US2693776A - Method and apparatus for handling ashes - Google Patents

Description

Nov. 9, 1954 l. E. MYLTING 2,693,776

METHOD AND APPARATUS FOR HANDLING ASHES Filed Nov. 4, 1947 2 Sheets-Sheet l A TOPNEYS 2 Sheets-Sheet 2 Awe/rz EMM Mn T//vs @moin/5K9 Nov. 9, 1954 L. E. MYLTING METHOD AND APPARATUS FOR HANDLING ASHES Filed Nov. 4, 1947 United States Patent O METHOD AND APPARATUS FOR HANDLING ASI-IES Lauritz Emil Mylting, Hamburg, Pa., assignor to The Allen-Sherman-Hoi Company, Philadelphia, Pa., a corporation of Pennsylvania Application November 4, 1947, Serial No. 783,965 7 Claims. (Cl. 110-165) The present invention relates generally to the art of handling hot finely divided and/or molten materials, and is more particularly concerned with a novel and very useful method for handling hot ashes and slag produced during steam boiler ring operations, and with novel means effectively implementing that method.

Powdered fuel red boilers are normally provided with ooded hoppers in which ashes produced in the boiler combustion chamber are received. In hoppers of this type, considerable dihculty has been experienced due to the tendency for hot ashes and slag to agglomerate on walls of the combustion chamber with the result that relatively large chunks of very hot material fall from these walls into the water in the hopper, causing explosions which often damage the hoppers.

Two seemingly practical proposals for overcoming this diiculty have been advanced, but to the best of my knowledge have not proven particularly satisfactory. In accordance with one of these proposals, the water in the hopper was to be maintained at a low level so that blast pressures developed in the water would be dissipated largely upwardly rather than to the submerged portions of the hopper. The diiculty is that slag builds up in the center of the hopper and rises above the surface of the liquid. This action results in incomplete fragmentation and uneven quenching and frequently an adherence of slowly cooling masses to the lining of the hopper. Such adherence interferes with ready removal of the slag from the hopper and may damage the lining.

The other proposal involved the installation of a grid in the upper part of the hopper to break up materials falling into the hopper before they reach the water in the lower part of the hopper. It was thought that hopper damaging explosions could thereby be substantially eliminated regardless of the amount of water in the hopper, but the maintenance of the grid in eifective working operation was difficult and expensive. Slag soon choked the grating and prevented the passage of materials from the combustion chamber into the lower part of the hopper.

In accordance with the present invention, diiculties of the prior methods may be eliminated and at the saine time the possibility of hopper damaging explosions occuring as a result of hot materials falling from the combustion chamber into the water in the hopper may be eliminated. A further important advantage of the present invention is attributable to the fact that, unlike previous flooded hopper operations, in which the level of water in the hopper was at all times close to the combustion chamber, in this process the water level is originally relatively low and remote from the combustion chamber and only for a relatively short period at the end of the cycle is the water of the hopper close to said chamber. Considerable heat is saved in this manner for useful eifect in the combustion chamber, since it is not extracted therefrom by the relatively cool water in the hopper, as in the conventional practice. It is expected that an average saving in eiiciency in the boiler of at least 1/2% may thus be realized in commercial scale operations.

This invention involves the novel steps of introducing water into the hopper and thereby providing a relatively shallow pool into which hot materials may fall and be rapidly cooled and broken up, raising the water level and increasing the amount of water in the hopper to a predetermined maximum as the slag volume in the hopper increases, and periodically emptying the hopper of water s 2,693,77b Patented Nov. 9, 1954 ICC and accumulated slag and ashes. As I prefer to carry out the method, however, it involves the additional step of removing water from the hopper in such a manner,

that the depth of water in the hopper is constantly gradually increased until a predetermined maximum point 1s reached, whereupon the slag, ashes and water lare substantially completely removed from the hopper, and the hopper is flushed out in preparation for a repetition of the cycle. Alternatively, the amount and level of water in the hopper may be increased intermittently to accomplish the objects of this invention. Through the automatic operation of one form of apparatus embodying this invention and subsequently to be described, three distinct Water levels are established and maintained in a hopper at various stages of the process, so that when the amount of solid material accumulated in the hopper bottom exceeds a predetermined maximum the original low water level will be increased first to an intermediate point and then to a high level to assure contact of water with additional hot materials and fragmentation of the ,latter as rapidly as it falls into the hopper.

