US1916713A

US1916713A - Water cooled stoker

Info

Publication number: US1916713A
Application number: US398924A
Authority: US
Inventors: Joseph S Bennett
Original assignee: American Engineering Co Ltd
Current assignee: American Engineering Co Ltd
Priority date: 1929-10-11
Filing date: 1929-10-11
Publication date: 1933-07-04
Anticipated expiration: 1950-07-04

Description

July 4, 1933.

J. S. BENNETT WATER COOLED STOKER Filed Oct. 11,. 1923 3 Sheets-Sheet l I J. S. BENNETT WATER COOLED STOKER July 4, 1933.

Filed Oct. 11, 1929 3 Sheets-Sheet 2 July 4, 1933. J. s. BENNETT WATER COOLED STOKER 3 Sheets-Sheet 3 Filed Oct. 11, 1929 Patented July 4, 1933 UNITED STATES PATENT OFFICE I JOSEPH S. BENNETT, OE PHILADELPHIA, PENNSYLVANIA, ASSIGNOIL TO AMERICAN ENGINEERING COMPANY, OF PHILADELPHIA, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA WATER GOOLED STOKER Application filed October 11, 1929. Serial No. 398,924.

This invention relates to a water-cooled stoker furnace.

An important object of the invention is the provision of a stoker arrangement permitting cooling ofthe tuyeres or of the tuyeres and retort walls as desired, thus increasing the life of the various stoker parts affected by the increasing tendency to use of highly pre-heated air therein.

A further object of the invention is to provide a construction of this nature which will permit the cooling to be extended to the overfeed section.

A still further object of the invention is to provide a construction of this character which, if so desired, may be extended to include the adjacent wall of the crusher pit.

A further object of the invention is to provide a structure of this character which may be employed to provide cooling of any or all of these sections.

A still further object of the invention is the production of a structure of this character which may be incorporated in a stoker furnace without materially modifying the construction thereof.

A further object of the invention is to provide a stoker structure wherein the entire area of the stoker body and furnace walls within the fire zone is Water-cooled.

A still further and more specific object of the invention is to provide a structure permitting cooling of the pushers and partition plates thereof.

These and other objects I attain by the construction shown in the accompanying drawings wherein, for the purpose of illustration, I have shown a preferred embodiment of my invention and wherein:

Fig. 1 is a vertical sectional view through a stoker furnace embodying water-cooling of the portions thereof lying'within the fire zone and of the crusher pit wall;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig. 3 is a section on line 33 of Fig. 1',

Fig. 4 is a vertical longitudinal sectional view through the stoker of Fig. 1;

Fig. 5 is a similar section through a slightly modified stoker construction;

Fig. 6 is an elevation of a stolrer section constructed in accordance with the showing ing of the under-feed section where such these sections are cooled and in which a header 13 is arranged at the front wall and a header 14 at the bottom of the crusher pit wall, these headers being connected by tubes 15 which extend along the under-feed section, preferably in contact with the tuyeres thereof as more particularly shown in Fig. 3.

At the over-feed section 11 the over-feed pusher 16 is preferably increased in depth so that an'increased arc in bending the tubes, as indicated at 17, may be provided. From the bend 17 these tubes extend downwardly along the front pusher pit wall and connect to the header 14. In a construction of this character any of the tuyre and retort wall cooling arrangements of Figs. 4 and 7 to 11 may be provided. Such a construction is, however, disadvantageous to a certain extent in that it does not permit of cooling of the sections 12a of the crusher pit wall which are in alignment with the retort. Where cooling of these sections is desired the arrangement of Figs. 5 and 6 is employed. In these figures an intermediate header 18 is disposed between the headers 13 and '14 and at the top of the crusher pit wall. The tubes 15 are divided into sections 150, and 15b of which the sections 15a extend from'the front wall to the header 18 and the sections 155 from the header 18 to the header 14, the firstnamed sections cooling the tuyeres, and, if desired, the retort walls, While the last-named sections cool the crusher pit wall in alignment with the tuyeres.

