US1812799A - Means for the mechanical preparation of pulverized solid materials - Google Patents

Description

June 30, 1931. M. MADORE 1,812,799

MEANS FOR THE MECHANICAL PREPARATION OF PULVERIZED SOLID MATERIALS Filed July 1, 1950- 3 Sheets-Sheet 1 Fig-1 "June 30, 1931. M. MADoRE MEANS FOR THE MECHANICAL PREPARATION OF PULVERIZED SOLID MATERIALS Filed July 1, 19:50 a Sheets -Shet 2 June30,1931 MMA-DORE 1,812,799

MEANS FOR THE MECHANICAL PREPARATIONQEOF PULVERIZED somn MATERIALS 7 Filed July 1, 1930 3 Sheets-Sheet 3' I 25 FIB- I 26 V Emlyn/1'- faurl'cz 7a0ore 'W 7 WW, 95.

Patented June 30, 1931 Iran auras MAURICE MADORE, F ALFORT, FRANCE W8 FOR THE MECHANICAL PREPARATION OF PULV'ERIZED SOLID KATERIALS Application filed July 1, 1930, Serial No.

This invention relates to means for the mechanical preparation of pulverized solid materials, particularly fuels.

, In the following description it is assumed d that coal is the material to be pulverized.

. According to the invention there is provided for conveying'the coal through a drycircuit a conveying device such as an himedean screw, for example, which adat any instant to the drying circuit a constant quantity of coal and in the same time extracts from suchdrying circuit a. quantity of dry coal equal to the quantity of pulverized coal taken by the consuming apparatus; the coal dried in the drying circuit is transferred to a ulverizing circuit;

feed hopper or funnel urnishes to the conveying device a quantity of fresh coal equal to that extracted from the drying circuit.

The pulverizing circuit is branched from the drying circuit and receives at any instant from the drying circuit exactly the quantity of dry coal necessary to compensate for the quantity of pulverized fuel consumed. Instead of a single pulverizing circuit there may be provided several pulverizing circuits which may be operated in unison or separately, each circuit including a pulverizer.

in each of said pulverizing circuits beyond the pulverizer is intercalated a separating circuit comprising separating or classifying apparatus which rejects the insufficiently pu ver'ized fuel and delivers the fine coal to a storage circuit or storage receptacle until. a predetermined level is attained. When. this level is attained, the fine coal in excess is returned by a conveyor along with the rejected or insufiiciently pulverized fuel to the entrance to the pulverizing circuit or circuits which the fine coal in excess and the rejected coal enter in priority to the fresh fuel coming from the drying circuit.

From the store of ulverized fuel the fine fuel is drawn off to eed the consuming apparatus.

This invention obviates drawbacks associated with prior arrangements and ensures certainty of operation comparable with that of central pu verizing ap aratus which accoinulate a stock of pulverized coal in respect 465,175, and in Trance March 28, 1930.

that the feeding of each pulverizer is constant and regular and the pulverizer is always working under optimum conditions.

For the better understanding of the invention there are hereinafter described, by Way of example only, practical embodiments illustrated in the accompanying drawings in which Fig. 1 is a diagram representing the prin ciple on which the invention is based.

Fig. 2 is a side elevation partly in section showing the general arrangement of a machine assembly according to the invention.

Fig. 3 is a corresponding plan view.

Fig. 4. is an end view partly in section taken from the side of the pulverizing circuit.

Fig. 5 is a transverse section on the line V-V of Fig. 6 showing a modified construc tion of dryer.

Fi 6 is a horizontal section on the line VI I of Fig. 5.

Fig. .7 is a longitudinal elevation partly in section. Referring to Fig. 1, a denotes the drying circuit; 0 the funnel which feeds this circuit with fresh coal travelling in the direction of the arrow A; b a conveyor screw and d a coni duit leading to the pulverizing circuit 6. The pulverized coal in this circuit 6 is drawn by an air current into the separating circuit f where it is classified by the se arator g. The rejected coal, that is the insu ciently pulverized coal, passes by way of the branch conduit g to the conveyor screw it which returns it to the pulverizing circuit 6 which it enters in priority to the fresh coal coming from the drying circuit a through the conduit d.

The fine coal ready for use and leaving the separator 9 passes by way of the conduit 2' to the storage receptacle j incorporating certain devices hereinafter described whereby the fineness of the fuel in storage may be controlled.

