US2729872A

US2729872A - Portable tunnel kiln

Info

Publication number: US2729872A
Application number: US203483A
Authority: US
Inventors: Forrest W Peterson
Original assignee: Ferro Corp
Current assignee: Vibrantz Corp
Priority date: 1950-12-29
Filing date: 1950-12-29
Publication date: 1956-01-10
Anticipated expiration: 1973-01-10

Description

Jan. 10, 1956 Filed Dec. 29, 1950 wig I X Illlllllll F. W. PETERSON PORTABLE TUNNEL KILN 3 Sheets-Sheet 1 INVENTOR. Forrest W. Peterson,

ATTORNEY Jan. 10, 1956 F. w. PETERSON PORTABLE TUNNEL KILN 5 Sheets-Sheet 2 Filed Dec. 29, 1950 INVENTOR. Forrest W. Peterson,

ATTORNEY Jan. 10, 1956 F. w. PETERSON PORTABLE TUNNEL KILN Filed Dec. 29, 1950 3 Sheets-Sheet 3 INVENTOR. Forrest W. Peterson, BY

ATTORNEY United States Patent 2,729,872 PORTABLE TUNNEL KlLN Forrest W. Peterson, Burbank, Califi, assignor, by nresne assignments, to Ferro Corporation, Cleveland, Ohio, a corporation of Ohio This invention relates generally to kilns and relates more particularly to tunnel kilns.

Tunnel kilns heretofore have generally been permanently installed and the plant laid out around the immovable kiln. Once installed the kiln could not be moved about and any attempt to move it would result in serious damage thereto.

It is therefore an object of the present invention to provide a tunnel kiln which will overcome the above disadvantageous features.

It is another object of the invention to provide apparatus of this character which is readily portable.

It is still anotherobject of the invention to provide a device of this character that may be easily installed in a relatively short time.

It is a further object of the invention, to provide apparatus of this character incorporating flexible structural features so that it will not be damaged when moved with reasonable care. i I

It is a still further object of the invention to provide apparatus of this character having high efliciency and improved temperature control. i

It is another object of the invention to provide apparatus of this character that will occupy a relatively small space. i i i It is still another object of the invention to provide apparatus of this character whichmay be produced at relatively low cost.

Further objects and advantages of the invention will appear in the following part of the specifications.

Referring more particularly to the drawings which are for illustrative purposes only;

Fig. l is an isometric view of a kiln embodying the present invention;

Fig. 2 is an enlarged sectional view taken of Fig. 1;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 2;

Fig. 4 is a sectional view taken on line 4--4 of Fig. 2;

on line 2--2 Fig. 5 is an enlarged fragmentary isometric view of a 1 joint of the muffle;

Fig. 6 is an enlarged fragmentary view taken on line 6-6 of Fig. 2; and

Fig. 7 is an enlarged view of one ofthe screwsfor vertically adjusting the end tunnel sections.

Referring more particularly to Fig. 1, the kiln includes an entrance section, indicated generally at 10, an intermediate section, indicated generally at 11,and an outlet section, indicated generally at 12., p

The entrance section includesa tunnel portion 13 having side walls 14 constructed of suitable masonry, such as refractory brick, a bottom 15 of refractory tile and a top 16 which is also formed of refractory tile. Adjacent the inner bottom corners are longitudinally extend- 2,729,872 Patented Jan. 10, 1956 2 ing guides 17 which are also formed of suitable refractory material.

The entrance tunnel is supported on a metal framework, indicated generally at 18, comprising upper and lower

longitudinal side sections

19 and 20 respectively inter connected by support members 21 and upper and

lower cross members

22 and 23. A pair of rails 24 are mounted on the frame 18 in parallel relationship and in alignment with the guides 17, said rails being for supporting slabs which are moved by suitable pusher mechanism not shown but which is of known character. The frame 18 is vertically adjustable by means of adjusting screws 26, there being one such screw at least at each corner of the frame. Vertical adjustment of the entrance tunnel section is effected by said screws 26 to position the inner end thereof in line with the recess 74 prior to insertion of said inner end in said recess.

