US3387895A - Non-clogging splitter unit for dividing the flow of fluid-conveyed material - Google Patents

Description

June 1968 F. w. HOCHMUTH ETAL 3,387,895

NON-CLOGGING SPLITTER UNIT FOR DIVIDING THE FLOW OF FLUID-CONVEYED MATERIAL 5 Sheets-Sheet 1 Filed Dec. 29, 1966 INVENTORS FRANK W HOCl/MU TH Jbse u F MUM-EN June 11, 1968 F. W. HOCHMUTH ETAL NON-CLOGGING SPLITTER UNIT FOR DIVIDING THE FLOW OF FLUID-CONVEYED MATERIAL Filed Dec. 29, 1966 FLOW DIV/PER K 5 Sheets-Sheet 2 3 Sheets-Sheet 3 HOCHMUTH ETAL OF FLUID-CONVEYED MATERIAL June 11, 1968 NON-CLOGGING SPLITTER UNIT FOR DIVIDING THE FLOW Filed Dec. 29, 1966 R QWQSR ZONM INVENTORS FRANK M HOC'IIMUI'H JOSEPH F- MULLEN United States Patent LOGGING SPLITTER UNIT 1 0R DIVIDING IE FLOW 0F FLUID-CGNVEYED MATERIAL Frank W. Hochmnth, West Simsbury, and Joseph F. M ullen, West Hartford, Conn, assignors to Combustion Engineering, Inc, Windsor, Conan, a corporation of elaware D Filed Dec. 29, 1966, Ser. No. 605,766

2 Claims. (Cl. 302-64) ABSTRACT 61* THE DISCLOSURE In a Y-type flow divider for splitting a main stream of fluid-conveyed material flow into branch streams, tne flow-splitting member at the apex juncture of the two branch conduits being made of plate stock which has small openings in large number distributed thereover. Such splitting member is shaped with a frontal portion that faces into the flow of the incoming main stream; it has first and second side portions that extend downstream from the frontal portion into flow-guiding relation with the branch conduits; and it is provided with means for establishing through the openings a generally upstream flow of compressed medium in the form of jets which create along the plate front and sides a boundary layer Whose effect is to prevent the material in the incoming main stream from building up on the flow-splitter plate.

Summary of the invention Our invention relates to the pneumatic or other fluid transport of fuels and other materials, and it has special reference to an improved method of and apparatus for dividing a main stream of such transported material into two or more branch streams.

Broadly stated, the object of our invention is to accomplish such flow division in an improved way which prevents the material fibers and other particles from depositing upon and adhering to the throat of the div ding device and there accumulating with resultant restrlction or blockage of flow into and through the branch aths.

p A more specific object is to achieve the above through a novel injection of compressed air or steam or other gas between the flow-divider throat and the material 1n the approaching main stream, which injection establishes and maintains a controllable boundary layer by which such main-stream material is kept from adhering to the throat member.

Another object is to accomplish the foregoing by using a divider throat plate which contains a large number of free openings of small diameter and by passing the mentioned compressed medium through those plate openings in directions which are generally counter to the mainstream fiow and which produce jets having an energy content suflicient to keep the material fibers and other particles from adhering to the throat plate, and the effect of which injection is to divert said material along the resulting low-friction boundary layer around the plate and into the branch outlets of the divider.

Other objects and advantages will become apparent from the following description of illustrative embodiments of the invention when taken in conjunction with the accompanying drawings.

Description of drawings FIG. 1 is a diagrammatic representation of one form of fuel transport system wherein the flow-dividing improvements of the present invention are usable with practical advantage;

FIG. 2 shows one of the flow-dividing devices of FIG.

3,387,895 Patented June 11, 1968 1 to an enlarged scale and indicates how that represented divider unit K can be organized and constructed in accordance with a first embodiment of our invention;

and

FIG. 3 is a similar showing of our improved flow-dividing unit when organized in accordance with a second embodiment of the invention.

Description of preferred embodiments Our invention enables fuels and other materials to have their main flow streams divided into branch streams without the hang-up and clogging difficulties encountered when using flow-dividing facilities of the prior art. Among the fuel materials whose flow division can be so benefited are those which the copending Mullen application Ser. No. 594,040, filed Nov. 14, 1966, specifies as the bagasse resulting from cane-sugar production, waste wood products like tree bark and Wood chips and shavings, and industrial and municipal wastes. Non-fuel materials likewise can gain comparable flow-dividing benefits from a use of our invention in connection therewith.

