GB2588974A

GB2588974A - Mould wash apparatus

Info

Publication number: GB2588974A
Application number: GB1916761.8A
Authority: GB
Inventors: Wolloch Matthew
Original assignee: Rolls Royce PLC
Current assignee: Rolls Royce PLC
Priority date: 2019-11-18
Filing date: 2019-11-18
Publication date: 2021-05-19
Also published as: GB201916761D0

Abstract

A mould wash apparatus 50 comprising: an inlet seal sealing a space 51 around a first opening of mould 60; an outlet seal sealing a space 52 around at least one second opening 62 of the mould; a washing fluid supply 70 that supplies washing fluid to the space around the first opening of the mould and removes washing fluid from the space around at least one second opening of the mould. The supply may comprise a filter to remove particulate from the washing fluid. A controller 71 may be present to operate the washing fluid in either a continuous or pulsed mode. A gas supply may provide bubbles of gas with a controller supplying the bubbles in either a continuous or pulsed mode. An oscillator may be present to oscillate the mould during washing. The mould may comprise a plurality of component moulds joined by a supply sprue joined to the first opening of the mould, and each component mould comprises at least one riser connect to a second opening, and may be a ceramic mould used in the formation of components for a gas turbine engine.

Description

MOULD WASH APPARATUS

Field of the disclosure

The present disclosure relates to the preparation of moulds, such as ceramic moulds, used in the formation of components, such as components of a gas turbine engine, including turbine blades and nozzle guide vanes.

Background of the disclosure

The quality of components formed in moulds, such as ceramic moulds, may be affected by particles or debris within the moulds, which may be in the form of dried slurry, stucco, pieces of broken filter, dried ceramic shell or dust. It is therefore desirable to provide a system to minimise the presence of such particles or debris prior to use of the moulds to form the components.

Summary of the disclosure

According to a first aspect there is provided a mould wash apparatus, comprising an inlet seal, configured to seal a space around a first opening of a mould to be washed; an outlet seal, configured to seal a space around at least one second opening of the mould; and a washing fluid supply configured to supply washing fluid to the space sealed around the first opening of the mould and to remove washing fluid from the space around the at least one second opening of the mould.

In an arrangement, the washing fluid supply is configured to filter particulates from washing fluid removed from the space around the at least one second opening of the mould and supply the filtered washing fluid to the space around the first opening of the mould.

In an arrangement, the mould wash apparatus comprises a washing fluid supply controller configured to control the washing fluid supply to operate in at least one of a continuous mode, in which washing fluid is continuously supplied to the space around the first opening of the mould, and a pulsed mode, in which washing fluid is intermittently supplied to the space around the first opening of the mould.

In an arrangement, the mould wash apparatus further comprises a gas supply, configured to provide bubbles of gas into the washing fluid as it passes through the mould.

In an arrangement, the mould wash apparatus comprises a gas supply controller, configured to control the gas supply to operate in at least one of a continuous mode, in which bubbles of gas are continuously supplied to the washing fluid, and a pulsed mode in which bubbles of gas are intermittently supplied to the washing fluid.

In an arrangement, the supply of gas bubbles can be controlled independently from the supply of washing fluid.

In an arrangement, the mould wash apparatus further comprises an oscillator, configured to oscillate the mould during a mould washing operation.

In an arrangement, the mould wash apparatus comprises an oscillator controller, configured to control the oscillator to operate at required periods during the mould washing operation.

In an arrangement, the mould wash apparatus is configured to hold the mould in a single orientation during a mould washing operation.

In an arrangement, the mould wash apparatus is configured to hold the mould in a single orientation from a time at which washing fluid is introduced to the mould until a time at which all washing fluid has been removed from the mould.

In an arrangement, the mould wash apparatus further comprises a drain opening; wherein the mould wash apparatus is configured such that, when a mould is held within the mould wash apparatus for a mould washing operation, the drain opening is lower than the mould.

In an arrangement, the mould wash apparatus comprises a drain opening controller, configured to open the drain opening at required times during the mould washing operation in order to partially or completely drain the washing fluid from at least one of the mould and the mould washing apparatus.

In an arrangement, the outlet seal comprises a seal plate, configured to be positioned adjacent a surface of the mould that includes the at least one second opening; and a resilient member that surrounds the at least one second opening and, when the seal plate is positioned adjacent the surface of the mould, is compressed between the seal plate and the mould.

In an arrangement, the washing fluid supply comprises a supply conduit to supply washing fluid to the first opening; the inlet seal is mounted at an end of the supply conduit; and the supply conduit is mounted to, and passes through, the seal plate.

In an arrangement, the seal plate and supply conduit are configured to enable the supply conduit to move relative to the seal plate such that the distance from inlet seal to the seal plate changes.

In an arrangement, the mould wash apparatus further comprises an actuator configured to move the supply conduit relative to the seal plate and an actuator controller configured to control the actuator.

In an arrangement, the washing fluid supply comprises an outlet conduit to remove washing fluid from the space around the at least one second opening; and the outlet conduit is mounted to, and passes through, the seal plate.

In an arrangement, the supply conduit is positioned within the outlet conduit.

In an arrangement, the mould wash apparatus comprises a system controller, configured to control independently a plurality of mould wash apparatus component controllers, which may include a washing fluid supply controller, a gas supply controller, an oscillator controller, a drain opening controller and an actuator controller, in order to implement a mould washing operation.

In an arrangement, the system controller is configured receive an input selecting a mould washing cycle from a plurality of predetermined mould washing cycles that define periods of operation of each of the component controllers and implement a mould washing operation corresponding to the selected mould washing cycle.

In an arrangement, the mould wash apparatus is configured to wash a mould that comprises a plurality of component moulds joined by a supply sprue; and the first opening of the mould is connected to the supply sprue.

In an arrangement, each of the component moulds comprises at least one riser connected to a respective second opening.

As noted elsewhere herein, the present disclosure may relate to a gas turbine engine. Such a gas turbine engine may comprise an engine core comprising a turbine, a combustor, a compressor, and a core shaft connecting the turbine to the compressor. Such a gas turbine engine may comprise a fan (having fan blades) located upstream of the engine core.

Arrangements of the present disclosure may be particularly, although not exclusively, beneficial for fans that are driven via a gearbox. Accordingly, the gas turbine engine may comprise a gearbox that receives an input from the core shaft and outputs drive to the fan so as to drive the fan at a lower rotational speed than the core shaft. The input to the gearbox may be directly from the core shaft, or indirectly from the core shaft, for example via a spur shaft and/or gear. The core shaft may rigidly connect the turbine and the compressor, such that the turbine and compressor rotate at the same speed (with the fan rotating at a lower speed).

