CA2085165C - Air return for venturi system - Google Patents
Air return for venturi systemInfo
- Publication number
- CA2085165C CA2085165C CA 2085165 CA2085165A CA2085165C CA 2085165 C CA2085165 C CA 2085165C CA 2085165 CA2085165 CA 2085165 CA 2085165 A CA2085165 A CA 2085165A CA 2085165 C CA2085165 C CA 2085165C
- Authority
- CA
- Canada
- Prior art keywords
- air
- air return
- product flow
- region
- screen
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
- B65G53/00—Conveying materials in bulk through troughs, pipes or tubes by floating the materials or by flow of gas, liquid or foam
- B65G53/34—Details
- B65G53/58—Devices for accelerating or decelerating flow of the materials; Use of pressure generators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
- F15D1/00—Influencing flow of fluids
- F15D1/02—Influencing flow of fluids in pipes or conduits
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Engineering & Computer Science (AREA)
- Jet Pumps And Other Pumps (AREA)
Abstract
An air return is useable in a venturi system having an upstream air induction member feeding a product flow line downstream of the air induction member. The air return itself comprises a housing having a product flow region to be fitted in line with the product flow line, an air draw region separated from the product flow region by a perforate divider with a baffle internally of the divider and an air flow line from the housing to be fitted back to the air induction member.
Description
20~16~
SJ-8646 & A-92 - 1 -TITLE: AIR RETURN FOR VENTURI SYSTEM
FIELD OF THE INVENTION
The present invention relates to an air return which is used in an inline venturi system.
BACKGROUND OF THE INVENTION
In line venturi systems are used to move product from place to another. An example of an inline venturi system is described in my own United States Patent 5,002,092 issued March 26, 1991 where I use a blower feeding air to a venturi device to create a low pressure region causing air to be drawn into and through the system.
One of the keys to my earlier patented system is the use of a static regain chamber downstream of the venturi device which substantially enhances capacity of my system.
In line venturi systems are typically limited in the length of conduit that they can service simply because the amount of air flow that can be generated at the upstream end of the conduit drops over the length of the conduit. After a certain conduit length, the air flow drops to the point that the product will no longer move through the conduit. With prior art techniques, the only way to overcome this problem is to first drop the material into a settling box or cyclone and then pick it up with a further venturi and blower. This will not work with certain types of material such as continuous strips of material because the material would ball up once it is settled into the box. Furthermore, whenever dust is associated with ythe product and you drop it into the settling box or cyclone it creates a serious dust problem.
This requires the addition of a dust collection substantially adding to the cost of the prior art systems.
208~165 SJ-8646 & A-92 - 2 -SUMMARY OF THE INVENTION
The present invention relates to an air return which is used in an inline venturi system of the type having an upstream blower operated air induction member causing a flow of induced air to move through a conduit downstream of the air induction member.
The air return itself comprises a housing having a product flow region to be fitted inline with the conduit and an air draw region separated from the product flow region by a perforate divider. A baffle is provided internally of the divider. The air return further includes an air return line from the air draw region to be fitted back to the negative pressure side of the blower of the air induction member.
The air return not only provides the static regain, but in addition, because air is drawn from it by the blower, it causes increased draw through the conduit at the location of the air return. Therefore, by adding as many venturies, air returns and blowers as are necessary, the length of the conduit can be virtually limitless.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other advantages and features of the present invention will be described in greater detail according to the preferred embodiments of the present invention in which;
Figure 1 is a schematic view of a venturi system fitted with an air return unit in accordance with a preferred embodiment of the present invention;
Figure 2 is a perspective view of the air return unit when removed from the system of Figure l;
208516~
SJ-8646 & A-92 - 3 -Figure 3 is a perspective view of an internal baffle arrangement used within the air return unit of Figure 3;
Figure 4 is an enlarged perspective view of a section from the baffle unit of Figure 3;
Figure 5 is a perspective view showing insertion of the baffle unit of Figure 3 into the housing of the air return unit of Figure 2;
Figure 6 is an end view of the housing with baffle arrangement after assembly;
Figure 7 is a perspective view of a region of the housing of Eigure 2 with part of the housing removed for inspecting the internal construction of the air return unit;
Figure 8 is a sectional view through the air return unit of Figure 2;
Figure 8a is an enlarged sectional view through some of the conical baffles used in the air return unit of Figure 2.
