Claims
- 1. The method of applying granules to a coated asphalt sheet comprising accumulating granules in a nozzle having an opening at the bottom for discharging the granules onto the coated asphalt sheet, discharging a flow of granules through the opening onto the coated asphalt sheet, and changing the air pressure in a buffer chamber positioned in communication with the accumulation of granules to control the flow of granules through the opening.
- 2. The method of claim 1 in which the step of changing the air pressure comprises reducing the pressure in the buffer chamber to stop the flow of granules through the opening.
- 3. The method of claim 2 in which the air pressure in the buffer chamber is decreased to a pressure within the range of about -5 to about -10 inches of water gauge pressure (about -9.3 to about -37.3 mm Hg) to stop the flow of granules through the opening.
- 4. The method of claim 2 in which the step of changing the air pressure comprises increasing the air pressure in the buffer chamber to initiate a flow of granules through the opening, and reducing the pressure in the buffer chamber to stop the flow of granules through the opening.
- 5. The method of claim 4 in which the air pressure in the buffer chamber is increased to a pressure within the range of about 5 to about 20 inches of water gauge pressure (about 9.3 to about 37.3 mm Hg) to initiate the flow of granules through the opening, and decreased to a pressure within the range of about -5 to about -10 inches of water gauge pressure (about -9.3 to about -37.3 mm Hg) to stop the flow of granules through the opening.
- 6. The method of claim 2 in which the reduced pressure in the buffer chamber creates an upward flow of air through the granules at the opening, the upward flow of air being sufficient to prevent the granules from flowing down through the opening by gravity, but insufficient to create fluidization of the granules at the opening.
- 7. The method of claim 1 in which the coated asphalt sheet is moving beneath the nozzle, and further comprising changing the flow rate of granules through the opening in response to changes in the speed of the coated asphalt sheet.
- 8. The method of claim 1 in which the coated asphalt sheet is moving beneath the nozzle and in which a supply of pressurized air is connected to the buffer chamber, and further comprising operating a control means, operatively connected to the supply of pressurized air to the buffer chamber, to vary the flow rate of granules through the opening in response to changes in the speed of the coated asphalt sheet.
- 9. The method of claim 1 in which the coated asphalt sheet is moving beneath the nozzle, and further comprising changing the size of the opening to vary the flow rate of granules through the opening in response to changes in the speed of the coated asphalt sheet.
- 10. The method of applying granules to a coated asphalt sheet comprising accumulating granules in a nozzle having a slot at the bottom for discharging the granules onto the coated asphalt sheet, discharging a flow of granules through the slot onto the coated asphalt sheet, and changing the air pressure in a buffer chamber positioned in communication with the accumulation of granules to control the flow of granules through the slot.
- 11. The method of claim 10 in which the step of changing the air pressure comprises reducing the pressure in the buffer chamber to stop the flow of granules through the slot.
- 12. The method of claim 11 in which the reduced pressure in the buffer chamber creates an upward flow of air through the granules at the slot, the upward flow of air being sufficient to prevent the granules from flowing down through the slot by gravity, but insufficient to create fluidization of the granules at the slot.
- 13. The method of claim 11 in which the air pressure in the buffer chamber is decreased to a pressure within the range of about -5 to about -10 inches of water gauge pressure (about -9.3 to about -37.3 mm Hg) to stop the flow of granules through the slot.
- 14. The method of claim 11 in which the step of changing the air pressure comprises increasing the air pressure in the buffer chamber to initiate a flow of granules through the slot, and reducing the pressure in the buffer chamber to stop the flow of granules through the slot.
- 15. The method of claim 14 in which the air pressure in the buffer chamber is increased to a pressure within the range of about 5 to about 20 inches of water gauge pressure (about 9.3 to about 37.3 mm Hg) to initiate the flow of granules through the slot, and decreased to a pressure within the range of about -5 to about -10 inches of water gauge pressure (about -9.3 to about -37.3 mm Hg) to stop the flow of granules through the slot.
- 16. The method of claim 10 in which the coated asphalt sheet is moving beneath the nozzle, and further comprising changing the flow rate of granules through the slot in response to changes in the speed of the coated asphalt sheet.
