US2808212A - Apparatus for comminuting exfoliated perlite - Google Patents

Description

Oct. 1, 1957 J. z. GOLDBERG 2,808,212

APPARATUS FOR COMMINUTING EXFOLIATED PERLITE Filed May 14, 1956 3 Sheets-Sheet 1 5s 54 0 s9 s7 F 2 2 L 5.9

.wcaa 2. 6040552 INVENTOR.

Oct. 1, 1957 J. z. GOLDBERG APPARATUS FOR COMMINUTING EXFOLIATED PERLITE Filed May 14, 1956 3 Sheets-Sheet 3 irraA /vfys United States Patent AFPARATUS FOR CGMMINUTING EXFOLIATED PERLITE Jacob Z. Goldberg, Los Angeles, Calif., assignor to International Minerals and Chemical Corporation, Chicago, 111., a corporation of New York Application May 14, 1956, Serial No. 584,675

14 Claims. (Cl. 241-39) This invention relates to comminuting apparatus and is particularly directed to improvements in devices for reducing the size of exfoliated perlite particles by causing them to travel at very high speeds and impinging them against stationary abutments. This invention relates to improvements over the apparatus disclosed in the copending application of Gindotf et al., Serial No. 410,065, filed February 15, 1954.

The exfoliation or popping of perlite is accomplished in a furnace and it is desirable to break up the exfoliated perlite particles immediately following the popping process, as pointed out in the Gindolf application. It is highly desirable to be able closely to regulate the speed at which the particles are carried through the comminuting apparatus in the blast of gases from the furnace, and to be able to make mechanical adjustments at various points along the path as required in order to control the speed and thereby produce the largest proportion of the desired product. It is desirable to have a relatively long zig-zag path which must be traversed, and to be able to recirculate through that path popped perlite material which is larger in size than desired in the final product. For example, in a specific case, exfoliated perlite particles varying in size from 40 microns to ,4 inch maximum dimension, may enter the input end of the comminuting apparatus while the size of the particles desired in the final product may vary from /2 to microns maximum dimension. In the particular case mentioned, the temperature of the particles striking the first transverse abutment or target may be about 1600 F., whereas the temperature of the particles leaving the outlet end of the comminuting apparatus may be about 800 F. In this example air may enter the lower end of the comminuting apparatus at a rate of about 4000 C. F. M. and leave the upper end at about one-half of that rate, due to cooling.

In order to provide maximum comminuting effect together with the feature of affording close control for speed of the particles in various portions of the apparatus along the path of flow, I provide concentric inner and outer members defining tortuous flow passages therebe tween. The surfaces of the passages are serrated to produce a maximum number of impingement abutments. In accordance with my invention, I form the restricted flow passages in a manner so that the cross sectional area thereof decreases in the direction of flow. Furthermore, I provide a series of expansion chambers between the re stricted passages in alternating sequence.

From this general description, it will be understood that the principal objects of my invention are to provide a new and improved apparatus for comminuting exfoliated perlite particles, to provide novel apparatus which enables the flow of particles to pass at high speed through restricted passageways provided with impingement abutments, such passageways alternating with expansion chambers to permit rearrangement of the particles within the gaseous stream which carries them. Other objects relate to the provision of a plurality of double-coned inner ele- 2,808,212 Patented on. 1, 1957 ments positioned end-to-end and encompassed by a series of telescopic outer elements, the outer elements being mounted for independent axial adjustment to vary the width of restricted flow passages defined between the inner and outer elements. Other and more detailed objects and advantages will appear hereinafter.

In the drawings: 7

Figure l is a side elevation showing a preferred embodiment of my invention.

Figure 2 is a top plan view taken substantially on lines 2-2 as shown in Figure 1.

Figure 3 is a sectional elevation taken substantially on the lines 33 as shown in Figure 2.

Figure 4 is an enlarged sectional view taken substantially on the lines 4-4 as shown in Figure 2.

Figure 5 is a sectional view taken substantially on the lines 5-5 as shown in Figure 4.

Figure 6 is a sectional plan view taken substantially on the lines 6-6 as shown in Figure 4.

Figure 7 is a sectional plan view taken substantially on the lines 7-7 as shown in Figure 1.

Figure 8 is a fragmentary detail showing a preferred form of serrations which provide the impingement abutments for the perlite particles passing through the apparatus.

Referring to the drawings, a supporting frame 10 carries a depending housing 11 which encloses an inner member 12 and an outer member 13. The inner member 12 preferably comprises a plurality of duplicate doubleconed elements 14 mounted end-to-end on a central tube 15. Each of the elements 14 is provided with an upwardly converging frustro-conical section 16 and a downwardly converging frustro-conical section 17, the sections being integrally joined at their large ends 18. The small ends of each element 14 are provided with central openings 19 to receive the central tube 15.