Figure 9 is a schematic view of an alternate venturi system from that shown in Figure 1 incorporating a plurality of blowers, venturies and air returns feeding in a common direction.
Figure 10 is a schematic view of still a further venturi system reversible in direction of operation..
DETAILED DESCRIPTION ACCORDING TO THE PREFERRED
EMBODIMENTS OF THE PRESENT INVENTION
Figure 1 shows a pneumatic conveying system generally indicated at 1. This system, like the system in my earlier issued patent has an air induction venturi member generally indicated at 3 at the upstream end of the system. A product and air flow conduit 5 is located downstream of the venturi device.
SJ-8646 & A-92 - 4 - 2085165 In my earlier patent, I describe the use of a static regain provided in the product flow conduit. This static regain, according to my earlier patent, is a very simple expansion of the conduit.
In the present application, rather than simply enlarging the conduit, I provide an air return unit generally indicated at 7. This air return unit not only forms a static regain, but in addition, substantially enhances the draw through the product flow conduit. This is achieved because the blower generally indicated at 21 which is used to operate the venturi device 3 draws its air from the air return unit and feeds that air to the venturi device, therefore, not only is there an air induction at the upstream end of the system, but in addition, there is an air draw through the air return unit pulling product downstream along the product flow conduit.
In order to produce an essentially endless venturi system, a series of air return units, and venturies may be provided at spaced intervals along the length of the conduit. Furthermore, if required, additional venturi devices may also be provided.
The air return unit itself comprises a main housing 8 having end connections 9 and 11 for fitting directly into the conduit 5. Internally of housing 8 is a product flow through region 13 which, as can be seen in Figure 1 is directly in line with and forms a continuation of conduit 5. An air draw region 15 surrounds the product flow region 13 and the two regions are separated from one another by means of a perforated screen 14. In the preferred embodiment, the air return unit, like the product flow conduit has a rounded configuration as best seen in Figure 2 of the drawings, and the screen dividing the product flow region form the air draw region is rolled upon itself in a cylindrical configuration.
SJ-8646 & A-92 - 5 - 2085165 Again,according to the preferred construction, screen 14 is more open than it is closed, i.e. it comprises about 40% screen body and about 60% openings through the screen body. The screen therefore allows a very substantial movement of air from the product flow region to the air draw region. However, at the same time, the screen acts to filter product carried by the air flow from moving from the product flow region into the air draw region.
The air return unit is looped or coupled back to the negative pressure side of fan 21 by means of an air return line 17. The air return line includes a divergent mouth 19 opening through the wall of housing 8 to the air draw region. The divergent shaping of mouth 19 adds to its efficiency in that it tends to draw air from all around the entire unit whereas, a straight mouth would tend to have a much more localized air draw. It is to be noted in Figure 1 that the mouth 19 of air return line 17 is of substantially the same configuration as the mouth 24 of air line 23 through which air is provided by the blower to the venturi device 3. This provides a balance of air flow from the air return unit back to the venturi.
In addition screen 14 with its open mesh construction provides an extremely efficient air spreader to once again assist in equalizing the air draw circumferentially and longitudinally of the air return unit rather than having a much more localized draw which would have a much greater tendency to undesirably pull the product into the screen.
In one embodiment of the present invention, the air return unit is provided with an internal baffle assembly generally indicated at 25. This baffle assembly as best seen having reference to Figures 3 through 8 of the drawings is provided to prevent clogging of screen 14. It SJ-8646 & A-92 - 6 - 2085165 allows the air to be drawn from the product flow region but blocks the product itself from being dragged into the screen.
