Patent Description:
Aircraft have power systems that are comprised of several components, such as an engine, an environmental control system (ECS) and a thermal management system. These systems are designed relatively independently from each other with power being transferred from one system to another.

The environmental control system supplies pressurized air to the cabin and flight deck of an aircraft. The ambient air is drawn either from the compressor stage of an engine (a bleed air system) or a dedicated compressor. At high altitude (e.g., greater than <NUM>,000ft (<NUM>)), the ambient air contains unacceptable levels of ozone (O<NUM>). Passenger comfort and/or compliance with regulations or agreements can limit the amount of ozone provided to the cabin and flight deck. As such, commercial aircraft generally include an ozone converter that converts ozone to oxygen (O<NUM>).

Ozone converters typically include an ozone-converting core (core) that includes a catalyst which causes the ozone to decompose to oxygen. In operation, such converters are usually connected in-line with the ECS. That is, the length of the combined ECS and the converter is typically extended by at least the length of the converter (if not more) as compared to the ECS alone.

<CIT> relates to a catalytic ozone converter.

According to the invention, an environment control system (ECS) is disclosed. The ECS is provided in claim <NUM>.

The subject matter which is regarded as the invention is pointed out and distinctly claimed in the claims included at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:.

<FIG> illustrates a system <NUM> in which embodiments of the present invention may be implemented. The system <NUM> can be part of an aircraft or any other type of apparatus that can cause the system <NUM> to be moved in a forward direction. For clarity, the following description will assume that the system <NUM> is part of an aircraft but it is not so limited.

The system <NUM> illustrated in <FIG> includes an environmental control system (ECS) <NUM>. The ECS <NUM> receives input air <NUM> and provides output air <NUM> to a location <NUM> within an apparatus. For example, the location <NUM> could be the flight deck or passenger compartment of an aircraft. It shall be understood that the ECS <NUM> shown in <FIG> is extremely simplified and could include many other or different elements.

As illustrated, the ECS <NUM> includes an air parameter adjusting unit <NUM>. The air parameter adjusting unit <NUM> may also be referred to as an air cycle machine (ACM) in certain instances herein. The ACM <NUM>, generally, converts the pressure and/or temperature of the input air <NUM> to a desired level. In one embodiment, the input air <NUM> is bleed air from a compressor section of an engine. For this arrangement, the ozone converter would typically be upstream of the ECS. In another embodiment, the input air <NUM> is ram air received directly from the atmosphere. For this arrangement, the ozone converter would typically be downstream of the ECS compressor such that there is sufficient temperature to facilitate the ozone conversion process.

Regardless of the source of the input air <NUM>, the air parameter adjusting unit <NUM> may include a parameter adjustment device <NUM> that can be operated to adjust the temperature/pressure of the input air <NUM>. The parameter adjustment device <NUM> includes a turbine and/or a compressor. In one embodiment, the parameter adjustment device <NUM> is an electric compressor that compresses ram air. The turbine and the compressor may be connected to one another by shaft and be coaxial with one another in some instances.

If the input air <NUM> is received while the aircraft is at high altitude, there may a requirement (e.g., contractual or regulatory) that ozone be removed from the input air <NUM> before being provided to location <NUM> as output air <NUM>. To that end, the ECS <NUM> also includes an ozone converter <NUM> coupled between the air parameter adjusting unit <NUM> and the location <NUM>. According to the invention, the exact location of the ozone converter <NUM> is varied from that shown in <FIG>.

<FIG> shows an example of a prior art ozone converter <NUM>. The ozone converter <NUM> includes an inlet <NUM> into which inlet air A enters the ozone converter <NUM> and an outlet <NUM> through which outlet air B exits the ozone converter <NUM>. Some or all of the ozone contained in inlet air A is removed in the ozone converter <NUM> such that the outlet air B has less ozone in it that the inlet air A. To this end, the ozone converter <NUM> includes a core that removes some or all of the ozone from the inlet air A to produce outlet air B. The core in the prior art and in embodiments herein can be formed of any type of material that causes or otherwise aids in the conversion of ozone into oxygen. For instance, in one embodiment, the core is formed at least partially of palladium.

In <FIG>, the ozone converter <NUM> is shown as including an inlet housing <NUM> and an outlet housing <NUM>. In one embodiment, one or both of the inlet and outlet housings <NUM>, <NUM> are formed of titanium or a titanium alloy. The inlet and outlet housings <NUM>, <NUM> are coupled together by a removable coupling <NUM> such as V- band coupling. It shall be understood that the removable coupling could be any type of removable coupling such as a bolted flange coupling or other means either now known or later developed for coupling two flanged members together. In the bolted flange coupling, the flanges (described below) can include holes through them and bolts or other fasteners are used to hold the elements together.

As discussed above, the ozone converter <NUM> may increase the length of the ECS <NUM> by at least the length of its outer housing. This increase in length may make it more difficult to locate the ECS <NUM> in an aircraft or may take up space that could otherwise be utilized by other components.

From the above, it is clear that the current art ozone converter consists of a diffuser, ozone converter core and reducing section that require a significant installation length and diameter. Disclosed herein is an annular ozone converter that provides a compact configuration that can be positioned coaxially to the ACM centerline and mounted to the ACM assembly. In such a case, the core may be sized to deliver same face area / flow velocity as a conventional converter in ~<NUM>% of the axial length. The coaxial position to the turbine outlet duct maximizes space utilization. In one embodiment, the housing of the converter may have a removable portion to allow for cleaning or replacement of life limited core.

