Molecular sieve abstract
A method of installing a molecular sieve bed gas enriching system
in a vehicle, the method including installing in the vehicle a system
controller, a product gas distribution conduit which extends to
at least one product gas distribution position, and a high pressure
gas supply conduit which extends from a high pressure gas source,
providing a plurality of molecular sieve bed modules, each module
including a container containing molecular sieve bed material, a
first gas communication port from the container with an outlet duct
for product gas produced in use during a charging phase of the molecular
sieve bed, the outlet duct including an outlet valve to prevent
ingress of gas into the container through the first gas communication
port, and the container including a second gas communication port
which is connected to a valve assembly which, depending upon the
controlled state of the valve assembly, in use permits of communication
between the interior of the container and one of a gas supply duct
during the charging phase of the molecular sieve bed and a venting
duct during a venting phase of the molecular sieve bed, introducing
each of the modules independently into the vehicle, connecting each
of the outlet ducts 14 to the product gas distribution conduit,
connecting each of the gas supply ducts to the high pressure gas
supply conduit, and connecting the controller to each of the valve
assemblies of the modules so that the controller is operable in
use to change the controlled state of each of the valve assemblies.
Molecular sieve claims
1. A method of installing a molecular sieve bed gas enriching system
in a vehicle, the system including a plurality of molecular sieve
beds each of which is operable in a charging phase to adsorb non-product
gas from a high pressure gas supply, and in a venting phase when
the sieve bed is connected to a low pressure, to release adsorbed
non-product gas from the molecular sieve bed, the method including
installing in the vehicle a system controller, a product gas distribution
conduit which extends to at least one product gas distribution position,
and a high pressure gas supply conduit which extends from a high
pressure gas source, providing a plurality of molecular sieve bed
modules, each module including a container containing molecular
sieve bed material, a first gas communication port from the container
with an outlet duct for product gas produced in use during the charging
phase of the molecular sieve bed, the outlet duct including an outlet
valve to prevent ingress of gas into the container through the first
gas communication port, and the container including a second gas
communication port which is connected to a valve assembly which,
depending upon the controlled state of the valve assembly, in use
permits of communication between the interior of the container and
one of a gas supply duct during the charging phase of the molecular
sieve bed and a venting duct during the venting phase of the molecular
sieve bed, introducing each of the modules independently into the
vehicle, connecting each of the outlet ducts to the product gas
distribution conduit, connecting each of the gas supply ducts to
the high pressure gas supply conduit, and connecting the controller
to each of the valve assemblies of the modules so that the controller
is operable in use to change the controlled state of each of the
valve assemblies.
2. A method according to claim 1 wherein each of the venting ducts
is connected at least in use of the system, to a low pressure.
3. A method according to claim 1 which includes connecting each
venting duct to a gas venting conduit which extends to a vent outlet
from the vehicle.
4. A method according to claim 1 wherein each of the valve assemblies
includes an electrically operated valve which in use responds to
a control signal from the controller to assume a controlled state,
and the method includes electrically connecting the electrically
operated valve to the controller during installation.
5. A method according to claim 4 wherein the method includes installing
control cables in the vehicle prior to introducing the modules into
the vehicle.
6. A method according to claim 1 wherein the vehicle includes a
gas turbine engine, and the high pressure gas is bled from the engine.
7. A method according to claim 6 wherein the vehicle is an aircraft
and the product gas is oxygen enriched gas.
8. A method according to claim 1 wherein the method includes programming
the controller to operate the valve assemblies of the molecular
sieve bed modules according to a control algorithm.
9. A method according to claim 8 wherein the method includes programming
the controller to select a control regime from a plurality of control
regimes automatically depending upon the number of molecular sieve
bed modules which are operable in the system.
