US2033757A

US2033757A - Flash drier

Info

Publication number: US2033757A
Application number: US720417A
Authority: US
Inventors: Crites Joe
Original assignee: RAYMOND BROTHERS IMPACT PULVER
Current assignee: RAYMOND BROTHERS IMPACT PULVER; RAYMOND BROTHERS IMPACT PULVERIZER Co
Priority date: 1934-04-13
Filing date: 1934-04-13
Publication date: 1936-03-10
Anticipated expiration: 1953-03-10

Description

March10,1936. J,RITES 2,033,757

FLASH DRIER Filed April 15, 934 4 Sfieets-Sheet 1 I if 16 B .F

Iva/811151 Joe @2223 h gm Am J; CRITES FLASH DRIER March 10, 1936.

Filed April 13, 1934 4 Sheets-Sheet March 10, 1936. J. cRli'ES 2,033,757

FLASH DRIER 1 Filed April 13, 1954 4 Sheets-Sheet. 3

Q I & Im/enm March 10, 1936. R

' FLASH DRIER Filed April 13, 1934 4 Sheets-Sheet Jr orne'g's,

Patented .Mar. 10, 1936 UNITED STATES PATENT oFFICE FLASH DRIER,

,Joe Orites, Evanston, Ill., assignor to Raymond Brothers Impact Pulverizer Company, Chicago, Ill. a corporation of Illinois Application April 13, 1934, Serial No. 720,417

9 Claims.

ing them to a rather finely divided condition,

and also for removing water from the materials especially from materials of high moisture content. I

While a great variety of wet materials may be dried by means of this improved apparatus, it has been particularly designed for treating sludge, that is the semifluid material which remains after sewage has been screened and filtered. This sludge may have a very high moisture content, for example about 65% to 80% by weight.

Briefly described, the apparatus comprises a mill or disintegrator having a substantially closed cylindrical casing in. which-one or more.disinte- 20 grating cage structures are mounted for rapid rotation about the central horizontal axis of the mill. The wet material, together with highly heated gases, is delivered into the casing through one end wall thereof, substantially in line with or adjacent to the central axis and within the rotary disintegrating elements of the cage structures. The material is broken up by the cage structures and thrown outwardly by centrifugal force against the inner peripheral wall of the casing, and the hot gases are also drawn or whirled outwardly through the cage structures so as to be brought into intimate. contact with the disintegrated material and absorb the moistur thereform. An opening is provided in the peripheral wall, preferably in the-lower. portion thereof, through which dried and disintegrated material and the gases may pass out. Arotary scraper is mounted in the casing for rotation, about the central axis,,in proximity to the inner peripheral wall of the casing, to. scrape loose the material and direct it toward the outlet opening. After being discharged through the outlet opening the dried material is carried away in any suitable -manner. In the form here shown,

this material is carried away partly in. suspension in the gases and partly by means of a mechanical conveyor. k v

The principal object of this "invention is to provide an improved drying apparatus .of the type briefly described hereinabove and disclosed more in detailin thespecifications which follow. Another object is to provide a drying apparatus of this type in which the hot gases are held in intimate contact vwiththe materials throughout the disintegrating'and drying processes.

Another object is to provide an improved form of disintegrating apparatus.

Another object is to provide an apparatus of this type in which the disintegrating cages are supported and rotated from the same side of the '5 enclosing casing.

Another object is to provide an apparatus of this type including an improved scraper for re-.

moving the materials from the inner peripheral surface of the casing. v 10 Another object is to provide means for rotating the scraper at a lower speed than the disintegrating elements.

Other objects and advantages of this invention will be more apparent from the following detailed 15 description of certain approved forms of mechanism constructed and operating according to the principles of this invention. H

In the accompanying drawings:

Fig. 1 is a side elevation of the assembled ap- 2o paratus, portions being broken away to show the interior construction.

Fig. 2 is a vertical section taken substantially on theline 22 of Fig. 1. a

Fig. 3 is a central vertical longitudinal section 25 through the disintegrating mill, the view being taken on a larger scale than Figs- 1 and 2.

Fig. 4 is a transverse vertical section taken substantially on the line 4-4 of Fig.3, with a portion of the mill casing broken away.

Fig. 5 isa partial end elevation and partial vertical section taken substantially on the line 5-5 of Fig. 3. V t

Fig. 6 is a detail vertical section showing a modified form of scraper.