In cases where it is undersirable to expose the bottom or" a hopper to heat from a combustion chamber thereabove, the slag and ashes in accordance with this invention are periodically selectively removed from the hopper, the water remaining in the hopper to keep the walls and bottom thereof cool.

Generally, the apparatus of my invention comprises an ash hopper of the flooded type equipped with means for introducing water continuously thereinto, means for removing water intermittently or continuously from the hopper to control the rate of increase in the amount of water in the hopper, and means for removing accumulated water and the solids, or solids alone, from the hopper when the water level in the hopper reaches a predetermined maximum.

With reference to the drawings accompanying and forming a part of this specification,

Figure l is a transverse cross-sectional view of a hopper embodying one form of this invention taken on line 1-1 of Fig. 2;

Figure 2 is a cross sectional View of the mid-section of the above hopper taken on line 2-2 of Fig. l;

Figure 3 is an elevational View partly in section of a modied form of means for selectively removing solids from the hopper of Fig. l;

Fig. 4 is a wiring diagram showing a conventional arrangement of conventional automatic control elements of the apparatus of Fig. l; and

Fig. 5 is a diagrammatic sketch illustrating the sequence of automatic control operations of the elements of the Fig. l apparatus, as indicated in Fig. 4.

The illustrated hopper is assembled with and disposed below a boiler combustion chamber C, and comprises side walls 10, end walls 1l and a bottom wall 12 denin'g a chamber having an open top communicating with boiler combustion chamber C. Bottom wall 12 is made up of a plurality of transversely extending ribs 1S and channels 16 therebetween sloping downwardly from one side wall to the other. In the lower portion of the side wall adjacent to the lower ends of these channels an opening 18 is provided for withdrawing materials accumulating in the hopper. A door 20 is provided for closing the opening and is operated by mechanism including a worm gear in a housing and a toggle 2l operatively connecting said gear and door and a motor Ml to drive said worm gear. In the other side wall water inlet jet pipes 24 open into the hopper centrally of each channel 16 and which have the additional function of sweeping ashes out of the hopper at the end of each ash accumulation cycle. Four water inlet pipes 26 (three illustrated) are provided in the ends and along one side of the hopper for delivering water rapidly into and ooding the hopper. Conventional solenoid operated valves V1, V2, and V3 (Fig. 4) are provided in pipes 3i? for automatic control of water flowing out of the hopper through these pipes. Above these pipes at three diiferent levels passages 25 are provided through which the water in the hopper may be controllably overowed and removed from the hopper by means to be described. These passages lead upwardly in each case with the uppermost passage terminating in the upper portion of the refractory section of wall 10. The lower two passages 25 communicate with lines 27 leading to a sluiceway 28 disposed below and adjacent to door 20 and are iltted with funnels 29 at their inlet ends to receive overllow from the hopper. Passages 25 are each connected to conduits 30 which serve to convey water from the passages to funnels 29 and lines 27, and the two lower conduits 30 are equipped with automatically timed, cylinder-operated gate valves 32 which close and open at regular intervals to maintain the desired Water level conditions within the hopper at all times. Gate valves 32 are conventional solenoid cooperated valves, the operating means being generally designated V1 and V1 Sol. and V2 and V2 Sol.

Water ilow to jets 24 is accomplished through a line 71 communicating with a suitable source of water under pressure (not shown). A branch 70 of line 71 terminates in an open end disposed adjacent to door 20 and directed toward the interior of the furnace so that the furnace may be flushed out by a plurality of water jets travelling in two different directions. A conventional solenoid control valve V is provided in line 71 to control the ilow of water to the jets and into the hopper as indicated in Figs. 1, 4 and 5.