10. A molecular sieve bed gas enriching system for a vehicle, the
system including a plurality of molecular sieve beds each of which
is operable in a charging phase to adsorb non-product gas from a
high pressure gas supply, and in a venting phase when the sieve
bed is connected to a low pressure, to release adsorbed non-product
gas from the molecular sieve bed, the system further including a
system controller, a product gas distribution conduit which extends
to at least one product gas distribution position in the vehicle,
and a high pressure gas supply conduit which extends from the high
pressure gas supply of the vehicle, the molecular sieve beds each
being provided as a component of a molecular sieve bed module, each
module including a container containing molecular sieve bed material,
a first gas communication port from the container with an outlet
duct for product gas produced in use during the charging phase of
the molecular sieve bed, the outlet duct including a valve to prevent
ingress of gas into the container through the first gas communication
port, and the container including a second gas communication port
which is connected to a valve assembly which, depending upon the
controlled state of the valve assembly, in use permits of communication
between the interior of the container and one of a gas supply duct
during the charging phase of the molecular sieve bed and a venting
duct during the venting phase of the molecular sieve bed, each of
the outlet ducts of the modules being connected to the product gas
distribution conduit, and each of the gas supply ducts being connected
to the high pressure gas supply, and the controller being connected
to each of the valve assemblies of the modules so that the controller
is operable in use to change the controlled state of each of the
valve assemblies.
11. A vehicle including a molecular sieve bed gas enriching system,
the system including a plurality of molecular sieve beds each of
which is operable in a charging phase to adsorb non-product gas
from a high pressure gas supply, and in a venting phase when the
sieve bed is connected to a low pressure, to release adsorbed non-product
gas from the molecular sieve bed, the method including installing
in the vehicle a system controller, a product gas distribution conduit
which extends to at least one product gas distribution position,
and a high pressure gas supply conduit which extends from a high
pressure gas source, providing a plurality of molecular sieve bed
modules, each module including a container containing molecular
sieve bed material, a first gas communication port from the container
with an outlet duct for product gas produced in use during the charging
phase of the molecular sieve bed, the outlet duct including an outlet
valve to prevent ingress of gas into the container through the first
gas communication port, and the container including a second gas
communication port which is connected to a valve assembly which,
depending upon the controlled state of the valve assembly, in use
permits of communication between the interior of the container and
one of a gas supply duct during the charging phase of the molecular
sieve bed and a venting duct during the venting phase of the molecular
sieve bed, introducing each of the modules independently into the
vehicle, connecting each of the outlet ducts to the product gas
distribution conduit, connecting each of the gas supply ducts to
the high pressure gas supply conduit, and connecting the controller
to each of the valve assemblies of the modules so that the controller
is operable in use to change the controlled state of each of the
valve assemblies.
12. A vehicle according to claim 11 which is an aircraft.
Molecular sieve description
TECHNICAL FIELD
[0001] This invention relates to a method of installing a molecular
sieve bed gas-enriching system in a vehicle.
[0002] Such systems typically include a plurality of molecular
sieve beds each of which is operable in a charging phase to adsorb
non-product gas from a high pressure gas supply, and in a venting
phase when the sieve bed is connected to a low pressure, to release
adsorbed non-product gas from the molecular sieve bed. The invention
has been developed particularly but not exclusively for a system
for producing oxygen enriched product gas for breathing, in an aircraft.
BACKGROUND OF THE INVENTION
[0003] Conventionally in such a system, the beds are operated in
pairs or triplets or groups of other numbers of beds, so that when
one or more beds of the system are operating in a venting phase,
at least one bed is operating in a charging phase, so that oxygen
enriched gas is continuously being produced.
[0004] It is essential for the integrity of the system, to protect
the molecular sieve bed material of the beds from contamination
such as particulate contamination, e.g. dust, which is most likely
to occur during installation in the aircraft, and from water ingestion
which is most likely to occur during storage of the molecular sieve
bed material. Also components and fittings for a bed tend to be
particular for that bed.
[0005] Thus to prevent the likelihood of contamination, water ingestion
and the exchanging of components and fittings between the beds,
groups of the beds e.g. two beds which are to be operated in tandem,
are conventionally provided as modules with all associated valves
etc. to enable the material of the bed to be isolated during storage
and installation, ready to be plumbed into supply and distribution
conduits of the aircraft.
[0006] However such modules thus tend to be heavy and difficult
to handle during installation and removal e.g. for repair or replacement.
