US1447929A - Drier - Google Patents

Description

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GEORGE B. DAMON, 0F BELVIDERE, NEW JERSEY', ASSTLGNOR TO VUIiCAN IRON WORKS, OF WILKES-BARRE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

'y DRIER.

Application led l'ulyy 17,

To all whom t may concern.'

Be it known. that l, GEORGE B. Barron, a citizen of the United States of America, residing at Belvidere, in the `county of Warren and State of New Jersey, have invented certain new and useful Improvements in Driers, of which the following is a specification.

My invention relates to driers, and particularly to driers of the double shell rotating type of construction. Among the objects of my invention may be specially mentioned (a) toafford an increased supply of heated gases to the drier and particularly to the annular space through which the materialundertreatment passes;.(b) to control the quantity and the temperature of the gases passing through the inner shell and independently of the quantity and temperature of the gases passing through the annular drying chamber; (c) to passthe gasesl through the drier in such direct fashion that the ordinary suction fan may be dispensed with and be replaced by an ordinary stack; (d) to provide heat storage means through which the gases pass to the drier, thus to maintain substantially uniform the predetermined temperature conditions; (e) to provide means for breaking up the stratification of the gases passing to the drier- (this means may be the same as that just mentioned) (7) to provide more room at the feed end of the drier for the introduction of the material to be treated. Other features of improvement will be hereinafter pointed out or illustrated in the accompanying drawings, in which- Fig. 1 is a. broken side elevation of a drier in which my invention is embodied in one form; l f

Figs. 2 and 3 are sections on the lines II-II and III-III, Fig. 1, respectively; and

Fig. 4 is a diagram of an alternative construction. i

i It is of course premised that the details of the construction shown may be varied in many ways while nevertheless embodying what I claim as my invention; and it is to be understood that the drawing shows but an illustrative embdiment of that invention. l

The material enters the drier at a feed hopper 5 of any suitable type, and passes to 1920. Serial N0. 397,055.

the'annular drying chamber afforded between the outer cylinder 6 and the inner shell or flue 7. The cylinder is arranged on an incline and rests on rollers r8 through bearing rings 9 of usual type, so that as it 1s rotated by spur gear 10, driven through bevel Wheels 11 and 12, and meshing with the gear ring 13 lon the cylinder, the material passes gradually through the cylinder and discharges through chute la tota trough'- like hopper 15, in which is arranged a screw conveyor 16, or other means for removing the material from the drier. The fluev is supported from the outer shell by spiders 17, which, as shown at 18, may be of flexible linlr type to permit relative longitudinal displacement of the parts incident to longitudinal expansion or contraction at the temperatures to which they are subjected. vAs

shown in F ig. 1, the Hue is conical, with its small end arranged toward the discharge end of the cylinder. Thisarrangement maybe reversed, as indicatedv diagrammatically in Fig. 4. ln any event, both inner and outer shells carry longitudinally extending flights 19 which project yinto the drying chamber and serve to cascade the material as it passes through the drying chamber during the rotation of the cylinder.

rlhe heated gases which are led through the drier comprise, in part, the products of combustion fromv the fire chamber 20. These pass from the fire chamber to a tempering chamber 21, thence through checker-work 22 to a second tempering chamber 23 (into which the intake of the flue 7, opens), thence throughl a `second checkerworl 24 toa third tempering chamber 25, to 'which cylinder i `It passes to this Hue through the checken cillary air with the products of combustion,

but also stores up this heat and imparts it to the gases, should the latter tall below desired temperature by reason `of a low lire in thechamber 20. ln chamber 23 the gases are urther tempered by the admission of more air and pass 'through checkerwork 24 `(having the same function 22) to chamber 25, where a further and inal admission oit air occurs before they pass into the annular space between the inner and outer shells.

lhe value of the present construction will be recognized vfrom the -t'olllowing consideration. The amount of vapor which a'space can carry lis controlled by and rapidly increases with the temperature. lt is there- -rore economy to operate the drier at relatively high (say 180-2000 F.) discharge temperature. On the other hand certain materials passing through the drier can be 'subjected without injury to higher temperature than others. Thus, for drying iron cresthe temperature ot' the flue may be as high as 10000 F., while for drying coal a temperature this high cannot be used with safety. The flexibility of temperature control by the valved ports 2." is therefore important-as well as the maintenance oit a uniform -temperature by the checlrerworlr grids through which the gases pass to the drier.

The construction ot the conical flue as shown in Fig. l, that is to say with its apex at the discharge end of the cylinder, is of value in drying such materials as give orf their moisture readily-such, Jior instance, as wet sand. The conical shape of the -lue accelerates the passage of the mate rial through the drier.

