Pneumatic solids transfer pump

Patent metadata

Field	Value
Publication number	US-9302857-B2
Application number	US-201313790142-A
Country	US
Kind code	B2
Filing date	Mar 8, 2013
Priority date	Apr 25, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A transfer pump for moving pellets of adhesive includes a pump housing with an adhesive inlet coupled to a supply hopper, an adhesive outlet coupled to an outlet hose, and an adhesive passage extending between the adhesive inlet and the adhesive outlet. A first air nozzle communicates with the adhesive passage adjacent the adhesive inlet and expels a first air jet that pushes pellets of adhesive through the adhesive passage. A second air nozzle communicates with the adhesive passage between the adhesive inlet and the adhesive outlet and expels a plurality of second air jets that draw pellets of adhesive through the adhesive passage by a vacuum force. The first and second air nozzles prevent clogging of pellets in the adhesive passage and enable movement of larger pellets than either air nozzle individually.

First claim

What is claimed is:

1. A hot melt dispensing system comprising:
a supply hopper for storing adhesive pellets, said supply hopper including a collector portion defining a lowermost surface of said supply hopper;
a transfer pump for transporting adhesive pellets from said supply hopper, said transfer pump comprising a venturi pump including a second air nozzle for creating a low pressure zone in said transfer pump for inducing flow of adhesive pellets from said supply hopper into said transfer pump; and said transfer pump further comprising a pump housing with an adhesive inlet positioned substantially at said lowermost surface of said supply hopper and at an angle relative to a horizontal orientation of said lowermost surface; and
a first air nozzle positioned with respect to said adhesive inlet of said transfer pump for applying a flow of air for agitating the adhesive pellets and moving the adhesive pellets toward said adhesive inlet, said first air nozzle comprising an outlet aimed towards said adhesive inlet of said transfer pump, wherein said outlet of said first air nozzle is positioned upstream of said adhesive inlet of said transfer pump,
said pump housing further including an adhesive outlet configured to be coupled to an outlet hose leading to an adhesive melter, and an adhesive passage located between said adhesive inlet and said adhesive outlet, said adhesive passage defining a passage axis and a passage periphery;
said first air nozzle being configured to expel a first air jet in a direction generally along said passage axis to push pellets of adhesive through said adhesive passage; and
said second air nozzle communicating with said adhesive passage between said adhesive inlet and said adhesive outlet, said second air nozzle configured to expel a plurality of second air jets in a direction generally along said passage periphery to draw pellets of adhesive through said adhesive passage with a vacuum force formed at said low pressure zone,
wherein said supply hopper and said pump housing collectively define a device footprint including a device depth, and said passage axis is angled from a horizontal direction to reduce said device depth and thereby minimize said device footprint.

2. A hot melt dispensing system comprising:
a supply hopper for storing adhesive pellets, said supply hopper including a collector portion defining a lowermost surface of said supply hopper;
a transfer pump for transporting adhesive pellets from said supply hopper, said transfer pump comprising a venturi pump including a second air nozzle for creating a low pressure zone in said transfer pump for inducing flow of adhesive pellets from said supply hopper into said transfer pump; and said transfer pump further comprising a pump housing with an adhesive inlet positioned substantially at said lowermost surface of said supply hopper and at an angle relative to a horizontal orientation of said lowermost surface; and
a first air nozzle positioned with respect to said adhesive inlet of said transfer pump for applying a flow of air for agitating the adhesive pellets and moving the adhesive pellets toward said adhesive inlet, said first air nozzle comprising an outlet aimed towards said adhesive inlet of said transfer pump, wherein said outlet of said first air nozzle is positioned upstream of said adhesive inlet of said transfer pump.

3. The hot melt dispensing system of claim 2 , further comprising:
a melter connected to said transfer pump for heating adhesive pellets into a liquid form; and
a dispenser for administering liquefied adhesive pellets from said melter.

4. The hot melt dispensing system of claim 2 ,
said pump housing further including an adhesive outlet configured to be coupled to an outlet hose leading to an adhesive melter, and an adhesive passage located between said adhesive inlet and said adhesive outlet, said adhesive passage defining a passage axis and a passage periphery;
said first air nozzle being configured to expel a first air jet in a direction generally along said passage axis to push pellets of adhesive through said adhesive passage; and
said second air nozzle communicating with said adhesive passage between said adhesive inlet and said adhesive outlet, said second air nozzle configured to expel a plurality of second air jets in a direction generally along said passage periphery to draw pellets of adhesive through said adhesive passage with a vacuum force formed at said low pressure zone.

5. The hot melt dispensing system of claim 4 , said first air nozzle operating as a gravity eductor for transferring pellets of adhesive to said adhesive outlet.

6. The hot melt dispensing system of claim 5 , said adhesive passage further including a throat portion including a narrowing inner diameter, and the plurality of second air jets is configured to be directed generally tangential to said throat portion such that said second air nozzle operates as a Venturi pump for transferring pellets of adhesive to said adhesive outlet.

7. The hot melt dispensing system of claim 4 , further comprising:
a controller operatively coupled to said first and second air nozzles and operable to control air supplied to each of said first and second air nozzles.

8. The hot melt dispensing system of claim 7 , wherein said controller operates said first air nozzle to force pellets of adhesive out of said adhesive inlet to prevent the pellets from clogging said adhesive inlet, and said controller operates said second air nozzle to throttle a flow of the pellets through said adhesive passage to prevent the pellets from clogging said adhesive passage or the outlet hose.

9. The hot melt dispensing system of claim 7 , wherein said controller is operable to perform the following steps when operation of said transfer pump is to be stopped:
stopping air flow to said first air nozzle to stop pushing pellets of adhesive from said adhesive inlet;
continuing to supply air flow to said second air nozzle for a period of time after stopping air flow to said first air nozzle such that said second air nozzle draws any pellets of adhesive remaining in said pump housing from said adhesive inlet; and
stopping air flow to said second air nozzle to stop transfer of the pellets of adhesive to the adhesive melter.

10. The hot melt dispensing system of claim 2 , wherein said first air nozzle is aligned with said adhesive inlet of said transfer pump.

11. The hot melt dispensing system of claim 10 , wherein said first air nozzle comprises:
an air hose extending into said supply hopper.

12. The hot melt dispensing system of claim 10 , wherein said supply hopper comprises:
a pellet inlet at a top of said supply hopper and a pellet outlet at a bottom of said supply hopper.

13. The hot melt dispensing system of claim 10 , wherein a portion of said supply hopper is substantially funnel shaped.

14. The hot melt dispensing system of claim 10 , further comprising:
an air source for supplying compressed air to said first air nozzle; and
an air control valve connected between said air source and said first air nozzle.

Assignees

• Nordson Corp

Inventors

• Clark Justin A

Classifications

• B05C11/1002

  Means for controlling supply, i.e. flow or pressure, of liquid or other fluent material to the applying apparatus, e.g. valves · CPC title

• B05D1/26

  performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface · CPC title

• B65G53/10 Primary

  with pneumatic injection of the materials by the propelling gas · CPC title

• B65G53/28

  Systems utilising a combination of gas pressure and suction (inducing feed of the materials by suction in gas pressure systems B65G53/14) · CPC title

• B65G53/50

  Pneumatic devices (incorporated in nozzles B65G53/42) · CPC title