Referring to Fig. 3, the illustrated apparatus includes a sump vessel 40 which encloses the lower end of a hopper including an unloading door 42, a set of metering and grinding rolls 43 in the sump vessel below door 42, and a pump 45 for removing solids from the sump through a conduit 46 communicating with the lower portion of the vessel. A hand hole cover 44 in the upper end of one side of the sump vessel 40 affords a means of access to the rolls 43. Door 42 may not seal and prevent water flow into vessel 40, in which case said vessel may be substantially lllled or flooded all the time it is in use and special means such as a conduit connecting the sump and hopper will not be necessary to prevent loss of water from the hopper when slag and other solids are discharged into vessel 40. A rod 47 connects door 42 to a piston which is moved in a cylinder 48 to close and open the door. r[his apparatus may be substituted for the hopper unloading mechanism shown in Figs. l and 2 when it is desired to remove solids selectively from a ilooded-type hopper. Operation of door 42 is accomplished by means ofuid pressure delivered into one end or the other of cylinder 48 through lines 49, a three-way valve 50 being provided to control flow of pressure fluid into said lines from a delivery line 51 communicating with a suitable source (not shown) of fluid under pressure.

In the operation of the apparatus of Figs. l and 2, as shown in Fig. 5, with the hopper empty and door 20 closed, water is continuously run into the hopper through the inlet pipes 24 as ashes and slag continuously fall into the hopper from the boiler combustion. chamber located thereabove. The hopper is very rapidly loaded with water until the water level reaches what might be considered an original or starting level. At this level water may overllow through the lowermost passage 2 5 and its communicating conduit 30. After a predetermined time during which normally a certain given amount of hot materials will fall into the hopper from the combustion chamber, the gate valve 32 controlling the ilow of water through the lowermost overflow conduit will close, causing the water level to increase rapidly to the intermediate level where the water overflows through the second or intermediate overflow channel 25 and its conduit 30. Again, after a predetermined period calculated to .be sufficiently brief to assure that all hot materials falling into the hopper will be contacted with water immediately and disintegrated for ready removal from the hopper, the second level gate valve 32 is closed and the level of the water rapidly increased until the water overllows through the uppermost channel 25 and communicating conduit 30. The water is maintained at the maximum level for another given period, at the end of which door 20 is cracked to allow water to ilow directly to sluiceway 28 and is finally fully opened so that the hopper may be ilushed out and accumulated solids may be removed. After the hopper is thus cleaned, door 20 is automatically closed by the worm operated mechanism, and the cycle is begun again, all as shown in Fig. 5.

Operation with the apparatus of Fig. 3 substituted for the hopper dumping means of Figs. l and 2 would suitably be generally as above described but instead of both liquid and solid hopper contents being removed together,

only the solids would be discharged into vessel 40. The solids are ground to size in rolls 43, collected in the sump vessel bottom and pumped therefrom continuously or intermittently, as desired, by pump 45. Since the vessel or hopper 40 communicates with hopper 10 and the latter always contains water suflicient substantially to cover the bottom of the hopper and solids therein, it follows that hopper 40 is maintained full of water and solids at all times in normal operation. When solids are being removed from hopper 40 by pump 45, considerable quantities of the water in the hopper are removed simultaneously but are replaced by water from hopper 10 and the sipply thereto as shown in Figs. l and 2 and described a ove.

Although I have described the present invention only with reference to a particular type of apparatus, it will be apparent from the above description and the appended claims that I contemplate other equivalent means of carrying out this invention.

The automatic means for controlling water llow referred to above and in the appended claims, and the motor driven means for opening and closing the door at intervals as set forth in the said claims are both well known and familiar to those skilled in the art. The door opening and closing means illustrated in Fig. 3, for example, is disclosed in detail in U. S. Patent No. 1,957,583, granted May 8, 1934 to Robert A. Foresman. The automatic water-ilow-controlling means is shown and described in detail in U. S. Patent No. 1,894,267, granted January 17, 1933 to Robert A. Foresman.

Having thus described my invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is defined by what is claimed.

