Separator assembly

A filtering assembly for an air intake duct for a turbine device for normally removing particulate matter entrained in the air being introduced to the turbine device through the air duct. The improved filtering assembly comprises a filter element for removing particulate matter entrained in air passing therethrough which is mounted in the air duct so that at least a section of the filter element is movable between a filtering position and bypass position. More particularly, the filter element is mounted in the air duct so that when it is in the filtering position, substantially all of the air passing through the air duct passes through the filter element and so that when it is in the bypass position, a substantial amount of the air passing through the air duct bypasses the filter. A suitable sensing device is provided for sensing the pressure differential of the air across the filter element in the air duct and a clamping device is provided which normally clamps the filter element in the filtering position. The clamping device is actuable to release the filter element from the filtering position to allow the filter element to move to the bypass position when the pressure differential sensed by the sensing device is above a predetermined pressure difference. In this manner, air flow will be maintained to the turbine, even if the filter becomes clogged or stopped, thereby preventing a situation in which the turbine might otherwise be starved of sufficient air flow.

BACKGROUND OF THE INVENTION 
The present invention relates to a separator assembly, and more 
particularly to a separator assembly for a gas turbine for marine 
applications. For example, the separator assembly of the present invention 
is particularly useful as a moisture and/or particle separator for 
removing moisture and/or particulate matter entrained in the air entering 
the air intake of a gas turbine of a ship. 
Moisture separators are provided for gas turbines for marine applications 
as the moisture particles in the air generally contain salt which, if they 
should be introduced into the turbine, would deleteriously affect the 
component parts of the turbine, as for example, by chemical corrosion. 
Further, the dry particles entrained in the air, for example sand and/or 
salt crystals, can cause "pitting" of the turbine components if they are 
not removed. However, by far the greatest concern is the moisture 
particles containing salt. 
Although various types of separator assemblies have been proposed for use 
in marine applications to minimize the passage of air containing such 
particles to the turbine, it will also be understood that of an even 
greater importance is the provision of a substantial air flow being 
maintained to the turbine. In fact, this is of such importance that it is 
deemed imperative that air always be delivered to the turbine, even if it 
means delivering air which might otherwise damage the turbine components, 
i.e. air having moisture and/or salt therein. 
Accordingly, in the past, doors or passageways, known as "blow in" doors, 
have been provided in the air ducts adjacent the moisture separators which 
are automatically opened if the pressure drop across the moisture 
separator increases too much, i.e., beyond a predetermined limit which 
might otherwise result in the turbine being starved of air flow. In 
accordance with these prior art arrangements, unfiltered air is thus 
allowed to flow into the air duct, bypassing the moisture separator, to be 
delivered to the turbine. 
Such an increase in the pressure drop, across the moisture separator can 
result from freezing or icing up of the moisture separators when the ships 
on which they are mounted are in cold or icy waters since the moisture 
separators for the gas turbines on such ships are generally located high 
up on the ship where they are unprotected from the elements. For example, 
the moisture that is removed from the air by the moisture separator can 
freeze in the moisture separator, thereby significantly blocking the flow 
of air through the separator which, in turn, causes the pressure drop 
across the moisture separator to increase, and a consequent decrease in 
the amount of air being delivered to the turbine. 
Thus, in the prior art, if this should occur, the auxiliary "blow in" doors 
or passageways are caused to open automatically by detection or sensing of 
an increase in the pressure differential across the separator device. 
As can be appreciated, such separate auxiliary doors require the 
manufacture of different components, as well as the provision of separate 
air passages into the air duct, thereby increasing the size and weight of 
the air ducts and separator assemblies for gas turbines on such ships. 
Still further, by having two separate passageways and two separate 
components in the separate passageways, the arrangement is quite 
complicated, bulky and cumbersome. 
