Document OEqZvQoE87zJKv3EY6r40XQdK

PLAINTIFF'S EXHIBIT 'THE FORCED DRAFT TRAVELING GRATE SIP 1SSB RILEY STOKER CORPORATION WORCESTER. MASS. ..tZ3 '.-.ERVERS - :n. R.--.- A-jees A':r. COMPLETE STEAM GENERATING UNITS i rSRH-ATERi .-.S HEATER. jJ.R-.E-.E `IITHAN T'L ZxCI.TLEC - >! N A _ t ,N3'._ATID ErTT'S" i RILEY HARRINGTON FRAME STRUCTURE WITH GRATE SURFACE REMOVED REAR TRACK ASSEMBLY SHOWING TRACK BASE AND RENEWABLE TRACKS {4} The Riley-Harrmgton Stoker is a massive, heavy-duty machine. Each detail of its con struction embodies great strength to insure long, continuous, trouble-free operation with a minimum of maintenance, resulting in maxi mum boiler availability. Frame Structure At Ihe front of the Riley-Harrington Stoker rugged heavily ribbed cast iron side frames are used .See illustration top next page.) A heavy welded structural steel girder is located at the rear, I-Beams arid channels are used as longitudinal and transverse members. The substantial framework thus formed affords proper stability under all conditions of opera tion. Ample provision for expansion is provided, permitting the use of high preheated air temperatures without strain or distortion. Rear Track Massive cast iron track bases are bolted to 'he welded rear girder. Hardened alloy renewacie tracks are then bolted to these bases. This construe tion insures low maintenance, as only the small easuv renewed tracks need to be replaced. Simplicity of construction at the rear of the stoker subjects a mini mum of parts to maintenance due to heat and ash AIR SEALS . . . Proper Air Sealing Important With iorced draft traveling grate stokers, if highest efficiency is to be obtained, it is essential to be able to control accurately different pressures m the various air zones To do this, adequate means must be pro vided to prevent air leakage from one air zone to another The excellent sealing Detween zones of RileyHarrington Stokers is well illustrated by the draft gage readings at the Otter Tail Power Company's Wahpe- ton, North Dakota, plant, America's leading lignite burning installation. Note that even a negative pressure is indicated m zones 1 and 2 where dampers are dosed. If excess air along the sides of the furnace is to be prevented, proper air sealing at the side walls is also necessary Proper air sealing at :he front oi the stoker prevents blowing of dust and gases into the boiler room. FRONT AIR 5EAL Front Air Seals The space between the front ol the first air compart ment and the transverse members tying the two side frames togetner is definitely sealed against air leakage with sheet steel sealing plates as illustrated. The posi tiveness of this sealing is indicated by the fact that when covers are supplied for the stoker front a negative pressure exists on the inside of *he cover--any air leakage, of course, would cause a positive pressure Side Air Seals The longitudinal zone between the top side channel :i the stoker frame and the chain air seals is sealed netimte.v against air leakage as .frustrated Before there could ce anv s;ae wail air leakage with a Riiey-Harnngton Stoker, air would have to pass from the chain air seal to the side of the stoker and beneath two rows of sealing dips before it could get cut at the side wall Effectiveness of the Riley-Harrington side air seals is proven by the absolute absence of side wall air ;.nfiltration '^ } T CROSS SECTION OF GRATE CLIPS {8} The grate surface is one of the most important parts of any stoker--it must afford uniform and proper air distribution over the entire stoker--must prevent siftings of fine coal particles to the air zones--must be able to stand the severe service to which it is subjected. These functions are admirably fulfilled by the Riley-Harrington Stoker grate surface. The Riley-Harrington Stoker grate surface is made up cf grate clips i of an inch wide, affording 300 air openings per square foot of grate surface. Each and every clip is active--no blank locking clips or other air obstructing constructions are required. When the grate passes around the rear of stoker, each row of clips is separated from adjoining rows, cleaning grate surface and assuring proper air supply. The clips have overlapping edges, reducing siftings to an absolute minimum. The grate clips are mounted on transverse racks which are bolted to the top of the heavy stoker chain links. The grate surface therefore merely supports the fuel bed and is not subject to any mechanical stress as is the case with chain grate stokers. This {10} The Fuel Gate The fuel gate consists of one or more heavy cast iron gate sections. When of more than one section, the sections are securely spliced together. The furnace side of the gate is pro tected by special fire brick tile which are supported by gate shoes held