The outer member 13 includes a plurality of duplicate shell elements 20, each having an upwardly converging frustro-conical section 21. Each section 21 cooperates with an adjoining section 16 on one of the inner elements 14 to define a restricted passage 22 between the inner and outer elements. Each restricted passage 22 is annular and converges upwardly. The surfaces of the elements 14 and 21 which define this restricted passage are serrated or otherwise provided with a series of projections 23 having impingement shoulders or abutments 24, as best shown in Figure 8.

The shell elements 20 may each be constructed in segments, if desired for ease of manufacture. In operation, however, each element 20 functions as a single integral unit.

The lower frustro-conical section 17 of each inner element 14 as well as the cylindrical portion 25 of each shell element 20 is serrated in the same manner. The upper flaring end 26 of each shell element 20 may be provided with the same type of abutment surfaces. To avoid contamination of the product, the material from which the elements 14 and 20 are constructed should not be subject to scaling at operating temperatures. I have found that nickel cast iron gives satisfactory results.

The upper end of each of the shell elements 20 is provided with a cylindrical periphery 27 Which is telescopically received Within alignment ribs 20 provided on the lower portion of the next adjacent shell element 20. As shown in Figure 6, these ribs 28 serve to maintain the telescoping end of the adjacent element 20 in concentric position.

Each of the shell elements 20 is supported for independent axial adjustment. As shown in the drawings, rods 29 are shouldered at their lower ends 30 to support the flange ring 31 on the lowermost shell element 20. These rods 29 extend loosely through openings provided in each of the other flange rings 31 on other shell elements 20. The upper ends of the rods 29 extend loosely through bushings 32 which rest on the supporting spider 33. These bushings 32 are in turn loosely received in openings 34 in the stationary support member 16. Nuts 35 on the rods 29 permit upward or downward adjustment. of the axial position of the rods 29', thereby aifording a means of adjusting the axial position of the lowermost shell element 26;

In a similar manner, rods 36, 37 and 33 support each of the other shell elements 20 for independent axial adjustment. All of the rods are supported on the spider 33 in the same manner. The spider 33 is suspended from the stationary supporting frame by means of the bolts 39 and nuts 48. The spider is, provided with a plurality of depending fingers 4]; which have guide surfaces 42 receiving the upper end of the topmost shell element 20 in sliding relationship. From this description it will be understood that the outer member comprising all of the shell elements 20' may be amally adjusted as a unit by turning the nuts 40 with rmpect' to the bolts 39. Independent adjustment of any one of the shell elements 29 is accomplished by turningof the nuts on the supporting rods 29, 36, 37 or 38. While I have shown four supporting rods for each of the shell elements 20, it will be understood that a greater or lesser number may be employed if desired.

Expansion chambers 43 are defined at the opposite ends of the restricted passages 22. These expansion chambers 43 are bounded on the inner periphery by the downwardly converging frustro-conical section 17 and the encompassing cylindrical section 25 on the outer elements 20. The cross sectional area of the expansion chambers 43 is substantially greater than the cross sectional area at any point in the restricted passages 22.

A delivery tube 45 extends from the upper end of the furnace 46 into the lower end of the housing 11 and this tube has a flaring section 47 which communicates with the lowermost expansion chamber 43a. The lower surface 48 on the lowermost inner element 14 and the end surface 49 on the plug 59 constitute the target on which the exfoliated perlite particles initially impinge as they pass upwardly through the tube 45. The particles are then carried into the first expansion chamber 43a and then into the restricted passages 22 and expansion chambers 43 in alternating sequence. The furnace 46 is preferably of the type disclosed in the-Gindofi et al. application referred to above but it is to be understood that any other suitable or desirable type of furnace may be employed if desired. Similarly, the separator 51 and the recycle pipe 52 correspond in operation andconstruction to that described in said Gindoif et al. application. Inlet connection 53 which communicates with the recycle pipe 52 is mounted tangentially to the housing 11 as best shown in Figure 7. Suitable spiral vanes 54 are provided for causing the flow of recycle particles to enter the lowermost expansion chamber 43a tangentially in a swirling motion to secure maximum turbulence and to eifect intimate mixing with the Particles entering the same expansion chamber from the furnace tube 45.