As illustrated in <FIG>, an ACM <NUM> that receives a medium (e.g., bleed or ram air) from an inlet <NUM> and provides a conditioned form of the air to a compressor output <NUM> is illustrated. The ACM <NUM> comprises a compressor <NUM> and a turbine <NUM> connected to the compressor <NUM> by a shaft (not illustrated) as is known in the art. As illustrated, the compressor <NUM> and the turbine <NUM> are coaxial with another and include known rotating parts that rotate about axis C.

The compressor <NUM> is a mechanical device that raises the pressure of the air received from the inlet <NUM>. Examples of compressor types include centrifugal, diagonal or mixed-flow, axial-flow, reciprocating, ionic liquid piston, rotary screw, rotary vane, scroll, diaphragm, air bubble, etc. Further, compressors can be driven by a motor or the air via the turbine <NUM>.

The turbine <NUM> is mechanical device that drives the compressor <NUM>. The turbine <NUM> can include a plurality of inlet gas flow paths from, for example, RAM or engine compressor bleed flow. As illustrated, the turbine <NUM> includes a turbine outlet <NUM> that may, for example, provide air to a downstream heat exchanger.

As illustrated, an annular ozone converter <NUM> (converter) is connected to the turbine <NUM>. The converter <NUM> includes a converter inlet <NUM> fluidly coupled to the compressor outlet <NUM>. As more fully explained below, the converter <NUM> includes a core that reduces ozone in the air exiting the compressor outlet <NUM>. The outlet of the converter <NUM> may be arranged such that is can be run in parallel with air exiting the turbine outlet <NUM> to save ducting space.

One or more connecting elements <NUM> may form an airtight seal between the converter inlet <NUM> and the compressor outlet <NUM>. The exact nature of these connecting elements may be varied.

Air that enters the converter inlet <NUM> fluidly from the compressor outlet <NUM> is initially provided into an inlet section <NUM>. Air travels in a generally circular path as indicated by arrow D, passes through a core within the converter <NUM> and enters an outlet housing <NUM> that includes converter outlet <NUM>. The outlet housing <NUM> may be removably attached to the inlet housing <NUM> by one more fasteners <NUM>. The fasteners are not limited to the screws shown in <FIG>.

<FIG> shows a cross-section taken along axis C of <FIG>. Air that enters the inlet housing <NUM> initially travels in an outer passage <NUM>. The outer passage <NUM> is at least partially separated from an inner passage <NUM> by a dividing wall <NUM>. The inner passage <NUM> is at least partially surrounded by the outer passage and, as such, is disposed radially inwardly from the outer passage. A core <NUM> is disposed in the inner passage <NUM>. The core removes ozone from air that has left the outer passage <NUM> and entered the inner passage <NUM>. The core is illustrated as being ring shaped and having inner (Id) and outer (Od) diameters. The movement of air from the outer passage <NUM> to the inner passage <NUM> is generally shown by flow arrows E. As can be seen in <FIG>, the converter <NUM> surrounds a portion of the turbine <NUM>. This may, in one embodiment, allow for a reduced length combination of ACM and ozone converter than was previously possible using, for example, an ozone converter as shown in <FIG>.

<FIG> and <FIG> are exploded views of the converter <NUM> and are discussed with reference to <FIG>. The inlet housing <NUM> is generally formed as a torus having an inner wall <NUM>. The inner passage <NUM> is generally defined as between the inner wall <NUM> and the dividing wall <NUM>. Of course, the inner passage could also include at least some volume not so constrained such as shown by region <NUM>.

The core <NUM> is disposed at least partially in the inner passage <NUM>. As illustrated, the core is contained between the inner wall <NUM> and the dividing wall <NUM>. A portion of the core may extend beyond the dividing wall <NUM> in certain embodiments but this is not required.

Air enters the inlet housing <NUM> and initially travels in a circular direction as illustrated by arrow D in outer passage <NUM>. The air then travels around the outer passage and eventually enters the inner passage <NUM> and passes through the core <NUM>. The movement from the outer passage <NUM> and through the inner passage <NUM> (and core <NUM>) is shown by arrows E.

The inlet housing <NUM> may include one or more mounting elements <NUM> that allow it to be coaxially mounted to the turbine <NUM>.

After passing through the core <NUM>, the air then enters the outlet housing <NUM>. The outlet housing <NUM> is, in one embodiment, a volute that includes outlet <NUM>. The volute shaping of the outlet housing <NUM> helps to cause the air to travel in the direction of arrow F to allow more uniform air travel through all or most portions of the core <NUM>.

With reference now to <FIG>, in one embodiment, the core <NUM> may include one or more flanges <NUM>, <NUM>. These flanges <NUM>, <NUM> may fit between the inlet housing <NUM> and the outlet housing <NUM>. When fastening elements <NUM> are secured, the core <NUM> may be held in place. Additionally, flanges <NUM> and <NUM> act as a seal, directing airflow through core <NUM> without leakage. Removal of the fastening elements <NUM> may allow the core <NUM> to be removed for cleaning or replacement.

Claim 1:
An environment control system (ECS) comprising:
an air cycle machine (<NUM>) including a turbine (<NUM>) and a compressor (<NUM>); and
an ozone converter (<NUM>) coupled to the turbine (<NUM>) and surrounding a portion of the turbine (<NUM>);
wherein the ozone converter (<NUM>) includes:
a toroidal shaped inlet housing (<NUM>), the toroidal shaped inlet housing (<NUM>) configured such that air entering the toroidal shaped inlet housing (<NUM>) travels in a circular path;
an outlet housing (<NUM>) that is removably coupled to the inlet housing (<NUM>); and
a ring shaped ozone removing core (<NUM>) disposed at least partially within the inlet housing (<NUM>).