WO2001018359A1

WO2001018359A1 - Dust suppression system for continuous type mining machines

Info

Publication number: WO2001018359A1
Application number: PCT/US2000/024053
Authority: WO
Inventors: Michael Dezeeuw; Edward Roussin; Patrick Sollars
Original assignee: RAG AMERICAN COAL HOLDING Inc
Current assignee: RAG AMERICAN COAL HOLDING Inc
Priority date: 1999-09-10
Filing date: 2000-09-01
Publication date: 2001-03-15
Anticipated expiration: 2002-03-10
Also published as: AU7341600A

Abstract

A dust suppression system (10) for suppressing dust associated with the operation of a continuous type mining machine (12) may comprise a housing (30) having an inlet (32) and an outlet (34). A venturi spray assembly (36) having an inlet end (38) and an outlet end (40) is mounted within the housing (30). A fluid injection system connected to the venturi spray assembly (36) provides a fluid under pressure (44) to the venturi spray assembly (36). The fluid under pressure (44) provided to the venturi spray assembly (36) causes the venturi spray assembly (36) to pull dust contained adjacent its inlet end (38) and discharge it adjacent its outlet end (40). The fluid (44) used to operate the venturi spray assembly (36) combines with a portion of the dust thereby suppressing a release of dust into a surrounding atmosphere.

Description

DUST SUPPRESSION SYSTEM FOR CONTINUOUS TYPE MINING MACHINES

Technical Field This invention relates to dust control systems in general and more specifically to dust suppression systems for suppressing dust produced by continuous type mining machines.

Background Art Continuous type mining methods, such as the longwall mining method, are well-known in the art and have been used for years in mining coal from underground deposits or coal seams. With reference now primarily to Figure 1 , longwall mining of a coal seam 11 is usually accomplished in two distinct phases. In the first phase, generally referred to as development mining or advance mining, the coal seam 11 to be worked is divided and subdivided into several discrete areas by driving sets of entries (i.e., main entry set 13, gateroad entry set 15, and bleeder entry set 17) into the coal seam 11 according to a development pattern established for the proposed mine. See Figure 1. Once the development phase is complete, the second phase, usually referred to as retreat mining, is initiated. Both mining phases, i.e., development and retreat, are usually carried out simultaneously in a given coal seam 11 , with retreat mining occurring in previously developed areas and with development mining occurring in new areas of the coal seam 11.

The entry sets (e.g., 13, 15, and 17) are used to divide and subdivide the coal seam 11 into discrete areas and generally comprise a plurality of tunnels or individual entries (i.e., entries 19 and 21) that are oriented in generally parallel, spaced-apart relation. The entries (e.g, 19 and 21) comprising each entry set are connected together by a plurality of cross-cuts (e.g., cross-cuts 23 and 25) generally located transverse to each entry in the entry set. The arrangement is such that the entries and transverse cross-cuts together define a grid-like pattern of tunnels that are separated by a plurality of in-situ coal pillars 27. The coal pillars 27 provide the primary roof support. The entry sets (e.g., 13, 15, and 17) may be classified into different groups or categories depending on their location and purpose within the mine. For example, the first entry set that is driven into the coal seam 11 is usually referred to as the main entry set 13 or, simply, "mains." The main entry set 13 may comprise as many as eight or more individual entries 19 in order to satisfy long-term mining requirements. Once the mains are established, a series of submain entries or cross-entry sets may be driven into the coal seam 11 at transverse angles (usually 90°, although other angles may be used) with respect to the mains 13 in order to further divide the coal seam 11 into smaller, more workable areas. Further subdivision of the coal seam 11 may be effected by driving room entries at transverse angles (again usually 90°) from the cross entries.

The entry sets that are driven into the coal seam 11 during the development phase conform to the development pattern, which itself is based on the type of mining system to be used. For example, if the coal is to be mined according to the longwall method, pairs of parallel entry sets 15, usually referred to as "gateroad entries" are driven into the coal seam 11 from the mains 13 or submains. A bleeder entry set 17 connects the far end 31 of each gateroad entry set 15.

Accordingly, the coal seam 11 developed for a longwall mining system may comprise a main entry set 13, a pair of gateroad entries 15, and a bleeder entry set 17. The arrangement is such that a longwall panel 29 is defined along either side by the pair of gateroad entries 15, and along either end by the bleeder entry set 17 and the main entry set 13. While the size of the longwall panel 29 defined by the various entry sets 13, 15 and 17 (i.e., mains, gateroads, and bleeder) may vary depending on the characteristics of the particular coal seam 11, most longwall panels tend to be rather large, having widths in the range of 500 to 1,000 feet and lengths of 6,000 to 15,000 feet or more.

In most longwall mining operations, it is common to develop the gateroad entries 15 so that they define several adjacent longwall panels, each of which is then mined in succession. Referring now to Figure 2, a typical multipanel longwall mining system may comprise a plurality of gateroad entry sets 15 that define a plurality of longwall panels 29, 33, and 35. Longwall panel 33 has already been mined (i.e., removed), creating a gob (indicated by the cross-hatched areas) and is referred to herein as the "previous panel." Longwall panel 29 is currently being mined and is referred to herein as the "current panel." As the current panel 29 is mined with a longwall shearing machine, the face 37 of longwall panel 29 is advanced into the longwall panel 29 in the direction indicated by arrow 39. Longwall panel 35 is the next panel to be mined and is referred to herein as the "next panel."

In accordance with mining nomenclature, the gateroad entry set 15 located between the previous panel 33 and the current panel 29 is referred to as the "tailgate entry" 41, while the gateroad entry set 15 located between the current panel 29 and the next panel 35 is referred to as the "headgate entry" 43. The identification of the gateroad entries changes as a current longwall panel is completed (i.e., fully removed) and a new panel is started. For example, the headgate entry 43 shown in Figure 2 will become a tailgate entry upon the start of mining of the next panel 35. Consequently, the headgate entry 43 may be referred to herein as a future tailgate entry.

As was mentioned earlier, the longwall panel 29, upon which the longwall shearing machine 12 (Figure 3) operates, extends between the tailgate and headgate entries 41 and 43. The end or portion of the longwall shearing machine 12 that is closer to the headgate entry 43 is usually referred to as the "headgate end," whereas that end or portion of the longwall shearing machine 12 that is closer to the tailgate entry 41 is usually referred to as the "tailgate end." As best seen in Figure 3 and in the embodiment shown and described herein, the left-hand side of the longwall shearing machine 12 is the headgate end, whereas the right-hand side is the tailgate end.

Referring now back to Figure 2, after the longwall panel has been defined during the development mining phase, a continuous type mining machine, such as a longwall shearing machine 12 (Figure 3), is set-up adjacent the face 37 of the longwall panel 29. The longwall shearing machine 12 is usually mounted on a face conveyer system so that it can travel back and forth along the face 37 of the longwall panel 29 in directions, indicated by arrows 45, that are generally transverse to the gateroad entry sets 15, removing coal from the face 37 as it does so. The coal removed from the panel face 37 by the longwall shearing machine is carried away by the face conveyor system. In most longwall mining operations, the extraction operation begins at the bleeders 17 and progresses toward the mains 13 or submains, hence the designation "retreat" mining. The area behind the longwall shearing machine is allowed to cave-in, forming the gob.

