fact that the frames J ^{1 are} rotatably attached to the levers K ¹ swinging around the horizontal rods k . One of the lower levers K ¹ carries a shoe on its hub K , in which the hand lever L is inserted. By continuously or intermittently moving the hand lever L up and down, all lever arms K ^{1 are brought} into oscillating motion, thereby moving groups J between the fixed groups / forwards and backwards. To automatically close the hand lever L

move, it is connected by a chain X to the pin W ^{1 of} a crank W set in rotation in any way. The weight Z ¹ is used to pull the lever L down again and again. In the position shown the movement of the lever will be great enough to take up the play in the joints, but the movable groups J of the rods will not accept any noticeable movement. If, on the other hand, the chain X is hooked into one of the notches in the lever L, which are closer to its pivot point, the groups / get a correspondingly larger movement. The stoker will very soon find the right incision to cause the fuel to move down the grate regularly, as is most appropriate to the desired effect.

The position of the weight L can be changed as required, for which purpose the lever L is best provided with incisions on the upper edge into which the weight L 'is hung.

M is the feed hopper for the fresh fuel. Its rear wall is formed by a hollow iron box O, which can also be made of other suitable material. The lower part of the same is provided with holes ο through which air, which enters the box O through registers N attached to the sides, flows into the furnace. The funnel M extends over the entire width of the grate. The coals (or some other chosen firing material) are already heated so strongly in the lower part of the funnel that they start to burn as soon as they are hit by the air flowing out of the holes ο. However, the quantity of air is too small to bring about complete combustion, especially when baking hard coals or the like are burned. The upper part of the grate will therefore evolve a quantity of still flammable gases, mixed with carbon dioxide gas, which, if they came into contact with the relatively cold boiler walls, would give off part of their heat and escape unburned.

In order to prevent this, the lower layer of the heating pipes is embedded at its front part in a ceiling R ¹ of refractory bricks or other suitable material. This ceiling extends over the entire width of the combustion chamber and connects to the rear with the hanging fire bridge R, which also occupies the entire width of the combustion chamber. The lower edge of the fire bridge R surrounds the above-mentioned pipe G , which is filled with water, and is protected by the same from burning. The water in the pipe G, which is always replaced, evaporates in the process.

While the coals now gradually descend along the step grate, receiving the air necessary for burning through the cracks of the bars, the products of combustion of the coals burning on the grate mix with the first-mentioned half-burned gases and carry them with them under the bridge R, very heated through, via the horizontal grate P adjoining the step grate, from the first hearth χ into the second hearth y. On this grate P, which is provided with a damper plate P ¹ , only coke that is properly burnt in embers gets from the step grate, so that the air passing through it from below still contains enough oxygen to reach the same from the first hearth λ; to release coming gases. The gases, which are very completely burned in this way, now rise, strongly heated, upwards through the front part of the heating pipes, up to below the steam collector A. On the rear wall F of the second hearth y, one rises vertically to the heating pipes B of the boiler prefabricated fire-resistant material protected partition wall T, to which, enclosing the topmost pipe layer a short distance to the front, the fire-resistant upper ceiling T ^{1 is} attached. A second partition U ¹ , which runs through the remaining part of the set of tubes, adjoins the inclined transverse wall U , which extends to the end of the steam collector A. The hot gases wash around the latter on the underside, then go down through the spaces between the heating pipes, around the lower edge of the partition U ¹ , up again through the heating pipes and from there into the chimney not shown in the drawing.

The damper plate P ^{1 is} covered with ash and particles of coal and thereby prevents the lower bars of the stair grate from melting. The slag that collects on the horizontal grate can be easily removed through the space between the damper plate P ^{1 and the step grate.}

The relationships between the two stoves χ and y shown in the drawing match for bituminous coal; if other material is fired, these must be changed accordingly. In some cases it will also be necessary to change the inclination of the air box O in order to feed the fuel from the funnel M to the step grate in the most suitable manner.

Claims (1)

Patent Claims: The following innovations on furnaces for Babcock-Wilcox boilers:
i. A step grate consisting of fixed and movable groups of horizontal, flat lying rods is so assembled that the movable groups J can be moved back and forth between the fixed groups /, e.g. B. with the aid of the device J ¹ K ¹ L and possibly the crank W and the 'chain X. The arrangement of the box O located behind the feed hopper in such a way that the access of air to it can be regulated by slide JV and the air is distributed through openings ο into the combustion chamber. The combination of a step grate IJ _{1 of} which one part J can be shaken by a device J ¹ K ¹ L, possibly also XW , with the feed hopper M, the horizontal grate P and the hanging bridge R with the ceiling J? ¹ , so arranged that it causes the gases to mix and burn completely. For this purpose ι sheet of drawings.