[0007] It has been proposed in U.S. Pat. No. 5549736 to provide
a modular sieve bed so that the area/volume of the sieve bed material
available for non-product gas adsorption can be tailored to a desired
product gas producing capacity. However, the modules of the arrangement
described are assembled by connecting together fittings which provide
manifolds for the inlet and outlet gases, such that although the
arrangement relieves the problem of overly heavy and bulky multiple
bed modules, the molecular sieve bed material is not isolated during
and prior to installation of the modules, making contamination and
water ingestion a possibility.
BRIEF SUMMARY OF THE INVENTION
[0008] According to a first aspect of the invention we provide
a method of installing a molecular sieve bed gas-enriching system
in a vehicle, the system including a plurality of molecular sieve
beds each of which is operable in a charging phase to adsorb non-product
gas from a high pressure gas supply, and in a venting phase when
the sieve bed is connected to a low pressure, to release adsorbed
non-product gas from the molecular sieve bed, the method including
installing in the vehicle a system controller, a product gas distribution
conduit which extends to at least one product gas distribution position,
and a high pressure gas supply conduit which extends from a high
pressure gas source, providing a plurality of molecular sieve bed
modules, each module including a container containing molecular
sieve bed material, a first gas communication port from the container
with an outlet duct for product gas produced in use during the charging
phase of the molecular sieve bed, the outlet duct including an outlet
valve to prevent ingress of gas into the container through the first
gas communication port, and the container including a second gas
communication port which is connected to a valve assembly which,
depending upon the controlled state of the valve assembly, in use
permits of communication between the interior of the container and
one of a gas supply duct during the charging phase of the molecular
sieve bed and a venting duct during the venting phase of the molecular
sieve bed, introducing each of the modules independently into the
vehicle, connecting each of the outlet ducts to the product gas
distribution conduit, connecting each of the gas supply ducts to
the high pressure gas supply conduit, and connecting the controller
to each of the valve assemblies of the modules so that the controller
is operable in use to change the controlled state of each of the
valve assemblies.
[0009] Thus by the installation method of the invention, the molecular
sieve bed material is isolated in the containers prior to use, reducing
the risk of contamination and water ingestion. Moreover the modules
include single molecular sieve beds, making them more easy to handle
during installation. Not only are the modules smaller than modules
including a group of molecular sieve beds, but the single bed modules
are lighter too.
[0010] The venting ducts of the modules may be is connected at
least in use of the system, to any low pressure. For example where
the vehicle is an aircraft, and the product gas is oxygen enriched
gas for breathing, where the system is intended only for use during
an emergency situation i.e. cabin decompression, the low pressure
may be established in the aircraft cabin or hold such that the venting
ducts simply open to the aircraft cabin or hold.
[0011] However particularly where it may be desired to operate
the system to provide oxygen enriched gas during non-decompression
conditions, e.g. for therapeutic purposes, the method of the invention
may include connecting each venting duct to a gas venting conduit
which extends to a vent outlet from the aircraft or other vehicle,
and preferably installing the gas venting conduit prior to introducing
the molecular sieve bed modules into the vehicle.
[0012] Each of the valve assemblies may include an electrically
operated valve which in use responds to a control signal from the
controller to assume a controlled state, and the method may include
electrically connecting the electrically operated valve to the controller
during installation.
[0013] To achieve this the method may include installing control
cables in the vehicle prior to introducing the modules into the
vehicle.
[0014] The vehicle may include a gas turbine engine, and the high
pressure gas may be bled from the engine although other sources
of high pressure gas may be used as desired.
[0015] Where the vehicle is an aircraft, the product gas may be
is oxygen enriched gas.
[0016] It is known to operate groups of molecular sieve beds according
to various control regimes either to maximise product gas enrichment,
and/or vary the degree of enrichment to suit operational conditions.
For example in an aircraft at highest altitudes, maximally oxygen
enriched gas for breathing would be required, whereas at lower altitudes,
less-oxygen enriched gas may be required. Whereas conventionally,
where a group of molecular sieve beds have been provided as a module,
the beds have been matched to be operated as a group according to
a particular control algorithm, according to the method of the invention
the controller may be programmed to operate the valve assemblies
of the individual molecular sieve bed modules according to any desired
control algorithm.