The gas turbine engine as described and/or claimed herein may have any suitable general architecture. For example, the gas turbine engine may have any desired number of shafts that connect turbines and compressors, for example one, two or three shafts. Purely by way of example, the turbine connected to the core shaft may be a first turbine, the compressor connected to the core shaft may be a first compressor, and the core shaft may be a first core shaft. The engine core may further comprise a second turbine, a second compressor, and a second core shaft connecting the second turbine to the second compressor. The second turbine, second compressor, and second core shaft may be arranged to rotate at a higher rotational speed than the first core shaft.

In such an arrangement, the second compressor may be positioned axially downstream of the first compressor. The second compressor may be arranged to receive (for example directly receive, for example via a generally annular duct) flow from the first compressor.

The gearbox may be arranged to be driven by the core shaft that is configured to rotate (for example in use) at the lowest rotational speed (for example the first core shaft in the example above). For example, the gearbox may be arranged to be driven only by the core shaft that is configured to rotate (for example in use) at the lowest rotational speed (for example only be the first core shaft, and not the second core shaft, in the example above). Alternatively, the gearbox may be arranged to be driven by any one or more shafts, for example the first and/or second shafts in the

example above.

The gearbox may be a reduction gearbox (in that the output to the fan is a lower rotational rate than the input from the core shaft). Any type of gearbox may be used.

For example, the gearbox may be a "planetary" or "star" gearbox, as described in more detail elsewhere herein. The gearbox may have any desired reduction ratio (defined as the rotational speed of the input shaft divided by the rotational speed of the output shaft), for example greater than 2.5, for example in the range of from 3 to 4.2, or 3.2 to 3.8, for example on the order of or at least 3, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4, 4.1 or 4.2. The gear ratio may be, for example, between any two of the values in the previous sentence. Purely by way of example, the gearbox may be a "star" gearbox having a ratio in the range of from 3.1 or 3.2 to 3.8. In some arrangements, the gear ratio may be outside these ranges.

In any gas turbine engine as described and/or claimed herein, a combustor may be provided axially downstream of the fan and compressor(s). For example, the combustor may be directly downstream of (for example at the exit of) the second compressor, where a second compressor is provided. By way of further example, the flow at the exit to the combustor may be provided to the inlet of the second turbine, where a second turbine is provided. The combustor may be provided upstream of the turbine(s).

The or each compressor (for example the first compressor and second compressor as described above) may comprise any number of stages, for example multiple stages. Each stage may comprise a row of rotor blades and a row of stator vanes, which may be variable stator vanes (in that their angle of incidence may be variable). The row of rotor blades and the row of stator vanes may be axially offset from each other.

The or each turbine (for example the first turbine and second turbine as described above) may comprise any number of stages, for example multiple stages. Each stage may comprise a row of rotor blades and a row of stator vanes. The row of rotor blades and the row of stator vanes may be axially offset from each other.

Each fan blade may be defined as having a radial span extending from a root (or hub) at a radially inner gas-washed location, or 0% span position, to a tip at a 100% span position. The ratio of the radius of the fan blade at the hub to the radius of the fan blade at the tip may be less than (or on the order of) any of: 0.4, 0.39, 0.38 0.37, 0.36, 0.35, 0.34, 0.33, 0.32, 0.31, 0.3, 0.29, 0.28, 0.27, 0.26, or 0.25. The ratio of the radius of the fan blade at the hub to the radius of the fan blade at the tip may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 0.28 to 0.32. These ratios may commonly be referred to as the hub-to-tip ratio. The radius at the hub and the radius at the tip may both be measured at the leading edge (or axially forwardmost) part of the blade. The hub-to-tip ratio refers, of course, to the gas-washed portion of the fan blade, i.e. the portion radially outside any platform. The radius of the fan may be measured between the engine centreline and the tip of a fan blade at its leading edge. The fan diameter (which may simply be twice the radius of the fan) may be greater than (or on the order of) any of: 220 cm, 230 cm, 240 cm, 250 cm (around 100 inches), 260 cm, 270 cm (around 105 inches), 280 cm (around 110 inches), 290 cm (around 115 inches), 300 cm (around 120 inches), 310 cm, 320 cm (around 125 inches), 330 cm (around 130 inches), 340 cm (around 135 inches), 350cm, 360cm (around 140 inches), 370 cm (around 145 inches), 380 (around 150 inches) cm, 390 cm (around 155 inches), 400 cm, 410 cm (around 160 inches) or 420 cm (around 165 inches). The fan diameter may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 240 cm to 280 cm or 330 cm to 380 cm.

The rotational speed of the fan may vary in use. Generally, the rotational speed is lower for fans with a higher diameter. Purely by way of non-limitative example, the rotational speed of the fan at cruise conditions may be less than 2500 rpm, for example less than 2300 rpm. Purely by way of further non-limitative example, the rotational speed of the fan at cruise conditions for an engine having a fan diameter in the range of from 220 cm to 300 cm (for example 240 cm to 280 cm or 250 cm to 270cm) may be in the range of from 1700 rpm to 2500 rpm, for example in the range of from 1800 rpm to 2300 rpm, for example in the range of from 1900 rpm to 2100 rpm. Purely by way of further non-limitative example, the rotational speed of the fan at cruise conditions for an engine having a fan diameter in the range of from 330 cm to 380 cm may be in the range of from 1200 rpm to 2000 rpm, for example in the range of from 1300 rpm to 1800 rpm, for example in the range of from 1400 rpm to 1800 rpm.

zo In use of the gas turbine engine, the fan (with associated fan blades) rotates about a rotational axis. This rotation results in the tip of the fan blade moving with a velocity Utip. The work done by the fan blades 13 on the flow results in an enthalpy rise dH of the flow. A fan tip loading may be defined as dH/Utip2, where dH is the enthalpy rise (for example the 1-D average enthalpy rise) across the fan and Utip is the (translational) velocity of the fan tip, for example at the leading edge of the tip (which may be defined as fan tip radius at leading edge multiplied by angular speed). The fan tip loading at cruise conditions may be greater than (or on the order of) any of: 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39 or 0.4 (all units in this paragraph being) Jkg-1K1/(ms-1.)2.. The fan tip loading may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 0.28 to 0.31, or 0.29 to 0.3.