In general, the apparatus comprises the disintegrating mill A- in which are the rotary dis integrating elements B and C which aresupported and rotated by the assembly indicated at D positioned outside of the mill casing at oneend 40 thereof. The mill also includes the scraper E rotated by the gearing assembly indicated atF. The wet material is. delivered by feeder'G, and the hot gases through conduit H, into the drying tower'J, the materials being delivered by feeder 45 K from the lower end of the tower into the cen prises a substantially horizontal hollow shaft 4 which is rotatably supported in

bearings

5 and 6 carried by the supporting structure 1. An inner shaft 8 is rotatable in bearings 9 and Ill within the hollow shaft 4. A head keyed on the inner end of the hollow shaft 4 projects through the end wall 2 of the casing which is bowed inwardly, as indicated at I2, so as to make a close fit about the head and substantially close this wall of the mill casing. The disintegrating structure or cage indicated as an entirety at B comprises the supporting plate or disc l3 secured to head II at M, the plate l3 extending radially from the head and substantially parallel to the adjacent end wall 2 of the casing. An outer circular series of spaced apart breaker bars l5 are each secured at one end in the disc I 3, the bars preferably extending horizontally substantially parallel tothe peripheral wall 3 of the casing. These bars are here shown as of circular cross-section, although they might be given a different cross-sectional configuration if desired. The opposite ends of the several breaker bars l5 of this circular series are connected by a ring |6. A second circular series of breaker bars are also mounted at one end in disc I 3 and connected at the other end by a ring I8. The bars may be in all respects the same as the bars l5, but the circular series is of lesser diameter.

A head I9 is keyed at 29 on the reduced inner end portion of the inner shaft 8, and the supporting plate or disc 2| of the second cage or disintegrating structure C is carried by head IS. The cage C comprises two circular series of breaker bars 22 and 23 which may be similar in all respects to the breaker bars l5 and I1 except for the fact that the circular series are of different diameters. The inner circular series 22 is secured at one end in disc 2 the opposite ends of tially in vertical alignment with the ring l6 of cage B. The circular series of breaker bars 23 is mounted at one end in disc 24, the opposite ends of the several bars 23 being connected by a ring 25.

It will be noted that the space within the cages is substantially closed at one end by disc I3 and at the other end by the disc 24 and ring l6 so that material delivered centrally within the cages must pass radially outward between the several breaker bars before it reaches the peripheral wall 3 of the casing. Preferably the several inner edges of the discs and rings are beveled inwardly, as indicated at 26, so as to tend to direct the material toward the center of the mill (that is away from the side walls I and 2), thus preventing clogging of the cage structures and tending to prevent an accumulation of material on the side walls of the casing and the scraper mechanism hereinafter described.

A bevel gear 21 is secured on the outer end portion of hollow shaft 4, and a similar bevel gear 28 is secured on the outer end of shaft 8, these two gears meshing with an intermediate beveled pinion 29 keyed on drive shaft 30 mounted in roller bearings 3| and 32. The shaft 30, driven in any suitable manner, will rotate the shafts 4 and 8 in opposite directions, thus causing the two cage structures B and C to rotate in 'opposite directions within the mill casing. It will now be noted that each circular series of breaker bars rotates in a direction opposed to the direcis to be understood that each cage may be provided with one or a plurality of series of these bars, as may be found necessary.

In the example here shown, the bevel gears 21 and 28 are enclosed in a housing 33 which holds a bath of oil 34 which may be put in through the filling opening 35. tions of the

gears

21 and 26 rotate in this oil bath, and since the gears are rotating in opposite directions, one of them will throw up oil into the trough 36 and the other one into the trough 31, these troughs being positioned at opposite sides of the upper portion of the casing. Oil drains from trough 36 through conduit 38 into the h0us ing 39 so as to oil the marings 3| and 32. Oil drains from trough 31 through pipe 49 and passage 4| formed in shaft 8, and thence into the space 42 between shaft 8 and the hollow shaft thence back into the oil well 43 and through pipe 44 into the oil well 45, so as to lubricate the

bearings

5 and 6. Suitable oiling rings 46 are provided for this purpose. The excess oil eventually drains back into the bath 34 which is cooled by means of the submerged coil 41 through which cold water is forced through pipe 48.

The scraper E is for the purpose of. dislodging the dried and partially dried material which is thrown out against the peripheral wall 3 of the mill casing. In its simplest form, as shown at E in Fig. 6, this scraper may consist of one or more transverse scraper bars 49 supported by side struts 50 from the outermost cage structure B so-that the bar or bars 49 will rotate in close proximity to the inner surface of peripheral wall 3 of the easing. The cage structures rotate at a very high speed and it will ordinarily be preferable to rotate the scraper at a much slower speed, and for this reason the form of scraper indicated at E in Figs. 1, 2, 3 and 4 is preferred.