The actual construction of the baffle assembly is best shown in Figure 3 of the drawings. It is formed by a plurality of generally conical members 27 which are secured side by side in line with one another by means of a baffle frame comprising a longated securing strips 31 provided at circumferentially spaced intervals around the baffle assembly. The opposite ends of each of the strips 31 are secured to an end cap 33 which terminates in an extended mouth 34. As best seen in Figure 8 of the drawings, each of the mouths 34 extends beyond the coupling ends 9 and 11 of the air return unit. As best seen in Figure 6 of the drawings, the air return unit itself includes a quick connect coupler, one being provided at each end of the unit for direct connection of the air return unit to the product flow line with the opposite end mouths 34 of the baffle unit being fitted to the inside of the conduit.
Each of the cones 27 is turned or bent at its inner free end 29 to lie essentially parallel with the direction of air movement through the air return unit. This is best seen having reference to figures 8 and 8a of the drawings.
The bending of the cone ends parallel to the direction of air flow reduces turbulence in the air return unit. It also prevents product from catching on the end of the cone.
Furthermore, it eliminates anything in the way of sharp edges to which product would otherwise be exposed while moving downstream to the baffle.
The baffle assembly provides a guide for product flowing through the air return unit and because of the downstream angling and substantially overlapping positioning of the cones, they prevent product from moving outwardly to the dividing screen between the product flow SJ-8646 & A-92 - 7 - 2 0 8 ~ 1 6 ~
region and the air return region of the unit. However, because of the radial gapping betweenthe cones, they do not adversely affect the air draw from the product flow region to the air draw region of the unit.
As clearly described above, the baffle assembly is put together as a unitary structure outside of the air return unit. This unitary structure is then fitted into one end of the air return unit as shown in Figure 5 of the drawings. The fully inserted position of the baffle or assembly is shown in Figure 6 of the drawings.
When working with the baffle assembly the diameter of the screen is widened relative to the product flow conduit into the air return unit leaving room for the baffle assembly so that the interior diameter of the cones matches the interior diameter of the conduit once again maintaining a uniform product flow passage through the system.
The above above assembly of the air return unit is very simple and efficient. As will be appreciated the baffle assembly can be removed just as easily from the air return unit if needed for maintenance purposes. In addition, screen 14 can also be made removable from the unit for cleaning and the like.
As best seen in Figure 2 of the drawings, the housing 8 of the air return unit includes a removable cover plate generally indicated at 35. Figure 7 of the drawings shows the housing with the cover plate removed which allows easy inspection of the interior of the air unit.
Figure 9 shows a system incorporating a plurality of air return units 14, each cooperating with an associated venturi 3 and blower 21 and feeding along a common feed path 5. As will be seen, when using the air return units SJ-8646 ~ A-92 - 8 - 208~16~
there is no need to add settling boxes and dust collectors.
The system of Figure 9 is extremely simple and efficient and can be extended to substantially any desired length.
The system shown in Figure 1 feeds in one direction only. Figure 10 shows a further venturi system generally indicated at 41 which is reversible in its direction of feed. This system includes a pair of venturi devices 3a and 3b both of which operate using a single blower 21 common to both venturi devices. Blower 21 supplies induction air along air flow path 43 feeding to venturi device 3b or in the alternative along air flow path 43a feeding venturi device 3a. A shut off device 45 is provided in flow path 43a and a shut off device 47 is provided in flow path 43b.
Located between the two venturi devices 3a and 3b are conduit sections 5a and 5b with air return unit 6 being placed between the two conduit sections. Air return unit 6, feeds to an air return path 18 back to blower 21.
If it is desired to operate the system such that the product flows from the left to the right hand side of system 41, i.e. from venturi device 3a towards venturi device 3b, shut off 47 in flow path 43b is closed and shut off device 45 is left open such that the induction air from blower 21 feeds to venturi device 3a along flow path 43a and the return air is drawn along line 18 back to the blower. In this example, conduit section 5a, the air return unit, conduit section 5b and venturi device 3b are all located downstream of venturi device 3a.
If it is desired to have product flow in the opposite direction, then shut off device 45 is closed and shut off device 47 is open. Blower 21 then feeds induction air along line 43b to venturi device 3b. The return air 208~16~
SJ-8646 ~ A-92 - 9 -from the air return unit feeds identically, i.e. along line 18 and back to blower 21.