SUMMARY OF THE INVENTION 
These and other disadvantages are overcome with the present invention in 
which there is provided a simplified separator assembly for the air intake 
duct of a turbine device which itself, or at least a section thereof, is 
movable in the air duct to allow air to bypass the separator and be 
directly introduced into the turbine. More particularly, in accordance 
with the present invention, the separator assembly comprises separating 
means for removing particulate matter entrained in the air passing 
therethrough, and mounting means for mounting the separating means in the 
air duct so that at least a section of the separating means is movable in 
the air duct between a separating position and a bypass position. The 
separating means, when the movable section is in the separating position, 
is arranged so that substantially all of the air passing through or into 
the air duct will pass through the separating means and, when the movable 
section is in the bypass position, is arranged so that air passing through 
the air duct bypasses at least the movable section of the separating means 
without passing therethrough. Sensing means are provided for sensing the 
pressure differential of the air across the separating means in the air 
duct. Further, means are provided responsive to sensing means for causing 
the movable section of the separating means to move to the bypass position 
when the pressure differential sensed by the sensing means is above a 
predetermined pressure difference. In this manner, the required air flow 
will be maintained to the turbine device. 
More particularly, in accordance with the preferred embodiment of the 
present ivention, frame means are provided for supporting the separating 
means and the mounting means serves to mount the frame means for movement 
in the air duct between first and second positions corresponding to the 
separating and bypass positions of the separating means. That is, the 
mounting means preferably comprises pivot mounting means for pivotably 
mounting the frame means for movement between a first position in which 
separating means is arranged substantially normal to the air flow into the 
air duct, and a second position in which the separating means is inclined 
with respect to the nomal separating position so that air may flow around 
and bypass the separating means, and instead pass directly to the turbine. 
The pivot mounting means may comprise a pair of pin members mounted on the 
opposite side of the frame means in alignment with one another for 
providing pivotable movement about an axis passing through the pair of pin 
members, or may comprise hinge means along one edge of the frame means for 
hingedly supporting the frame means in the air duct for swinging type 
movement. 
In each of these embodiments, suitable clamping means are provided for 
normally maintaining the frame means in the normal separating position and 
which are releasable in response to the pressure sensing means to allow 
the frame means to pivot or swing freely in response to the air flow being 
drawn into the air duct. 
In a still further embodiment, the separating means comprises first and 
second separating stages, the second separating stage preferably being 
hingedly mounted to the first separating stage and movable relative 
thereto between a position in which it is arranged to tandem to the first 
separating stage and a bypass position in which it is inclined relative to 
the first separating stage. This arrangement is similar to the other 
arrangements noted above with the exception that the air passing through 
the air duct is still partially separated by the first separating stage. 
These and further features and characteristics of the present invention 
will be apparent from the following detailed description in which 
references made to the enclosed drawings will illustrate the preferred 
embodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now to the drawings in which like reference characters represent 
like elements, there is shown in FIG. 1 a separator assembly 10 in 
accordance with the present invention for an air intake duct 12 for a 
turbine device (not shown). The turbine device, for example, may comprise 
a gas turbine, although it could be employed with respect to other types 
of turbines. Also, as the separator assembly 10 of the present invention 
is particularly usefl as a moisture separator for use with gas turbine on 
ships or other amphibious vehicles, it will be described with reference to 
such use. However, it should also be understood that the separator 
assembly 10 of the present invention could be used in any environment in 
which it is desirable to filter particles entrained in air being 
introduced to the turbine through the air intake duct 12 and in which it 
might also be necessary to allow unfiltered air to bypass the separating 
means thereof to prevent starvation of air to the turbine. 
In gas turbines for marine applications, the turbines are operated to draw 
air into the air intake duct 12 across a moisture separator 14 to provide 
a desired amount of air to the turbine. Generally, the air ducts are 
placed high up in the ship or the vehicle so that as little moisture as 
possible might be entrained in the air being introduced into the gas 
turbine. In such instances, the moisture separator 14 is normally mounted 
at the inlet entrance 16 to the air duct 12. 