The longwall shearing machine normally comprises one or more rotating cutting drums that dislodge coal from the panel face 37. Although the rotating cutting drums are effective in rapidly removing coal from the face 37, they do tend to generate substantial amounts of coal dust during the coal removal process. The dust problem is exacerbated by the rotation of the cutting drums which tends to induce significant air flow in the area around the face 37. Besides posing a health hazard to mining personnel that may be located nearby the longwall shearing machine, high airborne dust levels can pose a significant explosion hazard as well. Consequently, the control and/or suppression of the amount of airborne dust produced by the longwall shearing machine and other continuous type mining machines is a critical concern in nearly all cases.

Various types of dust suppression or "scrubber" systems have been developed and are being used in order to ameliorate some of the problems associated with the high dust levels produced by such continuous mining machines. One type of dust control or scrubber system, commonly referred to as a water spray system, utilizes a plurality of water nozzles positioned in the high dust areas (e.g., near the cutting drums in a longwall shearing machine). The water stream or spray emanating from each nozzle tends to capture or absorb the airborne dust particles, thereby "washing" the dust from the air, thereby reducing the ambient dust level.

While such water spray systems are effective in reducing airborne dust, they are not without their problems. For example, the streams or sprays of water emerging from the nozzles can impair visibility, particularly if strong spotlights or floodlights are used to illuminate the region on the panel face being excavated by the longwall shearing machine. Another problem associated with such conventional water spray systems is that they are not particularly efficient, and require a substantial flow of water compared with the amount of dust suppressed. Such excess water can pose problems of collection and disposal and also tends to adversely affect coal quality. Yet another problem associated with water spray systems of the type described above is that they generally involve a substantial amount of exposed hose or piping to conduct the water to the various spray nozzles, thereby increasing the likelihood that such exposed hose or piping will become damaged or broken during the mining operation. Such damaged or broken hose or piping can have a significant adverse impact on overall mine production and costs if the continuous type mining machine must be shut-down in order to make the necessary repairs.

Consequently, a need exists for a dust control system that is effective at suppressing dust produced by continuous type mining machines, such as a longwall shearing machine, but that does not suffer the disadvantages of currently available scrubber systems.

Disclosure of Invention A dust suppression system for suppressing dust associated with the operation of a continuous type mining machine may comprise a housing having an inlet and an outlet. A venturi spray assembly having an inlet end and an outlet end is mounted within the housing. A fluid injection system is connected to the venturi spray assembly and provides a fluid under pressure to the venturi spray assembly. The fluid under pressure provided to the venturi spray assembly causes the venturi spray assembly to pull dust contained adjacent its inlet end and discharge it adjacent its outlet end. The fluid used to operate the venturi spray assembly combines with a portion of the dust thereby suppressing a release of dust into a surrounding atmosphere. Also disclosed is a method for suppressing dust associated with the operation of a continuous type mining machine. One step involves providing a housing having an inlet and an outlet. Another step involves providing a venturi spray assembly having an inlet end and an outlet end. Yet another step involves mounting the venturi spray assembly within the housing. Still yet another step involves connecting a fluid injection system to the venturi spray assembly. A final step involves providing a fluid under pressure to the venturi spray assembly so that the fluid under pressure causes the venturi spray assembly to pull dust contained adjacent its inlet end and discharge it adjacent its outlet end, the fluid combining with a portion of the dust to suppress a release of dust into a surrounding atmosphere.

Brief Description of the Drawings Illustrative and presently preferred embodiments of the invention are shown in the accompanying drawings in which: Figure 1 is a plan view of an entry set structure for use with a longwall mining system;

Figure 2 is a plan view of a longwall mining system showing the panel currently being mined, the previous panel, and the next panel, gob is indicated by the cross-hatched areas;

Figure 3 is a side view in elevation of the dust suppression system and longwall shearing machine according to one preferred embodiment of the invention; Figure 4 is a plan view of the dust suppression system and longwall shearing machine illustrated in Figure 3;

Figure 5 is a plan view of the first support arm assembly and the headgate end dust suppressor assembly with the cover removed to show the arrangement of the venturi spray assemblies and blower assembly; Figure 6 is an end view in elevation of the headgate end dust suppressor assembly showing the dropped or angled inlet plenum with respect to the outlet plenum;

Figure 7 is a side view of the first support arm assembly and the headgate end dust suppressor assembly;

Figure 8 is an enlarged plan view of the headgate end dust suppressor assembly with the cover removed to show the inlet and outlet plenums and the arrangement of the venturi spray assemblies and blower assembly;

Figure 9 is a cross-section view in elevation of a venturi spray assembly; Figure 10 is a cross-section view in elevation of a second embodiment of the venturi spray assembly; Figure 11 is a plan view of the second support arm assembly and the tailgate end dust suppressor assembly with the cover removed to show the arrangement of the venturi spray assemblies and the blower assembly;

Figure 12 is a side view of the second support arm assembly and the tailgate end dust suppressor assembly; and Figure 13 is an enlarged plan view of the tailgate end dust suppressor assembly with the cover broken removed to show the outlet plenum and the arrangement of the venturi spray assemblies and the blower assembly. Best Mode for Carrying Out the Invention

A dust suppression system 10 according to one preferred embodiment of the present invention is shown in Figure 3 and described herein as it could be used with a dual drum continuous miner or longwall shearing machine 12 of the type commonly used in longwall coal mining operations. In such an application, the dust suppression system 10 suppresses dust associated with the operation of the longwall shearing machine 12. Alternatively, and as will be explained in greater detail below, the dust suppression system 10 may be used in conjunction with any of a wide range of other types of continuous type mining machines to suppress dust from any of a wide range of other types of dust producing materials.

The longwall shearing machine 12 on which the dust suppression system 10 may be used may comprise a pair of cutting drums 14 and 16 mounted for rotation on respective ranging arms 18 and 20 which, in-tura, may be pivotally mounted to the main body or chassis 22 of longwall shearing machine 12. The longwall shearing machine 12 may be slidably mounted to a face conveyor system 24 positioned adjacent a face 37 of the longwall panel 29 so that the longwall shearing machine 12 may be moved back and forth along the panel face 37 in the directions indicated by arrows 45. Since the longwall panel 29 extends between the headgate and tailgate entries 43 and 41 (Figure 2), the end or portion of the longwall shearing machine 12 that is closer to the headgate entry 43 is usually referred to as the "headgate end," whereas that end or portion of the longwall shearing machine 12 that is closer to the tailgate entry 41 is usually referred to as the

"tailgate end." In the embodiment shown and described herein, the left-hand side of the longwall shearing machine 12 is the headgate end, whereas the right-hand side is the tailgate end.

The dust suppression system 10 may be mounted to the longwall shearing machine 12, and may comprise a headgate end dust suppressor assembly 26 and a tailgate end dust suppressor assembly 28. The headgate end dust suppressor assembly 26 may comprise a housing 30 having an inlet end 32 and an outlet end 34. The housing 30 is sized to receive at least one, and preferably a plurality, of venturi spray assemblies 36. The headgate end dust suppressor assembly 26 is mounted to the longwall shearing machine 12 by a support arm or boom 62 which positions the headgate end dust suppressor assembly 26 adjacent the headgate drum 14, as best seen in Figures 3 and 4.