Regardless of the direction of flow, only a single air return unit is required because of its symmetrical construction very similar to the constructionused in air return unit 8 earlier described, except in this case it is preferable to eliminate the baffle assembly which might otherwise catch product flowing against the taper of the baffle cones in the baffle.
It also should be noted that each of the venturi devices has an essentially straight through internal construction which allows product to flow completely through therein if desired.
The shut off devices 45 and 47 can either be automatically or manually operated. Furthermore, they can be replaced with a single diverter located at the juncture of the air flow paths 43a and 43b. The diverter would then be appropriately positioned to direct air flow to either one or the other of the two air flow paths and shut off the flow of air to the unselected path.
The reversible system as described immediately above has many different applications and one of particular note is for use as an office message transmission system.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
SJ-8646 & A-92 - 1 -TITLE: AIR RETURN FOR VENTURI SYSTEM
FIELD OF THE INVENTION
The present invention relates to an air return which is used in an inline venturi system.
BACKGROUND OF THE INVENTION
In line venturi systems are used to move product from place to another. An example of an inline venturi system is described in my own United States Patent 5,002,092 issued March 26, 1991 where I use a blower feeding air to a venturi device to create a low pressure region causing air to be drawn into and through the system.
One of the keys to my earlier patented system is the use of a static regain chamber downstream of the venturi device which substantially enhances capacity of my system.
In line venturi systems are typically limited in the length of conduit that they can service simply because the amount of air flow that can be generated at the upstream end of the conduit drops over the length of the conduit. After a certain conduit length, the air flow drops to the point that the product will no longer move through the conduit. With prior art techniques, the only way to overcome this problem is to first drop the material into a settling box or cyclone and then pick it up with a further venturi and blower. This will not work with certain types of material such as continuous strips of material because the material would ball up once it is settled into the box. Furthermore, whenever dust is associated with ythe product and you drop it into the settling box or cyclone it creates a serious dust problem.
This requires the addition of a dust collection substantially adding to the cost of the prior art systems.
208~165 SJ-8646 & A-92 - 2 -SUMMARY OF THE INVENTION
The present invention relates to an air return which is used in an inline venturi system of the type having an upstream blower operated air induction member causing a flow of induced air to move through a conduit downstream of the air induction member.
The air return itself comprises a housing having a product flow region to be fitted inline with the conduit and an air draw region separated from the product flow region by a perforate divider. A baffle is provided internally of the divider. The air return further includes an air return line from the air draw region to be fitted back to the negative pressure side of the blower of the air induction member.
The air return not only provides the static regain, but in addition, because air is drawn from it by the blower, it causes increased draw through the conduit at the location of the air return. Therefore, by adding as many venturies, air returns and blowers as are necessary, the length of the conduit can be virtually limitless.
BRIEF DESCRIPTION OF THE DRAWINGS
The above as well as other advantages and features of the present invention will be described in greater detail according to the preferred embodiments of the present invention in which;
Figure 1 is a schematic view of a venturi system fitted with an air return unit in accordance with a preferred embodiment of the present invention;
Figure 2 is a perspective view of the air return unit when removed from the system of Figure l;
208516~
SJ-8646 & A-92 - 3 -Figure 3 is a perspective view of an internal baffle arrangement used within the air return unit of Figure 3;
Figure 4 is an enlarged perspective view of a section from the baffle unit of Figure 3;
Figure 5 is a perspective view showing insertion of the baffle unit of Figure 3 into the housing of the air return unit of Figure 2;
Figure 6 is an end view of the housing with baffle arrangement after assembly;
Figure 7 is a perspective view of a region of the housing of Eigure 2 with part of the housing removed for inspecting the internal construction of the air return unit;
Figure 8 is a sectional view through the air return unit of Figure 2;
Figure 8a is an enlarged sectional view through some of the conical baffles used in the air return unit of Figure 2.
Figure 9 is a schematic view of an alternate venturi system from that shown in Figure 1 incorporating a plurality of blowers, venturies and air returns feeding in a common direction.
Figure 10 is a schematic view of still a further venturi system reversible in direction of operation..