to the gate by wedges. The protecting tile also extends over the nose of the gate shoes to protect them. The gate opening can be adjusted from ap proximately 2 inches to 15 inches with corres ponding variation in depth of fuel bed An indicator, located at the front of the stoker, shews the amount of gate opening. Gate Lifting Mechanism The depth of the fuel bed is controlled by adjusting the heigh: of the gale The gate lifting mechanism consists of a worm gear reduction operated by means of a large handwheel at the front of the stoker where it is readily accessible. A position indicator shows the extent of gate opening. For wide stokers, lifting mechanisms are provided on both sides of the stoker. i I The Drive The Riley-Harnngton Stoker drive is a double worm and gear reduction unit. Hobbed gears and worms are carefully machined to give per fect contact between teeth of worms and gears. Roller thrust bearings are used on mam worm shaft and roller thrust bearings on the inter mediate worm shaft. Bearings for all shafts and gears are of large proportions to assure long Me The reduction gears are housed in an oil ana dust proof rugged cast iron housing Proper lubrication is obtained through oil reservoirs m the mam and intermediate gear chambers and by pressure grease fittings. Safety Device Connection between the intermediate gear and mam worm shaft is through driving and driven couplings assembled on the main worm shaft. These two couplings are tied together by means of a shearing pin. This pm shears if there is any obstruction to the grale travel, permitting the intermediate gear to operate freely without movement of the mam worm and gear. This safety device affords protection for all moving parts of the drive and stoker. It is located at the Iront of the drive where it is readily accessible. {12} OPERATING CHARACTERISTICS Undisturbed Fuel Bed To burn efficiently fuels of high ash content and low fusion temperature on any stoker, it is necessary to keep an undisturbed fuel bed. With the Riley-Harrington Traveling Grate Stoker, the fuel is carried from the fuel gate at the front to the ash discharge at the rear, without agitation or disturbance of the fuel bed. No agitation or weaving can occur because the grate surface is definitely supported over the entire length by strong longitudinal members. Progressive Combustion Combustion taxes place progressively from ignition at the front to complete combustion near or at the rear where ash is disoharged continuously. The fuel is completely burned out uniformly across the stoker, resulting in low ash pit loss. With the Riley-Harrington Stoker, divided unto compartments or air zones, and with proper air sealing between zones, air pressures are correctly maintained at all points of the fuel bed for most efficient operation. The design of the grate surface assures uniform air distribution. High Efficiency A few examples of actual and guaranteed efficien cies with Harrington Stokers-- Ohio Salt Co., Rittman, Ohio Actual 85.3' . Guaranteed 63 8 Iowa State College, Amee. Iowa 85 48'. 63.7 Container Corporation. Chicago, Illin.au 79.55' 77 6 Hercules Powder Co . Kenvd. N. J 81 : 7S.C Correct Air Distribution Correct distribution of air under comparatively low air pressures is a major requisite to obtain maximum efficiency. The grate sur face of the Riley-Harnngtcn Stoker is made up of grate clips less than one inch wide. There are over 35 grate clips, providing over J00 Air Opening* per ,q. 300 air openings, for each 5quare foo( gra(e ^ face. Each and every grate clip is active. There are no blank locking clips and no air obstructing construc tions beneath the grate surface. The fuel bed is active over the entire surface--there are no black dead { 14 } specs or streaks. With 300 a:r openings per square foot, uniform distribution oi air at low pressure is ob tained and all blew torch actions eliminated. The ability to obtain desired burning rates at compara tively low air pressures reduces rc a minimum the carry over of fine fuel .r.to the boiler passes. Positive Air Sealing Air at different pressures is required throughout the length of the stoker for efficient performance. To maintain the desired air pressure in the various air zones under varying boiler steaming rates it is neces sary to have positive air seal between the zones. The compartment and chain air seals with the Harrington Stoker definitely seai one compartment from the other. The effectiveness of this sealing is indicated by draft gage readings at the Otter Tail Power installation at Wahpeton, where even a negative pressure is indicated m those zones where air dampers were closed. No Side Wall i- ^^icage In order to prevent excess air entering the furnace along the side walls where the fuel bed offers