On the contrary, when the material is of such character that itis slowr to give off its moisture-as 'for instance coal, loam, cla-y, some iron ores, limonite, etc-the reverse arrangement of the flue illustrated in Fig. 2l is preferable, since this construction retards the passage of the material through the drier. Furthermore, the gases passing through the flue 'contract as they cool, and theiconstruction accommodates this condition. Again, it affords increased room at the end of the drier to which the material is fed and permits the use ot' mechanical feeders, which may be required for feeding plastic materials, such as clay, etc. Again, by reason of its retarded travel through the flue, the material is retained Jfor the longest period in contact with the hottest portion of the shell, viz, the lire-box end, and this is what is needed for materials that are loath to part with their moisture. The gases entering tl e annular drying chamber are hottest at the re-bo-X end, and 'in the best condition to evaporate the least vestige of moisture in the material: briefly, the hottest gas strikes the driest material. Moreover, by providing a damper X at the stack end interese et" a llian l", when needed, is contemplated. IThe velocity of the gases passing tlirougn the annular drying chamber can be so reg- ?ulated yby a Idamper D in, and the height of, the chimney, and by the forced draft in the ashpit, that 'a condition oi ba'l'anced drattcan be'created. lllhat is :to say, the pull ot the stack (or oi the tan, when used) may be lso regulated as to Icarry oll the products of combustion trom the lire chamber,plus the ancillary air admitted through the port-s 27 and passing through the flue 7 and the annular space between the latter and the shell '6, together with the moisture taken up trom the material passing through the drier. Furthermore, this regulation may be so accurate that the gases emerging from the annular chamber are just below the point ot' moisture saturation. The value offsuch an arrangement is obvious.

rEhe details of construction may be varied in many ways and .ter different materials under treatment. The constructions shown and described constitute but an illustrative embodiment of what claim as vinvention.

l claiml. A drier comprising a Vrotary inner flue affording between them 4an annular drying chamber ot gradually increasing area trom one end to the other, and having its bottom inclined in one direction, gas inlets and outlets at opposite ends of the drier, means for feeding material to the annular chamber at the gas outlet end thereof, and means for receiving said'material as discharged at the gas inlet end of said chamber.

2. A drier comprising arotary`- shell and inner flue affording between them an annular drying chamber of gradually kincreasing arca from one end to the other, and having its bottom inclined in one direction` gas inlets and outlets at opposite ends oi" the drier, means for feeding material to the annular chamber at the gas outlet endv thereof, and means for reeeivino` said material as discharged at the gas inlet end of said chamber, together with means for admitting hot gases at different temperatures respectively to saidv flue and annular drying chamber.

3. The combination Ywith a rotary drier having an outer shell and inner liuc affording between them an annular drying chamber, ot aV source o/supply of heated gases and an intake for the flue closer to thejsaid source than the intake for the drying chamber.

shell and li. The combination with a rotary drier having an outer shell and an inner flue affording between them an annular drying chamber, of a fire chamber and tempering chambers interposed between the same and the drier, the intake for the drying chamber being arranged in a tempering chamber more remote from the ire chamber than that for the intake of the Hue.

5. rlhe combination with a rotary drier, of a re chamber for supplying heated gases thereto, and tempering chambers arranged in extension of the drier and interposed between the fire chamber and the intake for the drier.

6. The combination with a rotary drier, of a iire' chamber for supplying heated gases to the drier, a group of heat storage elements through4 which the products of combustion pass to the drier to vequalize the temperature of the gases supplied thereto under varying fire conditions, said heat storage elements being arranged in series, together with means for admitting gases to the drier from different points in said heat storage series.

7. The combination with a rotary drier of a lire chamber, checkerwork partitions interposed between the iire chamber and the drier, and intakes to the drier opening to the areas between different partitions, for

.the purpose described.

8. The combination with a rotary drier, of a lire chamber, a checkerwork partition interposed between the fire chamber and the drier, and excess air inlets opening to the lire-box side of said partition to temper the gases from the fire chamber, said checkerwork serving to mingle the ancillary air and gases from the fire chamber.

9. The combination with a rotary drier having an outer shell and inner flue, of a fire chamber for supplying heated gases to the drier, a checkerwork through which the gases pass to the annular drying chamber between the shell and flue, the intake of the latter extending through said checker work.

10. The combination with a rotary drier having an outer shell and inner flue, of a fire chamber for supplying heated gases to the drier, a checkerwork through which the gases pass to the annular ,drying chamber between the shell and flue, the intake of the latter extending through said checkerwork,

together with ports admitting excess air to gases from the re chamber which enter the drying chamber.

11. ln a rotary drier, the combination with a rotary shell and inner flue affording an annular drying chamber, a stack to which said chamber and ue admit the gases passing therethrough, means for feeding mate rial to the chamber at the stack end thereof, a fire box at the opposite end of the drier, and independent intakes therefrom to the flue and drying chamber respectively.

12. in a rotary drier, the combination with a rotary shell and inner flue affording an annular drying chamber, a stack to whichv said chamber and flue admit the gases passing therethrough, means for feeding material to the chamber at the stack end thereof, a lire box at the opposite end of the drier, and independent intakes therefrom to the flue and drying chamber respectively, the intake from the flue being arranged to receive hotter gases than those admitted to the drying chamber.

13. In a rotary drier, the combination with an outer shell and inner flue affording an annular drying chamber between the same, of means for flowing gases at different temperatures in the same direction through said flue and chamber.

14:. In a rotary drier, the combination with an outer shell and inner flue affording an annular drying chamber between the same, of means for flowing gases at different temperatures in the same direction through said fiue and chamber, together with .a common stack to which said gases discharge.

15. The combination with a rotary drier, of a fire box, means for mingling excess air with the products of combustion therefrom, and means for breaking up the stratification of said excess air and products of combustion before they are admitted to the drier.

16. A drier comprising a rotary shell and an inner flue affording between them an annular drying chamber of gradually increasing area from .one end to the other of the drier together with means for leading gases at different temperatures in the same direction through said flue and annular drying chamber.

In testimony whereof I have signed my name to this specication.

GEORGE B. DAMON.

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