DETAILED DESCRIPTION ACCORDING TO THE PREFERRED
EMBODIMENTS OF THE PRESENT INVENTION
Figure 1 shows a pneumatic conveying system generally indicated at 1. This system, like the system in my earlier issued patent has an air induction venturi member generally indicated at 3 at the upstream end of the system. A product and air flow conduit 5 is located downstream of the venturi device.
SJ-8646 & A-92 - 4 - 2085165 In my earlier patent, I describe the use of a static regain provided in the product flow conduit. This static regain, according to my earlier patent, is a very simple expansion of the conduit.
In the present application, rather than simply enlarging the conduit, I provide an air return unit generally indicated at 7. This air return unit not only forms a static regain, but in addition, substantially enhances the draw through the product flow conduit. This is achieved because the blower generally indicated at 21 which is used to operate the venturi device 3 draws its air from the air return unit and feeds that air to the venturi device, therefore, not only is there an air induction at the upstream end of the system, but in addition, there is an air draw through the air return unit pulling product downstream along the product flow conduit.
In order to produce an essentially endless venturi system, a series of air return units, and venturies may be provided at spaced intervals along the length of the conduit. Furthermore, if required, additional venturi devices may also be provided.
The air return unit itself comprises a main housing 8 having end connections 9 and 11 for fitting directly into the conduit 5. Internally of housing 8 is a product flow through region 13 which, as can be seen in Figure 1 is directly in line with and forms a continuation of conduit 5. An air draw region 15 surrounds the product flow region 13 and the two regions are separated from one another by means of a perforated screen 14. In the preferred embodiment, the air return unit, like the product flow conduit has a rounded configuration as best seen in Figure 2 of the drawings, and the screen dividing the product flow region form the air draw region is rolled upon itself in a cylindrical configuration.
SJ-8646 & A-92 - 5 - 2085165 Again,according to the preferred construction, screen 14 is more open than it is closed, i.e. it comprises about 40% screen body and about 60% openings through the screen body. The screen therefore allows a very substantial movement of air from the product flow region to the air draw region. However, at the same time, the screen acts to filter product carried by the air flow from moving from the product flow region into the air draw region.
The air return unit is looped or coupled back to the negative pressure side of fan 21 by means of an air return line 17. The air return line includes a divergent mouth 19 opening through the wall of housing 8 to the air draw region. The divergent shaping of mouth 19 adds to its efficiency in that it tends to draw air from all around the entire unit whereas, a straight mouth would tend to have a much more localized air draw. It is to be noted in Figure 1 that the mouth 19 of air return line 17 is of substantially the same configuration as the mouth 24 of air line 23 through which air is provided by the blower to the venturi device 3. This provides a balance of air flow from the air return unit back to the venturi.
In addition screen 14 with its open mesh construction provides an extremely efficient air spreader to once again assist in equalizing the air draw circumferentially and longitudinally of the air return unit rather than having a much more localized draw which would have a much greater tendency to undesirably pull the product into the screen.
In one embodiment of the present invention, the air return unit is provided with an internal baffle assembly generally indicated at 25. This baffle assembly as best seen having reference to Figures 3 through 8 of the drawings is provided to prevent clogging of screen 14. It SJ-8646 & A-92 - 6 - 2085165 allows the air to be drawn from the product flow region but blocks the product itself from being dragged into the screen.
The actual construction of the baffle assembly is best shown in Figure 3 of the drawings. It is formed by a plurality of generally conical members 27 which are secured side by side in line with one another by means of a baffle frame comprising a longated securing strips 31 provided at circumferentially spaced intervals around the baffle assembly. The opposite ends of each of the strips 31 are secured to an end cap 33 which terminates in an extended mouth 34. As best seen in Figure 8 of the drawings, each of the mouths 34 extends beyond the coupling ends 9 and 11 of the air return unit. As best seen in Figure 6 of the drawings, the air return unit itself includes a quick connect coupler, one being provided at each end of the unit for direct connection of the air return unit to the product flow line with the opposite end mouths 34 of the baffle unit being fitted to the inside of the conduit.