Gas turbine engines in accordance with the present disclosure may have any desired bypass ratio, where the bypass ratio is defined as the ratio of the mass flow rate of the flow through the bypass duct to the mass flow rate of the flow through the core at cruise conditions. In some arrangements the bypass ratio may be greater than (or on the order of) any of the following: 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, 15, 15.5, 16, 16.5, 17, 17.5, 18, 18.5, 19, 19.5 or 20. The bypass ratio may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of form 12 to 16, 13 to 15, or 13 to 14. The bypass duct may be substantially annular. The bypass duct may be radially outside the engine core. The radially outer surface of the bypass duct may be defined by a nacelle and/or a fan case.

The overall pressure ratio of a gas turbine engine as described and/or claimed herein may be defined as the ratio of the stagnation pressure upstream of the fan to the stagnation pressure at the exit of the highest pressure compressor (before entry into the combustor). By way of non-limitative example, the overall pressure ratio of a gas turbine engine as described and/or claimed herein at cruise may be greater than (or on the order of) any of the following: 35, 40, 45, 50, 55, 60, 65, 70, 75. The overall pressure ratio may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 50 to 70.

Specific thrust of an engine may be defined as the net thrust of the engine divided by the total mass flow through the engine. At cruise conditions, the specific thrust of an engine described and/or claimed herein may be less than (or on the order of) any of the following: 110 Nkg-'s, 105 Nkg-ls, 100 Nkg-'s, 95 Nkg-'s, 90 Nkg-ls, 85 Nkg-ls or 80 Nkg-ls. The specific thrust may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 80 Nkg-ls to 100 Nkg-ls, or 85 Nkg-ls to 95 Nkg-ls. Such engines may be particularly efficient in comparison with conventional gas turbine engines.

A gas turbine engine as described and/or claimed herein may have any desired maximum thrust. Purely by way of non-limitative example, a gas turbine as described and/or claimed herein may be capable of producing a maximum thrust of at least (or on the order of) any of the following: 160kN, 170kN, 180kN, 190kN, 200kN, 250kN, 300kN, 350kN, 400kN, 450kN, 500kN, or 550kN. The maximum thrust may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds). Purely by way of example, a gas turbine as described and/or claimed herein may be capable of producing a maximum thrust in the range of from 330kN to 420 kN, for example 350kN to 400kN. The thrust referred to above may be the maximum net thrust at standard atmospheric conditions at sea level plus 15 degrees C (ambient pressure Zo 101.3kPa, temperature 30 degrees C), with the engine static.

In use, the temperature of the flow at the entry to the high pressure turbine may be particularly high. This temperature, which may be referred to as TET, may be measured at the exit to the combustor, for example immediately upstream of the first turbine vane, which itself may be referred to as a nozzle guide vane. At cruise, the TET may be at least (or on the order of) any of the following: 1400K, 1450K, 1500K, 1550K, 1600K or 1650K. The TET at cruise may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds). The maximum TET in use of the engine may be, for example, at least (or on the order of) any of the following: 1700K, 1750K, 1800K, 1850K, 1900K, 1950K or 2000K. The maximum TET may be in an inclusive range bounded by any two of the values in the previous sentence (i.e. the values may form upper or lower bounds), for example in the range of from 1800K to 1950K. The maximum TET may occur, for example, at a high thrust condition, for example at a maximum take-off (MTO) condition.

A fan blade and/or aerofoil portion of a fan blade described and/or claimed herein may be manufactured from any suitable material or combination of materials. For example at least a part of the fan blade and/or aerofoil may be manufactured at least in part from a composite, for example a metal matrix composite and/or an organic matrix composite, such as carbon fibre. By way of further example at least a part of the fan blade and/or aerofoil may be manufactured at least in part from a metal, such as a titanium based metal or an aluminium based material (such as an aluminium-lithium alloy) or a steel based material. The fan blade may comprise at least two regions manufactured using different materials. For example, the fan blade may have a protective leading edge, which may be manufactured using a material that is better able to resist impact (for example from birds, ice or other material) than the rest of the blade. Such a leading edge may, for example, be manufactured using titanium or a titanium-based alloy. Thus, purely by way of example, the fan blade may have a carbon-fibre or aluminium based body (such as an aluminium lithium alloy) with a titanium leading edge.

A fan as described and/or claimed herein may comprise a central portion, from which the fan blades may extend, for example in a radial direction. The fan blades may be attached to the central portion in any desired manner. For example, each fan blade may comprise a fixture which may engage a corresponding slot in the hub (or disc). Purely by way of example, such a fixture may be in the form of a dovetail that may slot into and/or engage a corresponding slot in the hub/disc in order to fix the fan blade to the hub/disc. By way of further example, the fan blades maybe formed integrally with a central portion. Such an arrangement may be referred to as a bladed disc or a bladed ring. Any suitable method may be used to manufacture such a bladed disc or bladed ring. For example, at least a part of the fan blades may be machined from a block and/or at least part of the fan blades may be attached to the hub/disc by welding, such as linear friction welding.

The gas turbine engines described and/or claimed herein may or may not be provided with a variable area nozzle (VAN). Such a variable area nozzle may allow the exit area of the bypass duct to be varied in use. The general principles of the present disclosure may apply to engines with or without a VAN.

The fan of a gas turbine as described and/or claimed herein may have any desired number of fan blades, for example 14, 16, 18, 20, 22, 24 or 26 fan blades.

As used herein, cruise conditions have the conventional meaning and would be readily understood by the skilled person. Thus, for a given gas turbine engine for an aircraft, the skilled person would immediately recognise cruise conditions to mean the operating point of the engine at mid-cruise of a given mission (which may be referred to in the industry as the "economic mission") of an aircraft to which the gas turbine engine is designed to be attached. In this regard, mid-cruise is the point in an aircraft flight cycle at which 50% of the total fuel that is burned between top of climb and start of descent has been burned (which may be approximated by the midpoint -in terms of time and/or distance-between top of climb and start of descent. Cruise conditions thus define an operating point of, the gas turbine engine that provides a thrust that would ensure steady state operation (i.e. maintaining a constant altitude and constant Mach Number) at mid-cruise of an aircraft to which it is designed to be attached, taking into account the number of engines provided to that aircraft. For example where an engine is designed to be attached to an aircraft that has two engines of the same type, at cruise conditions the engine provides half of the total thrust that would be required for steady state operation of that aircraft at mid-cruise.

In other words, for a given gas turbine engine for an aircraft, cruise conditions are defined as the operating point of the engine that provides a specified thrust (required to provide -in combination with any other engines on the aircraft -steady state operation of the aircraft to which it is designed to be attached at a given mid-cruise Mach Number) at the mid-cruise atmospheric conditions (defined by the International Standard Atmosphere according to ISO 2533 at the mid-cruise altitude). For any given gas turbine engine for an aircraft, the mid-cruise thrust, atmospheric conditions and Mach Number are known, and thus the operating point of the engine at cruise conditions is clearly defined.