- 17. The method of claim 10 in which the coated asphalt sheet is moving beneath the nozzle and in which a supply of pressurized air is connected to the buffer chamber, and further comprising operating a control means, operatively connected to the supply of pressurized air to the buffer chamber, to vary the flow rate of granules through the slot in response to changes in the speed of the coated asphalt sheet.
- 18. The method of claim 10 in which the coated asphalt sheet is moving beneath the nozzle, and further comprising changing the width of the slot to vary the flow rate of granules through the slot in response to changes in the speed of the coated asphalt sheet.
- 19. The method for applying granules to a coated asphalt sheet comprising the steps of:
- providing a nozzle for holding an accumulation of granules supplied to the nozzle, the nozzle having an opening at the bottom for discharging a flow of granules from the accumulation onto a coated asphalt sheet,
- supplying granules to the nozzle to make an accumulation of granules therein,
- providing a buffer chamber positioned in communication with the accumulation of granules,
- providing a source of vacuum in communication with the buffer chamber for reducing an air pressure in the buffer chamber,
- discharging a flow of granules from the accumulation through the opening onto the coated asphalt sheet, and
- operating the vacuum source to stop the flow of granules through the opening by drawing air through the nozzle opening at the bottom of the nozzle.
- 20. The method of claim 19 in which the coated asphalt sheet is moving relative to the nozzle along a path and the opening is a slot arranged transverse to the path of the coated asphalt sheet, and further including providing a source of positive gauge pressurized air in communication with the buffer chamber for increasing an air pressure in the buffer chamber, and operating the source of positive gauge pressurized air to assist the flow of granules through the opening.
- 21. A method for applying granules to a moving web of generally planar material coated with an asphaltic substance to which the granules adhere in the formation of roof covering material, comprising the steps of:
- providing a supply of granules,
- providing a nozzle for holding an accumulation of granules, said nozzle having a top and a bottom,
- supplying granules to said nozzle from said supply to form an accumulation of granules in said nozzle, said accumulation being supplied by delivery means which maintains said accumulation substantially constant in volume in said nozzle in use, said accumulation having a top surface to said accumulation within said nozzle, with an opening at the bottom of said nozzle for discharging a flow of granules from said accumulation onto an asphaltic substance coating a moving web of generally planar material,
- providing an air buffer chamber positioned in communication with said accumulation of granules,
- Providing vacuum means in communication with said buffer chamber for reducing an air pressure in said buffer chamber,
- discharging a flow of granules from said accumulation through said opening onto the asphaltic substance of the moving web, and
- operating said vacuum means to cause an airflow through said opening of said nozzle and into said accumulation to substantially stop said flow of granules through said opening.
- 22. The method of claim 21 in which said opening of said nozzle is an elongated slot, said slot being arranged transverse to a path defined by the moving web, and further including the steps of providing pressurized air means in communication with said buffer chamber for increasing an air pressure in said buffer chamber, and operating said pressurized air means to assist in discharge of granules through said slot from said accumulation.
- 23. A method for applying granules to a moving web coated on a side with a material to which the granules adhere in the formation of roofing material, comprising the steps of:
- providing a container for holding an accumulation of granules, said container having a discharge opening through which granules from said accumulation pass along a discharge path defined by granule flow within said container;
- supplying granules to said container to establish said accumulation and then replenish said accumulation in response to removal of granules through discharge so as to substantially maintain said accumulation at a constant volume;
- providing means for generating and controlling a fluid flow through said accumulation which fluid flow is mixed with said granules and follows a fluid flow path extending along said discharge path, and
- operating said means for generating and controlling a fluid flow to thereby control a flow of granules through said discharge opening onto the coated web.
- 24. A method for applying granules to a moving web coated on a side with a material to which the granules adhere in the formation of roofing material, comprising the steps of:
- providing a container for holding an accumulation of granules, said accumulation having a top surface defined by granules in said container, said container having an elongated discharge opening which is oriented generally transverse to a path defined by the moving web and through which discharge opening granules from said accumulation can pass to drop onto the web under the influence of gravity,
- supplying granules to maintain said accumulation from a hopper holding granules therein and forming a head of granules within said hopper, said hopper having a granule outlet which is in contact with said accumulation and supplies granules from said head to said accumulation by gravity flow in response to removal of granules from said accumulation,
- providing a housing including a buffer plenum chamber enclosing said accumulation of granules,
- providing air pressure means for changing the pressure in said buffer plenum chamber to affect airflow along an airflow path through said accumulation which airflow path extends from said discharge opening to said surface,
- providing control means for said air pressure means to modify said airflow to thereby control a flow of granules through said discharge opening,
- discharging a flow of granules through said discharge opening onto the web, and
- operating said control means in one mode of operation wherein air pressure in said buffer plenum chamber is rapidly reduced to create a reverse airflow along said airflow path to draw air through said discharge opening into said container, said reverse airflow through said discharge opening being controlled to rapidly stop granules from flowing through said discharge opening in said one mode of operation.
