US1760256A - Underfeed stoker - Google Patents

Description

May 27, 1930. R. s. RILEY UNDER FEED sToKEE Filed April 22, 1922 2 Sheets-Sheet l IN VEN TOR.

R. 's. RILEY UNDER FEED STOKER May 27, 1930.

Filed April 22. 1922 2 Sheetsj-Sheet 2 @MJF I N VEN TOR.

Patented May 27, 1930 UNITED ASTATES vPMLNT onirica ROBERT SANFORD RILEY, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO RILEY STOIKER CORPORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MAS- SACHUSETTS UNDERFEED STOKER Application filed April 22,

This invention relates to a mechanical stoker of the underfeed type in which fuel is supplied through a plurality of retorts, each receiving fresh fuel at its upper or front end and discharging ash and refuse from the f rear end thereof onto an overfeed 'grate eX- Ltension and thence to the ash'dump.

Adjacent retorts are separated by air-con ducting side walls supporting the usual tuyre blocks and it is one of the objects of my invention to separately control the Vair supply for different parts orsections of these side ywalls and tuyre blocks andthe overfeed I grate section. This featureV of my invention is of particular importance in very large stokers in which the condition of the fuel bed may vary greatly in different parts of the .furnac-e, rendering it very desirable to be able "to independently increase or decrease the air pressure at any desired point.

In one form of my invention, the sectional overfeed grate mounted at the rear of the retort has its middle portion fixed and the side portions mounted to move with the retort side walls. Itis a second obj ect of my invention to provide a separate air supply for the fixed overfeed grate elements and particularly to combine this separate air supply for the iiXed overfeed grate portion with the independent air supply for different sections of the side walls.

Furthermore, my invention contemplates provision for` suitable air supply for the rocking ash discharge or dumping plates at the rear of the retorts and overfeed grates, and in the pref-erredeform, l associate with the air supply for the dumping plates the air supply for the movable side elements of the overfeed grates.

An additional object of my invention is to provide means to prevent overheating of the clinker grinding and ash removing mechanism of my improved furnace'.

My invention further relates to certain arrangements and combinations of parts which 1922. Serial No. 556,011.

will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of my invention is shown in the drawings in which Fig. 1 is a partial plan view of my improved stoker;

e Fig. 2 is 'a sectional elevation taken along the line 2-2 in Fig. l; y 4

Fig. 3 is apartial sectional elevation taken along the line 3 3 in Fig. 1. n

Fig. 4 is a detail view of the driving anism of the clinker grind-er; and

Fig. 5 is a sectional elevation ofthe clinker grinder, taken along the line 5--5 in Fig. 4.

mech- Referring to the drawings, I have yshown` parts of a Stoker which, in its general arrangement and construction, closely resembles a well known commercial type ,and in'- cludes a hopper 2O connected to a. cylinder k21 from which coal or other fuel is forced by a ram 22 through a feed chute or casing 23 into the upper end of the associated retort. The casing 23 is mounted in the front wall 24 of the furnace and the ram 22 is regularly reciprocated by a connecting rod 25 actuated by a crank shaft 26.r The shaft 26 is provided with a worm wheel 27 engaged and driven by a wormvnot shown, the mechanism Vthus far described being of the usual constructionand forming'no part of my present invention.

The retorts are inclined rearwardly and downwardly and are provided with side walls 28 preferably having lost motion connections 29 with the ram 22. The side walls 28 ar-e thus reciprocated with the ram 2,2 duringv a portion only of each stroke of the ram. The extent of movement of the side walls may be increased as desired by placing U-shaped collars 30 on the' lost motion vconnections 29, thereby reducing the lost motion between the parts. The side walls of adjacent retorts are spaced apart sufficiently to form air passages, the construction and function of which will be'hereinafter described; l

`My improved Stoker is provided with air admitting ash discharge plates pivotally mounted at the rear of the retorts and connected by an air conduit 61, to an air chamber 62 extending beneath the several retorts. A damper 63 may be provided tocontrol the flow of air from the chamber 62 to the conduit 61.

A main wind trunk 64 is connected to the chamber 62 bya passa-ge 65, controllcd'by a damper 66. The wind trunk 64 is also connected to aV second air chamber 67by a passage 68 controlled by a damper 69.

The separate side walls 28 of the retorts deline air passages Vthrough which air is supplied` to the tuyre blocks 71. vPartitions 72 divide the side wall passages into upper and lower portions, the upper portion being in direct communication with the air chamber 67 and the lower portion being similarly connected with the air chamber 62. The tuyre blocks are thus disposed in two groups and the air pressure for each group may be separately controlled by means of the dampers 66 and 69.

A series of overfeed grates are provided bctween the rear ends of the retorts and the ash discharge plates 60'and these overfeed grates areshown as each comprising side portions 73 and 74, and an intermediate portion 75. The intermediate portion 75 is fixed in position and serves as a continuation of the stationary'bottom of the retort, while the side portions 73 and 74 are movable with the retort side walls 28.