The tailgate end dust suppressor assembly 28 is similar in construction to the headgate end dust suppressor assembly 26 just described and may include a housing 30' having an inlet end 32' and an outlet end 34'. The housing 30' is sized to receive at least one, and preferably a plurality, of venturi spray assemblies 36', which, in the embodiment shown and described herein, may be identical to the venturi spray assemblies 36 utilized in the headgate end dust suppressor assembly 26. The tailgate end dust suppressor assembly 28 is mounted to the longwall shearing machine 12 by a support arm or boom 64 which positions the tailgate end dust suppressor assembly 28 adjacent the tailgate drum 18, as is also best seen in Figures 3 and 4.

The various venturi spray assemblies or jet pumps 36, 36' utilized in the headgate and tailgate end dust suppressor assemblies 26 and 28 may be identical and comprise inlet ends 38, 38' and outlet ends 40, 40'. As will be described in greater detail below, the venturi spray assemblies 36, 36' pull or draw dust contained in the atmosphere adjacent their respective inlet ends 38, 38' and discharge it from their respective outlet ends 40, 40' as respective mist streams 58, 58'. In the embodiment shown and described herein, the various venturi spray assemblies 36, 36' are mounted within their respective housings 30, 30' so that the inlet ends 38, 38' of the venturi spray assemblies 36, 36' are in series fluid communication with the respective inlets 32, 32' of the housings 30, 30'. Similarly, the outlet ends 40, 40' of the venturi spray assemblies 36, 36' are in series fluid communication with the respective outlets 34, 34' of the housings 30, 30'.

The headgate end dust suppressor assembly 26 optionally may be provided with a blower assembly 50 (Figures 5-8) to augment air flow through the housing 30. It is preferred, but not required, that the blower assembly 50 be positioned between the inlet 32 and outlet 34 of the housing 30. The blower assembly 50 and the venturi spray assemblies 36 may be used in combination or independently to draw dust laden air 52 into the inlet 32 of the housing 30.

Similarly, the tailgate end dust suppressor assembly 28 may be provided with a blower assembly 50' positioned between the inlet 32' and the outlet 34' of the housing 30' of tailgate end dust suppressor assembly 28. See Figures 11-13. Finally, the headgate and tailgate dust suppressor assemblies 26 and 28 may be provided with respective floodlight assemblies 54, 54' to provide increased illumination of respective portions of the face 37 of longwall panel 29.

The dust suppression system 10 may be operated as follows to suppress dust associated with the operation of the longwall shearing machine 12. Assuming that the longwall shearing machine 12 is operating with its cutting drums 14, 16 generating dust, the dust suppression system 10 may be activated by supplying a pressurized working fluid 44 (e.g., water, Figure 9) to the injector nozzles (e.g., 42) provided in each of the venturi spray assemblies 36, 36'. The optional blower assemblies 50 and 50' also may be activated. The pressurized water 44 provided to each nozzle (e.g., 42) is discharged from the nozzle as a fluid stream (e.g., 48) which creates a low-pressure zone within the venturi spray assembly (e.g., 36, 36'). The low-pressure zone contained within each venturi spray assembly (e.g., 36, 36') causes dust laden air 52, 52' to be first drawn into the inlet 32, 32' of each respective housing 30, 30' and then into the inlet ends 38, 38' of the venturi spray assemblies 36, 36'. The dust particles entrained in the dust laden air 52, 52' combine with the working fluid 44 in the fluid stream 48. The resulting mixture is discharged from the outlet end 38, 38' of each venturi spray assembly 36, 36' as a particle laden mist stream 58, 58', which is ultimately discharged from the outlet 34, 34' of each respective housing 30, 30'. The liquid vapor tends to collect the coal dust (not shown) contained in the dust laden air 52, 52', thereby "washing" it from the air stream. Since the outlets 34, 34' of the housings 30, 30' are directed generally back toward the face 37 of longwall panel 29 and also generally toward the tailgate entry 41, the mist stream 58, 58' may be carried away with the return air flow.

A significant advantage of the present invention is that it requires less water than the various other types of dust suppression systems, including systems which utilize one or more open nozzles positioned adjacent high dust areas (e.g., the cutting drums 14, 16 of the longwall shearing machine 12) to spray water into the air. Because the present invention is more efficient than other dust suppression systems, the amount of excess water and the problems associated with such excess water (i.e., collection, disposal and diminished coal quality) are significantly reduced.

Another advantage of the present invention is that it improves operator visibility when compared to the systems that utilize open nozzles located in the high dust areas (i.e., adjacent the cutting drums 14, 16 of the longwall shearing machine 12) to control the dust produced by the continuous type mimng machine. As discussed briefly above and in much greater detail below, the nozzles (e.g., 42) are contained within the venturi spray assemblies 36, 36'. Thus, the floodlight assemblies 54, 54' associated with the respective dust suppressor assemblies 26 and 28 are able to more effectively illuminate the face 37 of the longwall panel 29 free of the "rainbow" effect typically associated with open spray nozzles. The additional illumination improves operator visibility which allows the operator (not shown) to operate the continuous type mining machine at higher speeds than may be otherwise possible without the additional illumination.

Yet another advantage of the present invention is that it uses little, if any, exposed hose or piping to conduct the water to the various venturi spray assemblies 36, 36'. As will be discussed in greater detail later, the pressurized working fluid 44 is conducted from the fluid injection system (not shown) to the venturi spray assemblies 36, 36' through the hollow members 60, 60' of support arm assemblies 62 and 64. Thus, the likelihood of exposed hose or piping becoming damaged during the mining operation is greatly reduced. With other dust suppression systems, damaged hose or piping often required the continuous type mining machines to be shutdown for repairs resulting in decreased overall mine production and increased costs.

Still yet another advantage of the present invention is that it achieves a significant reduction in ambient dust levels associated with the operation of the longwall shearing machine 12, but without requiring filters or other apparatus for mechanically trapping the dust. The dust suppression system 10 also does not require the provision of electricity, thereby simplifying installation and operation.

Having briefly described the dust suppression system 10 according to one embodiment of the present invention, as well as some of its more significant features and advantages, the various preferred embodiments of the dust suppression system will now be described in detail. However, before proceeding with the description, it should be noted that while the dust suppression system

10 is shown and described herein as it could be used to suppress dust associated with the operation of a longwall shearing machine 12 to mine coal from an underground deposit or seam 11 , the dust suppression system 10 could be used in any of wide range of other applications and in conjunction with any of a wide range of other dust producing materials. Consequently, the present invention should not be regarded as limited to the particular components, applications, configurations, and dust producing materials shown and described herein.

With the foregoing considerations in mind, one preferred embodiment of the dust suppression system 10 according to the present invention is shown and described herein as it could be used with a longwall shearing machine 12 of the type commonly used in underground longwall coal mining operations.

Briefly, the longwall shearing machine 12 may comprise a pair of cutting drums 14 and 16 which are mounted for rotation on respective ranging arms 18 and 20. The ranging arms 18 and 20 in-turn may be pivotally mounted to the main body or chassis 22 of the longwall shearing machine 12. The pivotal mounting of the ranging arms allows the longwall shearing machine 12 to be utilized with longwall panels 29 of varying heights. The longwall shearing machine 12 may be slidably mounted to a face conveyor system 24 positioned adjacent the panel face 37. The face conveyor system 24 carries away coal dislodged from the face 29 and also provides support for the longwall shearing machine 12, allowing the shearing machine 12 to be moved back and forth along the panel face 37 in the directions indicated by arrows 45. The face conveyor system 24 may comprise a chain conveyer system (not shown) of the type commonly used in longwall operations.