The air flow to be introduced to the turbine in such marine applications, 
which typically is required to be on the order of magnitude of 2000 cubic 
feet per second or greater, is dependent upon the cross sectional area of 
the air intake duct 12 through which the air is introduced and the 
velocity of the flow of air therethrough. For example, if the flow 
velocity through the air intake duct 12 can be increased, the cross 
sectional area of the duct 12 (and thus the size of the duct 12) can be 
reduced substantially. On the other hand, the pressure drop across the 
moisture separator 14 placed in the air intake duct 12 must be maintained 
at an acceptable level, i.e. for example, less than 6 inches of water. As 
the pressure drop across the moisture separator 14 is dependent both on 
the flow resistance offered by the moisture separator 14 itself and also 
on the velocity of the flow therethrough, the pressure drop thus serves as 
a limit on the increase in flow velocity which can be obtained to satisfy 
the requirements for a given mass flow rate. Therefore, as it is desirable 
to decrease the size of the air duct 12 (to save on costs, weight, and 
size) it is desirable to design the moisture separator 14 so as to have as 
low a flow resistance as possible. At the same time, however, the 
reduction in flow resistance offered by the moisture separator 14 must not 
be such as to impair the efficiency to remove the moisture particles from 
the air passing through the moisture separator 14. For example, in many 
marine applications, high flow velocities through the moisture separators 
on the order of 20 feet per second and greater are desired. 
These parameters as have been discussed hereinabove thus go into 
determining the precise design for any given type of moisture separator 14 
for the air intake duct 12 of the turbine, as well as the size of the air 
intake duct 12 itself, so as to provide the required mass flow to the 
turbine, while at the same time maintaining the pressure drop across the 
moisture separator 14 at acceptable levels. 
However, despite designs which are intended to place the moisture 
separators 14 in the air intake ducts 12 in an environment such that they 
will not clog or freeze up, i.e. placing them high up on the ship, the 
possibility still exists that the moisture separators 14 will clog during 
operation. As can be appreciated, such clogging increases the flow 
resistance presented by the moisture separator 14 for air flow into the 
air intake duct 12 of gas turbines. As the mass flow rate to the turbine 
is dependent on the resistance presented to the flow of air into the air 
intake duct 12, it can be appreciated that if the resistance presented by 
the moisture separator 14 increases, the amount of air flow delivered to 
the turbine will correspondingly decrease. As it is imperative that a 
sufficient amount of air always be delivered to the turbine, if the 
moisture separator 14 should clog or the resistance presented thereby 
increases beyond an acceptable limit, it is necessary to provide some 
means for bypassing the moisture separator 14 to deliver the required air 
flow to the turbine. 
Accordingly, as discussed in The Background of the Invention section 
herein, "blow in" doors have been provided in that past which comprise 
separate doors or elements which automatically open if the pressure drop 
across the moisture separator 14 increases beyond a set limit. This thus 
allows unfiltered air to flow into the air duct 12, bypassing the moisture 
separator 14, to be delivered to the turbine. 
In accordance with the present invention, the moisture separator 14 itself, 
or at least a section thereof, is movably mounted in the air duct 12 to 
provide this "blow in" feature for the separating assembly 10, thereby 
eliminating the need for separate "blow in" doors in flow communication 
with the air duct for bypassing the moisture separator 14. 
More particularly, in accordance with the general principles of the present 
invention, as for example seen in FIGS. 1 and 2, the separator assembly 10 
is mounted at the entrance 16 to the air intake duct 12 to the gas 
turbine. The end 16 of the air intake duct 12 remote from the turbine 
preferably includes an entrance cover plate 18 attached thereto and having 
an opening 19 therethrough which defines the inlet entrance for air flow 
into the air duct 12. The moisture separator 14 is mounted in the air 
intake duct 12 adjacent the opening 19 in the cover plate 18 and is of a 
size corresponding to the size of the inlet opening 19 so that it may be 
positioned to encompass the inlet opening 19 whereby substantially all of 
the air drawn into the air intake duct 12 flows through the moisture 
separator 14. Further, the moisture separator 14 is mounted so that if the 
pressure drop thereacross increases beyond a predetermined value, the 
moisture separator 14 is operative to move or open away from the inlet 
opening 19 to allow air to pass therearound, thus bypassing the moisture 
separator 14 and instead passing directly to the gas turbine. In this 
manner, an improved separator assembly 10 is provided which is less 
cumbersome and bulky than the prior art arrangements and which will still 
maintain the air flow to the turbine under virtually all conditions. 
In the embodiment shown in FIGS. 1 and 2, the moisture separator 14 
comprises a two stage moisture separator arranged at the inlet end 16 of 
the air intake duct 12 to receive unfiltered air being drawn into the 
intake duct 12 to filter and process same to remove particulate matter, 
such as moisture and salt therefrom prior to conduction to the turbine. 
