US1846209A - Separator - Google Patents

Description

Feb. 23, 1932. E. KRAMER 1,846,209

SEPARATOR 7 Filed June 2, 1928 2 Sheets-Sheet 1 Filed June 2, 1928 2 Sheets-Sheet 2 ffa/ I Patented Feb. 23, 1932 UNITED STATES ERWIN KRAMER, OF BERLIN, GERMANY, ASSIGNOR TO HARTSTOFF-METALL AKTIEN- GESELLSCHAFT, (HAMETAG) OF BERLIN-COPENICK, GERMANY SEPABATOB Application filed June 2, 1928, Serial No. 282,332, and in Germany June 2, 1927.

My invention relates to a method of, and an apparatus for, operating mills in which the material ground in the mill proper is convefyed out of the same by a blast-and is then si ted in a preliminary separator or foresifter from which the not yet sufliciently grpund material is conveyed back into said mi 1.

WVith the old apparatus of this fineness of'the sifting in the fore separator or sifter is influenced greatly by the intensity of the blast used for conveying the ground material out of the mill. When the blast is throttled, the material conveyed out of said sifter is finer, and reversely.

My invention starts, in contradistinction to what has just been stated, from the idea to make the sifting of the material in the fore separator practically independent of the intensity of the blast coming from the mill, and to regulate it also independently, whereby the quality of. the product is improved and the entire procedure is rendered more economic. Every mill grinds most economically when the already sufliciently comminuted material is conveyed completely out of the mill immediately after the desired degree of fineness has been attained so that it does not remain in the mill and constitutes therein an undesired ballast which, besides, has a detrimental effeet upon the comminution of the other particles of the material. On the other side however, it is also known that when the mill is blown out a considerable portion of the material which has not yet been reduced to the desired fineness is also conveyed out of the mill. The more intense the blast is, the larger is the amount of material conveyed unintentionally out of the mill, and the more type the diflicult is it to separate it from the other par:

ticles in the fore separator. Furthermore,

however, in the old apparatus referred to, the degree of fineness of the powder leaving the fore-separator is diminished when the blast is intensified, and the necessity has, therefore, arisen to adjust'the blast in such a manner that the fore separator separates the material just at that point of time when its fineness is that desired. The drawback of this procedute is, however, that the complete removal of the sufficiently comminuted material is rendered questionable. Finally, the attempts to separate the fine particles and the coarse ones to a sufficient degree in the fore separator have not been successful, because, sufficiently comminuted material was conveyed back from the fore separator into the mill.

Now, the present invention enables sufl'iciently comminuted material to be conveyed out of the mill practically completely without any detrimental det-ainmenh thereof in the mill, and to improve materially at the same time the separation of the coarse particles from the fine ones within the fore separator. These effects are attained by regulating the blast used for the sifting in the fore separator independently of the intensity of the blast used for conveying the material out of the mill. This blast can, in this way, be kept at such a degree of intensity that the sufliiciently comminuted material is conveyed out of the mill within practical limits instantly after the comminution has been effected, whereas from out of the fore separator onlythose particles I I are conveyed which have attained the desired degree of fineness.

Another useful effect is this that the separation of the fine particles from the coarse ones can be carried out far more perfectly in the fore separator. The too long detainment of the sufficiently comminuted material in the mill whereby with many kinds of material the form of thegrain is affected in an undesired way, or the properties of the grains are changed by heat, is considerably shortened. 35 Finally, a comminution beyond the desired degree or fineness is prevented.

The invention is particularly im ortant in connection with mills in which the eed opening and the.discharge opening cannot have any desired size. -In such mil-ls the sifting in the mill by means of the'conveying blast can be dispensed with withoutimpairing the finenessof the material drawn from the fore separator.