Purely by way of example, the forward speed at the cruise condition may be any point in the range of from Mach 0.7 to 0.9, for example 0.75 to 0.85, for example 0.76 to 0.84, for example 0.77 to 0.83, for example 0.78 to 0.82, for example 0.79 to 0.81, for example on the order of Mach 0.8, on the order of Mach 0.85 or in the range of from 0.8 to 0.85. Any single speed within these ranges may be part of the cruise condition. For some aircraft, the cruise conditions may be outside these ranges, for example below Mach 0.7 or above Mach 0.9.

Purely by way of example, the cruise conditions may correspond to standard atmospheric conditions (according to the International Standard Atmosphere, ISA) at an altitude that is in the range of from 10000 m to 15000 m, for example in the range of from 10000 m to 12000 m, for example in the range of from 10400 m to 11600 m (around 38000 ft), for example in the range of from 10500 m to 11500 m, for example in the range of from 10600 m to 11400 m, for example in the range of from 10700 m (around 35000 ft) to 11300 m, for example in the range of from 10800 m to 11200 m, for example in the range of from 10900 m to 11100 m, for example on the order of 11000 m. The cruise conditions may correspond to standard atmospheric conditions at any given altitude in these ranges.

Purely by way of example, the cruise conditions may correspond to an operating point of the engine that provides a known required thrust level (for example a value in the range of from 30kN to 35kN) at a forward Mach number of 0.8 and standard atmospheric conditions (according to the International Standard Atmosphere) at an altitude of 38000ft (11582m). Purely by way of further example, the cruise conditions may correspond to an operating point of the engine that provides a known required thrust level (for example a value in the range of from 50kN to 65kN) at a forward Mach number of 0.85 and standard atmospheric conditions (according to the International Standard Atmosphere) at an altitude of 35000 ft (10668 m).

In use, a gas turbine engine described and/or claimed herein may operate at the cruise conditions defined elsewhere herein. Such cruise conditions may be determined by the cruise conditions (for example the mid-cruise conditions) of an aircraft to which at least one (for example 2 or 4) gas turbine engine may be mounted in order to provide propulsive thrust.

According to an aspect, there is provided an aircraft comprising a gas turbine engine as described and/or claimed herein. The aircraft according to this aspect is the aircraft for which the gas turbine engine has been designed to be attached. Accordingly, the cruise conditions according to this aspect correspond to the mid-cruise of the aircraft, as defined elsewhere herein.

According to an aspect, there is provided a method of operating a gas turbine engine as described and/or claimed herein. The operation may be at the cruise conditions as defined elsewhere herein (for example in terms of the thrust, atmospheric conditions and Mach Number).

According to an aspect, there is provided a method of operating an aircraft comprising a gas turbine engine as described and/or claimed herein. The operation according to this aspect may include (or may be) operation at the mid-cruise of the aircraft, as defined elsewhere herein.

The skilled person will appreciate that except where mutually exclusive, a feature or parameter described in relation to any one of the above aspects may be applied to any other aspect. Furthermore, except where mutually exclusive, any feature or parameter described herein may be applied to any aspect and/or combined with any other feature or parameter described herein.

Brief description of the drawings

Embodiments will now be described by way of example only, with reference to the Figures, in which: Figure 1 is a sectional side view of a gas turbine engine; Figure 2 is a close up sectional side view of an upstream portion of a gas turbine engine; Figure 3 is a partially cut-away view of a gearbox for a gas turbine engine; Figures 4 to 7 schematically depict mould wash apparatus according to the present disclosure; and Figure 8 schematically depicts further detail of a mould wash apparatus according to

the present disclosure.

Detailed description

Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art.

Figure 1 illustrates a gas turbine engine 10 having a principal rotational axis 9. The engine 10 comprises an air intake 12 and a propulsive fan 23 that generates two airflows: a core airflow A and a bypass airflow B. The gas turbine engine 10 comprises a core 11 that receives the core airflow A. The engine core 11 comprises, in axial flow series, a low pressure compressor 14, a high-pressure compressor 15, combustion equipment 16, a high-pressure turbine 17, a low pressure turbine 19 and a core exhaust nozzle 20. A nacelle 21 surrounds the gas turbine engine 10 and defines a bypass duct 22 and a bypass exhaust nozzle 18. The bypass airflow B flows through the bypass duct 22. The fan 23 is attached to and driven by the low pressure turbine 19 via a shaft 26 and an epicyclic gearbox 30.

In use, the core airflow A is accelerated and compressed by the low pressure compressor 14 and directed into the high pressure compressor 15 where further compression takes place. The compressed air exhausted from the high pressure compressor 15 is directed into the combustion equipment 16 where it is mixed with fuel and the mixture is combusted. The resultant hot combustion products then expand through, and thereby drive, the high pressure and low pressure turbines 17, 19 before being exhausted through the core exhaust nozzle 20 to provide some propulsive thrust. The high pressure turbine 17 drives the high pressure compressor 15 by a suitable interconnecting shaft 27. The fan 23 generally provides the majority of the propulsive thrust. The epicyclic gearbox 30 is a reduction gearbox.

An exemplary arrangement for a geared fan gas turbine engine 10 is shown in Figure 2. The low pressure turbine 19 (see Figure 1) drives the shaft 26, which is coupled to a sun wheel, or sun gear, 28 of the epicyclic gear arrangement 30.

Radially outwardly of the sun gear 28 and intermeshing therewith is a plurality of planet gears 32 that are coupled together by a planet carrier 34. The planet carrier 34 constrains the planet gears 32 to precess around the sun gear 28 in synchronicity whilst enabling each planet gear 32 to rotate about its own axis. The planet carrier 34 is coupled via linkages 36 to the fan 23 in order to drive its rotation about the engine axis 9. Radially outwardly of the planet gears 32 and intermeshing therewith is an annulus or ring gear 38 that is coupled, via linkages 40, to a stationary supporting structure 24.

Note that the terms "low pressure turbine" and "low pressure compressor" as used herein may be taken to mean the lowest pressure turbine stages and lowest pressure compressor stages (i.e. not including the fan 23) respectively and/or the turbine and compressor stages that are connected together by the interconnecting shaft 26 with the lowest rotational speed in the engine (i.e. not including the gearbox output shaft that drives the fan 23). In some literature, the "low pressure turbine" and "low pressure compressor" referred to herein may alternatively be known as the "intermediate pressure turbine" and "intermediate pressure compressor". Where such alternative nomenclature is used, the fan 23 may be referred to as a first, or lowest pressure, compression stage.