The first stage of the moisture separator 14 comprises a conventional 
inertia separating device 20 through which the air flow to be introduced 
to the turbine first passes to provide partially processed air. This 
inertia device 20, for example, may comprise a plurality of chevron or 
V-shaped vanes 22 vertically oriented and closely spaced relative to one 
another. However, it should, of course, be understood that other types of 
inertia devices could be used, as for example, cyclone separators. The 
plurality of vanes 22 are supported in a support frame member 24 which 
peripherally surrounds the vanes 22 and holds the upper and lower ends 
thereof in a fixed position. 
As the air flows through the vanes 22, it must turn or bend several times 
to follow the path between the peaked sections of adjacent vanes 22. As 
the entrained particles, such as for example, moisture particles 
containing salt, sand or other particular matter are generally of a larger 
mass than the air particles, the entrained particles are thrown outwardly 
during the turns against the surfaces of the vanes 22 due to the 
centrifical force exerted thereon. That is, the lighter air particles are 
capable of making the turns through the series of peaked sections whereas 
the heavier mass particles are not, thereby resulting in the larger 
particles impacting on the surface of the vanes 22. Each of the peaks of 
the vanes 22 may include stops for preventing the impacted particles from 
sliding along the surface of the vanes 22 and becoming reentrained by 
virtue of the aerodynamic drag force exerted by the air flow. 
Such an arrangement is particularly useful for removing the heavier 
particles entrained in the air, since such particles are more likely to 
impact on the vanes and thus be removed from the air flow. On the other 
hand, lighter particles may have a tendency to successfully follow the 
flow path and remain entrained in the air. For example, such inertia 
separator devices 20 have been found to be efficient in removing moisture 
particles of a size over 8 microns (25.4 microns approximately equallying 
0.001 inches) in the range of the high flow velocities with which moisture 
separators 14 for gas turbines are concerned, i.e., greater than 20 feet 
per second. However, the plurality of vanes 22 have not exhibited a high 
efficiency for removing moisture particles in the lower size droplet 
range, namely 8 microns and below. Thus, it may be desirable to utilize 
further separating stages or devices for removing such lower size 
particles. 
In this regard, in the embodiment shown in FIGS. 1 and 2, after being 
partially processed by the first stage 20 of the moisture separator 14, 
the air is introduced through the second stage 26 which serves to further 
process the air to remove particles still entrained therein. For example, 
this second stage 26 of the moisture separator 14 may comprise one or more 
layers each comprising a plurality of fiber elements or wires. The layers 
of fiber elements are housed within a peripheral frame member 28 which is 
arranged in tandem to the first stage 20 in a suitable manner, such as for 
example by affixing the second stage frame member 28 to the downstream 
side of the first stage frame member 24. The second stage 26 is preferably 
designed to remove the smaller sized particles entrained in the air to 
provide fully processed air in which virtually all of the moisture 
particles and other particulate matter are removed therefrom. 
Although in the preferred embodiments of the present invention described 
herein only two stage moisture separators 14 are provided, it should of 
course be realized that additional separating stages could be provided and 
mounted in tandem to the first two stages downstream thereof. The 
particular design of any moisture separator 14, of course, is dependent 
upon the particular circumstances and environment in which the moisture 
separator 14 will be placed, as well as the desired characteristics for 
the processed air. However, in accordance with the present invention, it 
should also be appreciated that it is preferable that the number of stages 
be kept at a minimum while, at the same time, maximizing the efficiency of 
removal of moisture particles, in order to minimize the size and weight of 
the moisture separator 14 in the air intake duct 12. In this regard, 
generally speaking, as the number of stages increase, the flow resistance 
increases, as does the weight of the device which, as mentioned above, is 
undesirable. 
Further, in accordance with the embodiment shown in FIG. 1, the moisture 
separator 14 is rotatably supported in the air duct 12 so as to be 
vertically rotatable about an axis defined by means of vertically aligned 
pin members 30, 32 provided on the upper and lower surfaces of the first 
stage frame member 24. These pin members 30, 32 are each received in 
suitable sockets 34, 36 provided in the upper and lower inner surfaces of 
the air duct frame 12. In this manner, the moisture separator 14 may be 
arranged in a separating position in which it is normal to the direction 
of the air flow into the duct 12 (see FIG. 1) so that substantially all of 
the air being introduced into the air duct 12 must pass through the first 
and second separator stages 20, 26. The moisture separator 14 is also 
pivotable to a bypass position in which it is inclined to the direction of 
the air flow (see FIG. 2). When in this bypass position, as can best be 
seen in FIG. 2, air will be introduced into the air duct 12 around the 
outer peripheral edges of the first and second stage frame members 24, 28 
of the moisture separator 14, thus completely bypassing the moisture 
separator 14. 