The fuel transport system illustratively shown in FIG. 1

FIG. 1 indicates how our improved flow divider unit can be installed at the two locations K in a system which is organized for the pneumatic transport of fuel from a source 18 at the drawing-view left to a fuel-burning furnace 12 at the drawing-view right. Such fuel transport is effected through pneumatic lines 10 over distances from the fuel-supply location 18 to the furnace location 12 which range from comparatively short spans up to exceedingly long spans of thousands of feet or even of miles.

As the above-mentioned Mullen application Ser. No. 594,040 more fully brings out, this FIG. 1 organization takes the fuel 18 from a conveyor 14 whose chain 15 is continuously moving from left to right carries pockets of the fuel between slats 19 horizontally spaced along the chain length. The fuel in these moving pockets 18 drops by gravity into the hoppers of fuel metering feeders 21. Rotating feeder drums equipped with blades then meter that fuel 18 at a predetermined rate into air locks 24 and thence into the associated transport lines 10 at points downstream of the air compressors 16 at the left or inlet ends of these lines.

Introduced by each compressor 16 behind or upstream of the fuel 18 so entering the associated line 10 is compressed transport air adequate for moving the air-fuel mixture through the entire length of the line and into the associated nozzle A or B or C or D of the furnace 12. This primary or transport air enters the lines 10 from the compressors 16 at a pressure ranging from about 2 pounds per square inch up to as high as 50 pounds per square inch, depending upon the transport distance to be spanned. Each pound of such primary air serves to transport four or more pounds of the fuel 18 through its line 10 at the relatively high speed of from 50 to feet per second.

In arriving at the furnace or receiving end of the FIG. 1 system, this fast-moving fuel enters the furnace 12 via the earlier-mentioned nozzles shown at A-BC-D in the right portion of FIG. 1. As here represented, these nozzles direct their fuel-air streams tangent to an imaginary firing circle 13 within the furnace, thereby facilitating both suspension drying and suspension burning of the fuel in the advantageous way which the copending Mullen application Ser. No. 594,040 more fully explains.

How our non-clogging flow dividers K benefit the illustrative FIG. 1 system The pneumatic transport organization of FIG. 1 just described utilizes our improved flow divider unit at each of the two points marked K. At the upper of these two points the .fiow divider K is installed in the right or delivery end of the transport line a where it serves to divide the main transport stream from that line between the two fuel nozzles 26 and 27 of furnace burner B. And at the lower of those two points a second fiow divider K similarly serves to split the main flow from transport line 10b between the two branch conduits 28 and 29 respectively leading to furnace burners A and D. The main flow streams here divided is illustratively shown as combining at line 10bs entrance end the flows from both of the two feeder-compressor units 21-2516 which lead into the flow combiner designated 30 in FIG. 1.

This second or line 10b utilization of our improved divider K enables the single transport conduit 10!) to sup ply both of the furnace burners A, and D with their needed fuel-air streams, with such two branch streams being split at K from the main flow stream which the entering end of that line 10b receives at 30 from the two feeder-compressor units 21-25-16 mentioned immediately above. Those two fuel-air introducing units can if desired be replaced by a single unit 21-2546 whose capacity is double that of each of those two. And the first or upper FIG. 1 utilization of our non-clogging divider K similarly enables the two nozzles 2627 of furnace burner B to receive their fuel-air supply through the single transport line 10a of FIG. 1. In systems of this FIG. 1 type involving transport distances of hundreds of feet or thousands of feet or even longer, such use of the single transport line 10a to supply both burner nozzles 26 and 27 and such use of the single pneumatic line 10b to supply both of the furnace burners A and D opens the way for installation savings of such high order as to be economically attractive.

The invention embodiment which FIG. 2 hereof shows In the embodiment of our invention represented in FIG. 2, the throat plate 32 at the juncture of the two branch conduits there designated 34 and 35 is provided with small openings 36 in large number distributed throughout the center portion of the plate directly facing the main pneumatic conduit 10 and also throughout the adjoining side portions which lead to the two branch paths 34 and 35. Immediately downstream of the so-perforated throat plate or flow divider 32 is a transverse seal plate 37 which completely covers the opening downstream of the throat plate and the periphery of which is attached to the opening-defining members in a fluid-tight manner as by welding. In this way there is produced a chamber 39 defined at its downstream side by plate 37 and whose upstream and lateral sides are defined by the perforated throat plate or flow splitter member 32, here shown as being shaped in the form of a spherical head. Other shapings or profiles for this plate 32 can of course be substituted if desired.

An inlet conduit or pipe 38 leading through plate 37 into the so-formed chamber 39 serves to supply the chamber interior with air or steam or other gas at a pressure higher than that within transport line 10 at the point of its connection with divider K. For each installation such chamber 39 pressure is chosen to be enough greater than the pressure of the main flow stream as to develop the energy required for establishing around throat plate 32 the boundary layer earlier mentioned. In practice this dilterential can be selected within the range of from 1 to 100 pounds per square inch, depending upon system characteristics and the nature of the material being transported and divided.