[0017] The method may include programming the controller to select
a control regime from a plurality of control regimes automatically
depending upon the number of molecular sieve bed modules which are
operable in the system. Thus a common molecular sieve bed gas-enriching
system may be provided for a plurality of applications irrespective
of the number of individual molecular sieve beds which are provided.
Moreover, in the event of a malfunction of any bed or modules, the
controller may be programmed automatically to change the operating
regime to operate the remaining operable beds to provide product
gas with a desired degree of enrichment.
[0018] According to a second aspect of the invention we provide
a molecular sieve bed gas-enriching system for a vehicle, the system
including a plurality of molecular sieve beds each of which is operable
in a charging phase to adsorb non-product gas from a high pressure
gas supply, and in a venting phase when the sieve bed is connected
to a low pressure, to release adsorbed non-product gas from the
molecular sieve bed, the system further including a system controller,
a product gas distribution conduit which extends to at least one
product gas distribution position in the vehicle, and a high pressure
gas supply conduit which extends from a high pressure gas source
of the vehicle, the molecular sieve beds each being provided as
a component of a molecular sieve bed module, the module including
a container containing molecular sieve bed material, a first gas
communication port from the container with an outlet duct for product
gas produced in use during the charging phase of the molecular sieve
bed, the outlet duct including a valve to prevent ingress of gas
into the container through the first gas communication port, and
the container including a second gas communication port which is
connected to a valve assembly which, depending upon the controlled
state of the valve assembly, in use permits of communication between
the interior of the container and one of a gas supply duct during
the charging phase of the molecular sieve bed and a venting duct
during the venting phase of the molecular sieve bed, each of the
outlet ducts of the modules being connected to the product gas distribution
conduit, and each of the gas supply ducts being connected to the
high pressure gas supply conduit, and the controller being connected
to each of the valve assemblies of the modules so that the controller
is operable in use to change the controlled state of each of the
valve assemblies.
[0019] According to a third aspect of the invention we provide
a vehicle including a molecular sieve bed gas-enriching system installed
by a method of the first aspect of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an illustrative view of a gas-enriching system
for installation by the method of the invention;
[0021] FIG. 2 is an illustrative view of a molecular sieve bed
module for use in the system of FIG. 1.
[0022] FIG. 3 is an illustrative view of a part of a modified system
installed by the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] Referring to FIGS. 1 and 2 of the drawings 1 there is shown
a molecular sieve bed gas enriching system 10. In this example the
system 10 is for producing oxygen enriched gas for breathing, in
an aircraft.
[0024] The system 10 includes a plurality of molecular sieve bed
modules 11a, 11b, 11c etc. which each includes a container 12 containing
molecular sieve bed material, in this case, for adsorbing nitrogen
from high pressure air. Each container 12 includes a first gas communication
port 13 to which is connected an outlet duct 14 for product gas,
the outlet duct 14 including an outlet valve 15 which in this example
is a simple non-return valve, which closes to prevent the ingress
of gas into the container 12 through the first gas communication
port 13.
[0025] Each container 12 further includes a second gas communication
port 16 which is connected to a valve assembly 17. The valve assembly
17 includes an electrically operable valve 18 which in use, and
depending on its controlled state, permits of communication between
the interior of the container 12 via the second gas communication
port 16 and one of a gas supply duct 19 during the charging phase
of the molecular sieve bed and a venting duct 20 during the venting
phase of the molecular sieve bed.
[0026] Thus each module 11a, 11b, 11c etc. is sufficiently small
and light to enable the modules 11a, 11b, 11c individually and independently
to be readily handled during installation and removal in the system
10 as hereinafter explained.
[0027] The electrically operable valves may conveniently be solenoid
operated, although motor driven valves could alternatively be used.
The valve assemblies 17 may include diaphragm of other valves to
ensure complete isolation of the venting ducts 20 from the gas supply
ducts 19 during the charging and venting phases of operation.
[0028] The system further includes a system controller 25 which
is programmed as hereinafter explained to operate the modules 11a,
11b, 11c etc., a product gas distribution conduit 28 which extends
to at least one product gas distribution position in the aircraft,
such as a face mask for personal breathing, and a high pressure
gas supply conduit 29 which extends from a high pressure air supply
which in this example is a pressurised air bled from an aircraft
engine downstream of an engine turbine which pressurises the air.