Each of the cones 27 is turned or bent at its inner free end 29 to lie essentially parallel with the direction of air movement through the air return unit. This is best seen having reference to figures 8 and 8a of the drawings.
The bending of the cone ends parallel to the direction of air flow reduces turbulence in the air return unit. It also prevents product from catching on the end of the cone.
Furthermore, it eliminates anything in the way of sharp edges to which product would otherwise be exposed while moving downstream to the baffle.
The baffle assembly provides a guide for product flowing through the air return unit and because of the downstream angling and substantially overlapping positioning of the cones, they prevent product from moving outwardly to the dividing screen between the product flow SJ-8646 & A-92 - 7 - 2 0 8 ~ 1 6 ~
region and the air return region of the unit. However, because of the radial gapping betweenthe cones, they do not adversely affect the air draw from the product flow region to the air draw region of the unit.
As clearly described above, the baffle assembly is put together as a unitary structure outside of the air return unit. This unitary structure is then fitted into one end of the air return unit as shown in Figure 5 of the drawings. The fully inserted position of the baffle or assembly is shown in Figure 6 of the drawings.
When working with the baffle assembly the diameter of the screen is widened relative to the product flow conduit into the air return unit leaving room for the baffle assembly so that the interior diameter of the cones matches the interior diameter of the conduit once again maintaining a uniform product flow passage through the system.
The above above assembly of the air return unit is very simple and efficient. As will be appreciated the baffle assembly can be removed just as easily from the air return unit if needed for maintenance purposes. In addition, screen 14 can also be made removable from the unit for cleaning and the like.
As best seen in Figure 2 of the drawings, the housing 8 of the air return unit includes a removable cover plate generally indicated at 35. Figure 7 of the drawings shows the housing with the cover plate removed which allows easy inspection of the interior of the air unit.
Figure 9 shows a system incorporating a plurality of air return units 14, each cooperating with an associated venturi 3 and blower 21 and feeding along a common feed path 5. As will be seen, when using the air return units SJ-8646 ~ A-92 - 8 - 208~16~
there is no need to add settling boxes and dust collectors.
The system of Figure 9 is extremely simple and efficient and can be extended to substantially any desired length.
The system shown in Figure 1 feeds in one direction only. Figure 10 shows a further venturi system generally indicated at 41 which is reversible in its direction of feed. This system includes a pair of venturi devices 3a and 3b both of which operate using a single blower 21 common to both venturi devices. Blower 21 supplies induction air along air flow path 43 feeding to venturi device 3b or in the alternative along air flow path 43a feeding venturi device 3a. A shut off device 45 is provided in flow path 43a and a shut off device 47 is provided in flow path 43b.
Located between the two venturi devices 3a and 3b are conduit sections 5a and 5b with air return unit 6 being placed between the two conduit sections. Air return unit 6, feeds to an air return path 18 back to blower 21.
If it is desired to operate the system such that the product flows from the left to the right hand side of system 41, i.e. from venturi device 3a towards venturi device 3b, shut off 47 in flow path 43b is closed and shut off device 45 is left open such that the induction air from blower 21 feeds to venturi device 3a along flow path 43a and the return air is drawn along line 18 back to the blower. In this example, conduit section 5a, the air return unit, conduit section 5b and venturi device 3b are all located downstream of venturi device 3a.
If it is desired to have product flow in the opposite direction, then shut off device 45 is closed and shut off device 47 is open. Blower 21 then feeds induction air along line 43b to venturi device 3b. The return air 208~16~
SJ-8646 ~ A-92 - 9 -from the air return unit feeds identically, i.e. along line 18 and back to blower 21.
Regardless of the direction of flow, only a single air return unit is required because of its symmetrical construction very similar to the constructionused in air return unit 8 earlier described, except in this case it is preferable to eliminate the baffle assembly which might otherwise catch product flowing against the taper of the baffle cones in the baffle.
It also should be noted that each of the venturi devices has an essentially straight through internal construction which allows product to flow completely through therein if desired.
The shut off devices 45 and 47 can either be automatically or manually operated. Furthermore, they can be replaced with a single diverter located at the juncture of the air flow paths 43a and 43b. The diverter would then be appropriately positioned to direct air flow to either one or the other of the two air flow paths and shut off the flow of air to the unselected path.