Alternatively, other types of conveyor systems may be used.

Since longwall shearing machines and face conveyor systems are well-known in the art and could be easily provided by persons having ordinary skill in the art, the longwall shearing machine 12 and face conveyor system 24 that may be utilized in one preferred embodiment of the present invention will not be described in further detail herein.

The headgate end dust suppressor assembly 26 may be mounted to the chassis 22 of the longwall shearing machine by a support arm assembly 62. The support arm assembly 62 supports or suspends the headgate end dust suppressor assembly 26 adj acent the first or headgate end cutting drum 14. See Figures 3 and 4.

Referring now to Figures 5-8, the headgate end dust suppressor assembly 26 may comprise a housing 30 having an inlet end 32 and an outlet end 34. In the embodiment shown and described herein, the housing 30 is in the form of an irregular polygon and is sized to receive five venturi spray assemblies 36, as well as various other ancillary components. Alternatively, the housing 30 may comprise shapes other than the irregular polygon shown and described herein and may be made larger or smaller depending on the particular dust suppression capacity required. It is generally preferred, but not required, that the housing 30 be configured so that the inlet end 32 is angled downward slightly with respect to the outlet end 34, as best seen in Figures 6 and 7. The downward cant of the inlet end 32 tends to enhance the dust collection efficiency of the headgate end dust suppressor assembly 26. It is generally preferred, but not required, that the inlet 32 of housing 30 be provided with an inlet screen 114 to prevent large objects (e.g., pieces of coal) from entering and possibly plugging the venturi spray assemblies 36 (Figure 7). The outlet end 34 of housing 30 is angled such that the mist stream 58 is discharged generally back toward the face 37 of longwall panel 29 and also generally toward the tailgate entry 41. See also Figure 4.

In the embodiment shown and described herein, the housing 30 of headgate end dust suppressor assembly 26 is pivotally mounted to the support arm assembly 62 by three (3) hinges 66 which allow the headgate end dust suppressor assembly 26 to be pivoted about pivot axis 68. See Figure 6. The pivotal mounting of the headgate end dust suppressor assembly 26 allows an operator (not shown) to adjust the vertical positions of the inlet and outlet ends 32 and 34 of the housing 30 in order to optimize dust collection. The pivotal mounting aπangement also allows the position of the headgate end dust suppressor system 26 to be varied to accommodate changes in the vertical position of the headgate end cutting drum 14.

The headgate end dust suppressor assembly 26 may be provided with a plurality of venturi spray assemblies or jet pumps 36, each of which is provided with an inlet end 38 and an outlet end 40. Each venturi spray assembly 36 pulls dust contained adjacent its inlet end 38 and discharges it adjacent its outlet end 40. In the embodiment shown and described herein, the headgate end dust suppressor assembly 26 comprises five separate venturi spray assemblies 36. However, a greater or lesser number of venturi spray assemblies 36 may be used depending on the applicable volume flow rate of dust laden air 52 that is to be processed by the headgate end dust suppressor assembly 26 in a particular installation. Consequently, the present invention should not be regarded as limited to the particular number of venturi spray assemblies 36 shown and described herein. With reference now primarily to Figure 9, the venturi spray assemblies 36 are essentially identical, so only one venturi spray assembly 36 is described in detail herein. Venturi spray assembly 36 may comprise a generally cylindrically shaped outer wall or tube 56 which defines a central passage or bore 70 therethrough. The central passage 70 may comprise a converging- diverging passage or venturi having an inlet end 38, a diffusing section 72, a converging section 74, a throat section 76, a diverging section 78, and an outlet end 40. The inlet end 38 may comprise a generally rounded or flared inlet mouth which substantially improves the flow uniformity into the diffusing section 72 of the venturi spray assembly 36. The diffusing section 72 may comprise a substantially straight section that forms a transition between the inlet end 38 and the converging section 74. The converging section 74 forms a transition between the diffusing section 72 and the throat section 76. The throat section 76 discharges into the diverging section 78.

An injector nozzle 42 may be mounted within the central bore 70 generally along the central axis 80 of tube 56. In the embodiment shown and described herein, the injector nozzle 42 is mounted generally in the diffusing and converging sections 72 and 74 so that it discharges into the throat section 76. Alternatively, the injector nozzle 42 may be mounted at slightly different positions, depending on the particular shape of the central bore 70 in order to maximize performance of the venturi spray assembly 36. The injector nozzle 42 may be connected to a fluid injection system (not shown) which provides a fluid under pressure 44 (e.g., water) to the nozzle 42.

The arrangement of the nozzle 42 is such that when the pressurized working fluid 44 is provided to the nozzle 42, the nozzle 42 discharges a fluid stream 48 which creates a low pressure zone within the central bore 70 of tube 56. The low pressure zone then draws in dust laden air 52 adjacent the inlet end 38 of the venturi spray assembly 36. The fluid stream 48 then expels the dust laden air 52 from the outlet end 40 of venturi spray assembly 36 as a particle laden mist stream 58. The fluid 44 used to operate the venturi spray assembly 36 may combine with a portion of the dust thereby suppressing a release of dust into the suπounding atmosphere. Stated differently, each venturi spray assembly 36 operates as a jet pump to pull dust laden air 52 contained adjacent its inlet end 38 and discharge a mist stream 58 adjacent its outlet end 40.

The venturi spray assembly 36 may be made from any of a wide range of materials (e.g., metals or plastics) suitable for the intended application. In one prefeπed embodiment, each tube section 56 may comprise steel tubing. The diameters of the various sections (i.e., diffusing section 72, converging section 74, throat section 76 and diverging section 78) as well as the lengths of the sections, may be varied depending on the volume flow rate of dust laden air 52 that is to be processed by each respective venturi spray assembly 36. By way of example, in one prefeπed embodiment, each tube section 56 may have an outside diameter 82 of about 3.5 inches and an overall length 84 of about 8.0 inches. The diffusing section 72 may have a diameter 86 of about 2.25 inches and a length 88 of about 2.5 inches. The converging section 74 may have a length 90 of about 1.0 inches which terminate at the throat section 76. The throat section 76 may have a diameter 92 of about 1.5 inches and a length 94 of about 1.0 inches. The diverging section 78 may extend from the end of the throat section 76 to the outlet end 40 and may form a diverging angle 96 of about 15 degrees.

The injector nozzle 42 may comprise any of a wide range of nozzles suitable for discharging the working fluid 44 (e.g., water) to form the fluid stream 48. By way of example, in one prefeπed embodiment, each nozzle 42 may comprise a type No. 1 nozzle available from Senior Conflow of Clinton, PA. The nozzle may be rated at a flow rate of about 0.7 gallons per minute (gpm) at a pressure of about 100 pounds per square inch gauge (psig) and a flow rate of about 1.8 gpm at a pressure of about 200 psig.

