US2727631A

US2727631A - Centrifugal drier

Info

Publication number: US2727631A
Application number: US313457A
Authority: US
Inventors: Robert L Pate
Original assignee: McNally Pittsburg Manufacturing Corp
Current assignee: McNally Pittsburg Manufacturing Corp
Priority date: 1952-10-07
Filing date: 1952-10-07
Publication date: 1955-12-20
Anticipated expiration: 1972-12-20

Description

Dec. 20, 1955 Filed Oct. '7, 1952 I xaziitzzzzzzexc s R. L. PATE CENTRIFUGAL DRIER 3 Sheets-Sheet l INVENTOR.

iobarz Z. Pate, B

Dec. 20, 1955 R. PATE CENTRIFUGAL DRIER 3 Sheets-Sheet 2 Filed Oct. 7, 1952 INVENTOR; Z2066)? Z. P4255, BY

Dec. 20, R L. FATE CENTRIFUGAL DRIER 3 Sheets-Sheet 3 Filed Oct. 7, 1952 INVENTOR. 2205615 Z. Paie,

United States Paten CENTRIFUGAL DRIER.

Robert L. Pate, Pittsburg, Kans., assignor to The McNally- Prttsburg Manufacturing Corp., Pittsburg, Kane, :1 corporation of Kansas The present invention relates to centrifugal driers, and more in particular to such driers adapted to treat fine comminuted material, such as fine coal and the like.

Among the objects of the present invention is to provide improved structure for a centrifugal drier which is simple in construction, yet highly efiicient in its operation and wherein those parts which are subjected to rapid wear may be readily and easily replaced, thus avoiding lengthy shut-down periods before the drier may again be put in operation.

Another object of. the present invention is to provide a novel centrifugal drier in which the rotating screen assembly is directly mounted upon and driven by the driving shaft of a motor.

Still another object of the present invention is to provide a centrifugal drier of the type immediately hereinabove described in which the motor and the screen assembly is entirely independent of the housingstructure and all of which parts are readily accessible for repair or replacement through an access opening in the housing structure.

A further desideratum of the present invention is to provide a novel centrifugal drier having a screen assembly directly mounted on the drive shaft of a motor and wherein the screen element is detachably secured in the assembly whereby the same may be readily and easily replaced when the same has become worn.

Still a further object of the present invention is to provide a novel centrifugal drier of the type hereinbefore described in which the mounting for the motor includes a housing completely enclosing the lower portion of the motor casing to prevent the treated material from entering said casing, the housing being in communication with the exterior of the drier by means of one or more ducts which serve to bring air into the interior of the motor casing to prevent overheating which would otherwise cause damage to the motor. More particularly the mounting for the motor is provided adjacent the top thereof with a deflector plate which directs the air passingthroughthe motor toward the screen assembly thereby assisting in speed the extracting process.

Still another object of the present invention is to provide a centrifugal drier as hereinbefore described in which the housing structure is provided with inner and outer walls defining a trough for the extracted liquid whereby the same may be discharged from the drier. More particularly the invention contemplates a trough which varies in depth from a minimum on one side of the discharge opening in the housing structure to a maximum on the other side thereof, thereby providing an abutment which facilitates removal of the liquid.

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2 wear inasmuch as the treated material is discharged against the material held by said rings.

Another object of the invention is to provide a novel screen structure for a centrifugal drier which comprises a series of spaced convolutions formed by helically winding a piece of wire, the said spacing and shape of the screen being maintained by reinforcing members secured in transverse relation to the convolutions. The invention contemplates such a screen wherein the diameter of the convolutions increases from one end of the screen to the other to form a conical shaped screen.

Other objects, features, capabilities and advantages are comprehended by the invention, as will later appear and as are inherently possessed thereby.

