Removable wash spray apparatus for gas turbine engine

An engine wash spray apparatus is releasably connected to the leading edge of a gas turbine engine for dispersing a cleaning, rinsing, or preservative fluid to the air intake area of the engine and on into the engine's internal air flow path. The apparatus includes a manifold having a plurality of nozzles of specific configuration and specific spaced relationship to achieve a uniform spray pattern, with each nozzle issuing an elongated spray, the longitudinal axis of which is generally perpendicular to a radius of the engine inlet, and with the nozzles being arranged within the engine inlet to achieve the overlapping wash spray. The cleaning fluid is dispersed within the air flow path of the engine while the engine is cranked, whereby the fluid is carried through the entire engine flow path for cleaning of the engine components.

The subject invention relates to a new and improved wash spray apparatus to 
be releasably connected to a gas turbine engine for maintenance of the 
engine and more particularly, for spraying into an engine, while the 
engine is being cranked, a cleaning, rinsing or preservative fluid in a 
desired spray pattern for impingement on the various components of the 
engine as the fluid is drawn through the gas turbine engine. 
As is readily apparent in the operation of a gas turbine engine associated 
with an aircraft or helicopter, salt and dust substances tend to adhere to 
the various internal components of the gas turbine engine, including the 
blades, the cowling, and the like. Unless such salt and dust is removed 
from the internal components of the gas turbine engine at periodic 
intervals, the buildup of the dust or salt on the components could cause a 
loss in efficiency of the engine. Generally, to operate engines 
efficiently, the internal portions of the engine should be cleaned daily 
in salt laden atmosphere or as often as other atmospheric conditions may 
require. 
Heretofore, it has been known to attempt to clean a gas turbine engine by 
simply spraying a water spray from a conventional garden hose into the 
inlet of the engine, while the engine is cranked. Of course, the problem 
associated with the spray from a simple garden hose is that it can be 
relatively concentrated and bulky, and could cause localized stress on a 
portion of a component within the engine, possibly leading to subsequent 
failure of the engine component, such as a blade. 
It has also been known, as exemplified by U.S. Pat. No. 4,059,123 which 
issued on Nov. 22, 1977 to Boddis et al and is entitled "Cleaning and 
Preserving Preservation Unit for Turbine Engine", which patent is assigned 
to the assignee of the subject application, to provide a mobile 
cart-mounted unit including a relatively simple spray ring assembly to be 
releasably connected to the intake of a gas turbine engine. The spray ring 
assembly basically comprises a tubular section including a plurality of 
annular holes therein, which provide generally conical sprays of the 
preservative or cleaning fluid. Although the spray pattern from the spray 
ring assembly is more uniform as compared to the spray from a garden hose, 
the conical distribution of the individual spray results in limited 
overlapping of adjacent sprays, whereby the components of the engine 
located adjacent the intake, and in particular, the struts, or portions 
thereof, which extend between the central hub and the outer cowling, may 
not be fully washed by the spray, thereby resulting in incomplete washing 
of the engine components. 
It has been known to provide a manifold spray assembly about an engine 
housing, and more particularly externally thereof, with a series of spray 
nozzles, also of conical spray dispersion pattern, with the axes of the 
sprays extending radially relative to the engine intake. In such assembly 
the sprays are directed generally perpendicular to the air flow path 
through the engine. Hence, the spray pattern of the radially directed 
sprays may not be effective to insure that the components of the engine 
adjacent the intake are fully immersed in the spray. 
Accordingly, it is an object of the subject invention to overcome the 
shortcomings of the prior art apparatus for cleaning and preserving a gas 
turbine engine, and more particularly to provide an engine wash spray 
apparatus comprising a manifold assembly which is releasably connected to 
the leading edge of the engine and includes an array of spray nozzles. The 
spray nozzles are located at specific locations within the engine relative 
to the radially extending struts, and each nozzle has an elongated spray 
pattern, the longitudinal axis of which is generally perpendicular to a 
radius of the engine inlet. By this arrangement, the sprays emanating from 
the nozzles within the inlet achieve the desired overlapping wash spray, 
and are effective to completely wash the entire length of the adjacent 
strut structures disposed in the engine inlet.