- 25. The method of claim 24 further comprising the step of operating said control means in a second mode of operation wherein air pressure in said air buffer plenum is increased to initiate a flow of granules through said discharge opening.
- 26. The method of claim 24 in which said air pressure means creates an upward flow of air through said accumulation of granules at said discharge opening, said upward flow of air being sufficient to prevent said granules from flowing down through said discharge opening by gravity, but insufficient to create fluidization of said granules at said top surface.
- 27. The method of applying granules to a coated asphalt sheet comprising the steps of:
- establishing an accumulation of granules in a non-foraminous nozzle having a top and a bottom with an opening at the bottom for discharging a flow of granules, a surface for said accumulation being defined by said granules which are farthest from said opening in said accumulation,
- establishing a buffer zone in communication with said accumulation of granules at said surface,
- discharging a flow of granules from said accumulation through said opening onto a coated asphalt sheet, and
- changing the air pressure in said buffer zone to control the flow of granules through said nozzle, the air pressure being rapidly decreased in said buffer zone in a first mode of operation to thereby generate an airflow through said nozzle opening and into said accumulation whereby the flow of granules through said nozzle opening is quickly stopped, said airflow being selected to maintain granules forming said surface of said accumulation substantially unentrained in said airflow.
- 28. The method of claim 27 in which a source of vacuum is in communication with said buffer zone, and wherein said step of changing the air pressure comprises operating a control means to connect said source of vacuum to said buffer zone to stop the flow rate of granules through said nozzle opening.
- 29. The method of claim 28 in which a source of pressurized air is in communication with said buffer zone, and wherein said step of changing the air pressure further comprises operating said control means in a second mode of operation to connect said source of pressurized air to said buffer zone to increase the air pressure in said buffer zone to forcibly discharge granules through said opening.
- 30. The method of applying granules to a coated asphalt sheet comprising the steps of:
- establishing a reservoir of granules in a container having a discharge opening, said reservoir having a surface area;
- establishing a fluid flow path through said discharge opening which fluid flow path is in contact with said granules in said reservoir;
- discharging a flow of granules from said reservoir through said discharge opening onto a coated asphalt sheet,
- establishing a flow rate of fluid through said discharge opening,
- changing the flow rate of fluid through said discharge opening to thereby control a flow of granules through said discharge opening, and
- maintaining said reservoir at a substantially constant volume by providing an uninterrupted supply of granules to said reservoir.
- 31. The method of applying granules onto a web coated with asphaltic material which web is moving beneath a source of granules, comprising the steps of:
- establishing a pile of granules in a vessel having a discharge opening, which pile has a top surface area,
- maintaining said pile at a substantially constant volume of granules in response to discharge of granules from said pile;
- establishing an airpath in said pile and through said discharge opening, which airpath is coincident with a discharge path within said vessel defined by a flow of granules from said pile through said discharge opening;
- establishing an air buffer zone in communication with said airpath;
- discharging a flow of granules from said pile through said discharge opening onto a moving web coated with asphaltic material; and
- reducing the air pressure in said buffer zone to generate an airflow through said pile which mixes with said granules and follows said airpath in a direction opposite to said flow of granules along said discharge path to thereby control a flow of granules through said discharge opening by creating a flow of air through the granules at said discharge opening, said airflow through said discharge opening being adjusted at a maximum to prevent said granules from flowing through said discharge opening but insufficient to create entrainment of granules from said surface area in said airflow.