The epicyclic gearbox 30 is shown by way of example in greater detail in Figure 3. Each of the sun gear 28, planet gears 32 and ring gear 38 comprise teeth about their periphery to intermesh with the other gears. However, for clarity only exemplary portions of the teeth are illustrated in Figure 3. There are four planet gears 32 illustrated, although it will be apparent to the skilled reader that more or fewer planet gears 32 may be provided within the scope of the claimed invention. Practical applications of a planetary epicyclic gearbox 30 generally comprise at least three planet gears 32.

The epicyclic gearbox 30 illustrated by way of example in Figures 2 and 3 is of the planetary type, in that the planet carrier 34 is coupled to an output shaft via linkages 36, with the ring gear 38 fixed. However, any other suitable type of epicyclic gearbox 30 may be used. By way of further example, the epicyclic gearbox 30 may be a star arrangement, in which the planet carrier 34 is held fixed, with the ring (or annulus) gear 38 allowed to rotate. In such an arrangement the fan 23 is driven by the ring gear 38. By way of further alternative example, the gearbox 30 may be a differential gearbox in which the ring gear 38 and the planet carrier 34 are both allowed to rotate.

It will be appreciated that the arrangement shown in Figures 2 and 3 is by way of example only, and various alternatives are within the scope of the present disclosure. Purely by way of example, any suitable arrangement may be used for locating the gearbox 30 in the engine 10 and/or for connecting the gearbox 30 to the engine 10. By way of further example, the connections (such as the linkages 36, 40 in the Figure 2 example) between the gearbox 30 and other parts of the engine 10 (such as the input shaft 26, the output shaft and the fixed structure 24) may have any desired degree of stiffness or flexibility. By way of further example, any suitable arrangement of the bearings between rotating and stationary parts of the engine (for example between the input and output shafts from the gearbox and the fixed structures, such as the gearbox casing) may be used, and the disclosure is not limited to the exemplary arrangement of Figure 2. For example, where the gearbox 30 has a star arrangement (described above), the skilled person would readily understand that the arrangement of output and support linkages and bearing locations would typically be different to that shown by way of example in Figure 2.

Accordingly, the present disclosure extends to a gas turbine engine having any arrangement of gearbox styles (for example star or planetary), support structures, input and output shaft arrangement, and bearing locations.

Optionally, the gearbox may drive additional and/or alternative components (e.g. the intermediate pressure compressor and/or a booster compressor).

Other gas turbine engines to which the present disclosure may be applied may have alternative configurations. For example, such engines may have an alternative number of compressors and/or turbines and/or an alternative number of interconnecting shafts. By way of further example, the gas turbine engine shown in Figure 1 has a split flow nozzle 18, 20 meaning that the flow through the bypass duct 22 has its own nozzle 18 that is separate to and radially outside the core exhaust nozzle 20. However, this is not limiting, and any aspect of the present disclosure may also apply to engines in which the flow through the bypass duct 22 and the flow through the core 11 are mixed, or combined, before (or upstream of) a single nozzle, which may be referred to as a mixed flow nozzle. One or both nozzles (whether mixed or split flow) may have a fixed or variable area. Whilst the described example relates to a turbofan engine, the disclosure may apply, for example, to any type of gas turbine engine, such as an open rotor (in which the fan stage is not surrounded by a nacelle) or turboprop engine, for example. In some arrangements, the gas turbine engine 10 may not comprise a gearbox 30.

The geometry of the gas turbine engine 10, and components thereof, is defined by a conventional axis system, comprising an axial direction (which is aligned with the rotational axis 9), a radial direction (in the bottom-to-top direction in Figure 1), and a circumferential direction (perpendicular to the page in the Figure 1 view). The axial, radial and circumferential directions are mutually perpendicular.

The present disclosure provides a mould wash apparatus that may be used to clean a mould, such as a ceramic mould, used in the formation of components for a gas turbine engine such as that described above. In particular, the mould wash apparatus may be configured for use with narrow bore ceramic mould suitable for forming components such as turbine blades and/or nozzle guide vanes. It should be appreciated, however, that such a mould wash apparatus may also be used for other types of moulds.

Figure 4 schematically depicts a mould wash apparatus 50 for washing a mould 60. As discussed in more detail below, the mould wash apparatus 50 is configured to seal a space 51 around a first opening 61 of the mould 60. The mould wash apparatus 50 further seals a second space 52 around one or more second opening 62 of the mould 60.

As depicted in the Figures, the mould wash apparatus may be configured to wash a mould that comprises plural component moulds 65 that are joined by a supply sprue 66. In such an arrangement, the first opening 61 of the mould 60 may be connected to the supply sprue 66. For example, the first opening 61 may be the mould pour cup. Each of the component moulds 65, in which a respective component is to be formed, may have a respective riser 67. Each of the risers 67 may connect to a respective one of the second opening 62.

The mould wash apparatus 60 has a washing fluid supply 70 that provides washing fluid to the first space 51, around the first opening 61 into the mould 60 and extracts washing fluid from the second space 52 around the one or more openings 62 of the mould 60. Such an arrangement permits the washing fluid to be flushed through the mould 60 during a mould washing operation. Such an arrangement may ensure that particles or debris that are dislodged from a surface of the mould during a mould washing operation are quickly removed from the mould by the flow of the washing fluid rather than being retained in the mould 60 during the mould wash operation.

It should be appreciated that any of a number of washing fluids may be used in the mould wash apparatus. For example, the washing fluid may be water based. Additives may be included, for example surfactants, detergents and/or additives to promote the formation of a foam.

A washing fluid supply controller 71 may be provided to control the washing fluid supply 70. For example, the washing fluid supply controller 71 may control at least one of the pressure of the washing fluid, for example, the pressure of washing fluid supplied to the space 51 around the first opening 61 of the mould 60, and the flow rate of the washing fluid circulating through the mould 60.

Alternatively or additionally, the washing fluid supply controller 71 may be configured to operate the washing fluid supply 70 in different modes. For example, the washing fluid supply may be operated in a continuous mode, in which washing fluid is continuously circulated through the mould 60. The washing fluid supply may alternatively or additionally be configured to operate in a pulsed mode, in which washing fluid is circulated through the mould 60 in pulses. It should be appreciated that the control of the flow of washing fluid through the mould 60 may be used to agitate that fluid as it passes through the mould 60 and/or create turbulent flow in order to dislodge contaminants on the interior surfaces of the mould 60.