The stream of gaseous material carrying the perlite particles passes upwardly through the apparatus and through openings 55 provided in the spider 33. Material then passes upwardly into the cap 56 through opening 56a and is directed through outlet pipe 57 into the separator 51. The particles which have been reduced to the proper size pass, by suction through delivery pipe 58 and the remainder is recirculated through pipe 52. Supplementary air may be introduced through the port 59, and valve 5% in the cap 56.

Since each of the restricted passages 22 converges in the direction of flow, the velocity increases as the gases and perlite particles move upwardly within each restricted passage. This increasing velocity characteristic in each of the flow passages 22 is diminished to some extent by cooling of the material with consequent reduction in volume. However, the velocity is suificiently great to produce etfective comminuting action by impingement of the particles on the serrated surfaces defining the restricted passages.

Any one of the restricted passages 22 may be widened or narrowed by corresponding axial movement of the enclosing shell element 20. Such adjustments efiectively increase or decrease the velocity of material passing through any one of the restricted passages and this feature is important on controlling the size of the particles desired in the finished product. The perlite particles carried by the stream of gases are reoriented and regrouped in each of the expansion chambers 43 so that maximum comminuting efiect is achieved in each of the following restricted passages 22.

The plug 50 rests on a tapered seat 60 on the lowermost inner element 14. Should an explosion occur in the furnace 46 or in the tube 45, the excessive pressures act to unseat the plug 50 and move it into the central cavity 61. These pressures are then vented through the interior of the tube 15, lifting the upper plug 61 from its seat 62' and escaping into the cap 56. A rod 63 fixed to the upper plug 61 may be used to raise both plugs from their respective seats, if this should be required for any reason and to assist in resenting them. The plugs are connected by the chain 64.

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim:

1. Apparatus. for comminuting exfoliated perlite particles, or the like, comprising in combination: an inner member, an outer member encompassing the inner member, the inner member having a series of axially spaced upwardly converging frustro-conical portions, said portions each cooperating with one of a series of similar frustro-conical portions on the outer member to define a series of restricted passages, said frustro-conical portions having serrations on the surfaces thereof defining the boundaries of said restricted passages, said inner and outer members cooperating to define annular expansion cham bers at each end of the restricted passages, so that the expansion chambers and restricted passages are provided in alternating sequence, and means for delivering a flow of material to be comminuted into the lowermost expansion chamber.

2. In a comminuting apparatus, a combination of: an inner member, an outer member encompassing the inner member and comprising a series of substantially duplicate outer elements, the inner member having a series of axially spaced upwardly converging frustro-conical portions, each said portion cooperating with a similar frustroconical portion provided on an adjacent outer element to define a restricted passage, said frustro-conical portions having serrations on the surfaces thereof defining the boundaries of said restricted passage, said inner and outer members cooperating to define annular expansion chambers at each end of the restricted passages, so that the expansion chambers and restricted passages are provided in alternating sequence, and means for delivering a flow of material to be comminuted into the lowermost expansion chamber.

, 3.. The combination of claim 2 in which means are provided for effecting relative. axial movement of the outer elements to vary the width: of the restricted passages.

4. Commi-nuting apparatus for use in conjunction with a furnace for causing exfoliation of perlite particles or the like, comprising in combination: an inner member, each having a series of axially spaced upwardly converging frustro-conical portions, an outer member encompassing the inner member and comprising a series of substantially duplicate outer elements, each outer element having anupwardly converging frustro-conical portion defining a restricted passage with an upwardly 0on- 2,sos,212

verging portion on the inner member, the opposing surfaces defining said passages being serrated, the upper end of each of said outer elements extending telescopically into the lower end of the next adjacent outer element, means for effecting relative axial movement of said outer elements to vary the width of said restricted passages, and means for causing heated particles from the furnace to pass through said restricted passages.

5. comminuting apparatus for use in conjunction with a furnace for causing exfoliation of perlite particles or the like, comprising in combination: an inner member comprising a plurality of substantially duplicate inner elements, each inner element having a downwardly converging frustro-conical portion joined at its large end with an upwardly converging frustro-conical portion, said elements being mounted end-to-end with the upper end of one adjacent the lower end of another, an outer member encompassing the inner member and comprising a series of substantially duplicate outer elements, each outer element having an upwardly converging frustro-conical portion defining a restricted passage with an upwardly converging portion on an adjacent inner element, the opposing surfaces of the inner and outer elements being serrated, the upper end of each of said outer elements extending telescopically into the lower end of the next adjacent outer element, and means for effecting relative axial movement of said outer elements to vary the width of said restricted passages, and means for causing heated particles from the furnace to pass through said restricted passages.

6. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: a central stationary column, a series of telescoping shells encompassing the column, the column having a series of axially spaced upwardly converging frustro-conical portions, said portions each cooperating with a similar frustro-conical portion on one of the shells to define a series of restricted passages, said frustro-conical portions having serrations on the surfaces thereof defining the boundaries of said restricted passages, said column and shells cooperating to define annular expansion chambers at each end of the restricted passages, so that the expansion chambers and restricted passages are provided in alternating sequence, and means for delivering a flow of material to be comminuted into the lowermost expansion chamber.

7. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: an inner member, an outer member encompassing the inner member, the members cooperating to define a series of spaced restricted passages through which said particles may flow serially, the restricted passages being defined by walls having impingement abutments for contact with said particles, each of the restricted passages being shaped to increase the linear speed of particles passing therethrough, and means forming an expansion chamber between each pair of adjacent passages shaped to reduce the linear speed of said particles.

8. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: an inner member, an outer member encompassing the inner member, the members cooperating to define a series of separate restricted passages through which said particles may flow serially, the restricted passages being defined by walls having impingement abutments for contact with said particles, each of the restricted passages being continuous circumferentially and converging in the direction of flow, the outlet end of each restricted passage being of smaller dimensions than the corresponding dimensions of the inlet end of the next restricted passage downstream in the series.

9. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: an inner member, a concentric outer member encompassing the inner member, the members cooperating to define a series of axially spaced restricted passages through which said particles may flow serially, the restricted passages being defined by frustro-conical walls having impingement abutments for contact with said particles, each of the restricted passages being annular in cross section and converging in the direction of flow, the outlet end of each restricted passage being of smaller dimensions than the corresponding dimensions of the inlet end of the next restricted passage downstream in the series.

10. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: an upright inner member, an upright outer member encompassing the inner member, the members cooperating to define a series of axially spaced restricted passages through which said particles may flow serially in an upward direction, the restricted passages being defined by upwardly converging frustro-conical walls having impingement abutments for contact with said particles, each of the restricted passages being annular in cross section and converging upwardly, the outlet end of each restricted passage being of smaller dimensions than the corresponding dimensions of the inlet end of the next adjacent restricted passage upward in the series.

11. Apparatus for comminuting exfoliated perlite particles, or the like, comprising in combination: an inner member, a concentric outer member encompassing the inner member, the members cooperating to define a series of axially spaced restricted passages through which said particles may flow serially, the restricted passages being defined by substantially identical pairs of walls having impingement abutments for contact with said particles, each of the restricted passages being annular in cross section and converging in the direction of flow, the walls also defining an expansion chamber between each adjacent pair of restricted passages.

12. In a comminuting apparatus, a combination of: an inner member comprising a vertical series of substantially duplicate inner elements, an outer member comprising a vertical series of substantially duplicate outer elements each having a support flange, each inner element having an upwardly converging frustro-conical portion cooperating with a similar frustro-conical portion on an adjacent outer element to define a restricted passage converging in the direction of flow, said frustroconical portions having impingement abutments on the surfaces thereof defining the boundaries of said restricted passage, said inner and outer elements cooperating to define annular expansion chambers in alternating sequence with said restricted passages, each outer element having a plurality of tension rods connected to its support flange, each tension rod passing loosely through the support flanges of outer elements higher in the series.

13. In a comminuting apparatus, a combination of: an inner member comprising a vertical series of substantially duplicate inner elements, an outer member comprising a vertical series of substantially duplicate telescoping outer elements each having a support flange, each inner element having an upwardly converging frustro-conical portion cooperating with a similar frustroconical portion on an adjacent outer element to define a restricted passage converging in the direction of flow, said frustro-conical portions having impingement abutments on the surfaces thereof defining the boundaries of said restricted passage, each outer element having a plurality of tension rods connected to its support flange, each tension rod passing loosely through the support flanges of outer elements higher in the series, and means at the upper ends of the tension rods for adjusting the axial position of the outer elements.

14. Comminuting apparatus for use in conjunction with a furnace for causing exfoliation of perlite particles or the like, the combination of: an inner member, an outer member encompassing the inner member, the members cooperating to define a series of separate restricted passages through which said particles may flow serially, the restricted passages being defined by walls having impinge- Z ment ahutments 01" contact with said particles, me'anssaid rgeycle means including" means fm introducing the forming'amannular chamher adjacefit the inlefend of-th6 particles tangentially into said'chamber to-pro'mnte turfirst restrictedpassage means"- fon'ihtroducing aflow: of bulence.- particles from the furnace substantially uniformly into said chamber meansfon recycling; a portion of the 5 N0 references Citedparticles leaving; the-last restricted passage in: the series;-v

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