As was mentioned above, the injector nozzles 42 of the various venturi spray assemblies 36 are all connected to a fluid injection system (not shown) which provides a fluid under pressure 44 (e.g., water) to each nozzle 42. The fluid injection system (not shown) may comprise any of a wide range of well-known and commercially available fluid injection systems capable of providing a fluid 44 at a pressure and flow rate suitable for the operation of the injector nozzles 42. For example, the fluid injection system may comprise a supply of pressurized fluid (not shown) and a conduit (e.g., 60) connected between the pressurized fluid supply and the nozzles 42. Accordingly, the fluid injection system may comprise a conventional mine water delivery system which may deliver water under a pressure in the range of about 100 (psig) to about 150 psig at a flow rate sufficient to accommodate the injector nozzles 42. Alternatively, the fluid injection system may comprise a supply of nonpressurized fluid (i.e., a fluid reservoir), a pump (not shown) that is connected to the fluid supply contained in the fluid reservoir, and a conduit connecting the pump to the nozzles 42. The pump may be energized so that the fluid 44 is delivered to the nozzles 42 at the desired pressure and flow rate. However, since such pressurized fluid injection systems are well known in the art and could be easily provided by persons having ordinary skill in the art after having become familiar with the teachings of the present invention, the particular fluid injection system utilized in one prefeπed embodiment of the invention will not be described in further detail. A second embodiment 136 of a venturi spray assembly is illustrated in Figure 10. The second embodiment 136 of the venturi spray assembly does not have the converging-diverging arrangement of the first embodiment 36 described above. However, the second embodiment 136 of the venturi spray assembly will produce satisfactory results in many applications. The second embodiment 136 of the venturi spray assembly may comprise a generally cylindrically shaped tube 156 having an inlet end 138 and an outlet end 140 with a substantially cylindrical central passage or bore 170 therethrough. An injector nozzle 142 may be mounted within the central bore 170, generally along the central axis 180 of bore 170. The nozzle 142 may be connected to the fluid injection system (not shown) which provides a working fluid 144 to the nozzle 142. Like the nozzle 42 in the first embodiment 36, the nozzle 142 of the second embodiment 136 of the venturi spray assembly may discharge a fluid stream 148 which creates a low pressure zone within the central bore 170 oftube 156. The low pressure zone draws in dust laden air 152 adjacent the inlet end 138. The fluid stream 148 then combines with a portion of the dust and expels the dust laden air 152 from the outlet end 140 as a particle laden mist stream 158.

The various venturi spray assemblies (e.g., 36 or 136) comprising the headgate end dust suppressor assembly 26 may be mounted within the housing 30 so that each venturi spray assembly 36 is positioned between the inlet end 32 and outlet end 34 of the housing 30. More specifically, each venturi spray assembly 36 may be mounted within the housing 30 so that the inlet end 38 of each venturi spray assembly 36 is in series fluid communication with the inlet end 32 of housing 30 and so that the outlet end 40 of each venturi spray assembly 36 is in series fluid communication with the outlet 34 of housing 30. An inlet plenum 98 may be defined between the inlet ends 38 of the venturi spray assemblies 36 and the inlet end 32 of housing 30. The venturi spray assemblies 36 may be mounted within the housing 30 by any convenient fastening system or device. By way of example, each venturi spray assembly 36 is welded to the housing 30.

As used herein, two devices are said to be "in series fluid communication" when the outlet end of either device is positioned generally upstream from the inlet end of the other device such that a portion of the flow emanating from the outlet end of the first device is discharged adjacent to and may be drawn into the inlet end of the second device, notwithstanding the presence of other devices positioned between the first and second devices and/or the presence of other devices being in series fluid communication with either the first or second device. Similarly, two devices are said to be "in parallel fluid communication" when their respective outlet ends and/or their respective inlet ends are generally located side-by-side. Stated differently, two devices are in parallel fluid communication if their respective inlet ends draw a portion of air from a common source or if the flow emanating from each respective outlet end is discharged into a common area or region.

It is generally prefeπed that the housing 30 be provided with a top cover (not shown) and that the portions of the outlet end 34 between the various venturi spray assemblies 36 be sealed so that dust laden air 52 is drawn in through the inlet 32 of housing 30 and does not "short circuit" by entering the housing 30 through other openings. Alternatively, the inlet end 38 of each venturi spray assembly 36 may be provided with an inlet duct (not shown) to fluidically connect the inlet ends 38 of the venturi spray assemblies 36 with the inlet end 32 of housing 30. In the embodiment shown and described herein, the headgate end dust suppressor assembly

26 is provided with a blower assembly 50 to augment air flow through the headgate end dust suppressor assembly 26. See Figures 5-8. The blower assembly 50 and the venturi spray assemblies 36 may be used in combination or independently to draw dust laden air 52 into the inlet 32 of housing 30. With reference now primarily to Figure 8, the blower assembly 50 includes an inlet end 102 and an outlet end 104. Blower assembly 50 may be positioned between the inlet end 32 and the outlet end 34 of the housing 30 so that the blower inlet end 102 is in series fluid communication with the inlet end 32 of housing 30 and so that the blower outlet end 104 is in series fluid communication with the inlet ends 38 of the venturi spray assemblies 36. In the embodiment shown and described herein, the blower assembly 50 is positioned within the housing 30 so that an inlet plenum 98 is defined between and fluidically connects the blower inlet end 102 and the inlet 32 end of housing 30. Similarly, an outlet plenum 100 is defined between and fluidically connects the blower outlet end 104 and the inlet ends 38 of venturi spray assemblies 36.

The blower assembly 50 may comprise any of a wide range of blower types that are now known in the art or that may be developed in the future. By way of example, in one embodiment, the blower assembly 50 comprises an axial type blower having an axial fan 106 that is mounted for rotation within the blower housing 108. A hydraulic motor 110 connected to the axial fan 106 rotates the fan 106 within the housing 108. The hydraulic motor 110 may be connected to a suitable hydraulic source (not shown) via hydraulic lines 112. In an alternative aπangement, the axial fan 106 may be driven by other types of drive systems, such as by an electric motor (not shown), as would be obvious to persons having ordinary skill in the art after having become familiar with the teachings of the present invention.

Other placements and configurations are possible for the blower assembly 50. For example, the blower assembly 50 may be positioned generally downstream from the venturi spray assemblies

36 and generally upstream from the outlet end 34 of housing 30 so that the blower inlet end 102 is in series fluid communication with the outlet ends 40 of the venturi spray assemblies 36 and so that the blower outlet end 104 is in series fluid communication with the outlet end 34 of housing 30. In still another alternative aπangement, the blower assembly 50 may be positioned generally downstream from the outlet end 34 of housing 30 so that the blower inlet end 102 is in series fluid commumcation with the outlet end 34 of housing 30. In yet another configuration, the blower assembly 50 may be positioned generally upstream of the inlet end 32 of housing 30 so that the blower outlet end 104 is in series fluid communication with the inlet 32 of housing 30. In still yet another possible configuration, the blower assembly 50 may be positioned so that its inlet end 102 is in parallel fluid communication with the inlet ends 38 of the venturi spray assemblies 36, and so that its outlet end 104 is in parallel fluid communication with the outlet ends 40 of the venturi spray assemblies 36. The blower assembly 50 also may be positioned so that its inlet end 102 is in parallel fluid communication with the inlet end 32 of housing 30, and so that its outlet end 104 is in parallel fluid communication with the outlet end 34 of housing 30.