For keeping such difierential pressure at or close to its selected value, use may if desired be made of the control system shown in FIG. 2. There a controller 54 responsive to signals from taps 55 and S6 adjusts the valve 57 in supply line 38 so as automatically to hold the pressure within chamber 39 at its said selected value above the line 10 pressure at the flow divider entrance.

Such compressed gaseous medium as so delivered into the divider chamber 39 by pipe 38 may be derived from any suitable source. In the illustrative system of HG. 1 such source is represented in the form of an air pump 42 driven by motor 41 and serving to keep an accumulator tank 43 filled with air at the particular pressure which the system flow dividers K require in order to prevent hang-up and clogging of the fuel or other material being passed therethrough.

Such air or steam or other gas under compression is led from tank 43 to each divider inlet pipe 38 through the pressure-control valve 57 already mentioned. Asthe description proceeds, it will become evident that this accumulator tank 43 of FIG. 1 can if desired have the compressed air therein replaced by some other gaseous medium such as steam from a suitable source not shown. Nitrogen or argon or other inert gas suitably compressed likewise may be utilized in the FIG. 1 tank 43 in situations where the presence of oxygen or moisture in the fiow divider chambers 39 may be undesirable.

How the flow divider of our invention prevents hang-up and clogging of the material being passed therethrouglr In operation of our improved flow dividers K the fuel or other material delivered thereinto by the associated transport line 10 is split in a uniquely advantageous way by the throat plate or flow divider member 32 into the two branch streams 34 and 35.This advantageous form of splitting is in sharp contrast to divider constructions of the prior art wherein the throat elements correspond ing to plate 32 of FIG. 2 is unperforated and thus functions merely as a simple mechanical splitter of theincoming main flow stream. When handling materials such as the fiber-containing bagasse and bark fuels as earlier mentioned as well as non-fuel materials, such prior-art flow dividers have typically been unsatisfactory in that the material coming into physical contact with the splitter element 32 between outlet branches 34 and 35 adheres to and builds up upon such element with resultant decrease in outflow through either or both of the branch paths and eventual clogging of those paths.

Such troublesome and unsatisfactory operation is eliminated by the improved flow dividers K of our present invention. The arrangement of our FIG. 2 accomplishes this through the medium of the mentioned jets of compressed gas, whether it be air or steam or an inert medium, which flow from the internal chamber 39 out through the throatplate openings or perforations 36. These jets of com- I pressed gas so emanating from the central openings 36 directly oppose the main stream flow from transport line 10, while the companion jets so emanating from the side perforations of throat plate 32 supplement the center ones by diverting the material in the divided flows away from the plate sides in out-of-contact relationship therewith.

The higher pressure maintained within the divider chamber 39 is sufliciently above the main-stream pressure at the divider entrance as to give the opening 36 jets an energy or potential force which is higher than that of the material fibers and other particles that are advancing toward or contacting the throat plate or flow splitter member 32. This results in establishing upstream of the plate center and also along each of the two plate sides the mentioned boundary layer of said compressed medium.

Such layer minimizes physical contact by the main stream fibers or particles with the flow splitter or throat plate 32, around which plate the material flow in such main stream divides into the two branch streams 34 and 35. In the event some of the material fibers or particles do get through the boundary layer and lodge upon the flow splitter plate 32, such lodging is only temporary because the high-energy jets from perforations 36 therebeneath act physically to lift all of such temporarily lodged material away from plate 32s surface and back into one or the other of the divided branch streams 34 and 35.

Further concerning the small openings 36 in the throat plate 32, it may be desirable in some instances to have various sized openings in differing areas of the plate in order to obtain an optimum effect of the jets upon the flow of conveyed material through the divider. For example, those openings 36 on the frontal portion of throat plate 32 can be made larger than those long the plate sides with resultant greater energy in the front jets than in the side jets.

The foregoing functioning on the part of our FIG. 2 flow divider K prevents the material passing therethrough from hanging up at the point of division between outlet branches 34 35 and thereby eliminates the objectionable clogging so characteristic of the comparable flow dividers of the prior art.

