US1796381A - Conveying apparatus for pulverized material - Google Patents

Description

March 17, 1931. L. MANICO CONVEYING APPARATUS 1 0R PULVERIZ'ED MATERIAL Filed Jan. 13. 1930 B X [NV ENTOiM a I I Patented Mar. 17, 1931 UNITED STATES PATENT OFFICE LEONARD MANICO, OF LONDON, ENGLAND, ASSIGNOR, BY MESNE ASSIGNMENTS, TO

FULLER COMPANY, A CORPORATION OF DELAWARE CONVEYING APPARATUS FOR PULVERIZED MATEItIAL Application filed January 13, 1930, Serial No. 420,453, and in- Great Britain January 23, 1929.

This invention relates to the conveying of pulverized or finely divided materials such as pulverized coal, cement, and starch, and

more particularly to an improved pump for transporting these materials through pipe lines of small diameter.

The invention relates to an improvement in the so-called F tiller-Kinyon pum described in United States patents to I inyon 1,553,539, granted September 15, 1925, and

1,677,119, granted July 10, 1928. In the Kinyon patents the theory of operation is described in detail.

In these pumps or conveying devices, the, 'dry pulverized material to beconveyedis delivered to a hopper from any source of supply, such as a pulverizer mill, a storage bin, a collector screw, or the like. From the hopper, the material enters the barrel of the.

pump which is connected at one end. to the transport line. Within the barrel is a conveying element ordinarily in the form of a conveyor screw orworm which advances the material through the barrel and out into the line. Slightly beyond the terminal flight of the screw, compressed air is admitted at suit-' able pressures and in suitable volumes,'depending upon the quantity and nature of the material and thedistance it is to be conveyed. The principal function of the air is to change the characteristics of the mass of material and to render it fluent and liquid-like, in which condition it is advanced through the line by the pressure applied by the screw and wardly has the effect of slightly aerating the material between the flights of the screw,

. thus increasing the volume of the material and causing the screw to slip, so that the capacity of the system is reduced. Also under certain conditions of installation, the backward flow of air may create a dust nuisance. It is accordingly, the practice to so construct the barrel and screw that the material is compacted as it advances through the barrel toward the point of air admission, the material thus forming a zone of great density just in front of the point of air admission. The seal thus formed is effective to prevent short-circuiting or rearward flow of the air along the screw toward the hopper.

In Kinyon Patent No. 1,553,539, several diflerent arrangements for producing this seal of material are described. In one, the screw used is of diflerential pitch, the pitch of the flights decreasing toward the discharge end of the barrel. With this construction, air is admitted a short distance 'beyond the terminal flight of the screw and the materialis so compacted in the flights of the screw that it prevents flow of the air toward the hopper. If there is a substantial space between the terminal flight of the screw and the point of air admission, the material packs together-in this space and a seal is formed under these conditions, somewhat beyond the end of the screw. Incommercial practice, it is customary both to employ a differential pitch screw and to provide the seal space so that a highly effective seal is provided. Air cannot penetrate through the seal'so formed and the effectiveness of the seal can be increased by constructing the pumps with seal spaces, the length of which varies in accordance with the degree of scaling that is desired.

Under some conditions of operation, for example, when the material is lighter than those commonly handled, where the conditions of conveying are unusual, or where the quantity of material delivered to the pump is less than was originally anticipated, the seal formed by'the differential pitch screw and by the seal space between the terminal flight and the point of air admission may be insufiicient to prevent backward escape of air. practice to open the pump and cut back and remove pdrtions of the terminal flights until sufficient space is provided to effect the seal. This practice delays operation and is expensive and, if'the feed to the pump is increased at some later time, the screw must be built up to its original condition to avoid loss of Under these conditions, it has been the power due to the frictional resistance of the seal to the flow of material.

