The present invention generally relates to air purification and more particularly to catalytic purification of breathable air for an enclosed passenger cabin of a vehicle.
Some vehicles with human occupants may be required to operate in environments in which ambient air is contaminated. Typically such vehicles provide isolated enclosures for the occupants. Specialized air supply systems for such enclosures may provide de-contaminated, non-harmful breathable air for the occupants.
Such vehicles are often employed in military applications. For these applications, vehicle design standards may define requirements for de-contamination of ambient air which may contain nuclear, biological and/or chemical contaminants, so-called NBC contaminants. Examples of vehicles that may need NBC protection may include tanks, armored personnel carriers, low-altitude aircraft or enclosed patrol vehicles.
NBC decontamination in these vehicles may be performed by heating ambient air and passing the heated air through an on-board catalytic purification system. Dedicated heater units are typically provided within a vehicle to heat incoming ambient air to a temperature high enough to accommodate catalytic decontamination reaction. Dedicated heater units consume fuel and add weight and cost to a vehicle.
As can be seen, there is a need for a vehicular ambient-air decontamination which may operate without use of a dedicated heating unit or with reduced use of a heating unit.
In one aspect of the present invention, an air purification system for a vehicle may comprise a first heated-ambient-air source comprising an engine with an ambient air compressor and at least one heated-ambient-air outlet; a second heated-ambient-air source; a mixing valve; a first heated-ambient-air channel connected between the at least one heated-ambient-air outlet of the engine and the mixing valve; a second heated-ambient-air channel connected between the second heated-ambient-air source and the mixing valve; and a catalytic decontamination unit positioned between the mixing valve and an enclosed passenger cabin of the vehicle for removing contaminants from ambient air and producing decontaminated air to the enclosed passenger cabin.
In another aspect of the present invention, a vehicle may comprise: an enclosed passenger compartment isolated from ambient air; at least one inlet for ambient air; at least first and second sources of heat for heating the ambient air. At least a first one of the at least two sources of heat may comprise an engine with an ambient air compressor and at least a first heated-ambient-air outlet. The vehicle may also comprise a temperature-controlled mixing valve; a first heated-ambient-air channel connected between the at least one heated-ambient-air outlet of the engine and the mixing valve; a second heated-ambient-air channel connected between a second heated-ambient-air source and the mixing valve; a catalytic decontamination unit positioned between the mixing valve and an enclosed passenger cabin of the vehicle for removing contaminants from ambient air and producing decontaminated air to the enclosed passenger cabin. The first source of heat may produce heated ambient air suitable for the catalytic decontamination unit only when the vehicle operates under engine-loaded conditions; and the second source of heat may produce heated ambient air suitable for the catalytic decontamination unit when the vehicle is in an idling condition.
In still another aspect of the invention, a method for providing decontaminated air to an enclosed passenger cabin of a vehicle operated in contaminated ambient air may comprise the steps of: admitting ambient air into the vehicle; heating a first portion of the admitted ambient air with a first ambient-air heater comprising a compressor of an engine of the vehicle to produce a first portion of heated ambient air: delivering the first portion of heated ambient air to a mixing valve: heating the a second portion of the ambient-air with a second ambient-air heater to produce a second portion of heated ambient air; delivering the second portion of heated ambient air to the mixing valve: mixing the first and second portions of heated ambient air in the mixing valve to produce controlled-temperature heated ambient air at a temperature within an operating range of a catalytic decontamination unit of the vehicle; catalytically decontaminating the controlled-temperature heated ambient air to produce purified air; and introducing the purified air into the enclosed passenger compartment of the vehicle.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.
The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention.
The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
Various inventive features are described below that can each be used independently of one another or in combination with other features.
Broadly, embodiments of the present invention generally provide for ambient-air decontamination by using heat from an engine of the vehicle to raise the temperature of incoming ambient air so that catalytic decontamination may be performed. More particularly, embodiments of the present invention may extract heat for multiple locations of an engine system so that ambient air may be heated to a temperature that is within an operating range of an on-board catalytic oxidation or decontamination (CATOX) unit. Alternatively, embodiments of the present invention may extract heated ambient air from the engine and combine the engine-heated air with ambient air heated in a dedicated heater to provide an ambient-air temperature within the desired temperature range. Embodiments of the present invention may be particularly useful in vehicles which may be operated with varying engine loading conditions in which heated ambient air from any one location on the engine system may vary outside of an operating temperature range of the CATOX unit.
Referring now to
In the exemplary embodiment of
Referring now to
Referring back to
In a typical one of the vehicles 10, the CATOX unit 30 may be constructed to operate at various temperatures which range from about 400° F. to about 1100° F. For example a CATOX unit such as that disclosed in U.S. Pat. No. 7,132,086 (incorporated by reference herein) may have an operating temperature of between about 500° F. and about 830° F. However, heated air emerging from any one point of the engine 16 may not always be within the temperature range T3. Varying operating conditions of the vehicle 10 may result in variations of the temperatures T1 and T2.
Referring now to
But, it may be further noted that under any conditions other than tactical idling, the temperature T2 of the recuperated bleed air 24 may be higher than the desired temperature range T3. For example, during cross-country operation, secondary road operation and sustained grade operation, T2 may exceed 900° F. However, under these circumstances, the bleed air temperature T1 may be high enough to be within the desired T3 range.
Referring back to
Referring now to
Ambient air 20 may also be drawn into a second heated-ambient-air source 180 which may be a fuel-fired heater or a heat exchanger such as a recuperator heated with turbocharger exhaust, referred to hereinafter as a heater 180. The heater 180 may produce heated ambient air 124. A mixing valve 126 may combine the heated ambient air 122 and the heated ambient air 124 to produce a heated ambient air mixture 128. A catalytic decontamination unit 130 may receive the air mixture 128 from the mixing valve 126 and decontaminate the air mixture 128.
A temperature controller 190 may be provided to produce proportioning signals 190-1 to the mixing valve 126 and heating command signals to the heater 180. The signals 190-1 and 190-2 may vary in correspondence with operating conditions of the vehicle 100. For example, when the vehicle 100 is in an idling condition a temperature T4 of the heated ambient air 122 may be lower than an operating temperature range T5 of the catalytic decontamination unit 130. In that case the temperature controller 190 may produce a command signal 190-2 to the heater so that the heater 180 may heat the heated ambient air 124 to a temperature T6 which may be as high or higher than the operating temperature range T5 of the catalytic decontamination unit 130. The temperature controller may also produce a proportioning signal 190-1 to the mixing valve 126 so that the mixing valve 126 utilizes a proportionally higher volume from the heated ambient air 124 to produce the air mixture 128. Conversely, when the vehicle may be operated under engine-loaded conditions and when the temperature T4 may exceed equal or exceed the temperature T5, the temperature controller 190 may produce a command signal to turn off the heater 180.
Consequently, a vehicle 100 such as that shown in the embodiment of
In one embodiment of the present invention, a method is provided for providing decontaminated air to an enclosed passenger cabin of a vehicle operated in contaminated ambient air. In that regard the method may be understood by referring to
It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.