What is claimed is:

1. Ash handling apparatus for use with a high temperature combustion chamber comprising an ash hopper adapted to be disposed beneath and communicating directly with said chamber, means for continuously delivering water into said hopper, means including valve controlled outlets disposed at different levels for step-by-step raising the level of water in said hopper to predetermined maximums, and means for periodically emptying the hopper of ashes and water.

2. Ash handling apparatus comprising an ash hopper, means for continuously delivering water to said hopper, automatic means for removing water from the hopper whereby the amount of water in the hopper may be increased at a controlled rate to a predetermined maximum, and automatic means for emptying the hopper of ashes and water when the amount of water in the hopper reaches said predetermined maximum, said automatic water removing means comprising a plurality of conduits communicating with the hopper at different levels and a valve in each of certain of said conduits opening and closing at predetermined intervals to control flow of water through said conduits, and said emptying means comprising a door in the lower part of the hopper and motor driven means operatively connected to the door for opening and closing said door at regular intervals.

3. The method of handling products of combustion consisting of hot ashes or slag which comprises the steps of continuously running water into a hopper, continuously dropping said products into water in the hopper, intermittently removing water from said hopper, intermittently increasing the depth of water in the hopper substantially in proportion to the rate of increase in height of accumulated products in the hopper, subsequently emptying said hopper of water and said products when the water reaches a predetermined level, and repeating said cycle.

4. The method of handling products of combustion consisting of hot ashes or slag which comprises the steps of continuously running water into a hopper, continuously dropping said products into water in said hopper, intermittently removing water from said hopper, intermittently increasingthe depth of water in the hopper substantially in proportion to the rate of increase in height of accumulated products in the hopper, subsequently transferring said materials to a water-filled hopper and removing said materials from said water-filled hopper while maintaining said hopper substantially iilled with water.

5.`T he method of handling products of combustion consisting of hot ashes or slag which comprises the steps of continuously running water into a hopper, forming a pool of water in the hopper of predetermined relatively shallow depth, continuously dropping ashes into the hopper, raising the surface of the pool to a predetermined level to maintain substantially submerged the ash accumulation in the hopper, maintaining the surface of the pool at said predetermined level as ash accumulates in the hopper, again raising the surface of the pool to a second predetermined level to main substantially submerged the ash accumulation in the hopper, and subsequently discharging the ash accumulation from the hopper before the ash level exceeds the water level in the hopper.

6. The method of handling products of combustion consisting of hot ashes or slag which comprises the steps of continuously running Water into a hopper, forming a pool of water in the hopper of predetermined relatively shallow depth, continuously dropping ashes into the hopper, repeatedly and periodically raising the surface of the pool to successive predetermined levels to maintain substantially submerged ash accumulations in the hopper, and subsequently discharging the ash accumulation from the hopper before the ash level exceeds the water level in the hopper.

7. Ash handling apparatus for use with a high ternperature combustion chamber comprising an ash hopper adapted to be disposed beneath and communicating directly with said chamber, means for continuously delivering water into said hopper, means for regulating the level of water in the hopper and successively and periodically raising said level to predetermined maximums, and means for discharging ash accumulations from the hopper when the hopper has been substantially filled, said water level regulating means comprising a plurality of conduits communicating with the hopper at different levels, a valve in each conduit to stop ow of water through the conduit from the hopper, and automatic control means to operate said valves in sequence at predetermined intervals to maintain a predetermined depth of water over the ash accumulation in the hopper. l

References Cited in the le of this patent UNTTED STATES PATENTS Number Name Date 1,843,273 Foresman Feb. 2, 1932 1,843,274 Foresman Feb. 2, 1932 1,894,267 Foresman Jan. 17, 1933 1,957,583 Foresman May 8, 1934 1,977,181 Foresman Oct. 16, 1934 1,990,446 Allen Feb. 5, 1935 2,163,148 Linder June 20, 1939 2,275,652 Pursel Mar. 10, 1942 2,280,944 Foresman Apr. 28, 1942 2,379,998 Stokoe July 10, 1945 FOREIGN PATENTS Number Country Date 419,476 France Oct. 27, 1919 337,159 Great Britain Oct. 30, 1920 346,130 Germany Dec. 24, 1921

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