My improved method can be carried out by means of such apparatus as are shown diagrammatically by way of example on the ac companying drawings, on which Figure 1 is a side-view, partly in section, of one embodiment, and Figure 2 a side-view, also partly viz. that on the left, at the upper end, the

in section of another embodiment. closure may be effected also atthe lower end In Fig. 1, 1 denotes the casing of the mill by appropriately otherwise-arranged flaps or proper, and 2 and 3 are passages in the top of the like. I prefer, however, the embodiment the same. The passage 2 communicates with shown in the drawings in that no particles 70 a blower 4 which in turn communicates with can collect on the thus arranged flaps.

a pipe 7 whereby the blower is connected with The intensity of the blast produced by the a cyclone 6. Also the passage 3 is connected blower 4 can be regulated or varied either by with said cyclone by a pipe 5. The cyclone is varying suitably the number of revolutions the above mentioned fore separator. In other of the blower, or by means of throttling flaps 7 words, the fore separator is designed as a (not shown) or by both means. This having cyclone. The blast passes through the above been eil'ccted, the intensity of the air currents mentioned parts of the apparatus in this dipassing through the channels of the casing 6 rection: 4, 2, 1. 3, 5, 6, 7 4. From the cover is determined by the flaps 24 and which plate 8 of the fore separator is suspended a can be closed or opened or partly opened just so casing 9 which is open at its bottom, and of as suited in the given case. The sitting oi rectangular transverse section. and connected the material or particles carried away out of at its top with a pipe 10. This pipe termithe mill is determined by the velocity of the nates in another cyclone 11, from the top of air current or currents flowing through the which extends a pipe 14 to another blower 12 casing 9, i. e. through the channel or channels connected by abranch13 with the lower part of the same, as the case may be; more proof the cyclone or fore separator 6. T he dicisely, the speed of the air when entering into rection of the blast produced by this blower said channel or channels is the decisive teais as follows: 12. 13, 6, 9, 10, 11, 14, 12. ture for the degree or fineness of the sitting.

The comminuted material contained in the If the speed of the air at that place or at those mill is conveyed out of this latter by the blast places is high, also coarser particles are carof the blower 4 throughthe passage 3 and the ried upward and through the casing 9, wherepipe 5 into the fore separator 6 in which it as otherwise only finer particles are conveyed falls into the hopper-shaped lower part of through it to the cyclone 11.

the same where the particles are encountered It appears from the above explanation of by the blast produced by the blower 12. e the arrangement and combination of parts already suiiicicntly comm nu ed material, i. that it is possible to adjust or determine the e. the sufficiently fine particles, are carried fineness f th ti l conveyed i t the away by the second blast up into the a ing tube 10 independently of the velocity of the 9 and through it and the pipe 10 into the conveying blast passing through the tube 5,

. shown. The hopper 19 may always contain a cyclone 11 in Which latt fi fine Particles and the particles conveyed to and into the of the material are separated from the blast cyclone 11 are th fi th m re. th fla 24 and collected in a vessel 15, whereas the blast d 25 are Open, d er ly, By pening passes back to the blower 12. or closing the flaps, or the corresponding That part of the materia which has not channels respectively, the sectional area of yet been suffi ien ly ('mmllhlhted therethe casing 9 is correspondingly altered, and

fore has not been carried upward by the blast it is lte ed just where the sifting chiefly of the blower 12into the casing9falls through t k s lac iz, in the sifting zone proper.

a rotary conveying feeding member 16 without acting thereby upon the amount of back into the mill casing 1 through a passag the material conveyed away from the mill.

h Casing f fi 531d member 16 The finer the particles are which are carried made l a branch 18 and a feed away. the larger is, therefore. the sectional hopper 19, and another rotary feed member area of the sifting zone, and the sifting can arranged between the parts 19 and as be carried out the more carefully and in a better manner.

In the simplified construction shown in Fig. 2 only one blower 12 connected at one The casm 9.. 1n the to of the fore sepa a arator 6) is subdivided intd three passages or i by a f' f 'i gf y fi channels by two vertical partition walls 21 and on e )y a f h no and 22, and above these channels are flaps 24 cyclone 11 j h of thesame des gn as in and 25 hinged to the oblique top plate 23 of The lsln'ovlded f two P the casing 6. In Fig. 1 the flap 24 is in its g f f, of Whlch estdbhshes a closed position, whereas the flap 25 is open. It mllnl atlon Wlth the feed hopper 19 and the is obvious that the blast can pass now only pipe 7 and 3* establishes a connection with 1 5 through two of the three channels, and it also the pipe 5, the upper end of which comthe flap 25 were closed, the blast could flow municates with the fore-separator 6. A only through one channel, viz. that on the chamber 28 provided in the casing enclosing righthand side of the casing 6. Instead of the fore-separator is connected with the closing the other channels, or one of them, cyclone 11' by the pipe 10. Theway of the 0 certain store of the material to be comminuted in the mill.

blast is, thus, as follows: 12, 7 2, 6, 28, 10-, 11, 14-, 12*.

