US2781128A - Magnetic separators for ducts - Google Patents

Description

Feb. 12, 1957 D. E. STEM MAGNETIC SEPARATORS FOR DUCTS 5 SheetsSheet 1 Filed Sept. 13, 1954 INVENTOR. Dan 4w 5. 5 2 4 Feb. 12, 1957 D. E. STEM MAGNETIC SEPARATORS FOR DUCTS 3 Sheets-Sheet 2 Filed Sept. 13, 1954 INVENTOR. fiat 40.0 E 57 1 4 Feb. 12, 1957 D. E. STEM MAGNETIC SEPARATORS FOR DUCTS 3 Sheets-Sheet 3 Filed Sept. 13, 1954 INVENTOR. flan 441) E, 575

MAGNETIC SEIARATORS FOR DUCTS Donald E. Stem, Santa Rosa, Calif.

Application September 13, 1954, Serial No. 455,421 8 Claims. (Cl. 209-423 This invention relates to magnetic separators and particularly to ducts with magnetic separators.

This application is a continuation in part of my pending U. S. application, Serial No. 53,926, now Patent No. 2,699,871, filed October 11, 1948, for Magnetic Separator.

The primary object of this invention is to provide in connection with ducts for handling loose material like hay, and the like at comparatively higher rate of speed, a device to efficiently trap magnetic particles from the material traveling through the duct; the features of the present magnetic duct and particularly the magnet which render it more efiicient and prevent re-entry of magnetic particles into the material blown through the duct, include the following features: the opposite magnetic plates are each made in two magnetic sections separated by a non-magnetic strip and are highly polished and each magnet forms a north and south pole on the magnetic plate with the same polarity of the adjacent plates being nearer together so as to repel particles around and into the groove formed behind the free edge of each plate; the magnetic plate fits closely to the opposite sides of the duct and so that the plates are movable along the sides when swung open and closed but leave a minimum open slit or margin; a casting is formed for the complete inclosure of the magnet on the door thereby to prevent any magnetic particles to adhere to the magnet directly; the provision of completely enclosed magnet on the door of the duct; and in gravity operation the selective control of the flow of material to permit cleaning of a magnet without interrupting the duct operation.

I am aware that some changes may be made in the general arrangements and combinations of the several devices and parts, as well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the following specification, and as defined in the following claims; hence, I do not limit my invention to the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings.

With the foregoing and other objects in view, which will be made manifest in the following detailed description, reference is had to the accompanying drawings for the illustrative embodiment of the invention, wherein:

Fig. 1 is a perspective view of my duct with the door closed.

Fig. 2 is a perspective view of my duct with both doors open.

Fig. 3 is a side view of the duct with the casing being broken away to show the position of the doors.

Fig. 4 is a perspective view of the enclosed door structure.

Fig. 5 is a cross-sectional view of the closed door structure with the magnet therein.

Fig. 6 is a fragmental edge view of the inside of the door.

2,781,128 Patented Feb. 12-, 1957 Fig. 7 is a front view of the duct with a modified baflle arrangement.

Fig. 8 is a side View of said modified arrangement; and

Fig. 9 is a sectional, fragmental view of a bafiie in the duct.

In the illustrative embodiment I provide a duct 1 which has an inlet 2 at the bottom and an outlet 3 at its top in axial alignment. The inlet 2 and outlet 3 have suitable flanges thereon so as to form restricted passages at each end of the duct.

On opposite walls 6 and 7 of the duct are provided door structures 8 spaced from one another longitudinally with respect to the duct 1. Each door structure 8 is hinged at its lower edge by hinge structure 9 so that the door can swing outwardly or toward the inlet 2.

One of the novel features of the structure is the arrangement of the door 8. Each door structure 8 includes a door plate 11 and a handle 12 on the outside face of it for easier handling, and a latch device 13 on the side of the duct 1 adjacent to the upper edge 14 of the door plate 11 for latching the door in closed position.

The opening 16 on the respective sides of the duct is somewhat smaller than the outside contour of the door plate 11 so as to be completely covered thereby.

From the inner face of each door plate 11 extends in wardly at right angles a wall 17 to form the top of a compartment. Vertical side walls 18 of generally triangular shape form the sides of the compartment within "ice which a permanent magnet 19 is concealed in the mannershown in Fig. 5. A pocket '21 is formed in the door plate 11 for the purpose of accommodating one portion of the horseshoe exterior of the permanent magnet 19.

The open side formed between the inner edges of the walls 17 and 18 is covered by a magnetic plate 22. Each magnetic plate 22 fits very closely the width of the duct so as to reduce side clearance to a minimum.

This magnetic plate 22 is made of two magnetic strips 23 and 24 connected by a non-magnetic strip or gap 26 so as to form an integral plate of a smooth surface which on account of the connection to the opposite poles of the magnet 19 have opposite polarity. in the herein arrangement, the section 24 of the magnetic plate 22 nearer to the top of the lower door is of a north polarity while the other section 23 is sout polarity. The section 23 nearer to the hinge of the upper door is also of north polarity, while the outer or free end section 24 of the upper door is south polarity. The free edge of the upper segment 24 of each magnetic plate projects beyond the top wall 17 of the adjacent door and is rounded at its edge. A pocket or groove 27 is thus formed between the top plate 17 and the extension of the top section 24 of the magnetic plate within which the magnetic particles separated from the material are collected.