The dust suppression system 10 may further comprise a floodlight assembly 54 mounted to the headgate end dust suppressor assembly 26. See Figure 8. The floodlight assembly 54 may be used to illuminate a portion of the face 37 of longwall panel 29, typically that portion of the face

37 that is being operated on by the headgate end cutting drum 14, thereby improving operator visibility. The floodlight assembly 54 may comprise any of a wide range of floodlight systems that are well-known in the art and readily commercially available. Consequently, the floodlight assembly 54 that may be utilized in one prefeπed embodiment of the present invention will not be described in further detail herein.

Referring now back to Figures 3 , 4 and 5 , the headgate end dust suppressor assembly 26 may be mounted to the support arm assembly or boom 62 which positions the headgate end dust suppressor assembly 26 adjacent the headgate end cutting drum 14. The support arm assembly 62 also provides a means for conducting pressurized water, hydraulic, and electrical services to the headgate end dust suppressor assembly 26.

The support arm assembly 62 may comprise an elongate, generally hollow member having a proximal end 116 mounted to the longwall shearing machine 12 and a distal end 118 to which is mounted the housing 30 of headgate end dust suppressor assembly 26. The proximal end 116 may be provided with a mounting plate 124 to facilitate mounting of the support arm assembly 62 to the chassis 22 of longwall shearing machine 12 (Figure 2). As mentioned above, in the embodiment shown and described herein, the housing 30 of the headgate end dust suppressor assembly 26 is pivotally mounted to the outer section 120 of support arm assembly 62 so that the same may be pivoted slightly about pivot axis 68 (Figure 8). The pivotal mounting of the housing 30 of headgate end dust suppressor assembly 26 allows the operator to adjust the inlet 32 and outlet 34 of housing 30 to optimize dust collection. While any of a wide range of pivoting type mounting systems may be used, one prefeπed embodiment mounts the housing 30 to the outer section 120 of support arm assembly 62 via three (3) pivot hinges 66. A flexible hose 126 may be utilized to connect the water lines 130 of the venturi spray assemblies 36 with the support arm assembly 62 so that the headgate end dust suppressor assembly 26 may be pivoted without detaching the water supply lines. Similarly, flexible hoses (not shown) may be used to connect the hydraulic lines 112 associated with the blower assembly 50 to hydraulic lines (not shown) provided on the support arm assembly 62.

Note that in the embodiment shown and described herein, the outer and inner sections 120,

122 of support arm assembly 62 are not co-planar. More specifically, the outer section 120 is lowered with respect to the inner section 122 so that the headgate end dust suppressor assembly 26 is located at the vertical position with respect to the headgate cutting drum 14 that optimizes dust control. Alternatively, and depending on the application, the support arm assembly 62 may comprise a substantially straight member (not shown), or a member having an elevated outer section (not shown), as would be obvious to persons having ordinary skill in the art after having become familiar with the teachings of the present invention. As best seen in Figures 5, 7 and 8, the hollow member 60 of support arm assembly 62 may be provided with a suitable coupling or fluid inlet end 128 connected to the fluid injection system (not shown) and a supply line 126 connected to the fluid supply lines 130 associated with the venturi spray assemblies 36. In the embodiment shown and described herein, the fluid inlet end 128 is located at an end of the inner section 122 of support arm assembly 62. The fluid inlet end 128 is sized to receive a mating connector portion attached to a water supply line (not shown) . The fluid inlet end 128 allows a pressurized fluid 44 into the member 60 of support arm assembly 62. The fluid 44 travels through the hollow member 60 from the fluid injection system (not shown) and through flexible hose 126 to the fluid supply lines 130 connected to the individual venturi spray assemblies 36. The inner section 122 of support arm assembly 62 may also be provided with a housing portion 132 sized to receive one or more gauges 134 (Figure 3) to indicate the pressure of the fluid 44 being provided to the venturi spray assemblies 36.

The support arm assembly 62 may be made from any of a wide variety of materials (e.g., metals) suitable for the intended environment, as would be obvious to persons having ordinary skill in the art after having become familiar with the present invention. By way of example only, in the embodiment shown and described herein, the support arm assembly 62 is fabricated from a closed, tubular steel member having a square cross-section (Figure 6). Alternatively, members having other cross-sectional shapes may also be used. The support arm assembly 62 may be further provided with an isolation member 136. More specifically, the isolation member 136 may comprise a flexible curtain 138 (Figure 3) which helps to contain loose coal material by directing it onto the face conveyer system 24.

Referring back now to Figures 3 and 4, the dust suppression system 10 may also be provided with a second or tailgate end dust suppressor assembly 28. The tailgate end dust suppressor 28 may be mounted to the longwall shearing machine 12 via a second support arm assembly 64 so that the tailgate end dust suppressor assembly 28 is positioned adjacent the tailgate end cutting drum 16.

The tailgate end dust suppressor assembly 28 is similar to the headgate end dust suppressor assembly 26 just described and may be provided with a housing 30' having an inlet end 32' and an outlet end 34'. The housing 30' is also sized to receive a plurality of venturi spray assemblies 36'. In the embodiment shown and described herein, the housing 30' of tailgate end dust suppressor assembly 28 is fixedly mounted to the outer section 120' of support arm assembly 64. Alternatively, the housing 30' could be pivotally mounted to the support arm assembly 64 in a manner akin to the pivotal mounting of the headgate end dust suppressor assembly 26. Such a pivotal mounting would allow an operator to adjust the position of the tailgate end dust suppressor assembly 28 to optimize dust collection.

Referring to Figures 11 - 13 , the housing 30' of tailgate end dust suppressor assembly 28 may comprise an iπegular polygon and is sized to receive four venturi spray assemblies 36' as well as the other components comprising the tailgate end dust suppressor assembly 28. Alternatively, of course, the housing 30' could comprise other shapes, as would be obvious to persons having ordinary skill in the art after having become familiar with the teachings of the present invention. Unlike the headgate end dust suppressor assembly 26 described above, the inlet end 32' of the tailgate end dust suppressor assembly 28 is not angled downward with respect to the outlet end 34'. The downward cant of the inlet end 32' is not required due to the characteristics of the particular longwall shearing machine 12 utilized in the present invention. That is, the tailgate end dust suppressor assembly 12 provides adequate dust control without having to downwardly cant the inlet end 32' with respect to the outlet end 34'. Of course, depending on the particular longwall shearing machine that is to be used in conjunction with the dust suppression system 10, it may be desirable or advantageous to provide such a downward canting of the inlet end 32'. In view of the foregoing considerations, then, the present invention should not be regarded as limited to a tailgate end dust suppressor assembly 28 without a downward canting inlet end 32'.

The tailgate end dust suppressor assembly 28 may be provided with a plurality of venturi spray assemblies or jet pumps 36' each having an inlet end 38' and an outlet end 40'. In the embodiment shown and described herein, the tailgate end dust suppressor assembly 28 comprises four separate venturi spray assemblies 36'. However, a greater or lesser number of venturi spray assemblies 36' may be used depending on the applicable volume flow rate of dust laden air 52' that is to be processed by the tailgate end dust suppressor assembly 28 in a particular installation. Consequently, the present invention should not be regarded as limited to the particular number of venturi spray assemblies 36' shown and described herein.

The venturi spray assemblies 36' of the tailgate end dust suppressor assembly 28 may be substantially identical to the venturi spray assemblies 36 of the headgate end dust suppressor assembly 26, and thus will not be described in further detail herein. Similarly, the fluid injection system (not shown) that is connected to the venturi spray assemblies 36' comprising the tailgate end dust suppressor assembly 28 may be the same fluid injection system that is connected to the nozzles

42 of the venturi spray assemblies 36 comprising the headgate end dust suppressor assembly 26, thus will not be described in further detail herein.