The tunnel portion of the intermediate section 11 of the apparatus comprises side walls 30 of refractory brick and/or insulation, such construction being well known. The tunnel also has a bottom wall 31 and a top wall 32 suitably formed of refractory tile and/or insulating material or the like. The outer sides of the walls 30 are covered by sheets 30a of insulating material and the top 32 is covered with a granular insulating material 320, both the sheets 30a and material 32a being Well known.

The masonry of the tunnel portion is supported in a frame-work of steel, indicated generally at 33, which, as shown, comprises plates 34 on which the bottom 31 of the tunnel rests, said plates 34 being reinforced by angleirons 35. Beneath the plates 34 are

channel members

36 and 37, the members 36 running longitudinally of the tunnel and the members 37 extending transversely between the members 36 for connecting the ends thereof together. I beams 38 form the bottom supports for the frame and extend longitudinally thereof, the I beams 38 being connected to the channels 36 by vertical channel members 39. The tunnel portion is reinforced by steel members 40 along the various edges thereof. Metal side members 40:: connect the frame-work 33 with the frame members 40.

Within the tunnel of the intermediate section are arranged a plurality of pilasters 45 which are spaced apart longitudinally of the tunnel and also transversely of said tunnel, said pilasters extending upwardly from the bottom 31 and being formed of refractory brick.

The pilasters 45 provide supporting means for the muflle which is constructed of refractory material and which includes a bottom formed of tile 46. A second layer of tile 47 is provided on the tile 46, said second layer could, of course, be of brick. Guides 48 also rest on the tile 46 and extend alongside of the tile 47, the guides 48 being of refractory material and being spaced inwardly from the side edges of the tile 46. The masonry parts thus far described are secured together with mortar.

The side walls of the muifie comprise tile slabs 50 of refractory material and said slabs: are secured in position by having their ends loosely received in grooves 51 of mufiie holding bricks 52. The mufiie holding bricks are arranged to form vertical partitions, said bricks having their outer sides in engagement with the inner side of the tunnel walls 30. As shown, the bricks 52 are arranged in end-wise engagement with each other and the grooves 51 are formed in the sides for loose reception of the adjacent ends of the tile members 50. It will be noted that the lower of the bricks 52 have portions 52a which extend over the bottom tile members 46 and rest thereon, the lower tiles being notched at 55 to accommodate the adjacent guides 48. The upper holder bricks 52have notches 52b at their inner upper ends forreception of adjacent side edge portions of the tile members 56 which form the top of the muffle. It is to be noted that the mufile holder bricks 52', the side tile members 50 and the top tile members 56 are loosely assembled and secured together without mortar, the joints being dry slip joints having some play, about 2/8. It is also to be noted that the side tile members 50 r'est on the bottom tile members 46 and are not secured thereto by mortar. Thus the muflle will stand considerable twisting or distortion without breaking at the jointsor cracking of the parts.

It will be noted that the top, bottom and side walls of the muffle are in spaced relation to the respective parts of the tunnel, to permit the passage or circulation of heated air about said mufile. Also the muffie holder bricks 52 are arranged to form vertical partitions between the side walls of the muffle and the adjacent side walls of the tunnel, said partitions preventing the drifting of hot air longitudinally of the tunnel.

Thebottom 31 of the tunnel isprovided with a plurality of openings 60 therein which are spaced longitudinally apart from the entrance end of the intermediate section. Disposed in said openings 60 are heating devices shown as gas burners 61 which are supplied with gas through a supply pipe 62 connected with any suitable source of fuel supply.

Further along in the intermediate section are a plurality of openings 63 some of which are arranged in pairs, as best shown in Fig. 3 and which have gas burners 64 disposed therein and connected to the supply pipe 62. Peep holes 67 are provided in one of the side walls of the tunnel.