This arrangement is such that the free edge of the lower section of north polarity is closer to the north polarity portion of the upper magnetic plate, with the result that magnetic particles polarized on the upper.

section of the lower magnetic plate will be repelled by the lower portion of the upper magnetic plate so as to be returned into the pocket 27 and behind the free edge of the lower plate. 7

In the modified form shown in Figs. 7, 8 and 9 there is provided a so-called gravity type of duct where the material flows by gravity through the duct. form there can be provided an arrangement for so directing the flow of material as to permit the cleaning of the magnet without interrupting the operation of the duct. a

In such:

In this form the duct 31 has an intake 32 at its top and the outlet 33 at the bottom. Between the inlet and outlet are the magnetic traps or plates generally denoted by the numerals 34 and 35 which instructure are thesame as the magnetic traps heretoforej described in connection with the first form. These magnets in this instance are-inclined downwardly andinwardly oflthe trap named rtoward the outlet 33 thereof, The .polarity of the magnetic plates isarranged the same way espreviously so that the portions of the magnetic platesnearer to one another have the same'polarity so that the particles get into the magnetic field of'the subsequent mag net and they, are repelled by that field so as to-turn around 'the edge of the first magnetic plate and be trapped behind the same. In general it is to heuriderstood that the-magnetic particles which first hit: the portion of the magnet polarized south for instance, are themselves polarized south so that they are attracted toward the north side when they move over the same where ultimately they are repolarized again to north polarity so thatinstead of passing toward or into the magnetic field of the next magnet which is also north, they are repelled around and are trapped behind the free edge of the first plate. K

For directing the'flow of material through the duct, I provide baffles 36. One of thebafiles above the upper magnet 3 2- and the other baffie 36 is between the two magnets. While the bailies work in opposite directions, structurally and operationally they are the same, therefore the description of one will sufiice. Each baffie consists of a baflle plate 37 which closely fits across the entire Width of the duct arranged in an initial posi tion at right angles to the plane of the adjacent magnetic plate of the magnet. This bafile plate 37 is supported on a fulcrum or pivot shaft 38 at the lower end thereof. The shaft 38 is journalled in suitable journals on the respective opposite sides of the duct 31 and has on one end thereof a handle 39 for manipulating from the outside. The positions of the'bafiles'37' are defined by opposite abutments 41 and 42. The abutment 41 determines the position where free dropping or flow'of material is allowed against and unto the adjacent magnet. The abutment 42 determines the cleaning position of the baffle 37, where the bafiie 37 substantially covers the cross-sectional area above the magnetic plate of the upper magnet 34 and prevents the material from dropping on the magnet 34. Thus flow is limited to the half of the duct away from the magnet 34 and the magnet 34 may be swung open and cleared of trapped magnetic particles. These stops 41 and 42 are on the outside of the duct and generally adjacent to the respective handles 39 so that the handles 39 rest upon the respective stops in the respective positions.

In operation this duct is more efiicient and-superior to previous ducts in view of the novel features in connection with the totally enclosed door, with the very close vicinity of its edges to the side plate for movement in and out yet obstructing the passage practically completely, and the particular polarization of the magnetic plate. The above in combination with the suspending of the doors at the lower edges for easy swinging out of the duct passage for cleaning results in a superior separator for passages wherein the duct is interconnected. The baffle arrangement provides for superior gravity type operation.

I claim: 7 V 1. In a device 'for separating magnetic from nonmagnetic materials blown under pressure to -a duct, said duct having an opening on aside thereof between an inlet and an outlet of said duct, a door hinged on said side to cover. said opening and being swingable outwardly into open position, a closedframe on the'inside face of the door closed on its side and top so asto form an inclined plate support opening, a magnetic plate covering said opening, a magnet .enclosedin said frame and on said magnetic plate, the width of said magnetic plate being such that the side edges of said plate are in immediate proximity of the adjacent sides of the duct to.

obstruct flow past the side edges of said plate, said plate being held inclined so as to face the flow through said duct.

2. in a device for separating magnetic from nonmagnetic materials blown under pressure to a duct, said duct having an opening on aside thereof between an inlet and an outlet of said duct, a door hinged on said side to cover" said opening and being swingable outwardly into open position, a closed frame on the inside face of the door'closed on its side and top so as to form an inclined plate support opening, a magnetic plate covering said openings. magnet enclosed in said frame and on said magnetic plate, the width of said magnetic plate being such that the side edges of said plate are in immediate proximity of the adjacent sidesof the duct to 7 obstruct flow past the side edges of said plate, said plate being held inclined so as to face the flow through'said duct, said plate being extended beyond the top wall of said enclosure so asto form 'a troughbehind'the free edgerof the plate for collecting magnetic particles.

