Cleaning system and a method of cleaning

1. A method of cleaning gas paths in an engine core of a gas turbine engine, the method comprising the steps of:

vapourising an engine cleaning liquid to form an engine cleaning mist;

supplying the engine cleaning mist into the engine core of the gas turbine engine;

drawing the engine cleaning mist through the engine core to clean the gas paths within the engine core;

collecting the engine cleaning mist that has passed through the engine core and condensing the collected engine cleaning mist;

placing a delivery device in front of the engine core;

arranging a conduit between and interconnecting a rear engine core exhaust nozzle of the engine core and a condensing chamber, the conduit being connected to the rear engine core exhaust nozzle via a tooling; and

drawing the engine cleaning mist through the engine core via a pump to clean the gas paths within the engine core by creating a pressure difference that pulls the cleaning mist through the engine core, the pump further configured to deliver the engine cleaning mist to the condensing chamber via the conduit, the pump being arranged downstream of the rear engine core exhaust nozzle,

wherein placing the delivery device further comprises inserting the delivery device from a rear of the gas turbine engine through a bypass duct of the gas turbine engine, and

wherein, after the delivery device is inserted from the rear of the gas turbine engine, the delivery device extends from a bypass exhaust nozzle, through the bypass duct, and into a front end of the engine core.

2. The method according to claim 1 , further comprising supplying the engine cleaning liquid to an engine cleaning mist forming unit, wherein the engine cleaning mist forming unit vapourises the engine cleaning liquid to form the engine cleaning mist and supplies the engine cleaning mist into the engine core of the gas turbine engine.

3. The method according to claim 1 , wherein the delivery device includes at least one of at least one flexible hose and at least one pipe.

4. The method according to claim 3 , wherein the at least one of the at least one flexible hose and the at least one pipe extend from a source of the engine cleaning liquid, through the bypass duct, and to the front end of the engine core, and wherein the source of the engine cleaning liquid is one of a tank and a vessel.

5. The method according to claim 1 , wherein the engine core include a compressor having a low pressure compressor and high pressure compressor located axially aft of the low pressure compressor, a combustor located axially aft of the high pressure compressor, a turbine located axially aft of the combustor and having a high pressure turbine and a low pressure turbine located axially aft of the high pressure turbine, and the rear engine core exhaust nozzle located axially aft of the low pressure turbine, and wherein the front end of the engine core is located proximal the low pressure compressor.

6. The method according to claim 1 , wherein the tooling is a seal that provides a sealing interface between the conduit and the rear engine core exhaust nozzle.

7. The method according to claim 1 , wherein the pump generates a flow of the cleaning mist through the engine core such that the cleaning mist is drawn through the engine core and droplets of cleaning mist remain in the engine core.

8. The method according to claim 1 , wherein the pump is at least one of a vacuum pump and a fan.

9. The method according to claim 1 , wherein the pump is arranged in the conduit directly downstream of the rear engine core exhaust nozzle.

10. The method according to claim 2 , further comprising placing a portion of the delivery device in front of the engine core, wherein the delivery device is configured to supply the engine cleaning liquid to the engine cleaning mist forming unit.