The various venturi spray assemblies 36' comprising the tailgate end dust suppressor assembly 28 may be mounted in generally parallel, spaced-apart relation within the housing 30' so that the inlet end 38* of each venturi spray assembly 36' is in series fluid communication with the inlet 32' of housing 30', and so the outlet end 40' of each venturi spray assembly 36' is in series fluid communication with the outlet 34' of housing 30'. The venturi spray assemblies 36' may be mounted within the housing 30' by any convenient fastening device. By way of example only, in one prefeπed embodiment, each venturi spray assembly 36' is welded to the housing 30'. It is generally prefeπed that the spaces between the outlet ends 40' of the venturi spray assemblies 36* be closed or sealed so that dust laden air 52' does not "short circuit" the tailgate end dust suppressor assembly 28. Alternatively, the inlet end 38' of each venturi spray assembly 36' may be provided with an inlet duct (not shown) to fluidically connect the inlet end 38' with the inlet 32' of housing 30'. It is generally prefeπed, but not required, that the inlet 32' of housing 30' be provided with an inlet screen 114' (Figure 12) to prevent large objects (e.g., pieces of coal) from entering and possibly plugging the venturi spray assemblies 36'.

The tailgate end dust suppressor assembly 28 may also be provided with a blower assembly 50' to augment air flow through the tailgate end dust suppressor assembly 28. The second blower assembly 50' may be substantially identical to the blower assembly 50 shown and described above for the headgate end dust suppressor assembly 26, and may comprise an axial fan 106' that is driven by a hydraulic motor 110'.

The blower assembly 50' may be positioned adjacent the tailgate end dust suppressor assembly 28 such that the blower outlet end 104' is in series fluid communication with the inlet ends 38' of venturi spray assemblies 36'. For example, in the embodiment shown and described herein, the blower assembly 50' is positioned such that the blower inlet end 102' comprises the inlet 32' of housing 30', and the various inlet ends 38' of the venturi spray assemblies 36' are in fluid communication with the blower outlet end 104' via an outlet plenum 100' (Figure 13). Alternatively, the blower assembly 50' may be positioned such that its inlet end 102' is in series fluid communication with the outlet ends 40' of the venturi spray assemblies 36'. In yet another possible configuration, the blower assembly 50' may be positioned such that its inlet end 102' is in parallel fluid commumcation with the inlet ends 38' of the venturi spray assemblies 36', and so that its outlet end 104' is in parallel fluid communication with the outlet ends 40' of the venturi spray assemblies 36'. In still another arrangement, an inlet plenum (not shown) similar to the inlet plenum 98 associated with the headgate end dust suppressor assembly 26 may be defined between and fluidically connect the blower inlet end 102' and the inlet 32' of housing 30' (not shown).

The outlet plenum 100' may be provided with a guide vane 140 to assist in turning the flow of dust laden air 52' that is discharged from the blower outlet end 104'. Finally, the tailgate end dust suppressor assembly 28 may be provided with a floodlight assembly 54' to provide additional illumination to the face 37 of the longwall pane 29. In the embodiment shown and described herein, the floodlight assembly 54* is mounted to the housing 30'. The floodlight assembly 54' may be identical to the floodlight assembly 54 utilized on the headgate end dust suppressor assembly 26. Consequently, the floodlight assembly 54' will not be described in further detail herein. Referring to Figures 3, 4, and 11, the tailgate end dust suppressor assembly 28 is mounted to a second support arm assembly or boom 64 which positions the tailgate end dust suppressor assembly 28 adjacent the tailgate end cutting drum 16. The support arm assembly 64 is also used to conduct the pressurized water, hydraulic, and electrical services to the tailgate end dust suppressor assembly 28. As was the case for the first support arm assembly 62, the second support arm assembly 64 may comprise an elongate, hollow member 60' having a proximal end 116' mounted to the longwall shearing machine 12 and a distal end 118' upon which is mounted the housing 30' of the tailgate end dust suppressor assembly 28. The proximal end 116' may be provided with a mounting plate 124' to facilitate mounting of the support arm assembly 64 to the chassis 22 of longwall shearing machine 12. See Figure 4.

In the embodiment shown and described herein, the outer and inner sections 120', 122' of support arm assembly 64 are not co-planar. More specifically, the outer section 120' is lowered with respect to the inner section 122' so that the tailgate end dust suppressor assembly 28 is located at the vertical position with respect to the tailgate cutting drum 16 that optimizes dust control. Alternatively, and depending on the application, the support arm assembly 64 may comprise a substantially straight member (not shown), or a member having an elevated outer section (not shown), as would be obvious to persons having ordinary skill in the art after having become familiar with the teachings of the present invention. As shown in Figures 4 and 13, the outer section 120' of support arm assembly 64 includes an inward turning portion 142.

As best seen in Figures 11, 12 and 13, the hollow member 60' of support arm assembly 64 may be provided with a suitable coupling or fluid inlet end 128' connected to the fluid injection system (not shown). The fluid jupply lines 130' associated with the venturi spray assemblies 36' may be connected to the hollow member 60' so that the pressurized fluid contained therein is directly conducted to the supply lines 130'. In the embodiment shown and described herein, the fluid inlet end 128' is located at an end of the inner section 122' of support arm assembly 64 (Figure 11). The fluid inlet end 128' is sized to receive a mating connector portion attached to a water supply line (not shown). The fluid inlet end 128' allows a pressurized fluid into the member 60' of support arm assembly 64. The fluid travels through the hollow member 60' and directly into the fluid supply lines 130' associated with the venturi spray assemblies 36'. The inner section 122' of support arm assembly 64 may also be provided with a housing portion 132' sized to receive one or more fluid pressure gauges 134' (Figure 3).

As was the case for the first support arm assembly 62, the second support arm assembly 64 may be made from any of a wide variety of materials (e.g., metals) suitable for the intended environment, as would be obvious to persons having ordinary skill in the art after having become familiar with the present invention. By way of example only, in the embodiment shown and described herein, the support arm assembly 64 is fabricated from a closed, tubular steel member having a square cross-section. Alternatively, members having other cross-sectional shapes may also be used.

The support arm assembly 64 may be provided with an isolation member 136' which, in the embodiment shown and described herein, may comprise a flexible curtain 138'. See Figure 3. The isolation member 136' helps to contain loose coal material by directing it onto the face conveyer system 24.