The invention embodiment represented in FIG. 3

The basic approach exemplified by FIG. 2 hereof is repeated by the second embodiment of our invention as illustrated in FIG. 3. Here as in FIG. 2 the main stream flow from transport line .18 separates around throat plate 32, into the two branch streams of outflow conduits '34 and 35. But instead of all of the compressed air or steam or inert medium being continuously delivered through supply pipe 38 into the single internal chamber 39 of FIG. 2, the alternate organization of FIG. 3 utilizes two separate chambers 39a and 3% which are divided one from the other by a longitudinal plate 46. And further incorporated into the FIG. 3 design is additional provision for subjecting each of these two chambers 39a and 39b to short periods of internal pressure supply which are separated by intervening periods of supply pressure cut-off.

-In accomplishing the latter, we interpose a valving unit '48 between the main pressure supply pipe 38 and the two branch supply pipes 38a and 38b respectively leading to chambers 39a and 39b. Utilized by this unit 48 is a stationary ring member 5t) into which the branch supply pipes 3811-3812 lead at points circumferentially spaced one from the other as shown. Inside of this stationary ring 5%) there is installed a spoke-like structure 51 which is slowly rotated (via suitable drive means not shown), as at from 1 to 5 rpm. The compressed medium needed to accomplish non-clogging operation of the flow divider is conveyed by supply pipe 33 into the center of this rotating member 51, and the four represented spoke elements of that member 51 are in direct communication with such delivery end of that pip-e 33.

With this valving element 51 in the position shown by FIG. 3, the compressed medium supplied from pipe 38 flows through the spoke element in register with branch pipe 38a and then on through that branch pipe and into the chamber half 39a. Under this condition the other chamber half 3% is not connected with the main supply pipe 38 and thus is unpressurized. Rotation of the valving element 51 in the counter clockwise direction of the arrows brings the spoke element previously in register with 38a into a new position of register with branch pipe 38b and thereby transfers the supply of pressurized medium from the first chamber half 3% to the second chamber half 3%.

Continued rotation of valving element 51 at the appropriate slow speed earlier referred to has the effect of communicating the compressed-medium supply from pipe 38 alternately to first the chamber half 3941 and then the chamber half 39b and then back to 39a and so on, with the transfer cycle repeating itself at a frequency which depend-s upon the speed at which valving element "51 is driven. Such speed preferably is selected to result in several cycles per minute of the above pressure application 6 and shut-off as applied to each of the chamber halves 39a and 39b.

The operating advantages of our FIG. 3 embodiment are basically similar to those earlier described with reference to the first or FIG. 2 embodiment. But instead of the entire single chamber 39 being subjected to internal pressure all the time on a continuous basis, the extended design of FIG. 3 repeatedly switches the application of such internal pressure between the two chamber halves 39a and 3%. In consequence, the two perforated plate halves 32a and 32b alternately function to dislodge from their respective surfaces any fibers or particles of the material which the FIG. 3 flow divider receives from transport line 10 and Splits into the two separate flow paths 35 and 36. In certain situations and when handling certain materials such a pulsing action is found to be advantageous.

While we have shown and described two preferred embodiments of our invention, it is to be understood that the inventive improvements herein disclosed are not limited to those illustrative embodiments but may be otherwise variously embodied and practiced within the scope of the following claims.

What we claim is:

1. In a Y-type flow divider having an inlet conduit adapted to receive a main flow stream of fluid-conveyed material and having first and second branch conduits adapted to convey divided streams of said main flow material out of the divider from the inlet conduit interior, the combination of a flow divider of a Y-shaped configuration having a flow-splitting member disposed between the branch conduits at their apex juncture inside the divider body and formed from curved plate stock which has small openings in large number distributed substantially over the entire plate area and which is shaped to provide a frontal portion that faces into the how of said incoming main stream together with first and second side portions that extend downstream from said frontal portion into flow-guiding relation with the interiors of said first and second branch conduits, and means for establishing through the openings in the splitter plate and from the plates downstream side a generally upstream flow of compressed medium in the form of a large number of jets which create a boundary layer of said jetting medium over the entire plate area of said flow splitting member whose affect is to prevent the material in said incoming main stream from collecting and building up on the flowsplitter plate during operation of the divider.

2. A flow divider organized as defined by claim :1 wherein the said jets of ocmpressed medium issuing from the splitter plates said frontal portion do so in upstream directions which are opposite to the downstream fi-ow of the material in said incoming main stream, and further wherein the companion jets of said compressed medium issuing from said plates two side portions do so in a gen eral sidewise relationship to the flow directions taken by said divided branch streams during their passage along those plate side portions on their way into the dividers said branch conduits.

References Cited UNITED STATES PATENTS 3,149,885 9/1964 Walsh; 302-64 RICHARD E. AEGERTER, Primary Examiner.

EVON C. BIJUNK, ANDRES H. NIELSEN, Examiners.

M. L. AJEMAN, Assistant Examiner.

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