From the storage receptacle the pulverized fuel passes to the consuming apparatus by way of the conduit k. As already indicated, when the fine fuel in the storage receptacle j reaches a predetermined level Z, the excess returns by the conduit m to the conveyor screw 72. and re-enters the pulverizing circuit e in 109 direction of the arrow A.

priority to the fresh coal passing through the continuously by the feed hopper (Figs. 3

and 1) to the conveyor screw 6 which forms an adjunct to the dryer a. The conveyor 6 conveys the fresh coal in the direction of the arrow B, introduces it at 3 into the dryer and extracts it at 4 (Fig. 3); and as the feed hopper always fills the screw, the latter introduces at 3 a mixture of fresh coal and of coal already in circuit, the total quantity being constant.-

When the dry coal extracted at 4 by the screw 6 arrives above the opening (1 which establishes communication between the conveyor screws 1) and h it descends by gravity in suflicient quantity to complete the filling of the screw it; it is this quantity of coal which is then replaced in the screw 6 by the hopper c. It will be seen that the quantity of fresh coal introduced at any instant into the circuit is exactly equal to the quantity entrained by the screw it. This screw it feeds the coal to the passage 5 where it passes by gravity to the pulverizer e after having traversed either an electromagnetic separator or a magnetic drum (not shown) which detains any iron particles that may have been accidentally mixed with the coal.

After pulverization the coal leaves the pulverizing circuit 0 by the ipe f (Fig. 4) being entrained by a current 0 air produced by the fan 6 which leads it to a separator g constituted by several series of perforated plates 7, 8, 9 and 10 encountered successively by the coal. The fine pieces of coal pass to the end plates 10 while the larger particles stopped y the plates 7 and 8 fall directly into the screw which returns them to the pulverib ing circuit 6. The finest particles accumulate in the lower part 7' of the separator which constitutes the storage receptacle.

The pivoted shutter 13 mounted in the separator G andadjustable by means ofthe lever 14 serves to direct the pulverized and separated coal either to the conveyor screw it or to the storage receptacle j and thus furnishes a means of controlling instantly the fineness of the coal admitted to the receptacle 3'. Thus, position required to collect the coal stop (1 b the lates 8, 9, the product is less fine tii n i the s utter is positioned to collect only the coal stopped by the plates 10.

The air which has entrained the coal in the separatin circuit escapes at 11 and may be returned b suitable piping to the air intake opening oi the pulverizer e so that the air circulates in a closed circuit. An opening 12 which affords communication between the if the shutter 13 is shifted to the th separator g and the dryer a permits of maintaining suction in the latter and thus avoid ing escape of pulverized coal.

A screw 15 which extends the entire breadth of the separator g and thehalves of which are provided with screw threads of opposite hand returns to the screw it the material rejected by the separator.

When the storage receptacle j is filled up to the level Z with pulverized coal of the desired fineness, the fine coal delivered in excess of this quantity is taken up automatically by the end of the screw h'which returns it to he entrance to the pulverizing circuit e.

It will be seen that this fine coal reaches the entrance to the pulverizing circuit along with the material rejected by the separator in advance of the fresh coal extracted by the screw 6 from the dryer on, the latter only completing the filling of the screw it by way of the opening at.

It Will also be seen that the material rejected by the separator does not return to the dryer and does not come in contact with moist coal entering by way of the hopper c.

The coal pulverized to the degree of fineness required for the consuming apparatus is extracted at the bottom of the storage receptacle j by the screws 7: which lead it to the conduit 16 for feeding the burner or burners.

The hot air employed for dryin r enters the dryer a by way of an opening 17 ig. 4) and leaves at the opposite end of the dryer by way of an o ening 18 and then traverses the dust-extracting box 19 (Fig. 3) which is situated above the screw 1) and which contains the perforated plates 20. These plates 20 stop the dust and deposit it on the screw 6.

The air then escapes at 21 (Fig. 3). The air outlet 21 ma be connected either to the intake side of the primary air fans which carry the ulverized coal to the burners or to the inta e side of a fan which expels it into the atmosphere.

The moving elements of the assembly are operated by an electrical motor 24, suitable provision being made for permitting the control of the speed of the moving elements. For example, the speed of rotation of the screw it may be controlled by the use of coned pulleys 22, 23. v

In the drawings there is shown only a single pulverizer, it being understood that posed si e by side and operating in branches om the same drying circuit; in this case there will be as many separators as pulverizers, certain of such pulverizers and separators only being in service and the others in reserve.