The dust suppression system 10 may be operated as follows to suppress dust associated with the operation of the longwall shearing machine 12. Assuming that the longwall shearing machine 12 is operating with its cutting drums 14, 16 generating dust, the dust suppression system 10 is activated by supplying a pressurized working fluid 44 (e.g., water, Figure 9) to the injector nozzles (e.g, 42) of the venturi spray assemblies 36, 36'. The optional blower assemblies 50 and 50' may also be activated. The pressurized fluid 44 (e.g, water) supplied by the fluid injection system (not shown) is conducted through each hollow member 60, 60' of the respective support arm assemblies 62 and 64 to the fluid supply lines 130, 130' associated with the venturi spray assemblies 36, 36'. The pressurized water is then distributed to and ultimately enters each of the nozzles (e.g., 42). The pressurized water is discharged from the nozzles as a fluid stream (e.g., 48, Figure 9) which creates a low-pressure zone within each venturi tube (e.g, 56). The low-pressure zone and the optional blower assemblies 50, 50' cause dust laden air 52, 52' to be drawn in the inlets 32, 32' of housings 30, 30'. The dust laden air 52, 52' is ultimately drawn into the inlet end 38, 38' of each venturi spray assembly 36, 36'. The dust particles entrained in the dust laden air 52, 52' combine with the working fluid (e.g., 44) in the fluid stream (e.g., 48). The resulting mixture is discharged from the outlet end 40, 40' of each venturi spray assembly 36, 36' as a particle laden mist stream 58, 58' which is ultimately discharged from the outlets 34, 34' of housings 30 and 30'. The liquid vapor tends to collect the coal dust (not shown) contained in the dust laden air 52, 52' "washing" it from the air stream. Since the outlets 34, 34' of the respective housings 30 and 30' are angled such that the mist stream 58, 58' is discharged generally back toward the face 37 of longwall panel 29 and also generally toward the tailgate entry 41, the mist stream 58, 58' may be carried away with the return air flow.

It is contemplated that the inventive concepts herein described may be variously otherwise embodied and it is intended that the invention be construed to include alternative embodiments except insofar as limited by the prior art.

Claims

WHAT IS CLAIMED IS:

1. A dust suppression system for suppressing dust associated with the operation of a continuous type mining machine, comprising: a housing having an inlet end and an outlet end mounted to the continuous type mining machine so that the inlet end of said housing is located adjacent a high dust area; a venturi spray assembly having an inlet end and an outlet end, said venturi spray assembly being mounted within said housing; and a fluid injection system connected to said venturi spray assembly, said fluid injection system providing a fluid under pressure to said venturi spray assembly, the fluid under pressure causing said venturi spray assembly to pull dust contained adjacent the inlet end of said venturi spray assembly and discharge it adjacent the outlet end of said venturi spray assembly, the fluid combining with a portion of the dust to suppress a release of dust into a suπounding atmosphere.

2. The dust suppression system of claim 1, wherein said venturi spray assembly comprises: a tube having a sidewall defining a bore through said tube; and a nozzle mounted within said tube, said nozzle being connected to the fluid injection system.

3. The dust suppression system of claim 1, wherein said fluid injection system comprises: a supply of pressurized fluid; and a conduit connected between said supply of pressurized fluid and said venturi spray assembly.

4. The dust suppression system of claim 1, wherein said fluid comprises water.

5. The dust suppression system of claim 1, wherein said fluid injection system comprises: a supply of fluid; a conduit connected between said supply of fluid and said venturi spray assembly; and a pump operatively associated with said conduit for pressuring the fluid so that the fluid is delivered to said venturi spray assembly under pressure.

6. The dust suppression system of claim 1, wherein said housing is mounted adjacent the continuous type mining machine so that the inlet of said housing is exposed to a dust laden area.

7. The dust suppression system of claim 1, wherein said venturi spray assembly is mounted within said housing so that the inlet end of said venturi spray assembly is in series fluid communication with the inlet of said housing and so that the outlet end of said venturi spray assembly is in series fluid communication with the outlet of said housing, said fluid under pressure causing said venturi spray assembly to pull dust contained adjacent the inlet of said housing and discharge it to the outlet of said housing.

8. The dust suppression system of claim 1, further comprising an inlet plenum defined between the inlet end of said venturi spray assembly and the inlet of said housing, said inlet plenum fluidically connecting the inlet end of said venturi spray assembly and the inlet of said housing.

9. The dust suppression system of claim 1, further comprising an outlet plenum defined between the outlet end of said venturi spray assembly and the outlet of said housing, said outlet plenum fluidically connecting the outlet end of said venturi spray assembly and the outlet of said housing.

10. The dust suppression system of claim 1, further comprising a blower assembly having a blower inlet end and a blower outlet end, said blower assembly being positioned adjacent said venturi spray assembly.

11. The dust suppression system of claim 10, wherein said blower inlet end is in series fluid communication with the inlet of said housing.

12. The dust suppression system of claim 10, wherein said blower outlet end is in series fluid communication with the outlet of said housing.

13. The dust suppression system of claim 10, wherein said blower outlet end is in parallel fluid communication with the outlet of said housing.

14. The dust suppression system of claim 10, further comprising an inlet plenum defined between said blower inlet end and the inlet of said housing, said inlet plenum fluidically connecting said blower inlet end and the inlet of said housing.

15. The dust suppression system of claim 10, further comprising an outlet plenum defined between said blower outlet end and the inlet end of said venturi spray assembly, said outlet plenum fluidically connecting said blower outlet end and the inlet end of said venturi spray assembly.

16. The dust suppression system of claim 10, wherein said blower inlet end comprises the inlet of said housing.

17. The dust suppression system of claim 1 , further comprising a floodlight assembly positioned adjacent said housing.

18. The dust suppression system of claim 1 , further comprising a support arm assembly having a proximal end and a distal end, the proximal end being mounted to said continuous type mining machine, said housing being mounted to the distal end of said support arm assembly.

19. The dust suppression system of claim 18, wherein said support arm assembly comprises an elongate, generally hollow member having a fluid inlet end connected to said fluid injection system and a fluid outlet end connected to said venturi spray assembly so that the fluid under pressure is conducted from said fluid injection system to said venturi spray assembly through said support arm assembly.

20. The dust suppression system of claim 1 , wherein said housing is pivotally mounted to the continuous type mimng machine.

21. A dust suppression system for a continuous type mining machine, comprising: housing means for defining an inlet end and an outlet end, said housing means being mounted to the continuous type mining machine so that said inlet end is located in a high dust area associated with operation of the continuous type mining machine; venturi spray means mounted within said housing means for defining an inlet end and an outlet end; and fluid injection means for providing a fluid under pressure to said venturi spray means, the fluid under pressure causing said venturi spray means to pull dust contained adjacent the inlet end of said venturi spray means and discharge it adjacent the outlet end of said venturi spray means, the fluid combining with a portion of the dust to suppress a release of dust into a surrounding atmosphere.

22. A method for suppressing dust associated with the operation of a continuous type mining machine, comprising the steps of: providing a housing having an inlet and an outlet; providing a venturi spray assembly having an inlet end and an outlet end; mounting said venturi spray assembly within said housing; connecting a fluid injection system to said venturi spray assembly; and providing a fluid under pressure to said venturi spray assembly, the fluid under pressure causing said venturi spray assembly to pull dust contained adjacent the inlet end of said venturi spray assembly and discharge it adjacent the outlet end of said venturi spray assembly, the fluid combining with a portion of the dust to suppress a release of dust into a surrounding atmosphere.

23. A dust suppression system for suppressing dust associated with the operation of a continuous type mining machine, comprising: a tube having a sidewall defining a bore through said tube, the bore having an inlet end and an outlet end; a nozzle mounted within said tube, said nozzle being adapted to receive a fluid under pressure; and a fluid injection system connected to said nozzle, said fluid injection system providing a fluid under pressure to said nozzle, the fluid under pressure causing said tube to pull dust contained adjacent the inlet end of said bore and discharge it adjacent the outlet end of said bore, the fluid combining with a portion of the dust to suppress a release of dust into a surrounding atmosphere.