less Low Ash Pit Loss To maintain low ash pit losses it is necessarv :ha: the fuel be thoroughly consumed uniicrmlv across the stoker--uniform square cut-off of the fire must be obtained. This is obtained with the Riley-Harnngtcn Stoker because oi effective air sealing and effective utilization of the entire active grate surface, eliminating dead spots and streaks in the fuel bed which would carry iarge quan tities'of combustibles to the ash pit. Tests have indicated as low as 3'" to 5r"_ combustible in the ash with Riley-Harrington Stokers with boiler ratings over 250f" . Low Sifting Loss Photo of stokrr in operarii-n showing well burned cm: -ish If large quantities of fuel sift through the grate surface, serious sifting losses occur unless these siftings are returned to the furnace to be reconsumed. The Riley-Harrington Stoker is the only traveling grate stoker using overlapping non-sifting grate clips Carefully conducted weighed tests have proven that siftings from a Riley-Harrington Stoker even when burning fine sizes of anthracite is less than 1 4 of \r'( of the fuel burned. This means that over 800,000 pounds of fuel would have to be burned on the stoker to cause one-ton of siftings. resistance to air passage, it is necessary to maintain low air pressures at the side walls beneath the grate surface. To accomplish this, positive air seals must be provided at the side walls. In addition to definite air sealing, the side clips used with Riley-Harrington Traveling Grate Stokers are non-air admitting. These features prevent an leakage at the side walls. Low Power to Drive Net efficiency is also af fected by the power re quired to drive the stoker and forced draft fan. As there is no sliding fric tion with a Riley-Harring ton Stoker, little power is The Harnngtcn Stoktr Rolls required to drive it. As air pressures required are also comparatively low, power to drive the forced draft fan is low. {15} Grate Clips of Rugged Design The construction ot the grate c:ip gives them un usual strength against mechanical breakage As the grate clips merely support the fuel, mechanicai break tion. The superstructure ci the stoker is so ruggeo that it requires little or no attention. Air seals are heavy, rugged castings which scarcely ever require attention. About the cnly parts in the furnace which age is practically ml, all mechanical motion being imparted by the rugged chain links which are located m a cool zone over six inches before the grate surface. Roller Chain Principle The driving mechanism of chain links, side and center rollers and sprockets is based on the roller might require replacement are the rear tracks. These tracks are special alloy material, requiring but mirequent replacement and are small in size so that they are easily and cheaply replaced. Access to Air Zones The construction of the air zones and air zone dampers is such that access can be had to any zone while the stoker is in operation, without stopping the stoker. Access is readily had by doors located on the operating floor level. chain principle--all sliding friction being eliminated --resulting in low maintenance of these parts. Special alloy chain pins and rollers are used to further reduce maintenance There are no moving sprockets or other mechanisms at the rear of the stoker where they would be subjected to heat and ash. The driving sprockets and reduction gear are located at the front of the stoker in a cool, clean atmosphere. In the design oi each part of stoker, consideration has been given to maintenance m order to assure reliable, economical operation over years of service. Ease of Repair As every moving part to the stoker is either located at the front or comes to the front with each revolution ol the stoker, all moving parts are readily accessible and replacements are easily made. Grate surface parts can be easily replaced while stoker is in opera Low Auxiliary Power Low driving power is required, first because of the efficiency of the main driving worm gear reduction Second, because all moving parts roll--sliding fric tion being eliminated--the chains actuating the grate surface rolling on both upper and lower tracks. Low fan power is required because low air pressures are required under the gTate surface and because the stoker structure permits free passage of air to the grate surface. {17} Harrington Installation Burning Iowa Coal A r* 4 i d One 30.CCC .bs per hour Riiev Steam Generating Unit i:rec =y 18'0" x 19 0" RiieyHarr.ngton Stoker Pen'orman ce Data Po'jr.as ol Steam hr. Efficiency CO: Loss cue to Unburned Comb Air Pressure--Stoker Zone 00,000 !bs. 83-3 . 1 4.2 , 15'. 2 5" Typical Caal Analysis Ia*a Screenings Mo.sture Volatile Fixed Carbon Ash B T U as fired 15 44'. 32.68' . 33 26'. 18 62', 9282 B.TU {25} `j 4 1 i ti a "i J