Further on is a portion of the tunnel which is provided with a plurality of openings 68 in the bottom 31 for cold air, as will be hereinafter more fully described. Above the mufile is a chamber 70 which extends longitudinally of the intermediate section and which has a plurality of outlets 71 therein disposed generally in the portion of the apparatus containing the openings 63. Means may be provided for controlling the efiective size of the openings 71, such means may be, for example, damper bricks 75a which may be provided for any or all of said openings 71. The portion of the intermediate sectionincluding the longitudinally spaced openings 68 a is closed ofi from the rest of the section by a partition 72 and said portion has a plurality of outlet openings 73 in the upper wall 32 of the tunnel.

The entrance end of the intermediate section is provided with a recess 74 for the reception of an adjacent end portion of the entrance tunnel 13, as best shown in Fig. 2, and the opposite end of the intermediate section is provided with a similar recess 75 for reception of the adjacent end portion of the outlet tunnel, indicated genorally at 76.

The outlet section of the tunnel comprises side walls 77 of refractory brick, a bottom of refractory tile 79 and a top of refractory tile 80. The construction of the outlet .tunnel section is similar to the construction of the inlet tunnel section but the outlet section is longer than said inlet section. The outlet section 76 is supported on a metal framework, indicated generally at 85, and includes parallel upper and lower members 86 and 87 on each side, said members 86 and 87 being vertically spaced apart and connected together by suitable beams or the like 88 and connected together to the corresponding members on the opposite side with transverse members 89. The framework 85 extends beyond the free end of the outlet section and is provided with rollers 90 as best shown in Fig. 1.

the recess 75 so that said inner end may be inserted in saidrecessl In operation, the ware to be fired, such as the articles in Fig. 2, is put on slabs 96 at the entrance where the pusher mechanism, not shown, can move the slab along the rails 24. As each slab is pushed into the tunnel, the previously inserted slabs are pushed along.

The initial portion of the entire course traversed by the ware is considered the pre-heat zone and extends from the opening of the entrance section 13 to the adjacent end of the intermediate portion of section 11 which includes an intermediate part of the Inuffle having the top wall raised as indicated generally in 97 in Fig. 2. In other words, the pre-heat zone extends from the entrance of the kiln to the point 98, Fig. 2, and from this point to the partition 72 there is what is termed the hot zone where the ware is subjected to an intense firing. Beyond the hot zone to the end of the intermediate section is the controlled cooling zone and further cooling occurs in the outlet section '12. The slabs carrying the ware through the apparatus are pushed onto the rollers when they leave the outlet section 76 and the ware is then unloaded from the slabs, which are then removed from the rollers. V

The air heated by the burners 61 surrounds the muffle in the pre-heat zone and passes from the lower portion of the tunnel, about the sides of the muffle, into the chamber 70, and thence is discharged through the outlet openings 71 in the top 32 of the tunnel. As hereinbefore pointed out, the partitions formed by the muffle holders between the sides of the mane and the adjacent sides of the tunnel prevent the hot air from drifting longitudinally in the tunnel. I

The heated air in the hotzone follows a similar course and is, likewise, prevented from drifting in the tunnel by the partitions formed by the muffle holder bricks.

Whenthe air passes through the controlled cooling portion of the intermediate section, cold air passes upwardly into the openings 68, about the muffle portion, extending through the controlled cooling zone of the apparatus, and out through the outlet'openings 73. Here again, the partitions formed by the muffle holding bricks prevent drifting of the cool air and it is to be noted that said cool air may pass through the apparatus with or without forced draft. The muffie is also provided with a sulphur vent 56a.

It has'been found'that there is a considerable reduction in the drift of heated air within the muffle due to the portions 100 of the muffle holder bricks which extend into the interior of the muffle at the sides thereof and act as baffles within said, muffle. It will, therefore, be obvious from the foregoing that the present apparatus provides greatly improved temperature control so that there is a more uniform temperature applied to the ware being fired and hence there are improved results derived from the firing. It has also been found that by using the controlled cooling of the present invention and the subsequent cooling in the outlet section that the ware can be handled with the bare handsas soon as it is discharged from the tunnel. .This is an extremely advantageous feature. ,Moreover, because of the high efiiciency of thepresent invention, the apparatus is relatively small in size.