The middle portion v7 5 is Vseparately connected by a passage 76 to the wind trunk 64, the flow of air to the grate portion 7 5 being controlled by a sliding damper 77. The air for the side overfeed grate elements 73 and 74 is preferably drawn from the air space 61 to which the ash discharge plates 60 are'connected. Plates 78 (FigQ) separate the overfeed grate elements 73 and 74 from the lower air passage between the side walls 28.

Provision Vis thus made for supplying air at any desired pressure to the u per or lower sections of the tuyre blocks an to the middle section of the overfeed grate, and provision is alsoV made for supplying air at the pressure of the air chamber 62 or less/to the ash discharge plates 60 and to the overfeedgrate elements 73 and 74. f

The stoker shown in Figs. 1 and-2 also'em- Vbodies a clinker grinder or rollr 80 and a second series of ash discharge plates 81, mounted upon. the rear or bridge wall 82, and receiving air from a passage 83. The'diseharge plates 81 are preferably arranged in sections which may be moved separately or in small groups by the actuating mechanism shown, which comprises a shaft 85 having arms -86 connected by'links 87 to the plates 81 and having additional arms 88 connected by links 89 to'lifter rods 90. y

A hand wheel 91 is threaded on each rod 90 and a 4spring 92. is interposed between ythe struction of these parts vof the grinding u mechanism form no part of my present invention, and a complete description thereof will be found in my prior application Serial No. 386,848, filed J une 5, 1920. The roll may be intermittently actuated by a pawl 98 (Fig. 4) and ratchet wheel 99, the pawl being connected by a link 100 to actuating means not shown.L I v It is found that the clinker grinding rolls are often seriously distorted by the eXtreme heat to which they are occasionally subjected, and, as stated,`it is an obj ect of my invention to provide means to prevent such overheating of the rolls. For this purposeV the ends-of the tube or ypipe 95 are left open or are only partially closed by ringsgor flanges 101 and a water pipe 102 is introduced into one en'd of the pipe 95. nozzle 103, controlled by a valve 104, suitably connected by an arm 105 and linki106 to a sleeve 107. This sleeve is sli-dabler on 'the pipe 102 and is controlled in position by any suitable thermostat such as a bellows thermostat 108 of well known construction, one end "of which is secured to a collar 109 lirXed on the pipe 102.

The parts are so arranged that expansion and contraction of the thermostat, due to increase and decrease of temperature respectively, will move the sleeve 107 and turn the valve 104 and control the escape of water either the upper or lower portions of the sidel walls and tuyre blocks and also on the fixed portion of the overfeed grate may bel raised or lowered as desired and without reference to the pressure in the other portions ofthe stoker. y v

I havealso provided for a suitable supply of air, at any pressure not greater than that on the lower set of tuyre blocks, for the-airadmitting ash discharge plates and for the movable portions of the overfeed grate. In addition to this, I have 'provided novelmeans for preventing distortionand injury to the grinder rolls.- i v Lic It will be evident that changes and modifications can be made in my invention without departing from the spirit and Scope thereof 4as Set forth in the claims, and I do not wish to be otherwise limited to the details herein disclosed, but what I claim is l. An underleed stoker comprising walls defining a retort having a Astationary bottom, an overfeed grate Section having a stationary middle portion, serving as an extension of the retort bottom, side portions which are movable lengthwise of the Stoker relative to the stationary middle portion and means for actuating the movable portions of the grate.

2. An underfeed Stoker comprising walls defining an underfeed retort having a Stationary bottom, an overfeed grate section having tuyre openings therein, said section having a stationary middle portion which serves as an extension of the retort bottom and side portions which are movable lengthwise of the stoker, means for supplying air under pressure to said Overfeed grate section and means for actuating the movable portions of the grate.

3. An underfeed Stoker comprising a stationary bottom and movable side walls forming a retort therebetween, tuyre blocks on the side walls, a stationary overfeed grate section having tuyre openings therethrough which serves as an extension of the retort bottom and overfeed grate sections on each side of said stationary section which are movable lengthwise of the stoker with said retort side walls.

l. An underfeed Stoker comprising retorts having stationary bottoms and longitudinally reciprocable side walls arranged to provide an air space beneath the Stoker, tuyre structures surmounting said side walls and adapted to receive air from said Space and deliver it to the retorts, a transverse partition eX- tending between the reciprocable side walls which divides said space into forward and rear compartments, both of which deliver air to the retort tuyres, an air duct, means forming separate passages directly connecting said duct with each of said compartments, and sep arately adjustable damper means controlling the air flow through each passage, whereby the pressure in either compartment maybe regulated independently of the pressure in the other.

5. An underfeed stoker comprising walls defining retorts having tuyres therebetween, an overfeed grate extension at the rear end of said retorts having tuyre openings therethrough, means including a transverse partition extending beneath the retorts and forming forward and rear compartments, each adapted to supply air to part of the tuyres between the retorts, partitioning means forming an air compartment beneath the overfeed grate extension for Supplying air thereto, an air duct, means forming separate passages directly connecting said duct with each of said compartments, and separately adjustable damper means controlling the air tlow through each passage, whereby the pressure in any compartment may be higher or lower than the pressure in any other compartment.

In testimony whereof I have hereunto affixed my signature.

ROBERT SANFORD RILEY.

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