The present invention is accordingly directed to the provision of a pump of the type described in which the above difficulties are overcome, and in this new pump, the effectiveness of the seal may be increased or diminished as occasion requires without dismantling the pump or changing the construction of the screw. With the new arrangement, the pump may be operated at all times with a seal sufficient to prevent return flow of air, and this seal may be kept at the minimum required for the purpose, so that loss of power in overcoming the resistance of a seal greater than is required, is avoided. A further feature of the new pump is that the variation in the seal is accomplished without disturbing the balance of the screw, and this is a matter of considerable importance, since vibration occurs when, as in the earlier practice, portions of the terminal flight have been removed to increase the seal, and the pumps are then run empty or at fractions of their capacity.

In the new pump, the desired result is obtained by increasing the length of the conveyor screw shaft and its casing, and provid; ing the screw preferably at the discharge end with means by which endwise adjustment of the screw in the casing can be effected. The screw shaft is then driven through a flexible coupling or the like, the members of which may be moved relatively as the position of the shaft is altered.

For a better understanding of the invention, reference may be had to the accompanying drawing, in which Fig. 1 is a side elevation partly in section;

Fig. 2 is a longitudinal section of the discharge end bearing and screw shaft on an enlarged scale, and

Fig. 3 is an enlarged sectional view of the flexible coupling.

\Vith reference to Fig. 1, the pump mechanism is seen to consist of a bed plate 1, upon which is mounted a hopper 2, which opens into a hollow cylindrical barrel section 3, likewise secured at its forward end at 4 to the bed plate 1. Between the barrel section 3 and an offset discharge section 5, is an air ring 6 having an internal bushing 7 through which air is admitted to the barrel through a multiplicity of small openings (not shown) from the air delivery system 8. The screw shaft 9, having flights decreasing in pitch toward the discharge end, issupported near one end in a pillow block bearing 10 on the bed plate 1 and at its other end in a radial bearing 11 and thrust'bearing 12, the latter being shown in an enlarged scale in Fig. 2. The discharge end of the screw is threaded for a considerable distance as shown at 13 and is provided with a nut 14 and lock nut 15 to permit longitudinal adjustment of the shaft within the bearings. As the thrust of the shaft is rearwardly, the nut 14 is held in close engagement with the thrust collar 16.

Secured to the drive end of the shaft 9 is a movable element 17 of a flexible coupling.

Secured to the shaft 18 of the driving motor 19 is a fixed element 20 of the coupling. The spacing ring 21 and apertured disc 22 are secured in place by bolts 23 passing throu h them and through the element 20, and t 1e element, ring, and disc provide a hollow cylindrical space 24 in which the movable element 17 can be moved longitudinally without interfering with the drive through bolts 25 which pass through the member 20 and the disc 22. The bolts 25 are protected by a tubular covering of rubber fabric or similar material and are of lesser diameter than the apertures 26 in the movable member 17 through which they pass in order to compensate for slight angular mis-alignment of the motor shaft 18 with the pump shaft 9.

In order to adjust the screw longitudinally to compensate for change of air pressures, material densities or local conditions or operation, it is merely necessary to stop the pump, remove the cap 27 and change the position of nuts 14 and 15. The shaft can then be moved backwardly to a position where blowing back of the air is no longer apparent, and a seal of the desired effectiveness is thus obtained. Should conditions change so that so great a seal is not required, the shaft is moved forward to the position required and these operations can be carried on quickly and with only a short stoppage of the pump. The adjustments do not alter the structure in any way or disturb the balance of the screw and the pump can be operated at its greatest efiiciency under all conditions, whereas in earlier pumps, occasions arose when the pump sometimes operated at less than full efliciency due either to insuflicient seal cutting down the effectiveness of the screw or to too great a seal which uses up power in overcoming the resistance that the seal offers to the flow of material through it.

What is claimed is 1. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in the barrel, aeonveyor screw on the shaft for advancing the material through the barrel, means for introducin air into the material beyond the terminal fiig t of the screw, and means for varying the relative positions of the shaft and the air-introducing means.

2. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of ma terial, a shaft in the barrel, a conveyor screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal fllght of the screw, and means for moving the shaft endwise to vary the distance between the terminal flight of the screw and the point of air admission.

3. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in the barrel, a conveyor screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, means for moving the shaft endwise to vary the distance between the termi-' nal flight of the screw and the point of air admission, and a thrust bearing for the end of the shaft toward which the screw advances the material. v

4. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in the barrel, a conveyor screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, means for varying the relative positions of the shaft and air-introducing means, and driving means for the shaft permitting said variation while maintaining the driving connection.

5. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in the barrel, a conveyor screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, means for varying the relative positions of the shaft and'air-introducing means, a motor, and a coupling between said shaft and the motor shaft permitting said variation while maintaining the driving connection.

6. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in the barrel, a conveyor screw on the shaft for advancing the material connected at one end to a transport line and. having an opening for the admission of material, a shaft in said barrel, a conveyor screw. on the shaft for advancng the material through the barrel, means for introducing through the barrel, means for introducing air into the material beyond the terminal flight. of the screw, a driver shaft, a driving connection between the shafts permitting relative endwise adjustment'thereof, a thrust bearing for the screw shaft at its discharge end, said shaft projecting beyond said bearing. and means on the projecting end of the shaft for varying the position thereof by endwise movement.

9. In conveying apparatus for finely divid ed material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material,.a shaft in said barrel, a conveyor'screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, a. thrust;- be'aring for the shaft at its discharge end, and means for moving theshaftendwise to vary the distance between the terminal flight of the screw and. the point of air admission. I

10. In conveying apparatus for finely di-- vided material, the combination of abarrel connected at one end to atransportline and having an opening for the admission of material, a shaft in said-barreL-a conveyor screw on the shaft for advancing the 'material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, a driver shaft, a driving connec tion between the shafts including apair of members each fast on one of said shafts and connecting means between said members permitting relative movement thereof in a direction endwise of said shafts but preventing relative angular movement, and means for moving said screw shaft endwise.

11. In conveying apparatus for finely divided material, the combination of a barrel having an opening for the admission-of material, a shaft in said barrel, a conveyor screw onthe shaft for advancing the material through the barrel, means for introducing air connected at one end'to a transportlineand" into the material beyond the terminal flight of the screw, a driver shaft, a driving connection between the shafts including a pair of members each fast on one of said shafts, a plurality of elements connecting said members rigidly against relative angular movement while permitting their relative movement in a direction longitudinally of said shafts, and means for moving said screw shaft endwiso.

12. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in said barrel, a conveyor screw on the shaft for advancing the material through the barrel, means for introducing air into the material beyond the terminal flight of the screw, a driver shaft, a driving connection between the shafts including a pair of members each fast on one of said shafts, a plurality of elements rigidly connected to one member and extending through openings in the other, said members permitting relative movement of said members in a direction lengthwise of said shafts but preventing relative angular movement, and means for moving said screw shaft endwise.

13. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material, a shaft in'said barrel, a conveyor screw on the shaft for advancing the mat-erial through the barrel, means for introducing air into the material beyond the terminal flight of the screw, a driver shaft, a driving connection between the shafts including a pair of members each fast on one of said shafts, a plurality of elements rigidly connected to one member and extending through openings in the other, cushioning means between said elements and the walls of their openings, and means for moving said screw shaft endwise.

14. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and having an opening for the admission of material to be conveyed, a shaft in the barrel, a conveyor screw on the shaft for advancing material through the barrel, means atthe end of the barrel and beyond the terminal flight of the screw for introducing air into the material, the space between said terminal flight and the point of air admission containing a quantity of said material which acts as a seal against backward flow of air into the barrel, and means for varying the having an opening for the admission of material to be conveyed, a shaft in the barrel, a conveyor screw on the shaft for advancing material through the barrel, means at the end of the barrel and beyond the terminal flight of the screw for introducing air into the material, the space between said terminal flight and the point of air admission containing a quantity of said material which acts as a seal against backward flow of air into the barrel, and means operable from outside the barrel for varying the extent to which the barrel projects beyond the terminal flight of said screw to vary the length of the seal space and thereby vary the density of the material in said space and its effective ncss as a seal.

In testimony whereof I affix my signature.

LEONARD MANICO.

relative positions of the terminal flight of the screw and the end of said barrel to vary the length of the seal space and thereby vary the density of the materialin said space and its effectiveness as a seal.

15. In conveying apparatus for finely divided material, the combination of a barrel connected at one end to a transport line and

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