Adhesive melter and method having predictive maintenance for exhaust air filter

Patent metadata

Field	Value
Publication number	US-9889996-B2
Application number	US-201715402862-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jul 29, 2013
Publication date	Feb 13, 2018
Grant date	Feb 13, 2018

Abstract

An adhesive melter and a method for operating the adhesive melter enables predictive maintenance of an exhaust air filter used to remove pressurized air flow that delivers solid adhesive particulate from a fill system into the melter. To this end, the fill system repeatedly actuates to refill a receiving space, and a controller monitors a duration of each fill system cycle. When changes in a calculated average duration of a plurality of fill system cycles exceed a maintenance threshold, an alert is emitted at a user interface to prompt maintenance or replacement of the exhaust air filter before a complete shutdown of the fill system is caused by clogging of the exhaust air filter. Consequently, unplanned downtimes caused by clogged exhaust air filters in the adhesive melter can be minimized, regardless of any variable conditions occurring at the melter.

First claim

What is claimed is:

1. An adhesive melter, comprising:
a receiving space configured to receive a supply of solid adhesive particulate;
a heater unit configured to receive the solid adhesive particulate from the receiving space and melt the solid adhesive particulate into melted adhesive;
a fill system coupled to said receiving space and performing fill system cycles that refill said receiving space with solid adhesive particulate and a pressurized air flow;
an exhaust air filter communicating with said fill system and said receiving space, said exhaust air filter exhausting the pressurized air flow from said receiving space during fill system cycles; and
a controller operatively coupled to said fill system and configured to:
repeatedly actuate said fill system,
monitor a duration of each fill system cycle performed by said fill system,
calculate an average duration for a plurality of the fill system cycles,
detect a change in the average duration for the fill system cycles, and
generate a signal if the detected change exceeds a maintenance threshold indicative of said exhaust air filter becoming clogged and requiring maintenance.

2. The adhesive melter of claim 1 , further comprising:
a level sensor located in said receiving space, said level sensor repeatedly sensing a fill level of adhesive located within said receiving space,
wherein said controller is configured to actuate said fill system by starting operation of said fill system when said level sensor senses that the fill level has dropped below a refill threshold and by stopping operation of said fill system when said level sensor senses that the fill level has exceeded a full fill threshold.

3. The adhesive melter of claim 2 , wherein the level sensor comprises multiple level sensors in said receiving space.

4. The adhesive melter of claim 2 , wherein said receiving space is at least partially defined by a sidewall, and said level sensor further comprises:
a plate element;
an electrically driven electrode located on said plate element; and
a ground electrode located on said plate element, the ground electrode being electrically connected to said sidewall such that said sidewall forms at least a portion of said ground electrode, and said ground electrode being electrically connected to said electrically driven electrode for measuring a dielectric capacitance of air and adhesive between said electrically driven and ground electrodes.

5. The adhesive melter of claim 2 , wherein said controller is configured to generate the signal based solely on data received from said level sensor.

6. The adhesive melter of claim 2 , wherein the controller is configured to monitor the duration of each fill system cycle performed by said fill system by:
detecting a first time when the level sensor senses that the fill level has dropped below the refill threshold and a second time when the level sensor senses that the fill level has exceeded the full fill threshold;
calculating a difference between the first time and the second time, the difference corresponding to the duration of the selected fill system cycle; and
repeating the detecting and calculating a difference steps for each of the fill system cycles.

7. The adhesive melter of claim 1 , wherein said controller is configured to detect the change in the average duration for the fill system cycles by:
identifying a predetermined number of most recently calculated average durations for the plurality of the fill system cycles,
analyzing the predetermined number of most recently calculated average durations over time to determine a trend line for the most recently calculated average durations, and
calculating a slope of the trend line to detect the change in the average duration for the fill system cycles.

8. The adhesive melter of claim 1 , wherein the controller is configured to shut down the fill system if the average duration for the plurality of fill system cycles exceeds a maximum flow threshold.

9. The adhesive melter of claim 8 , wherein said controller is configured to generate an alert before the average duration for the plurality of fill system cycles exceeds the maximum flow threshold to provide a period of time for maintenance of said exhaust air filter before shut down of the fill system.

10. The adhesive melter of claim 1 , further comprising a user interface in electrical communications with the controller, wherein the controller is configured to generate the signal by generating an alert signal for transmission to the user interface if the detected change exceeds the maintenance threshold indicative of said exhaust air filter becoming clogged and requiring maintenance.

11. The adhesive melter of claim 10 , wherein the user interface comprises a display, and the display is configured to display an alert in response to reception of the alert signal.

12. The adhesive melter of claim 10 , wherein the user interface comprises a speaker, and the speaker is configured to emit an alert in response to reception of the alert signal.

13. The adhesive melter of claim 10 , wherein the controller is configured to continue generating the alert signal until either maintenance is performed on the exhaust air filter or the fill system shuts down.

14. The adhesive melter of claim 1 , wherein the controller is further configured to:
analyze the duration of each of the fill system cycles to identify outliers; and
discard the outliers before calculating the average duration for the plurality of the fill system cycles.

15. The adhesive melter of claim 1 , wherein the controller is further configured to:
determine that maintenance has been performed on the exhaust air filter;
evaluate a duration of each of the fill system cycles for an initial time period following maintenance of the exhaust air filter until the average duration for a plurality of fill system cycles stabilizes; and
discard the durations of the fill system cycles during the initial time period.

16. The adhesive melter of claim 1 , wherein the fill system is at an ambient temperature to maintain the adhesive particulate as solid adhesive particulate.

17. The adhesive melter of claim 1 , further comprising a reservoir holding the melted adhesive melted by the heater unit.

18. The adhesive melter of claim 17 , further comprising:
a dispenser configured to discharge the melted adhesive on a substrate; and
a pump configured to deliver the melted adhesive from the reservoir to the dispenser.

19. The adhesive melter of claim 1 , further comprising a cyclonic separator mounted to an inlet of the receiving space.

Assignees

• Nordson Corp

Inventors

• Bondeson Benjamin J
• Clark Justin A

Classifications

• B05C11/1042 Primary

  provided with means for heating or cooling the liquid or other fluent material in the supplying means upstream of the applying apparatus · CPC title

• Y10T137/8158

  With indicator, register, recorder, alarm or inspection means · CPC title

• Y10T137/0318

  Processes · CPC title

• B29B13/022

  Melting the material to be shaped · CPC title

• B05C11/00

  Component parts, details or accessories not specifically provided for in groups B05C1/00 - B05C9/00 (means for manipulating or holding work B05C13/00; enclosures for apparatus, booths B05C15/00; spray booths B05B16/00) · CPC title