Figs. 5, 6 and 7 refer to a modification of the dryer adapted to effect crushing and preliminary separation. In these figures a denotesthe drying chamber'in which is mounted ere ma be provided two, three'or more dis a shaft 1 with paddles 2 adapted to rotate at sulficient speed to efl'ect preliminary crushing or breaking of the coal and to deliver the coal thus crushed to a grating 25 which ermits the passage only of pieces of coal the desired size and stops the pieces which have circuit a is fresh coal or coal which has alread assed through the drying circuit but whic as not yet been delivered to the pulverizing circuit material rejected by the separator 9 does not return to the dryer.

The material rejected by the separator and the fine coal which is not stored at j return to the pulverizing circuit e in advance of the fresh and dry coal which furnishes only the complement to the charge of the screw it of the pulverizer.

The quantity of fresh coal delivered is equal to the quantity of fine coal which is consumed or put in stora e.

The feeding of the pu verizer-isconstant and regular. 1

In the pulverizing circuit the supply of dry coal is equal to the quantity consumed o put. in storage.

, izer.

he installation may'operate continuously in a completely closed circuit, the coal circulating without accumulating at any point other than in the storage receptacle.

The dryer may operate continuously in a In the case where several pulverizing circuits are provided these are independent of one another.

The stocking of fine coal in the storage receptacle j allows the apparatus to take care of temporary overloads, avoiding abrupt operation of the pulverizer.

The separating circuit is independentof the fans which serve the burners.

It is possible to control the proportions of the mixture of combustion-supporting air a and coal as desired, unlike the usual case in which the fans which feed the burners suck directly from the separator.

The fineness of the coal remains uniform for any given position of the shutter 13 since the separating circuit is independent; the degree of fineness may be controlled instantaneously.

The gases traversing the dryer leave the dust entrained thereby in the screw b'of the dryer.

From thestock of pulverized coal in the storage receptacle jthe burners may be fed before the machine comes into operation by simply turning the screws of the distributors so that a sufficient pressure may be set up in the boiler to operate the installation.

This advantage is of importance particularly in. the caseof a ship which is in port as it is not necessary to maintain a boiler under steam by stoking.

With the reserve of fuel also large cylindrical marine boilers may be heated.

The reserve of fuel also ensures certainty of operation in case of momentary or partial stoppage, particularly when two pulverizing circuits are provided. 7

The machine assembly is compact, and of low height, these being features of importance on board ship.

It is to be observed that without departing.

from the scope of the invention modifications .may be made in the arrangement and that any suitable material may be used in the construction of parts; further, the forms represented may be varied so long as the conditions indicated are specified and the desired result obtained.

In particular, the relative position'of the several members and devices may be modified provided that: the general arrangement answers to the diagram shown in Fig. 1. Also there may be utilized a combination of a number of these circuits and. parts, or any of these circuits and parts may be replaced by equivalents.

The driving motors, transmitting devices and the mechanism for controlling the speed of the several parts may be of any suitable type. The screw conveyors may be replaced for example by chain conveyors.

What I claim is 1. Means for the mechanical preparation of pulverized solid materials, comprising, in

combination, a drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the line material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer coarse pulverized material rejected by said separator and also fine material conveyed to said storage device in excess of that required to maintain said given level in said storage device.

2. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a' pulverizer receiving dried solid material from said drying device a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pul- VQIIZEI to said separator, a storage device for the fine material passing said separator,

said storage device being adapted to be filled to a given level, means for withdrawing l stored pulverized material from said storage device, means for returning to said pulverizer coarse pulverized material rejected by said separator and also fine material conveyed to said storage device in excess of that required to maintain said given level in said storage device, and means for extracting from said drying device dried material in quantity equal to that withdrawn from said storage device, and for admitting to said drying device a quantity of fresh material equal to that extracted.

3. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a pulverizer receiving dried solid material from said drying device, a separator for the material pulv verized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level. means for Withdrawing stored pulverized material from said storage device, means for returning to said pulverizer coarse pulverized material rejected by said separator and also fine material rejected by said storage device, and a conveyor conveying from said drying device to said pulverizer dried material in quantity equal to that withdrawn from said storage device and simultaneously conveying to said drying device a quantity of fresh material equal to that extracted.