This scraper assembly E comprises a pair of similar side supporting plates 5| and 52 in the form of annular discs which are rotatably mounted on the two series of rollers or

bearings

53 and 54 supported by the casing side walls I and 2, respectively. Each scraper element (of a which four are used in the example here shown) consists of a transverse scraper bar 55 adapted to rotate in proximity to the inner surface of wall 3, the bar 55 being supported by a pair a radial scraper bars 56 mounted on the discs 5| and 52, the bars 56 being adapted to scrape material from the side walls adjacent the outer corners of the mill. An annular driving rack is provided on the outer side of each disc 5| and 52, this rack consisting of a circular series of pins 51 supported between the

rings

58 and 59. The rack is made of this form so as to be self-cleaning, as will be hereinafter apparent. A pair of pinions 66 (see Fig. 4) mesh with the respective racks, the pinion teeth being of a form to punch out any material that may accumulate between the pins forming the rack teeth. These pinions are mounted on a pair of stub shafts 6| extending through the The lower por-v the hollow shaft 4. By suitably adjusting the speed reducer, the scraper assembly can be driven atany desired speed, and either in the same or in the opposite direction from the adjacent disintegrating cage B. For example, the cage structures may be rotated at a speed of from 200 to 400 R. P. Mpwhereas the scraper may be only rotated at 1 or 2 revolutions per minute. It will be understood that these speeds are merely illustrative and that any desired speed may be used.

The hot gases from any suitable source are forced or drawn in through conduit H into the upper portion of drying tower J, from the lower portion of which they flow through the horizontal feeding tube Ill which extends through casing wall I into the central space within the cage structures B and C. The sludge or-other wet material is propelled into the upper end portion of drying tower J by means of the screw conveyor H mounted in conduit G. The sludge falls downwardly through the drying tower in contact with the heated gases and is partially dried before it is propelled into the mill by the screw conveyor K mounted in feeding tube or conduit It. The conveyor K may be driven in any suitable manner, for example, by the worm gearing indicated at 12. A conical deflecting shield 13 is mounted on the inner end of the conveyor shaft 74 so as to direct the gases and solid materials outwardly into the cage structures and protect the inner end of the rotary shaft H.

The solid and liquid materials fall or are drawn by the whirling air currents created by the centrifugal action of the rotating cages between the several series of rapidly rotating breaker bars so that the solid materials are disintegrated or finely divided and eventually thrown outwardly against the outer peripheral wall 3 of the casing. The hot gases are also drawn outwardly by the centrifugal action of the rotating cages so as to remain in intimate contact with the solid and liquid materials throughout the space within the casing. The water is vaporized and absorbed or carried in suspension by the heated gases. The disintegrated and dried solid materials are partially carried in suspension inThe heated gases and partially accumulate against the outer peripheral -wall' of the casing, from which they are removed by the scrapers and directed toward and through the outlet opening L in the lower portion of the mill casing. The dried solid materials and the vapor laden gases pass through outlet L into the discharge conduit 15. The screw conveyor M in this conduit serves to carry out that portion of the solid materials yvhich is not carried in suspension in the gases. The materials and gases may be discharged into any suitable form of separator, from which-the moisture laden gases may be vented to the atmosphere or passed through a condenser. and the solid and dried materials may be collected or burned or disposed of in any desired inanner.

A disintegrating apparatus of this type may be used for drying very wet materials, and quite highly-heated gases maybe used in order to expedite the drying process. The rotary elements within the mill are designed to prevent clogging by an accumulation of the wet or sticky materials, and the rotary scraper is adapted to prevent the accumulation of materials within the outer.

portion of the mill'casing, and to help discharge the dried materials from the mill. It will be noted that both the wet materials and the heated gases are delivered into the mill substantially in line with or adjacent the axis of rotation of the,

disintegrating structures so that all of these substances, both gaseous, liquid and solid, will be forced outwardly in intimate contact with one another toward the outer peripheral wall of the casing. During this outward passage the materials are violently churned and brought in intimate contact with one another by means of the oppositely rotating cage structures. As a result the solid materials are thoroughly broken up or disintegrated and the moisture content is flashed into steam or vapor by contact with the heated gases. considerable drop in temperature in these gases As a result there will be a but the gases will still remain at a sufliciently high temperature to carry out the water in vapor form.

It will also be apparent that this apparatus may be used for simply disintegrating or pulverizing substantially dry materials or materials of low moisture content, in which case it is not essential that the gas stream be highly heated.

I claim:

1. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet opening in one end wall of the casing adjacent the central longitudinal axis of the casing, means for projecting material and gases into the casing through this inlet, an outlet for the material and gases leading from the periph eral wall of the casing, a pair of disintegrating cage structures mounted in overlapping relation within the casing for rotation about the central axis, means for rotating the cages in opposed directions, a scraper mounted within the casing for rotation independently of the cage structures in proximity to the inner surface of the peripheral wall of the casing, andmeans for rotating the scraper about the central axis at a slower speed than that of the adjacent cage structure.