3. In a device for separating magnetic from nonmagnetic materials blown under pressure to a duct, said duct having an opening an a side thereof between an inlet and an outlet of 'saididuct, a door hinged on said side to cover said opening and being swingable outwardly into open position, a closed frame on the inside face of the door closed on its side and top so as to form an inclined plate support opening, a magnetic plate covering said opening, a magnet enclosed in said frame and on' said magnetic plate, the width of said magnetic plate being such that the side edges of said plate are in immediate proximity of the adjacent sides of the duct to obstruct flow past the side edges of said plate, said plate being held inclined so as to face the flow through said duct, said magnetic plate being made in two sections united together by a non-magnetic strip to form arcontinuous plate, and a permanent magnet inside of said enclosure on said plate so as to polarize the respective sections of said magnetic plate of opposite polarity.

4. In a device for separating magnetic from nonmagnetic materials blown under pressure to a duct, said duct having an opening on a side thereof between an inlet and an outlet of saidduct, a'door hinged on said side to cover said opening and being swingable outwardly into open position, a closed frame on the inside face of the door closed on its side and top so as to form an inclined 1 proximity ofthe adjacent sides of the duct to'obstruct flow past the. side edges of said'plate, said plate'being held inclined so as to face the flow through said duct, said magnetic plate being rnade in two sections united together by'a non-magnetic strip to form a continuous plate, and a permanent-magnet inside of said enclosure on said plate so as to polarize the respective sections of said magnetic plate of opposite polarity, said division being transverse with respect to said plate so that said'difierently polarized sections of said plate extend transversely across theportion of said duct. I p a 5. In a device for separating, magnetic from 11011: magnetic materials blown under pressure to a duct, said duct having an opening on a side thereof between an inlet and an outlet of said duct, a door hinged on said side to cover said opening and being swingable outwardly into open position, a closed frame on theinside face of the door closed on its side and top so as to'form an inclined plate support opening, a magnetic plate covering said opening, a magnet enclosed in said frame and on said magnetic plate, the width of said magnetic plate being such that the side edgesof said plate are'in immediate proximity of the adjacent sides of the duct-to obstruct flow past the side edges of said plate, said plate being held inclined so as to face the how through said duct, said magnetic plate icing made in two sections united together by a non-magnetic strip to form a con tinuous plate, and a permanent magnet inside of said enclosure on said plate so as to polarize the respective sections of said magnetic plate of opposite polarity, said division being transverse with respect to said plate so that said differently polarized sections of said plate extend transversely across the portion of said duct and a second door and magnetic plate in said duct spaced from the first one, the magnetic plate of the second unit being polarized in opposite order as regard the transverse sections of the plate as the first unit so as to repel magnetic particles polarized at the free edge of the first plate.

6. In a magnetic door for an opening on a side of a duct between an inlet and an outlet for the passage of said duct, comprising :a door fitting over the opening, a support frame projecting firom the door inwardly of the duct and closed all around so as to form a plate support inclined with respect to the plane of said door and with respect to the passage through said duct, the outline of said projection being smaller than the door opening, a magnetic plate covering said plate support, a magnet inclosed in said support frame and operatively related to said magnetic plate, the width of said magnetic plate being such that the side edges of said plate are in the proximity of the adjacent sides of the duct to obstruct flow past the side edges of said plate, and a free edge of said plate projecting beyond the top of said plate support so as to confine a trough behind the free edge of the plate for collecting magnetic particles swept to and around the free edge of said plate.

7. In a duct having an inlet and an outlet, a magnetic device including a magnetic plate inclined inwardly with respect to the adjacent side of the duct so as to partially obstruct the flow through the duct, means to support said magnetic device and said plate in said inclined position and for moving said device and plate out of said duct, a bathe between the inlet and said magnetic plate extending transversely of the duct and being inclined to partially obstruct the flow through said duct, and adjustable support means for said bafiie selectively to position said bafile so as to direct flow toward said plate or away from the location of said plate so as to permit removal of said plate without interruption of flow through the duct.

8. in a duct having an inlet and an outlet and a passage from said inlet to said outlet, spaced doors alternately on opposite sides of said passage, a magnetic device on each door, a magnetic plate of each device being inclined inwardly of said passage so as to partially obstruct the how through said passage, each magnetic device and plate being removable from said passage by said door; a bafile between the magnetic plate nearest to the inlet and said inlet, and another bafiie between the magnetic plates, each bafiie being inclined, projecting into the passage so as to partially obstruct flow, and means to adjust each baifie at will to direct flow toward the adjacent magnetic plate or to obstruct flow to said magnetic plate and thereby permit Withdrawal of such plate with its door from the duct passage during operation of said duct.

References Cited in the file of this patent UNITED STATES PATENTS 2,612,268 Merwin Sept. 30, 1952 FOREIGN PATENTS 433,458 Great Britain Aug. 9, 1935 643,237 France May 15, 1928

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