By building the present kiln in a plurality of sections, it is possible to transport said sections. The lower portions of the frame, such as the

members

20, 38 and 87 of the respective entrance, intermediate and outlet sections, serve as skids and rollers may be used beneath said skids to facilitate moving the sections whether on the ground or foundation or onto and oif of trucks for transporting same. Due to the fact that the muflie'is flexibly assembled, such twisting or distortion as may occur in moving the various sections will not cause the muffle to break or crack.

When the apparatus is being assembled, the entrance and outlet sections may be raised or lowered and leveled by means of the jack screws 26 so that said sections are brought into alignment with the various parts of the intermediate section. :Also, a hood may be disposed over the openings 71 to provide means for carrying 011 the heated air discharged from said openings 71.

It is to be understood that the tunnel sections may be constructed of other material than refractory brick and/ or tile. There are various known insulating materials which may also be used instead of or in conjunction with said brick and/ or tile.

I claim:

1. A pusher slab type tunnel kiln, comprising: a plurality of tunnel sections removably connected together; skids for supporting each section; means for adjusting at least one section vertically relative to another section; and a muffle extending longitudinally in at least one section, said mufiie being formed of refractory material and having dry, slip joints so that said mufile is relatively flexible.

2. A portable pusher slab type tunnel kiln, comprising: a plurality of tunnel sections removably connected together; skids for supporting each section; and a mufile extending longitudinally in at least one section, said muffle being formed of refractory material and having dry, slip joints so that said muflie is relatively flexible.

3. A portable pusher slab type tunnel kiln, comprising: a plurality of tunnel sections removably connected together; skids for supporting each section; and a muffle extending longitudinally in at least one section, said mufile being formed of refractory material and having dry, slip joints so that said muffle is relatively flexible, said kiln having a pre-heat zone, a hot zone and a controlled cooling zone.

4. A pusher slab type tunnel kiln, comprising: a plurality of tunnel sections removably connected together; skids for supporting each section; and a muifie extending longitudinally in at least one section, said muflle being formed of refractory material including slab-like members and holding bricks provided with grooves in which portions of said slab-like members are loosely received, said holding bricks being arranged to form vertically extending partitions between the muflle and the adjacent walls of the tunnel; and a partition wall between the muffle and tunnel walls, said partition wall being spaced from the discharge end of the tunnel section.

5. In a kiln: a tunnel section having a bottom wall, side walls and a top wall, the bottom wall having a plurality of openings spaced longitudinally apart, and the top wall being provided with a plurality of openings spaced from each other; a muffle extending longitudinally within the tunnel section; means for supporting the rnufile in spaced relation to the bottom wall of the tunnel, said means comprising a plurality of supports spaced from each other; and a partition wall between the muffle and the respective side walls of the tunnel, said partition wall being spaced from the discharge end of the tunnel section, some of the openings in the bottom wall and top wall being between the partition wall and the outlet end of the tunnel section.

6. In a kiln: a plurality of tunnel units, each unit having a structure of refractory material forming a tunnel; metal frame-work for each unit for supporting the re fractory structure, one of said units having a recess in one end for reception of the adjacent end of the other unit so that the tunnels thereof are in register for forming a tunnel through the kiln; and means for at least one of the units for leveling same so as to bring the tunnel of said other section into register with the tunnel of said one section whereby the sections may be joined.

References Cited in the file of this patent UNITED STATES PATENTS 1,178,184 Simpson Apr. 4, 1916 1,285,862 Wiester Nov. 26, 1918 1,295,564 Morton Feb. 25, 1919 1,361,604 Milner et al Dec. 7, 1920 1,389,583 Frazier Sept. 6, 1921 1,471,875 Witte Oct. 23, 1923 1,472,139 Reid Oct. 30, 1923 1,520,408 Ebeling Dec. 23, 1924 1,548,794 Fuller Aug. 4, 1925 1,613,054 Prouty et a1. Jan. 4, 1927 1,661,309 Saxe Mar. 6, 1928 1,827,543 Robertson Oct. 13, 1931 1,903,281 Bowman Apr. 4, 1933 2,399,664 Clark May 7, 1946