Referring to the drawings:

Figure l is a vertical cross-sectional view of a centrifugal drier embodying the novel features of the present A further object of the invention is to provide a housing structure as immediately above described wherein one or more rings are secured to the inner face of the inner wall which extend horizontally inwardly into the path of movement of the treated material as it is discharged from the screen, said rings collecting and holdingtreated material which protects the inner wall from excessive invention; v

Figure 2 is a top plan view of the drier shown in Figure l ofthe drawings;

Figure 3 is an enlarged cross-sectional view taken in the plane represented by line 3-3 of Figure 1 of the drawings;

Figure 4 is a. cross-sectional view taken in the plane represented by line 4-4 of Figure l of the drawings;

Figure 5 is a fragmentary view partly in cross-section and partly in plan, taken in the plane represented by the line S--5 of Figure l of the drawings;

Figure 6 is a view in cross-section taken in the plane represented by line 66 of Figure 1 of the drawings; and

Figure 7 is a partial view in cross-section similar to Figure l of the drawings, but disclosing a modified form of construction for the screen.

Referring now more in detail to the drawings, an embodiment selected to illustrate the present invention discloses a centrifugal drier adapted to dry comminuted material, such as fine coal on the order of /4" x O or smaller. The drier comprises a housing structure, generally referred to by the reference numeral 2, within which is mounted a power unit, such as an electrically driven motor 4 having a screen assembly, generally referred to by the reference numeral 6, directly mounted on the substantially vertically disposed shaft 8 of the motor 4, the said screen assembly being adapted to receive material for extracting the moisture therefrom upon rotation of the screen assembly by the motor 4. The housing structure 2 is provided with a top closure or cover 10, having a centrally disposed intake member 12 provided with an opening 14 whereby the moist comminuted material is introduced into the screen assembly; Associated with the intake member 12 is a distributor cone 16 connected to the intake member 12 by means of a plurality of radially extending webs 18 to provide an annular passage 20 leading to the screen assembly 6.

The screen assembly 6 is provided with an inner frame structure, generally referred to by the reference numeral 22, which includes a hub 24 fixed to the motor shaft 8 in any desired manner and disposed in abutting relation with the shoulder 26 thereon. Radiating from the hub 24 are a plurality of webs or bars 28 to which are connected bars or ribs 30 which extend downwardly and outwardly with respect to the motor shaft 8 and the members 28, and to the lower end of which are connected bottom frame elements 32. The frame structure 22 is further characterized by a top plate 34 and an outer conical shaped imperforate wall 36 secured to the ribs, previously identified, in any desired manner, such as by means of welding or the like. The screen assembly further includes a perforated screen member 38 supported in assembled relation to the frame structure 22 by an upper screen support 40 having a hub 42 fixed in any desired manner to the motor shaft 8. Mounted on the shaft 8 between the hub 24 of the inner frame structure and the hub 42 of the upper screen support is a distributor plate 46, the same being disposed in axial spaced relation to the intake passageway 20. The screen assembly is secured on the motor shaft 8 by a nut 44 threaded on the threadedend thereof and drawn into engagement with the hub 42 by any suitable tool.

The screen '38 is of conical formation and is disposed in substantially parallel relation to the inner wall 36, the said screen at its lower end abutting an annular ring member 48 secured adjacent the outer ends of the bottom frame elements 32 by means of a plurality of bolts 50 or the like. 38 is mounted upon an impact or wear plate 52 carried by the upper screen support 40.

The screen member 38 is secured adjacent the upper portion thereof to the upper screen support by means of an annular rod 54 extending around the screen member 38 in engagement therewith, said rod 54 being forced into engagement with the screen member by a plurality of wedge members 56 movably mounted for radial movement on the bolts 58 threaded in the upper screen support 40.

The screen is further removably secured adjacent the lower portion thereof by a similar annular rod 60 having a plurality of washers 62 secured thereto at suitable intervals, as by means of welding or the like, which washers are adapted to receive the upper ends of elongated rods 64 secured at their lower end to the ring 48 in any desired manner. The upper ends of these rods are threaded to receive nuts 66 adapted to receive a tool for forcing the rod 60 into tight engagement with the screen.

