POWDER FEED CONTROL SYSTEM AND METHOD

• US 20180346261A1
• Filed: 05/31/2017
• Published: 12/06/2018
• Est. Priority Date: 05/31/2017
• Status: Active Grant

• Current Assignee: Oerlikon Metco (US) Inc. (Sulzer AG)
• Original Assignee: Oerlikon Metco (US) Inc. (Sulzer AG)
• Inventors: SPAULDING, Mark Frank, ARJONA, Daniel R.
• Granted Patent: US 10,401,246 B2
• Time in Patent Office: Days
• CPC Class Codes: B05B 7/1445 involving vibrations B05B7/145 takes precedence
• CPC Class Codes: B05B 7/1463 the means for supplying particulate material comprising a gas inlet for pressurising or avoiding depressurisation of a powder container
• CPC Class Codes: G01L 13/02 using elastically-deformable members or pistons as sensing elements
• CPC Class Codes: G05D 11/131 by measuring the values related to the quantity of the individual components G05D11/139 takes precedence
• CPC Class Codes: G05D 7/0605 specially adapted for solid materials

Abstract

Powder feed rate control system that includes a hopper adapted to contain a powder and to maintain a hopper pressure. A carrier conduit delivers a carrier gas flow and having an orifice. The carrier gas flow conveys powder entering through the orifice at a powder feed rate. A differential pressure transducer includes a first pressure input associated with the hopper pressure and a second pressure input associated with the carrier gas flow downstream of the hopper. The differential pressure transducer (PT) outputs a signal related to a differential pressure between the first pressure input and the second pressure input. An electro pneumatic regulator (EP) is adapted to communicate with a control and receiving the signal related to the differential pressure.

Claims

1. A powder feed rate control system comprising:

a hopper adapted to contain a powder and to maintain a hopper pressure;

a carrier conduit delivering a carrier gas flow and having an orifice, said carrier gas flow conveying powder entering through the orifice at a powder feed rate;

a differential pressure transducer comprising;

a first pressure input associated with the hopper pressure; and

a second pressure input associated with the carrier gas flow downstream of the hopper;

said differential pressure transducer (PT) outputting a signal related to a differential pressure between the first pressure input and the second pressure input; and

an electro-pneumatic regulator (EP) receiving the signal related to the differential pressure and adapted to communicate with a control.

2. The system of claim 1, wherein the control sets or regulates the carrier gas flow.

3. The system of claim 1, wherein the first pressure input is a high or higher pressure input and the second pressure input is a low or lower pressure input.

4. The system of claim 1, wherein the differential pressure is between 0 and 1 bar.

5. The system of claim 1, wherein the electro-pneumatic regulator (EP) receives a supply pressure of between 2 bar and 10 bar.

6. The system of claim 1, further comprising a spray device coupled to the carrier conduit and operating at a process pressure.

7. The system of claim 6, wherein the process pressure is between 0 bar and 8 bar.

8. The system of claim 6, wherein the spray device is coupled to the carrier conduit via a powder feed hose.

9. The system of claim 1, wherein the signal comprises signal voltage.

10. The system of claim 1, wherein the electro pneumatic regulator (EP) receives command signals from the control.

11. The system of claim 1, wherein the control receives signals from the electro pneumatic regulator (EP).

12. The system of claim 11, wherein the differential pressure is between 0 and 1 bar.

13. The system of claim 1, wherein the system is configured to maintain the differential pressure in real-time regardless of process pressure changes and without any input from the control.

15. A method of regulating powder feed rate with the powder feed rate control system of claim 1, the method comprising:

subjecting a hopper containing powder to a hopper pressure;

delivering a carrier gas flow via a carrier conduit having an orifice, said carrier gas flow conveying powder entering through the orifice at a powder feed rate;

supplying powder to a spray device at a process pressure;

measuring a differential pressure, via a differential pressure transducer, between the hopper pressure and the process pressure; and

outputting, to an electro pneumatic regulator, a signal related to the differential pressure.

16. The method of claim 15, wherein the electro pneumatic regulator communicates with a control and receives the signal related to the differential pressure.

17. The method of claim 15, further comprising regulating the carrier gas flow with the control, wherein the carrier gas flow is between 2 and 15 liters/minute.

18. The method of claim 15, wherein the electro pneumatic regulator receives a supply pressure of between 2 bar and 10 bar.

19. The method of claim 15, wherein the spray device is at least one of:

subject to a process pressure of between 0 bar and 8 bar; and

coupled to the carrier conduit via a powder feed hose.

20. The method of claim 15, wherein the signal comprises signal voltage and the differential pressure is between 0 and 1 bar.

14. A powder feed rate control system comprising:

a control;

a hopper adapted to contain a powder and to maintain a hopper pressure;

a carrier conduit delivering a carrier gas flow and having an orifice, said carrier gas flow conveying powder entering through the orifice at a powder feed rate;

a differential pressure transducer comprising;

a first pressure input coupled to a hopper pressure line; and

a second pressure input coupled to a process pressure line;

said differential pressure transducer outputting a signal related to a differential pressure between a hopper pressure and a process pressure; and

an electro pneumatic regulator receiving command voltage signals from the control and receiving the signal related to the differential pressure,

wherein the differential pressure is proportional to the powder feed rate and is maintained at a pressure of between 0 and 1 bar.