Referring to FIGS. 1 and 2, the wash spray apparatus of the subject 
invention is generally designated by the numeral 10 and is adapted to be 
releasably connected by suitable quick connect/disconnect means (not 
shown) to the air inlet 12 of a gas turbine engine. The air inlet is 
defined by the outer housing or cowling 14 which is generally annular and 
is spaced from the center body or central hub 16 within the air inlet by a 
plurality of radially extending struts 18-28. As shown in FIG. 2, each 
strut extends along the longitudinal axis of the engine 12 and includes a 
curved leading edge portion, as well as a generally straight rear edge. 
Disposed downstream of the struts 18-26 are the blades 30, 32 of the 
engine compressor. 
The wash spray apparatus 10 of the subject invention is designed to provide 
a controlled spray of cleaning fluid in order to remove dust and salt 
buildup on the internal walls of the outer housing 14, the struts 18-28, 
the central hub 16, as well as the blades of the compressor after which 
the fluid is drawn through the reamining portions of the engine. At such 
time, the gas turbine engine is cranked for creating an air flow path to 
aid in removing dust or salt deposits on the components within the gas 
turbine engine. In order to insure that all of the portions of the engine 
are thoroughly cleaned, especially in the leading edge portion of the 
engine where salt and dust deposits are built up to a greater extent, it 
is important that the wash spray be uniformly distributed in order to 
impinge on substantially all of the surfaces of the components within the 
air intake of the engine. To this end, the wash spray apparatus includes a 
manifold assembly including two manifolds 40, 40 which are releasable 
connected by suitable quick connect/disconnect means to the leading edge 
of the engine inlet, and are in communication with a source of fluid 
supply 42 by tubing 44. Each manifold 40 includes three spray nozzles 50, 
52 and 54 connected by suitable tubing 56 and 58. In the gas turbine 
engine as illustrated in FIGS. 1 and 2, the configuration of each manifold 
is such that each spray nozzle is disposed between two adjacent struts 
18-26, and located approximately one-half of the radial distance between 
the central hub 16 and outer housing 14. As shown in FIG. 3, each nozzle 
terminates in a tip 60 having two parallel, flat projections 62 and 64 
which control the spray pattern of the fluid discharged from the nozzle. 
The spray pattern from the nozzle tip 60 is generally pyramidal, having a 
generally rectangular base, as shown in dotted lines in FIG. 3. As mounted 
in the engine intake (see FIGS. 1 and 2) the spray patterns are generally 
elongated, pyramidal shape, with the elongated axis of the base of each 
pyramidal flow being perpendicular to a radius extending between the 
central hub 16 and the outer housing 14. In addition, as shown in FIG. 1, 
adjacent nozzles of each manifold 40 are located such that their 
pyramidal-shaped spray patterns overlap the strut intermediate such 
nozzles, thereby insuring complete 360.degree. coverage of the fluid spray 
into the engine intake. In addition, as shown in FIG. 2, the 
pyramidal-shaped spray pattern emanating from each nozzle is at a 
sufficient angle, on the order of 95.degree., so as to substantially 
impinge on the entire curved leading edges of the adjacent struts. The 
spray emanating from each nozzle is a fine atomized spray which is under 
pressure, usually on the order of 80 pounds per square inch. However, 
since the spray is atomized, it will not cause structural damage to the 
components within the engine intake. In addition to the direct impingement 
of the sprays on the engine components, by virtue of the relationship of 
the nozzles 50, 52 and 54 to the struts, as the spray patterns bounce off 
the sides and leading edges of the adjacent struts, the atomized fluid is 
deflected so as to insure that the complete air flow path through the 
engine is subjected to the spray. 
In a typical use of the subject wash spray apparatus, the manifolds 40, 40 
are releasably connected to the leading edge of the engine housing 14, 
with the spray nozzles 50, 52 and 54 being disposed intermediate the 
struts 20-28 at substantially 60.degree. intervals. Utilizing a mobile 
cart-mounted unit as described in U.S. Pat. No. 4,059,123, electricity is 
supplied by the cart to the various portions of the engine in order to 
crank the gas turbine engine, and a pressurized fluid cleaning agent is 
provided from fluid supply 42 via tubing 44 to the manifolds 40, 40 and 
then through the spray nozzles 50, 52, and 54. The overlapping spray 
patterns from the nozzles are designated by numerals 100-110 is FIGS. 1 
and 2, with the leading edge of each strut 18-26 being subjected to the 
high pressure spray on opposite sides thereof, and with the spray which 
bounces off the struts then being directed to other components within the 
engine intake. Following application of the cleansing agent, a water rinse 
would usually be provided through the manifolds 40 to the nozzles, and 
then a fluid preservative may be applied to the engine intake. After the 
application of the preservative, the manifolds 40, 40 are disconnected 
from the engine intake. 
Accordingly, there is provided a new and improved wash spray system having 
a "put-on/take-off" manifold capable of dispensing a cleaning, rinsing, or 
preservative fluid to the air intake area of a jet turbine engine, and 
then on into the engine internal air flow path, while the engine is being 
cranked. The exact structure used to clamp the manifold assembly in place 
will vary from engine to engine since it depends on the configuration of 
the engine housing. Each nozzle of the manifold assembly is specifically 
located relative to the engine intake struts, and also relative to one 
another such that the spray patterns of adjacent nozzles overlap, and are 
specifically designed to insure the complete washing of the struts, as 
well as the other portions of the engine intake. Each nozzle tip includes 
a specific configuration having two parallel flat projections which insure 
a generally pyramidal spray pattern, of elongated rectangular base. The 
spray patterns from the subject apparatus coact with the internal 
components of the air intake, and in particular, with the struts, to 
insure a uniform dispersion of fluid within the entire intake of the 
engine. The pressurized flow from the nozzles insures that dust and salt 
are removed from the critical engine components, such as the blade tips 
and the inside walls of the outer housing, as well as along the length of 
the center hub and the struts. 
Although a preferred embodiment of the invention has been illustrated and 
described, it should be understood that many additions, alterations, and 
variations may be made without departing from the scope and spirit of the 
invention as defined by the following appended claims.