In an arrangement, the washing fluid supply 70 may include a filter 72 used to remove particulates from washing fluid that has been extracted from the space 52 around the one or more openings 62 of the mould 60. The filtered washing fluid may then be re-supplied to the space 51 around the opening 61 into the mould 61, namely recirculated through the mould 60. Use of such an arrangement may reduce the amount of washing fluid required for a mould wash operation.

In such an arrangement, in which washing fluid that has been flushed through the mould 61 is re-used, it should be appreciated that the filter may periodically be cleaned and/or replaced. The washing fluid supply 70 may therefore be configured to monitor the condition of the filter 72 in order to identify when filter washing or replacement is required. During cleaning of the filter 72, for example, circulation of the washing fluid may be reversed, at least through the filter 72.

Alternatively or additionally, the washing fluid supply 70 may include one or more sensors configured to monitor the quality of the washing fluid, for example sensing its turbidity. When it is identified that the washing fluid is too dirty, it may trigger an operation to replace the washing fluid being circulated within the mould 60.

The washing fluid supply 70 may include a pump 73 in order to circulate the washing fluid through the mould 60 at a desired pressure and/or flow rate. Any suitable pump may be used, for example a centrifugal, regenerative or positive displacement pump.

In an arrangement as schematically depicted in Figure 5, the mould wash apparatus may include a gas supply 80 that provides bubbles of gas into the washing fluid as it passes through the mould 60. For example, as shown, the gas supply 80 may supply gas to apertures 81 that introduce gas into the flow of washing fluid as it circulates through the mould 60.

In an arrangement, the apertures 81 may be provided at the base of the mould wash apparatus 50 such that the buoyancy of the bubbles encourages them to flow upwards through a part of the mould with the flow of washing fluid. The gas bubbles may assist in dislodging particles or debris on the surface of the mould 60, which may then be flushed out of the mould 60 by the flow of washing fluid. In a variation of the arrangement depicted in Figure 5, the gas supply 80 may include one or more tubes that protrude into the interior of the mould 60 in order to release gas bubbles within the mould 60, for example at a specific location within the mould.

A gas supply controller 82 may be provided in order to control the gas supply 80. For example, the gas supply controller 82 may control at least one of the flow rate of gas provided into the mould 60 and/or the gas pressure. Alternatively or additionally, the gas supply controller 82 may be configured to operate the gas supply 80 in any one of plural modes or operation. For example, the gas supply 80 may operate in a continuous mode, in which bubbles of gas are continuously supplied to the washing fluid. The gas supple 80 may alternatively or additionally operate in a pulsed mode, in which bubbles of gas are intermediately supplied to the washing fluid.

In an arrangement, the gas supply 80 may supply compressed air to the mould 60. It should be appreciated, however, that other gases may be used. In an arrangement, the mould wash apparatus may include a compressor that compresses air for supply to the mould 60. In such an arrangement, the air may be filtered before being supplied to the mould 60 in order to reduce the likelihood of introducing further contaminants or particles to the mould 60.

In an arrangement, the supply of washing fluid to a mould 60 may be controlled independently from the supply of bubbles to a mould 60. This may enable the creation of mould washing operations in which the mould is subjected to a variety of conditions, promoted as thorough cleaning of the mould 60 as is possible.

In an arrangement, the mould wash apparatus 50 may include an oscillator 90, as schematically depicted in Figure 6, configured to oscillate the mould 60 during a mould washing operation. For example, the oscillator may be configured to reciprocally rotate the mould 60 about a vertical axis. It should be appreciated that the range of movement, namely the amplitude of the oscillation, may be limited. The oscillation of the mould may assist in agitating the washing fluid as it passes through the mould 60 and/or itself may assist in dislodging particles or debris stuck on the interior surface of the mould 60, which may then be flushed out of the mould 60 by the flow of washing fluid.

In order to transmit the oscillation to the mould 60, the oscillator 90 may be configured to oscillate one or more components, such as a base plate 53, of the mould wash apparatus 50 that support the mould 60 during a mould washing operation.

The oscillator 90 may include a motor 91, such as a servo or stepper motor, to generate the required oscillations. The motor may be a low voltage motor, which may be safer in an environment in which washing fluid spillages or leakages are possible. A controller 92 may be used to control the oscillator 90 as required during a mould washing operation. For example, the controller 92 may be configured to control the frequency and/or the amplitude of the oscillation. Alternatively or additionally, the oscillator 90 may be controlled to operate during specific phases of a mould washing operation.

It should be appreciated that, although the above description has described an arrangement in which the oscillator 90 oscillates the mould 60 rotationally about a vertical axis, the oscillator 90 may be configured to alternatively or additionally generate alternative modes of oscillation such as rotationally about different axes of rotation and/or lineally in one or more desired direction.

In an arrangement of a mould wash apparatus 50, with or without an oscillator 90, the apparatus may be configured to hold the mould 60 in a single orientation during the mould washing operation, for example, from a time at which washing fluid is introduced to the mould 60 until a time at which all washing fluid has been removed from the mould 60. Such an arrangement may be possible because the mould wash apparatus 50 is configured to flush washing fluid through the mould 60. Accordingly, particles and/or debris may be continuously flushed from within the mould 60 without a requirement to remove all washing fluid from the mould 60 and/or to turn over a mould 60 in order to do so. This may reduce the cost of the mould wash apparatus and/or may reduce the likelihood of damage to a mould 60 during a mould washing operation.

In an arrangement, the mould wash apparatus includes a drain opening 95 that may include a valve that can be opened or closed. As shown in Figure 7, the drain opening 95 may be configured such that when the mould 60 is held within the mould wash apparatus for a mould washing operation, the drain opening 95 is lower than the mould 60. Accordingly, when the drain opening 95 is in an open position, washing fluid may be drained from the mould wash apparatus 50 and the mould 60.

In an arrangement such as that depicted in Figure 7, the drain opening 95 may be provided in a bottom plate 53 that may support the mould 60 during a mould washing operation. The bottom plate 53 may include a seal 77 that seals a space 78 between the bottom plate 53 and the mould 60. As shown in the Figures, thee mould washing apparatus may be configured such that, during a mould washing operation, washing fluid being flushed through the mould 60 passes through this space 78. The seal 77 may be formed from any suitable resilient material. It should be appreciated that, although the bottom plate 53 depicted in Figure 7 only includes a single drain opening 95, if required, plural drain openings 95 may be provided in the bottom plate 53.