[0029] The system 10 includes in this example the following additional
components namely a product gas isolation valve 32 in the product
gas distribution conduit 28 a power supply 33 for the system controller
25 a gas venting conduit 34 which extends to a venting point 36
overboard of the aircraft, a pressure relief valve 38 and a pressure
reducing shut off valve 39 each for ensuring that the pressure
of the high pressure air supply to the modules 11a, 11b, 11c etc.
is within acceptable limits, a water separator 40 for drying the
high pressure air supplied, and an inlet valve 42 which enables
the high pressure air supply to be derived from alternatively the
aircraft engine as described above, or a ram air inlet 44.
[0030] The system 10 further includes a high pressure air pressure
sensor 46 and a high pressure air temperature sensor 47 both of
which provide inputs to the system controller 15 which operates
the shut off valve 39 and product gas isolation valve 32.
[0031] According to the invention, the system 10 is installed in
the aircraft first by installing the system controller 25 the product
gas distribution conduit 28 and the high pressure gas supply conduit
29 and all other components of the system 10 including cabling
C for connecting the controller 15 to the valves 39 32 and valve
assemblies 17 of the modules, but excluding the modules 11a, 11b,
11c etc. themselves.
[0032] The modules 11a, 11b, 11c etc. may then be introduced into
the aircraft independently of each other, one at a time as required,
by installation engineers handling the modules 11a, 11b, 11c etc.
singly.
[0033] The modules 11a, 11b, 11c etc. are then individually connected
into the remainder of the system 10 by connecting the outlet ducts
14 to the product gas distribution conduit 28 and the gas supply
ducts 19 to the high pressure gas supply conduit 29 and by connecting
the valve assemblies 17 to the system controller 15 via the cables
C.
[0034] Preferably the ducts and conduits are provided with connectors
which enable the modules 11a, 11b, 11c etc. readily to be connected,
and the valve assemblies 17 and cables are also provided with plug
and socket connectors which enable ready connection between them.
The modules 11a, 11b, 11c etc. may also need be mechanically secured
to the aircraft.
[0035] Also, where an overboard venting point 36 is provided the
vent ducts 20 will need to be connected to the venting conduit 34.
[0036] The system controller 15 in this example is programmed to
perform a self test to determine how many modules 11a, 11b, 11c
etc. are operatively connected in the system 10 and then the controller
selects an appropriate system control regime to that product gas
with a desired degree of oxygen enrichment for operating conditions
is produced.
[0037] For example, where an even number of modules 11a, 11b, 11c
etc. is provided, the modules 11a, 11b, 11c etc. may be operated
in pairs in tandem with the module of each pair being operated in
a charging phase for 50% of a time cycle and in a venting phase
for 50% of the time cycle, the time cycle being fixed or variable
depending upon operating conditions.
[0038] In another example, the modules 11a, 11b, 11c etc. may be
operated in groups of different numbers, e.g. groups of three with
each module charging for 33.3% of the cycle time and venting for
66.6% of the time cycle. Whatever operating regime is selected by
the controller 15 in the event that one or more of the modules
11a, 11b, 11c etc. malfunctions, for example as a result of the
molecular sieve bed material becoming contaminated, the controller
15 may bring the module off-line and select an alternative operating
regime to produce product gas with a desired degree of oxygen enrichment.
[0039] Various modifications may be made without departing from
the scope of the invention. Particularly the invention is not limited
to a system 10 for use in an aircraft but may be used in any vehicle
where it is desired to produce gas enriched product gas for breathing
or otherwise. For example it may be desired to produce a nitrogen
enriched product gas from air for use in providing a non-flammable
atmosphere for a fuel tank.
[0040] The system 10 my include additional components not shown
in the drawings or mentioned for the full performance of the system
10 as will be
EXAMPLE 1
[0041] Manufacture of Emulsion Compositions Containing Retinol
[0042] Seven formulations containing retinol (Examples I-VII),
as described in Table 1 were manufactured as set forth below. |