So far the construction described provides the same cooling as that provided by the construction originally described. However, header 18 may be connected with the header 14; by additional tubes 19 underlying the retort section which serve to cool those portions of the crusher pit wall in alignment with the retort sections. If desired, in a construction of the latter character the cooling may be confined to the tuyeres and the retort walls by omitting header 14 and pipe sections 15?) and 19. Similarly the cooling may be confined to the crusher pit wall by omitting the header 13 and pipe sections 15a. The

headers

13 and 14 may be either supplied with cooling fluid from a separate source or, as illustrated, be interconnected with the circulation system of the boiler through

conduits

21 and 22. This arrangement may be employed without any material modification of the stoker construction and will result in. a considerable saving due to the extension of the life of the parts aflected where the stoker is employed with highly pre-heated air. It may, of course, be previded in any stoker construction.

In many instances it may prove desirable to cool the pushers 23, partition plates 24: and the over-feed section 16 of the furnace. This is accomplished by making each of these sections in the form of a chamber having fluid feed and

return pipes

25 and 26 communicating therewith. The feed and return pipes leading to the over-feed section 16 and the pushers will, of necessity, include flexible sections since these parts are reciprocated through the usual mechanism generally designated at 27. Those leading to the partitions 24 may, however, be in the form of rigid tubes.

It will be noted that the lower portion of the front wall will be cooled by fluid from header 13 and by the vertically-extending conduits21. It will, therefore, be obvious that by combining with the features hereinbefore described a side wall structure such as set forth in my prior application, Serial No. 314,098, filed October22, 1928, for water wall and air cooled refractory construction the entire fire zone may be water-cooled.

The cooling structure described in said application includes headers 28 and 29 located adjacent the rear and front walls of the furnace and connected by inclined tubes 30 built into the side walls of the furnace, these tubes covering the entire fire zone of the furnace side wall. Circulation is established through the headers 28 and 29 and tubes 30 by connecting the same with the circulatory system of the boiler through conduits 31 and In Figs. 3 and 7 to 13 inclusive T have illustrated various arrangements of the tubes 15 which may be conveniently employed. In the usual practice these tubes will be covered by blocks 33 which may be either of the U type as illustrated in Figs. 3 and 7 to 11 inclusive or of the T type as illustrated in Fig. 12. It will be noted, however, from an inspection of Fig. 13 that it is not necessary that these tubes be covered, as they may actually form the retort side walls and the tuyere section as suggested in this figure.

Since the structure illustrated is capable of a considerable range of change and modi- I fication without in any manner departing from the spirit of my invention, I do not wish to be understood as limiting myself thereto except as hereinafter claimed.

1 claim 1. In combination with a stoker furnace having a crusher pit, a front wall and the usual under-feed and over-feed sections extending from the front wall to the upper end of the crusher pit wall, means for fluid cooling the tuyere sections and said crusher pit wall including fluid circulation tubes extending from said front wall to the lower end of said crusher pit wall, said tubes being formed in sections, there being a header at the upper end of the crusher pit wall with which adjacent ends of the sections communicate.

2. In combination with a stoker furnace having a crusher pit, a front wall and the usual under-feed and over-feed sections extending from the front wall to the upper end of the crusher pit wall, means for fluid cooling the tuyere sections and said crusher pit wall including fluid circulation tubes extending from said front wall to the lower end of said crusher pit-wall, said tubes being formed in sections, there being a header at the upper end of the crusher pit wall with which adjacent ends of the sections communicate and headers at the front wall and lower end of the crusher pit wall with which the remaining ends of the sections communicate.

3. In combination with a stoker furnace having a crusher pit, a front wall and the usual under-feed and over-feed sections extending from the front wall to the upper end of the crusher pit wall, means for fluid cooling the tuyere sections and said crusher pit wall including fluid circulation tubes extending from said front wall to the lower end of said crusher pit wall, said tubes being formed in sections, there being a header at the upper end of the crusher pit wall with which adjacent ends of the sections communicate and headers at the front wall and lower end of' the crusher pit wall with which the remaining ends of the sectionscommunicate, the last-named headers being connected in [the circulation system of the boiler.