A drain opening controller 96 may be provided that controls the drain opening 95 such that the washing fluid may be partially or completely drained from the mould washing apparatus 50 and/or the mould 60 during a mould washing operation. For example, the drain opening 95 may be opened during a mould washing operation in order to flush out larger particles and/or debris that may accumulate at the bottom of the mould wash apparatus 50 and/or mould 60. Alternatively or additionally, the drain opening 95 may be opened in order to remove washing fluid from the system such that it can subsequently be replenished with cleaner washing fluid from the washing fluid supply 70. It should be appreciated that the opening of the drain opening 95 during a mould washing operation may occur at predetermined times according to a desired mould washing operation and/or may occur in response to detected conditions, such as the quality of the washing fluid passing through the mould 60.

It should also be appreciated that the drain opening 95 may alternatively or additionally be opened at the end of a mould washing operation in order to remove all washing fluid from the mould 60 and/or the mould washing apparatus 50 on completion of the mould washing operation. This may avoid the necessity, for example, to change the orientation of the mould 60 in order to remove the washing fluid.

The description above describes arrangements of a mould wash apparatus 50 that do not require the orientation of the mould 60 to be changed during a mould washing operation or at the completion of the mould washing operation. It will be appreciated, however, that in some arrangements, the mould washing apparatus may be provided with an actuator that makes it possible to change the orientation of the mould 60. This may be used to facilitate removal of the mould washing fluid on completion of a mould washing operation and/or to improve the flow of washing fluid through specific regions of a mould 60. It should be appreciated that an actuator used to control the orientation of a mould 60 during a mould washing operation and/or at its end may also be used as part of an oscillator 90. Alternatively, separate actuators may be provided.

Figure 8 schematically depicts a part of a mould wash apparatus for providing the washing fluid to the space 51 around the first opening 61 into the mould and removing washing fluid from the second space 52 around the at least one second opening 61 from the mould 60. As shown, the outlet seal for sealing the second space 52 around the second opening 62 of the mould 60 includes a seal plate 53, which is configured to be positioned adjacent a surface 63 of the mould 60 that includes the one or more second openings 62. A resilient member 54 is attached to the seal plate 53 and, when the seal plate 53 is adjacent the surface 63 or the mould 60, is compressed between the seal plate 53 and the mould 60, creating a seal. The second space 52 is therefore sealed between the seal plate 53 and the mould 60. Any suitable resilient material may be used as the resilient member 54. In an arrangement as shown in Figure 8, a skirt 55 may be provided to the seal plate 53 to prevent any leaking washing fluid from shooting outward.

In order to insert a mould 60 into the mould wash apparatus, or remove a mould 60 from the mould wash apparatus, the seal plate 53 may be moved to a retracted position, shown in Figure 7, in which the seal plate 53 is moved away from the mould 60. After loading a mould 60 into the mould wash apparatus 50, the seal plate 53 may be advanced until the resilient member 54 contacts the mould 60. Although not depicted in the Figures, it will be appreciated that an actuator and corresponding controller may be provided in order to advance and retract the seal plate 53. In any case, the seal plate 53 may be advanced until a desired contact pressure is provided at the resilient member 54. The contact pressure may be selected to be sufficiently high that the risk of leakage is minimised but sufficiently low that the risk of damage to the mould 60 as a result of the contact pressure is minimised.

An outlet conduit 76 may pass through the seal plate 53 to enable washing fluid to be extracted from the space 52 around the one or more second opening 62 to the washing fluid supply 70. A sealed spherical bearing 77 may be provided between the outlet conduit 76 and the seal plate 53 to permit movement of the seal plate 53 relative to the outlet conduit 76, for example in the event of irregularities of the mould 60, and to permit rotation of the seal plate 53 about the outlet conduit 76, which may enable oscillations of the seal plate 53 and the mould 60, as discussed above.

In the arrangement depicted in Figure 8, in order to supply washing fluid to the first opening 61 of the mould, a supply conduit 75 extends to a location adjacent the first opening 61. A diaphragm made from a suitable resilient material forming inlet seal 57 is mounted to the end of the supply conduit 75 and extends to a surface 64 of the mould 60 that surrounds the first opening 61. In such an arrangement, the space 51 around the first opening 61 is defined by the surface 64 of the mould 60 around the first opening 61 and the inlet seal 57. Washing fluid provided to this space 51 through the supply conduit 75 accordingly passes into the mould 60 through the first opening 61.

Neoprene may be used as the resilient material to form one or more of the seals discussed above. It may be suitable for this use because it is a relatively soft compound and can therefore deform significantly to form a seal against a ceramic mould, which often has surfaces that are not flat and level. Furthermore, neoprene provides an effective water/air tight seal. It will be appreciated that other materials may be used.

In an arrangement, the first opening 61 into the mould 60 may be surrounded by a plurality of second openings 62. For such a mould arrangement, the supply conduit 75 may be arranged to pass through the seal plate 53 and through the space 52 around the second opening, as depicted in Figure 8.

The supply conduit 75 may be configured to be able to move relative to the seal plate 63, for example controlled by an actuator 58. This may enable the distance between the seal plate 53 and the inlet seal 57 to be changed. For example, when a mould 60 is first loaded into the mould wash apparatus 50, the supply conduit 75 may be retracted such that the inlet seal 57 is in a position closer to the seal plate 53. After the seal plate 53 has been advanced into contact with the mould 60, the supply conduit 75 may then be advanced toward the first opening 61 into the mould 60 until the inlet seal 57 contacts the surface 64 of the mould 60 in order to seal the first space 51 around the first opening 61.

In an arrangement, as shown in Figure 8, the supply conduit 75 may be within, and pass through, the outlet conduit 76. Such an arrangement may only require a single sealed spherical bearing 77 to pass both conduits through the seal plate 53. It should be appreciated, however, that in alternative arrangements, the supply conduit and the outlet conduit 76 may pass through the seal plate 53 at different locations.

The mould wash apparatus may include a system controller 100 that controls each of the component controllers discussed above, including the washing fluid supply controller 71, the gas supply controller 82, the oscillator controller 92, the drain opening controller 96 and an actuator controller 59, where each of those are provided, in order to implement a mould washing operation. It should be appreciated that although the component controllers are described as separate from the system controller 100, this need not be the case. In particular, each of these may be component parts within a single control system.