As will be apparent from the above description, comminuted wet material, such as fine coal or the like, is introduced through the opening 14 at which time it passes through openings between a plurality of ribs 68 extending outwardly, as shown in Figure 3 of the drawings, from the hub 42 to the outer wall 70 of the upper screen support 40. Such material then drops into contact with a distributor plate 46 which discharges the same rather evenly into the passageway between the screen 38 and the inner imperforate wall 36. It will be noted that the impact or wear plate 52 is located at the entrance to said passageway in order to protect the screen against wear at that point. Rotation of the screen assembly causes the comminuted material to pass downwardly through the passageway provided by the screen 38 and inner wall 36 at which time the moisture is extracted by centrifugal action and is discharged through the screen 38.

In order to assure holding a bed of comminuted material in the passageway between the screen 38 and the inner wall 36 in order to lessen the wear on the screen 38, a plurality of bed strips 72 are provided, which strips extend entirely around the inner surface of the screen 38 and are provided at spaced intervals, as disclosed. These strips are shown as being round, but for different comminuted materials and under varying operating conditions, it may be desirable to provide strips having different cross-sectional configurations and the same may be disposed horizontally as disclosed, or if conditions warrant, the same may be vertical or inclined to suit the particular conditions involved.

The housing structure 2 is suitably mounted in any desired manner upon a concrete floor or the like, as at 74, the said housing structure comprising an outer cylindrical wall 76 and an inner cylindrical wall 78 spaced therefrom to provide an annular trough 80 which is in communication with the chamber 82 exteriorly of the screen 38 to receive the liquid extracted from the material being treated. Such liquid in its passage to the trough 80 is guided by the deflector plate 84 secured to the annular ring 48 by the bolts 50, the same overhanging an inwardly extending flange 86 secured to the wall 78 and forming a part thereof. The trough 80 has a tangential outlet 88 for discharge of the liquid from the housing 2.

The upper marginal edge portion of the screen I terior of the housing structure 2.

This trough varies in depth from a minimum at 90 on one sideof the discharge outlet 88, to a maximum at the discharge as at 92, whereby an abrupt abutment 94 is provided to assure discharge of the liquid extracted from the material being treated. In the present embodiment this variation in depth is effected by using concrete having an upper surface which slopes downwardly from the point 90 to the point 2.

The motor 4 is mounted on a housing 96 which completely encloses the lower end of the motor casing and which protects the motor from the material being discharged from the screen assembly in its downward movement. This housing also provides a means whereby air may be circulated through the motor to prevent excessive heating, which would damage the same. As disclosed, a plurality of ducts 98 are provided which are connected to the housing 96 and the outer housing structure, and provide communication between the interior of the housing 96 and the exterior of the housing 2. As shown, these ducts extend radially across the passage-way 100 for the treated material and accordingly said ducts are formed with the wedge shaped upper wall structure 102 to prevent interference with the discharge of the treated material. The housing 96 for supporting the motor 4 is provided with an annularly arranged bafiie 97 extending outwardly and downwardly from the top part thereof which serves to deflect the air passing through the motor outwardly toward and through the material passing through the screen assembly 6, thus assisting in the drying operation.

The treated material passes downwardly through the chamber or passageway 100 and is discharged through a chute 104 to a collecting conveyor, bin, or any other device for collecting the treated material.

in order to prevent excessive wear on the inner wall 78, one or more rings 106 are secured to the inner face of the wall 78 and extend inwardly in a horizontal direction adjacent the discharge end of the screen 38 to collect and hold a certain amount of treated material so that the treated material being discharged contacts the treated material collected on such rings instead of the wall 78, thus greatly decreasing the wear which might otherwise take place on the wall 78.

For the purpose of inspecting the interior of the housing 2, and the discharge outlet 88,

removable covers

108 and 110, respectively, may be provided.

The upper bearing for the rotor may be lubricated through an axially arranged duct 112 in the motor shaft 8 which has a lubricating fitting 114 for introduction of a suitable lubricant, the line 116 being provided as a grease relief line for the upper bearing. Similarly, the lower bearing for the motor is lubricated through the line 118 having the lubricating fitting 120 accessible from the ex- In addition, the conduit 122 is connected to the motor housing and extends outwardly of the housing structure 2 for disposing of any excess lubricant in the lower part of the motor housing.

in order to allow air to enter the interior of the housing structure 2, one or more openings, such as 124 and 126, are provided in the housing structure 2.