It will be appreciated that in this embodiment shown in FIGS. 1 and 2, the 
first stage frame member 24 is constructed at its forward or upstream end 
to have an outer flanged portion 38 on one side of the pin members 30, 32 
(the right hand side in FIGS. 1 and 2) and an inner flanged portion 40 on 
the other side of the pin members 30, 32 (the left hand side of FIGS. 1 
and 2) so that the moisture separator 14 is freely pivotable in a 
clockwise direction as viewed in FIG. 2 from separating position to the 
bypass position. In separating position, these flanged portions 38, 40 
serve to seal the inlet opening 19 to the air duct 12. 
Thus, during normal operation on the ship, all of the air flow into the air 
intake duct 12 for the turbine must pass through the moisture separator 
14. This is the FIG. 1 position. However, should icing occur, or, should 
the moisture separator 14 become clogged, covered, etc. (virtually 
anything which would increase the flow resistance significantly presented 
by the moisture separator 14), the pressure drop across the separator 14 
will increase. This pressure drop across the separator 14 may be sensed 
with appropriate means, such as, for example, pressure sensors 46, 48 and 
a differential pressure sensor or switch 42. If a high limit is reached, a 
suitable locking or clamping device 44 will automatically be actuated to 
release the separator 14 from its separating position (see FIG. 2). 
More particularly, this pressure sensing means may comprise conventional 
components which have been used in the past for sensing the pressure 
differential across the moisture separator 14 and for operating the 
conventional "blow in" doors. For example, the pressure sensing means may 
comprise a pair of pressure sensors or tubes 46, 48, one of which is 
located internally in the air duct 12 and the other of which is located 
externally of the air duct 12, i.e., subject to atmospheric pressure. A 
suitable differential pressure switch 42 receives the outputs from each of 
the pressure sensors 46, 48 and determines the differential pressure for 
the air flow across the moisture separator 14 being introduced into the 
air intake duct 12. The differential pressure switch 42 is appropriately 
connected to the locking or clamping device 44 which normally holds the 
moisture separator 14 in the separating position such that, if a high 
limit on the pressure drop is reached, such as for example, greater than 6 
inches of water, the clamping device 44 will be automatically actuated to 
release the clamping or locking force for holding the moisture separator 
14 in the separating position. 
In the embodiment shown in FIGS. 1 and 2, this clamping device 44 comprises 
a two position clamping device which is mounted to the inner surface of 
the air intake cover plate 18, and is movable between first and second 
positions. This movement can be caused by either electrical, pneumatic or 
hydraulic means. In the first position, the clamping device 44 is adapted 
to engage the inner flanged portion 40 of the first stage frame member 24 
to lock it in a position in which the moisture separator 14 covers the 
entire inlet opening 19 into the air duct 12 so that all air flow must 
pass through the moisture separator 14 into the air intake duct 12. This 
clamping device 44 is movable to a second position in response to the 
differential pressure switch 42 sensing a high limit on the pressure drop 
to release the holding force on the moisture separator 14. Because of the 
increased pressure differential across the moisture separator 14, the 
moisture separator 14 will thus swing on the pins 30, 32, thereby allowing 
the air to flow into the duct 12 around the sides of the moisture 
separator 14, as shown in FIG. 2. 
In this regard, it will be appreciated that the pins 30, 32 are slightly 
offset relative to the vertical center line of the first stage frame 
member 24 so that the action of the pressure difference experienced by the 
moisture separator 14 between the exterior of the air duct 12 and the 
interior of the air duct 12 will cause the element 14 to swing about the 
pins 30, 32. This action of swinging open will thus insure that sufficient 
air will always be delivered to the gas turbine. 
To prevent the moisture separator 14 itself from becoming frozen in the 
opening 19 of the air duct 12, suitable heaters (not shown) may be 
provided around the perimeter of the opening 19 to prevent freezing, as is 
conventional with respect to the separate conventional "blow in" doors of 
the prior art. 
