Mobile system for deicing aircraft

• US 5,028,017 A
• Filed: 08/08/1989
• Issued: 07/02/1991
• Est. Priority Date: 08/08/1989
• Status: Expired due to Term

• Current Assignee: Federal Express Corporation (FedEx Corporation)
• Original Assignee: Federal Express Corporation (FedEx Corporation)
• Inventors: Thompson, James R., Simmons, Charles M., Harkins, Thomas V. Jr., Talleg, Charles W.
• Primary Examiner(s): Peters, Jr., Joseph F.
• Assistant Examiner(s): Ellis, Christopher P.
• Application Number:
  US07/390,707
• Time in Patent Office: 693 Days
• Field of Search: 244/134 C, 244/134 R, 239/130, 239/131, 239/172, 239/135, 239/423, 239/75, 219/301, 219/306, 236/93 R, 236/93 B, 236/12.12
• US Class Current: 244/134.00C
• CPC Class Codes: B64F 5/20 Ground installations for de-icing aircraft
• CPC Class Codes: B64F 5/23 by liquid application; Spraying installations therefor, e.g. fitted on vehicles

Abstract

A deicing system for applying a deicing mixture to an aircraft is provided. Water is enclosed in a first tank, and deicing fluid in a second tank. A first pump transfers water through a heater, to a heat exchanger located in the second tank. The deicing fluid is thereby heated to a desired operating temperature by the hot water flowing through the heat exchanger, with the flow of hot water controlled by a heater control device. The first pump and second pump transfer heated water and heated deicing fluid, respectively, to a mixing chamber. A mixing control means controls the respective flows to provide the desired mixture. The mixture of water and deicing fluid is then applied to the aircraft via a nozzle.

Claims

1. A deicing system for applying a deicing mixture to an aircraft, the system comprising:

a first tank for holding water;

a second tank for holding deicing fluid;

a water heater in fluid communication with said first tank for heating the water;

a heat exchanger, located in said second tank and in fluid communication with said heater, for accepting the heated water to heat the deicing fluid;

a first pump in fluid communication with said first tank for pumping water;

a second pump in fluid communication with said second tank for pumping deicing fluid;

heater control means, coupled with said first pump, for controlling flow of the heated water through said heat exchanger until the temperature of the deicing fluid in said second tank reaches a preselected temperature;

mixing means in fluid communication with said first and second tanks for mixing the water and the deicing fluid;

mixing control means for providing a choice of a plurality of selected mixtures of water and deicing fluid to said mixing means; and

a nozzle in fluid communication with said mixing means to apply one of the preselected mixtures to the aircraft.

2. The deicing system of claim 1 wherein said heat control means further includes means for resuming the flow of heated water through said heat exchanger if the temperature of the deicing fluid in the tank falls below the preselected temperature.

3. The deicing system of claim 1 further comprising means for activating said second pump when the spray nozzle is open and for deactivating said second pump when the spray nozzle is closed.

4. The deicing system of claim 3 wherein said activating means includes a pressure sensor for sensing the drop and rise associated with the opening and closing, respectively, of said nozzle and computer control means coupled with said pressure sensor means and said second pump for causing said second pump to turn on when the sensed pressure drops below a preselected low level and causing the second pump to turn Off when the sensed pressure reaches a preselected high level.

5. The deicing system of claim 4 wherein said pressure sensor is positioned between said mixing means and said second pump.

6. The deicing system of claim 1 further comprising means for selectively purging water from the elements of the system except the water tank and replacing the water with deicing fluid in order to prevent damage by freezing.

7. The deicing system of claim 1 wherein said heat exchanger includes a plurality of coils formed in said second tank.

8. The deicing system of claim 1 wherein said heat control means includes a temperature sensor for sensing the temperature of deicing fluid in said second tank, a control valve positioned between said water heater and said heat exchanger, and a computer control coupled with said temperature sensor and said control valve for interrupting the flow of heated water through said heat exchanger when the temperature sensed by said temperature sensor reaches said preselected temperature.

9. The deicing system of claim 1 further comprising a first temperature sensor in said first tank for sensing the temperature of the water in said first tank and control means for deactivating said heater when the water is heated to a preselected temperature.