As will be apparent from the drawings, the drier is constructed in such a manner as to provide for easy replacement of the screen 38 when it becomes necessary to do so. By simply removing the cover 10 from the housing structure 2 ready access is obtained to the screen assembly and by removal of the wedges 56 from engagement with the securing rod 54 and removal of the nuts 66, the screen may be lifted vertically and a new screen placed in position and secured in assembled relation as disclosed. Various other improved characteristics involving the ventilation of the motor and the various means provided for protecting wear at critical points assures longer life for the machine and infrequent repairs or replacements.

Figure 7 discloses a portion of a centrifugal drier conforming in all respects to the drier hereinabove described and like reference numerals have been applied to similar structure. This drier, however, discloses a modified form of screen which may be used in place of the perforated plate type screen 38 shown in Figure 1 of the drawings. In this modification, the screen is formed into conical shape as in the previously described embodiment and is made by winding a piece of wire with the wire 128 spaced to any desired opening so that the liquid contained in the material being treated may pass through the screen with any desired amount of fine material. The convolutions of the wire forming the screen are tied together by a plurality of tie rods 130 welded thereto to stiffen and maintain the shape of the cone. This screen is mounted in exactly the same manner as screen 38 in the first described assembly, and may be assembled and disassembled in the same easy manner as the screen 38.

While I have herein described and upon the drawings shown illustrative embodiments of the invention, it is to be understood that the invention is not limited thereto, but may comprehend other constructions, arrangements of parts, details and features without departing from the spirit of the invention.

I claim:

1. A centrifugal drier for coal and the like comprising a motor having a drive shaft, means mounting said motor whereby said drive shaft is disposed substantially vertically with the shaft being located above the motor, a screen assembly mounted on said shaft for rotation therewith, an intake passageway at the top of said screen assembly for introduction of material thereto, said screen assembly including an inner frame assembly providing a generally conically shaped imperforate wall, an outer supporting ring secured to the base of said inner frame assembly, a generally comically shaped screen having its lower edge in abutting relation with said outer supporting ring and being disposed outwardly in spaced parallel re" lation to said imperforate wall, an upper screen support fixed to said motor drive shaft above the inner frame assembly, the upper portion of said screen being operatively mounted in association with said upper screen support, a ring member embracing the upper portion of said screen,

wedge means mounted at spaced intervals on said upper screen support and engaging said ring member for releasably securing the upper portion of said screen to said upper screen support, a second ring member embracing the lower portion of said screen, and means carried by said outer supporting ring for drawing said second ring member into tight engagement with said screen for releasably securing the lower portion of said screen in assembled relation with said inner frame assembly.

2. A centrifugal drier as defined by claim 1, additionally including a distributor plate carried by the motor drive shaft adjacent the top of the inner frame assembly and between the same and the upper screen support, and wherein said upper screen support provides a wear plate disposed within the screen and in spaced peripheral relation with respect to the distributor plate.

3. A centrifugal drier as defined by claim 1, wherein said screen comprises a series of spaced convolutions formed by helically winding 21 single length of wire, and additionally including reinforcing members secured in transverse relation to said convoluted portions of said wire to maintain the desired spacing therebetween and the shape of said screen.

References Cited in the file of this patent UNITED STATES PATENTS 355,138 Cairns Dec. 28, 1886 614,764 De V. Robbe Nov. 22, 1898 1,136,988 Wendell Apr. 27, 1915 1,334,023 Elmore Mar. 16, 1920 1,342,743 Elmore June 8, 1920 1,609,933 Elmore et al. Dec. 7, 1926 1,644,121 Greene Oct. 4, 1927 1,782,264 Green Nov. 18, 1930 2,321,207 Howe June 8, 1943 2,489,292 Hobbs Nov. 29, 1949 2,516,963 Derbenwick et al. Aug. 1, 1950 FOREIGN PATENTS 45,649 Sweden Feb. 22, 1917