The embodiment of the present invention as shown in FIGS. 3 and 4 is 
directed to an alternative arrangement for the separator assembly 10' 
which is also operative to move the moisture separator 14' thereof to a 
position to allow the air being introduced into the air duct 12 to 
completely bypass the moisture separator 14'. Again, in this embodiment, 
the moisture separator comprises a two stage moisture separator in which 
both the first and second stages 20', 26.degree. are fixedly arranged in 
tandem. The two joined stages 20', 26' are together hingedly supported in 
the air intake duct 12 so that the entire moisture separator 14' is 
swingable about a horizontal axis extending along the upper surface or 
edge of the moisture separator 14' to allow the moisture separator 14' to 
be pivoted backwardly and upwardly to allow air flow to flow around the 
bottom and side edges thereof into the air intake duct 12. More 
particularly, a plurality of hinges 50 are provided with one plate 52 of 
each hinge 50 being secured to the frame member 24' of the first stage 20' 
of the moisture separator 14' and with the other plate 54 of each hinge 50 
being secured to the inner surface of the intake cover plate 18' adjacent 
to upper edge of the opening 19'. Alternatively, a single continuous hinge 
could be provided which extends across the width of the moisture separator 
14'. 
In this regard, the forward or upstream end of the first stage frame member 
24' has a sealing flanged portion 56 about the periphery thereof which is 
adapted to seal against the inner surface of the air intake cover plate 
18' around the inlet opening 19' thereof. The moisture separator 14' is 
normally maintained in coextensive relationship with respect to the air 
intake opening 19' so that substantially all of the air flow must pass 
through the moisture separator 14' into the air intake duct 12. The 
moisture separator 14' is maintained in this position by a suitable 
locking or clamping device 44' which may, for example, comprise a 
pivotable clamping element which engages and clamps the flanged member 56 
on the bottom of the first stage frame member 24' against the air intake 
cover plate 18'. The clamping device 44' is suitably actuable to move, for 
example by pivoting backwards, out of engagement with the flanged member 
56 of the moisture separator 14' so that the introduction of air flow into 
the air intake duct 12 will cause the entire element 14' to pivot 
backwardly and upwardly to allow air to pass around the bottom and lower 
side edges thereof. Again, as in the FIG. 1 and 2 embodiment, the clamping 
devices 44' of the FIG. 3 and 4 embodiment is actuable in response to a 
predetermined upper limit pressure differential being sensed by a 
differential pressure switch to move the clamping device 44' to the 
unlocking position. In the FIG. 3 and 4 embodiment, this differential 
pressure switch and the sensors therefor are not specifically shown, but 
may be of a conventional type, as with the embodiment shown in FIGS. 1 and 
2. 
FIGS. 5 and 6 show a third alternative embodiment for a separator assembly 
10" which is operative so that the air flow into the air intake duct 12, 
even during an icing up situation, still is partially filtered. In this 
embodiment, the moisture separator 14" again comprises a two stage 
moisture separator 14" in which both of the stages 20", 26" are normally 
arranged in tandem. However, in this embodiment, the second stage frame 
member 28" is hingedly supported from the first stage frame member 24" by 
means of hinged member 60 so that the second stage 26" is pivotable 
relative to the first stage 20". The first stage frame member 24" is, in 
turn, fixedly supported in the air duct 12 adjacent the air intake cover 
plate 18" to substantially encompass the inlet opening 19" thereof. A 
suitable clamp or locking device 44" is provided to normally maintain the 
first and second stages 20", 26" adjacent to one another in a 
substantially normal plane to the air flow passing into the air intake 
duct 12. This clamping arrangement 44" may, for example, comprise a 
slideable pin member 62 which is movable to a locking position so that the 
end of the pin member 62 is received in a suitable recess provided in a 
block 64 secured to the second stage frame member 28" (see FIG. 6). 
If the pressure differential across the moisture separator 14" exceeds the 
predetermined limit, as sensed by a suitable differential pressure switch 
and sensors (not shown), the clamping device 44" is simply actuated to 
release the holding or clamping force on the second stage 26" relative to 
the first stage 20". When this occurs, the introduction of the air flowing 
into the air intake duct 12 will cause the second stage 26" to pivot 
upwardly about the hinged members 60 away from the first stage 20" so that 
air will only flow through the first stage 20" and then around the lower 
bottom and side edges of the second stage 26". 