2. An apparatus of the character described comprising a substantially cylindrical closed cas ing, an inlet opening in one end wall of the easing adjacent the central longitudinal axis of the casing, means for projecting material and gases into the casing through this inlet, an outlet for the material and gases leading from the peripheral wall of the casing, a pair of disintegrating cage structures mounted within the casing for rotation about the central axis, each cage comprising a plurality of circular series of spaced apart breaker bars, each series being of a difierent diameter and a series of one cage being overlapping by a series of the other cage, means for the casing through this inlet, an outlet for the material and gases leading from the peripheral wall of the casing, a pair of disintegrating cage structures mounted within the casing for rotation about the central axis, each cage comprising a plurality of circular series of spaced apart breaker bars, each series being of a difierent diameter and a series of one cage being overlapped by a series of the other cage, a hollow shaft'journaled coaxially with the central axis in the end wall of the casing opposite the inlet opening, a second shaft journaled in the hollow shaft, one of the cages being carried by each shaft, means for rotating the shafts in opposite directions, a scraper mounted within the casing for rotation independently of the cage structures in proximity to the inner peripheral surface of the casing, and reduction gearing between the scraper and one of the shafts for rotating the scraper at a slower speed than the adjacent cage structure.

4. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet opening in one end wall of the casing adjacent the central longitudinal axis of the casing, means for projecting material and gases into the casing through this inlet, an outlet for the material and gases leading from the peripheral wall of the casing, disintegrating mechanism mounted for rotation within the casing about the central axis, a scraper mounted Within the casing for rotation in proximity to the inner surface of the peripheral wall, said scraper comprising a plurality of transverse scraper bars and annular discs positioned adjacent the end walls of the casing, bearings mounted on the end walls for rotatably supporting the annular plates, annular racks carried by the discs, stub-shafts mounted in the end walls of the casing, gears on the shafts meshing with the racks, and gearing mounted outside the casin for simultaneously rotating the stub-shafts.

5. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet opening in one end wall of the casing adjacent the central longitudinal axis of the casing, means for projecting material and gases into the casing through this inlet, an outlet for the dried material and gases leading from the peripheral wall of the casing, disintegrating mechanism mounted for rotation within the casing about the central axis, a scraper mounted within the casing for rotation in proximity to the inner surface of the peripheral wall, said scraper comprising a plurality of transverse scraper bars and annular discs positioned adjacent the end walls of the casing, bearings mounted on the end walls for rotatably supporting the annular plates, annular racks carried by the discs, stub-shafts mounted in the end walls of the casing, gears on the shafts meshing with the racks, means for rotating the disintegrating mechanism, and means including a speed-reducing mechanism for rotating the stub-shafts from the last-mentioned means.

6. In an apparatus of the character described comprising a substantially closed casing and oppositely moving disintegrating elements in the casing and adapted to project material against the wall of the casing, a scraper within the casing, and means for moving the scraper independently of the disintegrating elements in proximity to the casing wall to remove material therefrom.

7. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet in one end wall of the casing substantially in line with the central longitudinal axis of the casing, an outlet leading from the peripheral wall of the casing, disintegrating cage structures mounted within the casing for rotation about the central longitudinal axis, means for rotating the cage structures, a conduit for wet material and heated gases projecting into the casing through the inlet opening, a screw conveyor mounted within this conduit, means for rotating the conveyor, and a conical deflector mounted on the inner end of the screw conveyor.

8. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet in one end wall of the casing substantially in line with the central longitudinal axis of the casing, an outlet leading from the peripheral wall of the casing, disintegrating cage structures mounted within the casing for rotation about the central longitudinal axis, means journaled about the central axis and projecting through the wall of the casing opposite the inlet opening for supporting and rotating the cage structures, a drying tower, means for projecting wet material and heated gases into the upper portion of the tower, a conduit leading from the lower portion of the tower into the casing through the inlet opening, a screw conveyor in said conduit rotating about the central axis and projecting into the casing through the inlet opening, and means for rotating the conveyor.

9. An apparatus of the character described comprising a substantially cylindrical closed casing, an inlet in one end wall of the casing substantially in line. with the central longitudinal axis of the casing, an outlet leading from the peripheral wall of the casing, disintegrating cage structures mounted within the casing for rotation about the central longitudinal axis, means for rotating the cage structures, a drying tower, means for projecting wet material and heated gases into the upper portion of the tower, a conduit leading from the lower portion of the tower into the casing through the inlet opening, a screw conveyor in said conduit, means for rotating the conveyor, and a conical deflector on the inner end of the screw conveyor within the casing and cage structures for deflecting the material outwardly toward the rotating cage structures JOE CRI'I'ES.