- 32. A method for dispensing granules from an apparatus onto an asphalt-covered surface of a substrate moving past the apparatus comprising the steps of:
- providing a nozzle on the apparatus which nozzle has an elongated slot at the bottom of said nozzle for discharging a flow of granules,
- establishing an accumulation of granules in said nozzle, said accumulation of granules forming a weight in the bottom of said nozzle at said slot,
- providing a buffer chamber positioned in communication with said accumulation of granules,
- providing a vacuum source in communication with said buffer chamber for reducing air pressure in said buffer chamber,
- discharging a flow of granules from said accumulation through said slot onto an asphalt-covered surface of a moving substrate; and
- rapidly stopping said flow of granules through said slot by operating said vacuum source to effect an airflow through said slot and nozzle which airflow has a fluid force sufficient to suspend said weight of granules at said slot in a first mode of operation.
- 33. The method of claim 32 in which said slot is arranged transverse to a path defined by the moving substrate, and further including a source of pressurized air in communication with said buffer chamber for increasing air pressure in said buffer chamber, and comprising the further step of operating said source of pressurized air in a second mode of operation to assist discharge of granules through said slot.
- 34. The method of dispensing granules onto a moving substrate coated with a material to which the granules adhere, comprising the steps of:
- providing a container for holding an accumulation of granules, said container having a discharge opening through which said granules are dispensed, said granules moving within said accumulation along a discharge path defined by granule flow within said container from a top surface of said accumulation to said discharge opening;
- supplying granules to said container to initially establish an accumulation of granules in said container, and then further supplying granules to said container in response to removal of granules through discharge so as to substantially maintain said accumulation at a constant volume;
- discharging a flow of granules from said accumulation through said discharge opening onto a moving substrate coated with a material to which said granules adhere; and
- generating and controlling a fluid flow through said accumulation which fluid flow is mixed with said granules and follows a fluid flow path extending along said discharge path to thereby control said flow of granules through said discharge opening.
- 35. A method for applying granules onto a moving substrate coated with a material to which the granules adhere, comprising the steps of:
- providing a container for holding an accumulation of granules, said container having a discharge opening through which said granules are dispensed, said granules moving within said accumulation along a discharge path defined by granule flow within said container, said accumulation having a top surface of granules in said container which is spaced from said discharge opening;
- providing a housing defining an air buffer zone encompassing said surface;
- providing an air pressure modifying apparatus in communication with said air buffer zone;
- providing a controller for said air pressure apparatus to change air pressure in said air buffer zone;
- discharging a flow of granules from said accumulation through said discharge opening onto the moving substrate; and
- operating said controller to thereby effect a flow of air through said discharge opening and along said discharge path to control a flow of granules through said discharge opening, including one mode of operation wherein air pressure in said air buffer zone is rapidly reduced to create a reverse airflow along said discharge path to draw air through said discharge opening into said container, said reverse airflow through said discharge opening being controlled to rapidly stop granules from flowing through said discharge opening in said one mode of operation.
- 36. The method of claim 35 further including a second mode of operating said controller wherein air pressure in said air buffer zone is increased to assist a flow of granules through said discharge opening.
- 37. The method of claim 35 in which said discharge opening is an elongated slot, said slot being arranged in use transverse to a path defined by the moving substrate, and said air pressure apparatus includes a source of both pressurized air and negative gauge pressure air which are in communication with said buffer zone.
- 38. The method of claim 35 in which said reverse airflow creates an upward flow of air through said granules at said discharge opening sufficient to prevent said granules from flowing down through said discharge opening by gravity, but insufficient to create fluidization of said granules.
Parent Case Info
This is a continuation, of application Ser. No. 08/144,373, filed on Nov. 2, 1993, now abandoned.
US Referenced Citations (52)
Foreign Referenced Citations (4)
Number |
Date |
Country |
107626 |
May 1984 |
EPX |
125585 |
Nov 1984 |
EPX |
224621 |
Jun 1987 |
EPX |
2158813 |
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GBX |
Non-Patent Literature Citations (3)
Entry |
Pp. 1-7 of Chapter 1 "Fluidization Engineering," Second Edition, 1991, Kunii & Levenspiel. |
Pp. 68-74 of Chapter 3 "Fluidization Engineering", Second Edition, 1991, Kunii & Levenspiel. |
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Continuations (1)
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Number |
Date |
Country |
Parent |
144373 |
Nov 1993 |
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