Electronically controlled direct injection foam delivery system with temperature compensation
First Claim
1. A unit of fire fighting equipment having a direct injection foam delivery system, comprising:
- a water pump for pumping water through a first pipe;
a foam pump for pumping foam through a second pipe;
a mixing chamber having a first input coupled for receiving the water and a second input coupled for receiving the foam and an output for producing a water and foam mixture;
a control unit;
a first conductivity sensor for monitoring conductivity of the water and foam mixture and providing a first electrical signal to the control unit;
a second conductivity sensor for monitoring conductivity of the water and providing a second electrical signal to the control unit, wherein the control unit controls the foam pump in response to a difference between the first electrical signal and second electrical signal;
a flow meter monitors flow rate of the water and provides a third electrical signal to the control unit which in turn controls the foam pump in response to the third electrical signal; and
a temperature sensor monitors the water and provides a fourth electrical signal to the control unit wherein;
the control unit controls the foam pump flow for changes in water conductivity resulting from changes in water temperature, andthe control unit applies a correction factor to the flow meter to account for changes in water viscosity resulting from changes in water temperature.
3 Assignments
0 Petitions
Accused Products
Abstract
Fire fighting equipment uses an electronically controlled direct injection foam delivery system. A water pump pumps water through a pipe. A foam pump pumps foam into a mixing chamber within the pipe to produce a water-foam mixture. A microprocessor-based control unit controls the water pump and foam pump. A conductivity sensor is coupled in-line with the pipe for monitoring conductivity of the mixture and providing a feedback signal to the control unit to regulate the foam pump. A speed sensor monitors the foam usage. A second conductivity sensor monitors conductivity of the water and provides a feedback signal to the control unit. The foam delivery system can be controlled by monitoring the flow rate of the water and regulating the foam pump to maintain a constant water and foam mixture. A temperature sensor compensates the regulation process for changes in water and foam mixture temperature.
34 Citations
25 Claims
-
1. A unit of fire fighting equipment having a direct injection foam delivery system, comprising:
-
a water pump for pumping water through a first pipe; a foam pump for pumping foam through a second pipe; a mixing chamber having a first input coupled for receiving the water and a second input coupled for receiving the foam and an output for producing a water and foam mixture; a control unit; a first conductivity sensor for monitoring conductivity of the water and foam mixture and providing a first electrical signal to the control unit; a second conductivity sensor for monitoring conductivity of the water and providing a second electrical signal to the control unit, wherein the control unit controls the foam pump in response to a difference between the first electrical signal and second electrical signal; a flow meter monitors flow rate of the water and provides a third electrical signal to the control unit which in turn controls the foam pump in response to the third electrical signal; and a temperature sensor monitors the water and provides a fourth electrical signal to the control unit wherein; the control unit controls the foam pump flow for changes in water conductivity resulting from changes in water temperature, and the control unit applies a correction factor to the flow meter to account for changes in water viscosity resulting from changes in water temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A direct injection foam delivery system, comprising:
-
a water pump for pumping water through a first pipe; a foam pump for pumping foam through a second pipe; a mixing chamber having a first input coupled for receiving the water and a second input coupled for receiving the foam and an output for producing a water and foam mixture; a control unit; a first conductivity sensor for monitoring conductivity of the water and foam mixture and providing a mixture conductivity signal to the control unit; a second conductivity sensor for monitoring conductivity of the water and providing a water conductivity signal to the control unit, wherein the control unit controls the foam pump in response to a difference between the mixture conductivity signal and water conductivity signal; and a temperature sensor monitors the water and provides a temperature signal to the control unit wherein the control unit controls the foam pump flow to compensate for changes in water conductivity resulting from changes in water temperature. - View Dependent Claims (9, 10, 11, 12, 13, 14)
-
-
15. A system for mixing first and second fluids, comprising:
-
a conduit including a mixing chamber for transporting the first fluid under pressure, wherein the second fluid is injected into the conduit at the mixing chamber for producing a mixture of first and second fluids; a regulator for controlling a flow rate of the second fluid; a first conductivity sensor coupled to the conduit for monitoring conductivity of the first and second fluid and providing a mixture conductivity signal to the regulator; a second conductivity sensor coupled to the conduit for monitoring conductivity of the first fluid and providing a first fluid conductivity signal to the regulator, wherein the regulator controls the injection of the second fluid in response to a difference between the mixture conductivity signal and first fluid conductivity signal; and a flow meter coupled to the conduit for monitoring a flow rate of the first fluid and providing a flow signal to the regulator which controls the injection of the second fluid at the mixing chamber in response to the flow signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A method of injecting foam into water flow, comprising:
-
pumping water through a first pipe; pumping foam through a second pipe; mixing the water and foam to produce a water and foam mixture; monitoring flow rate of the water; sensing temperature of the water; and regulating the water and foam mixture, wherein the regulation includes; adjusting foam pumping flow to compensate for changes in water conductivity resulting from changes in water temperature, and adjusting the flow meter to account for changes in water viscosity resulting from changes in water temperature. - View Dependent Claims (25)
-
Specification