Aircraft fuel filter impending and actual bypass indication system

Patent metadata

Field	Value
Publication number	US-9441598-B2
Application number	US-201314075418-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Nov 8, 2013
Publication date	Sep 13, 2016
Grant date	Sep 13, 2016

Abstract

A fuel supply system includes a fuel supply line, a fuel filter, a filter bypass line, a first differential pressure sensor, a second differential pressure sensor, and a filter bypass valve. The fuel filter is disposed in series in the fuel supply line to remove particulate from the fuel. The filter bypass line has a fuel inlet upstream of the fuel filter, and an outlet that is downstream of the fuel filter. The first differential pressure sensor continuously senses differential pressure across the fuel filter, and the second differential pressure sensor selectively senses differential pressure across the fuel filter. The filter bypass valve is movable between a first non-bypassing position and a second bypassing position and controls whether only the first differential pressure sensor or both the first and second differential pressure sensors sense the differential pressure across the fuel filter.

First claim

What is claimed is:

1. A fuel supply system, comprising:
a fuel supply line adapted to receive fuel from a fuel pump and direct the received fuel to one or more fuel loads;
a fuel filter disposed in series in the fuel supply line and configured to remove particulate from the fuel supplied to the fuel supply line;
a filter bypass line having a bypass line fuel inlet and a bypass line fuel outlet, the bypass line fuel inlet coupled to the fuel supply line upstream of the fuel filter, the bypass line fuel outlet coupled to the fuel supply line downstream of the fuel filter;
a first differential pressure sensor configured to continuously sense differential pressure across the fuel filter;
a second differential pressure sensor configured to selectively sense differential pressure across the fuel filter; and
a filter bypass valve coupled to the filter bypass line and movable between a first position, in which only the first differential pressure sensor senses differential pressure across the fuel filter, and a second position, in which the first differential pressure sensor and the second differential pressure sensor both sense differential pressure across the fuel filter, the filter bypass valve comprising:
a valve body having a fuel inlet, a fuel outlet, a first sensor port, and a second sensor port, the fuel inlet in fluid communication with the bypass line fuel inlet, the fuel outlet in fluid communication with the bypass line fuel outlet, the first sensor port in fluid communication with the first differential pressure sensor, the second sensor port in fluid communication with the second differential pressure sensor; and
a valve element disposed within the valve body and movable between the first position and the second position, wherein in the first position (i) the fuel inlet is in fluid communication with the second sensor port, (ii) the fuel inlet is fluidly isolated from the first sensor port and the fuel outlet, and (iii) the fuel outlet is in fluid communication with the first sensor port, and wherein in the in the second position (i) the fuel inlet is in fluid communication with the fuel outlet, (ii) the fuel inlet is fluidly isolated from the first sensor port and the second sensor port, and (iii) the fuel outlet is in fluid communication with the first sensor port and the second sensor port.

2. The system of claim 1 , wherein the filer bypass valve moves from the first position to the second position when the differential pressure across the fuel filter exceeds a predetermined differential pressure.

3. The system of claim 1 , wherein:
the first differential pressure sensor is in fluid communication with the bypass line fuel inlet and the bypass line fuel outlet when the filter bypass valve is in the first position and the second position; and
the second differential pressure sensor is in fluid communication with the bypass line fuel inlet and the bypass line fuel outlet only when the filter bypass valve is in the second position.

4. The system of claim 3 , wherein the second differential pressure sensor is in fluid communication with only the bypass line fuel inlet when the filter bypass valve is in the first position.

5. The system of claim 1 , wherein the filter bypass valve further comprises a bias spring that biases the valve element toward the first position.

6. The system of claim 5 , wherein the bias spring sets the predetermined differential pressure.

7. The system of claim 1 , wherein the first and second differential pressure sensors are each configured to supply a signal representative of the differential pressure sensed across the fuel filter.

8. A fuel supply system, comprising:
a fuel pump having at least a pump inlet and a pump outlet, the pump inlet adapted to couple to a fuel source, the fuel pump adapted to receive a drive torque and configured, upon receipt of the drive torque, to draw fuel from the fuel source into the pump inlet and discharge fuel from the pump outlet;
a fuel supply line coupled to the pump outlet to receive fuel discharged therefrom and direct the received fuel to one or more fuel loads;
a fuel filter disposed in series in the fuel supply line and configured to remove particulate from the fuel supplied to the fuel supply line;
a filter bypass line having a bypass line fuel inlet and a bypass line fuel outlet, the bypass line fuel inlet coupled to the fuel supply line upstream of the fuel filter, the bypass line fuel outlet coupled to the fuel supply line downstream of the fuel filter;
a first differential pressure sensor configured to continuously sense differential pressure across the fuel filter;
a second differential pressure sensor configured to selectively sense differential pressure across the fuel filter; and
a filter bypass valve coupled to the filter bypass line and movable between a first position, in which only the first differential pressure sensor senses differential pressure across the fuel filter, and a second position, in which the first differential pressure sensor and the second differential pressure sensor both sense differential pressure across the fuel filter, the filter bypass valve comprising:
a valve body having a fuel inlet, a fuel outlet, a first sensor port, and a second sensor port, the fuel inlet in fluid communication with the bypass line fuel inlet, the fuel outlet in fluid communication with the bypass line fuel outlet, the first sensor port in fluid communication with the first differential pressure sensor, the second sensor port in fluid communication with the second differential pressure sensor; and
a valve element disposed within the valve body and movable between the first position and the second position, wherein in the first position (i) the fuel inlet is in fluid communication with the second sensor port, (ii) the fuel inlet is fluidly isolated from the first sensor port and the fuel outlet, and (iii) the fuel outlet is in fluid communication with the first sensor port, and wherein in the in the second position (i) the fuel inlet is in fluid communication with the fuel outlet, (ii) the fuel inlet is fluidly isolated from the first sensor port and the second sensor port, and (iii) the fuel outlet is in fluid communication with the first sensor port and the second sensor port.

9. The system of claim 8 , wherein the filter bypass valve moves from the first position to the second position when the differential pressure across the fuel filter exceeds a predetermined differential pressure.

10. The system of claim 8 , wherein:
the first differential pressure sensor is in fluid communication with the bypass line fuel inlet and the bypass line fuel outlet when the filter bypass valve is in the first position and the second position; and
the second differential pressure sensor is in fluid communication with the bypass line fuel inlet and the bypass line fuel outlet only when the filter bypass valve is in the second position.

11. The system of claim 10 , wherein the second differential pressure sensor is in fluid communication with only the bypass line fuel inlet when the filter bypass valve is in the first position.

12. The system of claim 8 , wherein the filter bypass valve further comprises a bias spring that biases the valve element toward the first position.

13. The system of claim 12 , wherein the bias spring sets the predetermined differential pressure.

14. The system of claim 8 , wherein the first and second differential pressure sensors are each configured to supply a signal representative of the differential pressure sensed across the fuel filter.

Assignees

• Honeywell Int Inc

Inventors

• Futa Paul W
• Kline Gregory
• Hechtl Eric

Classifications

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title

• F02M69/04 Primary

  Injectors peculiar thereto · CPC title

• B01D35/147

  Bypass or safety valves · CPC title

• F02M37/22

  Arrangements for purifying liquid fuel specially adapted for, or arranged on, internal-combustion engines, e.g. arrangements in the feeding system · CPC title

• B01D27/103

  Bypass or safety valves · CPC title