10. The deicing system of claim 1 wherein said second pump is a positive displacement pump.

11. The deicing system of claim 10 wherein said second pump is a pump selected for the group consisting of a diaphragm pump and a progressive cavity pump.

12. The deicing system of claim 1 wherein the fluid communication between said second tank and said mixing means consists essentially of a first length of smooth tubing between said second tank and said second pump, said second pump, and a second length of smooth tubing between said second pump and said mixing means.

13. The deicing system of claim 1 wherein said mixing means is a mixing tube having a first inlet in fluid communication with said first tank, a second inlet in fluid communication with second tank, and an outlet in fluid communication with said nozzle.

14. The deicing system of claim 13 wherein a mixing element is fixedly connected inside said mixing tube.

15. The deicing system of claim 6 wherein said purging means includes a purge valve in fluid communication with said second tank and said first pump and control means coupled with said purge valve and said first pump for causing a preselected amount of deicing fluid to flow through said heater and said heat exchanger to thereby replace water with deicing fluid.

16. The deicing system of claim 1 wherein said mixing control means includes means for sensing the speeds of said first pump and said second pump and a programmable computer coupled with said speed sensing means and said first and second pumps.

17. A deicing system for applying a deicing mixture including a Type II deicing fluid to an aircraft, the system comprising:

a first tank for holding water;

a second tank for holding Type II deicing fluid

a water heater in fluid communication with said first tank for heating the water;

a heat exchanger, located in second tank and in fluid communication with said heater, for accepting the heated water to heat the Type II deicing fluid;

a first pump in fluid communication with said first tank for pumping water;

a second pump in fluid communication with said second tank for pumping Type II deicing fluid without degenerating said Type II fluid;

a heater control means, coupled with said first pump, for controlling flow of the heated water through said heat exchanger until the temperature of the Type II deicing fluid in said second tank reaches a preselected temperature;

a mixing tube in fluid communication with said first and second tanks for mixing the water and the Type II fluid;

a mixing control means for providing a choice of a plurality of preselected mixtures of heated water and heated Type II deicing fluid to said mixing means;

as nozzle in fluid communication with said mixing means to apply one of the preselected mixtures to the aircraft; and

second pump control means for activating said second pump when the spray nozzle is open and for deactivating said second pump when the spray nozzle is closed.

18. The deicing system of claim 17 wherein said that exchanger includes coils of elongated tubing positioned with their longitudinal axes parallel the bottom of said second tank.

19. The deicing system of claim 18 wherein said heat control means includes a temperature sensor for sensing the temperature of deicing fluid insaid second tank, a control valve positioned between said water heater and said heat exchanger, and a computer control coupled with said temperature sensor and said control valve of r interrupting the flow of heated water through said heat exchanger when the temperature sensed by said temperature sensor reaches said predetermined temperature.

20. The deicing system of claim 19 wherein said coils are positioned proximate the bottom of said second tank.

21. The deicing system of claim 17 wherein said second pump is a positive displacement pump selected from the group consisting of a diaphragm pump or a progressive cavity pump.

22. The deicing system of claim 21 wherein the fluid communication between said second tank and said mixing means consists essentially of a first length of smooth tubing between said second tank and said second pump, said second pump, and a second length of smooth tubing between said second pump and said mixing means.

23. The deicing system of claim 17 wherein a discontinues spiral mixing element is fixedly connected inside said mixing tube.

24. The deicing system of claim 23 wherein said mixing tube includes a cylindrical sleeve and a cap manifold fixed to said sleeve, said spiral mixing element is fixed to said cap manifold and is slidably received within said cylindrical sleeve, and said cap manifold has two separate inlets positioned on opposite sides of said spiral mixing element, whereby water can be introduced on one side of the spiral mixing element and Type II deicing fluid can be introduced on the other side of the spiral mixing element.

25. The deicing system of claim 17 wherein said mixing control means includes means for sensing the speeds of said first pump and said second pump and a computer coupled with said speed sensing means and said first and second pumps for keeping the ratio of the speeds of said first and second pumps at a preselected, constant ratio.

26. The deicing system of claim 17 wherein all of the elements of the system are placed on a mobile vehicle.