It should be appreciated that in each of the different embodiments shown in 
FIGS. 1-6, as soon as the pressure differential switch 42 detects the 
differential pressure across the moisture separator 14 being above a 
predetermined limit, the clamping means 44 is released. Because of the 
resistance to air flow across the moisture separator 14, forces are 
created thereon to pivot or swing the moisture separator 14 or section 
thereof away from the separating position (in which it is substantially 
normal to the air flow) so that air being introduced into the air intake 
duct 12 for introduction to the turbine device may bypass at least the 
section of the moisture separator which is moved. In this regard, since 
the resistance to air flow through the moved moisture separator 14 (or 
moved section thereof) is substantially greater than the resistance to air 
flow around the moved moisture separator 14 (or the moved section thereof) 
when same has been pivoted or moved to the bypass position, substantially 
all of the air flow will pass around the moved section of the moisture 
separator and will not pass therethrough. Thus, substantially all of the 
air flow, or a great percentage thereof, will bypass the section of the 
moisture separator 14 which has been moved. While this may be 
disadvantageous from a viewpoint of separating particulate matter from the 
air, as the requirement for the delivery of air, even unfiltered air, to 
the turbine is of much more importance in terms of preventing significant 
damage to the turbine, the separator assembly 10 of the present invention 
desirably insures that air flow will be maintained to the turbine device 
under virtually all conditions. 
Thus, it will be appreciated that in accordance with the present invention, 
the moisture separator 14 itself comprises a "blow in" door as well as a 
separator element for filtering of the air during normal operation. As can 
be appreciated this reduces the number of components required to be 
manufactured and maintained, and in particular results in the elimination 
of a separate "blow in" door or entranceway required by the prior art, 
thus minimizing manufacturing costs, weight, size, etc. 
Also, while in the preferred embodiments described hereinabove, the 
movement of the separator element 14 (or section thereof) to the bypass 
position is simply caused as a result of release of the clamping device 44 
so that the air flow itself causes the pivoting or swinging movement of 
the separator element 14, it should also be appreciated that a positive 
moving or assist means could also be provided for positively moving the 
filtering element 14 to the bypass position. For example, suitable 
hydraulic pistons could be attached to the inner walls of the air duct 12 
and to the separator element 14 so that, when the pressure differential 
across the separator element 14 exceeds a predetermined limit, the 
positive moving or assist means is actuated to positively move the 
separator element 14 to the bypass position. In either event, that is 
either with any of the embodiments shown in the drawings or with an 
embodiment incorporating a positive moving or assist means, it will be 
appreciated that it is the separator element itself which moves to the 
bypass position, as opposed to separate doors or entranceways into the air 
intake duct being opened, as was the case in the prior art. 
Accordingly, it will be appreciated that in accordance with the present 
invention there is provided a separator assembly 10 for an air intake duct 
12 of a turbine device for normally removing partriculate matter entrained 
in the air being introduced to the turbine device. The separator assembly 
10 includes separating means 14 for removing particulate matter entrained 
in the air passing therethrough, and mounting means 30, 32 (or 50, or 60) 
for mounting the separating means 14 in the air duct 12 so that at least a 
section of the separating means 14 is movable in the air duct 12 between a 
separating position and a bypass position. The separating means 14, when 
the section is in its separating position, is arranged so that 
substantially all of the air passing through the air duct 12 passes 
through the separating means 14. The separating means 14, when the section 
is in the bypass position, is arranged so that air passing into the air 
duct bypasses at least the section of the separating means 14 which has 
been moved. Sensing means are provided for sensing the pressure 
differential across the separating means 14 in the air duct 12 and means 
44 responsive to the sensing means are provided for causing the movable 
section of the separating means 14 to move to the bypass position when the 
pressure differential sensed by the sensing means is above a predetermined 
pressure difference. In this manner, air flow will be maintained to the 
turbine device under virtually all conditions. 
While the preferred embodiments of the present invention have been shown 
and described, it will be understood that such are merely illustrative and 
that changes may be made without departing from the scope of the invention 
as claimed.