The control system overall may be implemented by any suitable means, for example by using a programmable logic controller, which may assist in fault finding and reprogramming. In an arrangement, the control of, for example, the washing fluid supply 70, the gas supply 80, the drain opening 95 and the actuator 58 controlling the position of the seal plate 53 may be implemented using a pneumatic control system. Use of a pneumatic control system may be safer in the context of a washing apparatus than an electronic control system based on solenoids for controlling these components. Furthermore, the pneumatic control system may be cheaper and easier to maintain.

The system controller 100 may be configured to receive an input selecting a specific mould washing cycle from a plurality of predetermined mould washing cycles, after which operation of each of the component controllers is controlled by the system controller in order to implement a mould washing operation that corresponds to the selected mould washing cycle. The selection may be made by an operator according to known requirements for a particular mould 60.

Alternatively or additionally, each of the predetermined mould washing cycles may be associated with a respective mould design. The mould wash apparatus 50 may therefore select the required mould wash cycle based on a recognition of a mould to be washed, for example, based on scanning a batch card and automatically implement the required mould wash cycle.

Alternatively or additionally, an operator may specify each of the steps required in a mould washing operation or may be able to amend the steps specified in a predetermined mould washing operation.

It will be understood that the invention is not limited to the embodiments above-described and various modifications and improvements can be made without departing from the concepts described herein. Except where mutually exclusive, any of the features may be employed separately or in combination with any other features and the disclosure extends to and includes all combinations and sub-combinations of one or more features described herein.

Claims

CLAIMS1. A mould wash apparatus, comprising: an inlet seal (57), configured to seal a space (51) around a first opening (61) of a mould (60) to be washed; an outlet seal (54), configured to seal a space (52) around at least one second opening (62) of the mould (60); and a washing fluid supply (70) configured to supply washing fluid to the space (51) sealed around the first opening (61) of the mould (60) and to remove washing fluid from the space (52) around the at least one second opening (62) of the mould (60).
2. The mould wash apparatus according to claim 1, wherein the washing fluid supply (70) is configured to filter particulates from washing fluid removed from the space around the at least one second opening (62) of the mould (60) and supply the filtered washing fluid to the space (51) around the first opening (61) of the mould (60).
3. The mould wash apparatus according to claim 1 or 2, comprising a washing fluid supply controller (71) configured to control the washing fluid supply (70) to operate in at least one of a continuous mode, in which washing fluid is continuously supplied to the space (51) around the first opening (61) of the mould (60), and a pulsed mode, in which washing fluid is intermittently supplied to the space around the first opening of the mould.
4. The mould wash apparatus according to any one of the preceding claims, further comprising a gas supply (80), configured to provide bubbles of gas into the washing fluid as it passes through the mould (60).
5. The mould wash apparatus according to claim 4, comprising a gas supply controller (82), configured to control the gas supply (80) to operate in at least one of a continuous mode, in which bubbles of gas are continuously supplied to the washing fluid, and a pulsed mode in which bubbles of gas are intermittently supplied to the washing fluid.
6. The mould wash apparatus according to claim 4 or 5, wherein the supply of gas bubbles can be controlled independently from the supply of washing fluid.
7. The mould wash apparatus according to any one of the preceding claims, further comprising an oscillator (90), configured to oscillate the mould (60) during a mould washing operation.
8. The mould wash apparatus according to claim 7, comprising an oscillator controller (92), configured to control the oscillator (90) to operate at required periods during the mould washing operation.
9. The mould wash apparatus according to any one of the preceding claims, wherein the mould wash apparatus (50) is configured to hold the mould (60) in a single orientation during a mould washing operation.
10. The mould wash apparatus according to claim 9, wherein the mould wash apparatus (50) is configured to hold the mould (60) in a single orientation from a time at which washing fluid is introduced to the mould until a time at which all washing fluid has been removed from the mould.
11. The mould wash apparatus according to any one of the preceding claims, further comprising a drain opening (95); wherein the mould wash apparatus is configured such that, when a mould (60) is held within the mould wash apparatus (50) for a mould washing operation, the drain opening (95) is lower than the mould (60).
12. The mould wash apparatus according to claim 11, comprising a drain opening controller (96), configured to open the drain opening (95) at required times during the mould washing operation in order to partially or completely drain the washing fluid from at least one of the mould (60) and the mould washing apparatus (50).
13. The mould wash apparatus according to any one of the preceding claims, wherein the outlet seal comprises a seal plate (53), configured to be positioned adjacent a surface (63) of the mould (60) that includes the at least one second opening (62); and a resilient member (54) that surrounds the at least one second opening (62) and, when the seal plate (53) is positioned adjacent the surface (63) of the mould (60), is compressed between the seal plate (53) and the mould.
14. The mould wash apparatus according to claim 13, wherein the washing fluid supply (70) comprises a supply conduit (75) to supply washing fluid to the first opening (61); the inlet seal (57) is mounted at an end of the supply conduit (75); and the supply conduit (75) is mounted to, and passes through, the seal plate (53).
15. The mould wash apparatus according to claim 14, wherein the seal plate (53) and supply conduit (75) are configured to enable the supply conduit (75) to move relative to the seal plate (53) such that the distance from inlet seal to the seal plate changes.
16. The mould wash apparatus according to claim 15, further comprising an actuator (58) configured to move the supply conduit (75) relative to the seal plate (53) and an actuator controller (59) configured to control the actuator (58).
17. The mould wash apparatus according to claim 14, 15 or 16, wherein the washing fluid supply comprises an outlet conduit (76) to remove washing fluid from the space (52) around the at least one second opening (62); and the outlet conduit (76) is mounted to, and passes through, the seal plate (53).
18. The mould wash apparatus according to claim 17, wherein the supply conduit (75) is positioned within the outlet conduit (76).
19. The mould wash apparatus according to any one of the preceding claims, comprising a system controller (100), configured to control independently a plurality of mould wash apparatus component controllers, which may include a washing fluid supply controller (71), a gas supply controller (82), an oscillator controller (92), a drain opening controller (96) and an actuator controller (59), in order to implement a mould washing operation.
20. The mould wash apparatus according to claim 19, wherein the system controller (100) is configured receive an input selecting a mould washing cycle from a plurality of predetermined mould washing cycles that define periods of operation of each of the component controllers and implement a mould washing operation corresponding to the selected mould washing cycle.
21. The mould wash apparatus according to any one of the preceding claims, wherein the mould wash apparatus is configured to wash a mould (60) that comprises a plurality of component moulds (65) joined by a supply sprue (66); and the first opening (61) of the mould (60) is connected to the supply sprue (66).
22. The mould wash apparatus according to claim 21, wherein each of the component moulds (65) comprises at least one riser (67) connected to a respective second opening (65).