The reversible system as described immediately above has many different applications and one of particular note is for use as an office message transmission system.
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.
Claims (18)
1. A venturi system having an upstream end provided with an air induction member, a product flow conduit downstream of said air induction member and air return means in said flow conduit, said air return means including an air pickup conduit looping in an upstream direction from said air return means to said air induction member, said air return means comprising a housing having a product flow region in line with said product flow conduit and said product flow region including baffle means internally thereof, said system having an air draw region separated from said product flow region by a perforate divider, said air draw region feeding to said air pickup conduit.
2. A venturi system as claimed in Claim 1, wherein said product flow region of said air return means is coaxial with and surrounded by said air draw region.
3. A venturi system as claimed in Claim 2, wherein said product flow region is separated from said air draw region by a tubular screen rolled upon itself.
4. A venturi system as claimed in Claim 3, wherein said tubular screen has a surface area comprised of screen body and screen openings through said screen body, the openings occupying more of the surface area than the screen body.
5. A venturi system as claimed in Claim 4, having about 40% screen body and about 60% screen openings.
6. A venturi system as claimed in Claim 1, wherein perforate divider comprises a screen and said baffle means is tapered inwardly downstream along said screen.
7. A venturi system as claimed in Claim 6, wherein said baffle means comprises a plurality of conical rings at spaced intervals interiorly of said screen in said product flow region.
8. A venturi system as claimed in Claim 7, wherein each conical ring has a free inner end bent rearwardly along said air return means.
9. A venturi system as claimed in Claim 7, wherein said baffle means comprises a plurality of aligned conical rings secured peripherally to one another by elongated securing strips forming a unitary baffle assembly removably secured in said air return means.
10. An air return unit for use in a venturi system controlled by a blower operated air induction device, said air return unit comprising a housing having first and second ends which open into said housing, a product flow region centrally through said housing, baffle means interiorly of said product flow region, said product flow region being surrounded by an air draw region and being separated from said air draw region by a perforate divider, said housing further including an opening from said air draw region to be coupled to an induction device air return line.
11. An air return unit as claimed in Claim 10 wherein said perforate divider comprises a screen rolled upon itself in a tubular configuration.
12. An air return unit as claimed in Claim 10, wherein said baffle means comprises a unitary baffle assembly internally of said perforate divider in said product flow region.
13. An air return unit as claimed in Claim 12, wherein said baffle assembly comprises a plurality of conical rings secured in spaced relationship to one another.
14. An air return unit as claimed in Claim 13, wherein said rings are secured to one another by a pluraltiy of elongated securing strips circumferentially spaced around said baffle assembly.
15. An air return unit as claimed in Claim 13 wherein each conical ring has an inner free end bent rearwardly of the ring.
16. A baffle assembly for use in an air return unit of an in-line venturi system, said baffle assembly comprising a plurality of coaxial conical rings secured in spaced relationship to one another.
17. A baffle assembly as claimed in Claim 16, wherein said rings are secured by a plurality of elongated securing strips peripherally of said rings.
18. A baffle assembly as claimed in Claim 17, wherein each of said rings has an inner end which is directed horizontally rearwardly of said baffle assembly.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2085165 CA2085165C (en) | 1992-12-11 | 1992-12-11 | Air return for venturi system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2085165 CA2085165C (en) | 1992-12-11 | 1992-12-11 | Air return for venturi system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2085165A1 CA2085165A1 (en) | 1994-06-12 |
| CA2085165C true CA2085165C (en) | 1997-05-13 |
Family
ID=4150834
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2085165 Expired - Lifetime CA2085165C (en) | 1992-12-11 | 1992-12-11 | Air return for venturi system |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2085165C (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3455566B1 (en) | 2016-03-07 | 2021-08-18 | Industries SnöFlake Inc. | Conveying assembly for snowmaking apparatus |
-
1992
- 1992-12-11 CA CA 2085165 patent/CA2085165C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| CA2085165A1 (en) | 1994-06-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKEX | Expiry |
Effective date: 20121211 |