4. Means for the mechanical preparation of pulverized solid materials, comprising, in combination. a drying device, means for admitting solid material to said drying device, a pulverizer receiving dried solid material from said drying device, a separator for the materialpulverized b \id pulverizer, means for conveying pulveri ed material from said pulverizer to said separator. a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means tor returning to said pulverizer material rejected by said separator and by said storage device along with fresh material equal in quantity to that withdrawn from said storage device.

5. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a pulverizer receiving dried solid material from said drying device, a separator for the material pulverized by said pulverizer, means for Conveying pulverized material from said pulverizer to said separator, a storage device for .verized by said pulverizer,

the fine material passing said separator. means for withdrawing stored pulverize material from said storage device, means for returning to the entrance to said pulverizer material rejected by said separator and means for extracting from said drying device dried material in quantity equal to that withdrawn from said storage device, and for admitting to said drying device a quantity of fresh material equal to that extracted.

6. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a pulverizer receiving dried solid material from said drying device, a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the line material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, means for returning to said pulverizer less fine pulverized material rejected by said separator and also fine material conveyed to said storage device in excess of that required to maintain said given level in said storage device, and means for conveying dried material. from said drying device to said pulverizer and for conveying to said pulverizer, in priority to said dried material, material rejected by said separator and material rejected by said storage device.

7. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, means for admitting solid material to said drying device, a pulverizer receiving dried solid material from said drying device, a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer material rejected by said separator and excess material rejected by said storage device, a conveyor for transferring dried material from said drying device to said pulverizer, and a hopper admitting to said conveyor a quantity of fresh material equal to that transferred.

8. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a pulverizer receiving dried solid material from said drying device, a separator for the materal pulmeans for conveying pulverized material from said pul verizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing Elli stored pulverized material from said storage device, a conveyor for returning to said pulverizer pulverized material rejected by said separator and also excess material rejected by said storage device, a conveyor for transferring from said drying device to said pulverizer dried material in quantity equal to that Withdrawn from said storage device, and for admitting to said drying device a quantity of fresh material equal to that transferred.

9. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pulverized by said pulverizer, a fan producing an air current for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer material rejected by said separator and excess material rejected by said storage device.

10. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pul-' verizer, a separator comprising series of perforated plates, means for passing the pulverized material from said pulverizer through perforations in said plates, a storage device for fine material passing certain plates of said separator. said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer coarse material rej ected by said separator and fine material rejected by said storage device.

11. Means for the mechanical preparation of pulverized solid materials, comprising, in

combination, a drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator comprising series of perforated plates, means for passing material pulverized by said pulverizer through perforations in said plates, a storage device for the fine material passing certain of said plates, said storage device being adapted to be filled to a given level, a shutter controlling the path of pulverized material traversing the perforations in certain of said plates, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer coarse material rejected by said separator and fine material rejected by said storage device.

12. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pulverized by said ulverizer, means for conveying pulverize material from said pulverizer to said separator, a storage device for the fine material passin said separator, said storage device being a apted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means including a conveyor screw having threads of opposite hand for returning to said pulverizer pulverized material rejectedllply said storage device.

13 cans for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a fan for circulating air in said drying device, means for admitting solid.material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and

means for returning to said pulverizer coarse material rejected by said separator and fine material rejected by said storage device.

14. Means for the mechanical preparation of pulverized solid materials, comprising, in combination, a drying device, a fan for circulating air in said drying device, means for admitting solid material to said drying device, a dust extractor for removing solid material from the air circulated in said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pnlverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage device, and means for returning to said pulverizer material rejected by said separator and madrying device to said pulverizer, a separator for the material pulverized by said ulverizer, means for conveying pulverize material from said pulverizer to said separator, a storage device for the fine material passing -said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized-material from said storage device, and means for returning to said pulverizer material'rejected by said separator and material rejected by said storage device.

16. Means for the mechanicalpreparation of pulverized solid materials, comprising, in combination, a drying device including a rotary breaker, an inclined grating for effecting preliminary separation of material broken in said drying device, means for admitting solid material to said drying device, a pulverizer, means for conveying dried solid material from said drying device to said pulverizer, a separator for the material pulverized by said pulverizer, means for conveying pulverized material from said pulverizer to said separator, a storage device for the fine material passing said separator, said storage device being adapted to be filled to a given level, means for withdrawing stored pulverized material from said storage devlce,

and means for returning to the pulverizer coarse material rejected by said separator and fine material rejected by said storage device.

In testimony whereof I have signed by name to this specification.

MAURICE MADORE.

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