4. A stoker furnace including retort walls, said retort walls comprising fluid circula tion tubes and refractory elements in heatconductive relation with said tubes and forming the effective wall surfaces, other fluid circulation tubes extending longitudinally between the upper ends of said retort walls, tuyere elements in heatconductive relation with said last-named tubes, and means for circulating fluid through said tubes.

' tuyeres and said 5. A stoker furnace including retort walls, said retort walls comprising,fluid circulation tubes, other fluid circulation tubes extending longitudinally between the upper ends of said retort walls and means for circulating fluid through said tubes, protective block facing the retort walls and tuyeres seated upon the last-named tubes.

6. In a stoker furnace, the. combination with an inclined grate structure consisting of alternately arranged longitudinally extending tuyeres and retorts, of an ash pit terminating the lower end of the grate, fluid circulation tubes in cooling and protective relation to the tuyeres and aligned portions of the wall of said pit, and other fluid circulation tubes in corresponding relation to those parts of the said wall in alignment with said retorts.

. 7. A mechanical stoker comprising an inclined grate consisting of alternately arranged longitudinally extending tuyeres and retorts, fuel-feeding pushers in the bottoms of said retorts, and fluid cooling means in cooling and protective relation both to the pushers.

8. In a stoker furnace, a grate comprising alternated tuyeres and retorts, means for advancing fuel in the retorts, an ash pit terminating said grate, and walls surrounding said grate and pit, and fluid cooling means -in cooling and protective relation to said walls, tuyeres, retorts, fuel advancing means, and with the walls of said pit and forming a completely fluid cooled enclosure embracing the entire fire zone of said furnace.

9L In a mechanical stoker, a plurality of parallel tubes arranged in groups and defining a plurality of spaced retorts, protective blocks secured to the tubes and forming the wall facings of said retorts, and tuyeres also associated with the tubes and'bridging the spaces between saidfretor'ts.

10. In a mechanical stoker, a plurality of parallel banks of fluid circulating tubes defining the' walls of spaced retorts, protective blocks secured to the tubes and forming the wall facings of the retorts, and tuferes bridging the spaces between the retorts.

1 1. In a mechanical stoker, a plurality of parallel banks of fluid circulating tubes defining the walls of spaced'retorts, protective blocks secured to the tubes and forming the wall facings of the retorts, tuyeresbridging 'the spaces between the retorts, and fluid cooled pushers operative in the bottoms ofsaid retorts. v

12. In an underfeed stoker. furnace, the combination with a boiler, of a series of inclined tuyeres forming a series of retorts,-

inclined longitudinally toward an ash discharge at the lower ends of the retorts, a transverse water header embodied in cooling and over which the ashes discharge, a downtake connection from the boiler feeding water to said header,-uptakes extending from the header along the tuyeres'in cooling relation thereto, and uptake connections from said uptakes to the boiler.

13. An underfeed furnace comprising a plurality of parallel underfeed retorts which are spaced apart to provide passages for air, means to feed fuel into the front ends of the retorts. wallsi providing a transverse ash dump in the rear of the retorts, water circulating means having portions mounted above the air passages and sloping downwardly toward the rear, means associated with said portions to distribute air from said passages into the fuel, the lower end of said into the fuel, means to supply water to the lower ends of the tubes, a transverse header at the front ofthe furnace into which the upper ends of the tubes are connected, and-a row of water wall tubes associated with the front furnace wall and connected at their lower ends to said header, said water wall tubes being arranged to absorb radiant heat from the furnace.

15. In an underfeed stoker furnace, the combination with a boiler, of a series of inclined tuyeres forming a-series of retorts, inclined longitudinally toward an ash discharge at'the lower ends of the retorts, a transverse water header embodied in cooling relation across the lower ends of the .retorts and over which the ashes discharge, a downtake connection from the boiler feeding wa te'r to saidheader, uptakes extendingfrom the header along the tuyeres in cooling rela- I tion thereto, and uptake connections from said uptakes to the boiler, said tuyeres being of section tapering upwardly to a ridge, with one of said water uptakes embodied in cooling relation within the ridge.

. I JOSEPH S. BENNETT.

relation across the lower ends of the retorts