The dimensions of the fore separator 6" are such that the entire amount of the comminuted material conveyed into it is separated from the blast and falls down upon the oblique bottom 36 of the separator, whereas the air passes through a channel 27 into the chamber 28 in which are provided a plurality of oblique, step-wise arranged plates 29, 30, 31, 32 lying between the bottom 36 of the fore-separator and the oblique bottom 33 of the chamber 28. At its lower end 37 this chamber communicates with a casing 38 made integral with the hopper casing and communicating also with the channel 2 of the mill casing 1. 16 and 20 are rotary feed members corresponding to the rotary feed members of Fig. 1.

The space between the bottoms 36 and 33 is subdivided into passages or channels by the plates 2932, and the lower three of the five passages or channels can be closed at will or as may be necessary by flaps 39, 40, 41 whereby it is rendered possible to vary the sectional area between the bottoms 36 and 33. The particles dribbling down from the bottom 36 to the lower portion of the plate 29 and further to the lower portions of the plate 30, 31 and 32 are subjected during this time to the action of the blast passing from the chamber 28 into the pipe 10, and those particles which the blast cannot carry away with it through the passages between the oblique plates fall down into the casing 38 from which they are conveyed back into the mill by means of the rotary feed member 16, whereas the other particles are conveyed into the cyclone 11 in which another separation takes place, aslhas alreTady beelrli described wit respec' 't to ig. 1. he finis ed roduct is czllected'in the vessel 15. p

In view of the size of the sectional areas as exlisting in the apparatus as actually built fer practical use the velocity of the blast passing through themill and the pipe 5 in order to convey the material into the foresd parator 6 is only immaterially varied by the opening or closing of one or more of the flaps 39, 40, 41. At any rate, opening a flap or the flaps means a diminution of the resistance which the passage presents the blast, that is .tosay, it means an increase of the speed of the air in the pipe in spite of the increase of the fineness of the sifting carried out at the same time.

There is in this embodiment presented a separate zone for the sitting operation in a still better way than in Fig. 1, this zone being located at those places where the material slides down from the bottom 36 to the plate 29, from this to the plate 30, and so on, and it is obvious that the advantages claimed with respect to Fig. 1 are attained with the modification illustrated in Fig. 2 in a still higher degree.

The separation of the particles from the blast in the chamber or fore separator 6 of Fig. 2 need by carried practically only so far that the blast passing from the fore separator into the chamber 28 does no longer contain coarser particles than are to be conveyed away through the pipe 10.

It is, of course, possible to choose another number of oblique plates, such as 29-32, and another number of This depends upon the degree of fineness aimed at.

I wish it to be understood that I do not limit myself to all details shown in the drawings. There may be departures in the details without a departure from the essence of the invention.

I claim:

1. A separator for comminuted material comprising a casing having an outlet opening in an upper portion thereon, a pair of pipes connected at spaced points with said casing and ada ted for connection at spaced flaps, such as 39-41.-

points, respectively, with a container for comminuted material, a blower for producing a circulation of air through said container and said pipes and said casing whereby comminuted material is adapted to be conveyed from the container to the casing by the air, means within said casing dividing the portion of the same adjacent to saidoutlet opening into a plurality of individual passa es leading to said outlet opening, and means or varying the effective cross sectional area of certain of said passages.

2. A separator for comminuted material comprising a casing having an outlet 0 wing in an upper portion thereon, a pair 0 pipes connected at spaced points with said casing and adapted for connection at spaced points, respectively, with a container for com minuted material, a blower for producing a circulation of air through said container and said pi es and said casin whereby comminute material is adapted to be conveyed from the container to the casing by the air, means within said casing dividing the portion of the same adjacent to said outlet opening into a plurality of individual passages leading to said outlet opening, and means for varying the effective cross sectional area of certain of said passages, the lower portion of said casing having an outlet opening adapted for connection with the container.

In testimony whereof I aflix my signature.

ERW'IN KRAMER.

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