1. Introduction.

Acoustic cleaner installation for exhaust gas boilers, (similarly on Aux. boilers and M/E air coolers), requires minimum modifications to existing piping and electric network of the vessel. Cleaning of tubes is realized by low frequency resonance of boiler tubes caused by the 2 low frequency horns which load the exhaust gas volume inside the boiler. Sound generated by the horns is audible so one can tell whether the system is operating, efficient as soot removed from the tubes, yet harmless to the boiler itself.  

System operates for 10secs every 10 minutes (which can be adjusted). Within this time soot builds up to a size that the resonance caused for 10secs is enough to brake it into particles that eventually not only will leave the boiler tubes carried by the gas flow but will not attach anywhere to the rest of the exhaust manifold ending up outside the system.

For satisfactory results installation must comply with the installation guidelines.

Parts and requirements.

Parts provided by manufacturer:

1) One low frequency horn type 360 with STELL HORN

2) One low frequency horn type 230 with ALUMINIUM HORN

3) Air unit (pressure regulator, filter and manometer), 2pcs

4) Electric unit (timer), 2pcs

5) Solenoid valve type 220, 2pcs

Required parts (to be fabricated by the installer):

1) Mounting plate/inspection opening for horn type 360

2) Mounting plate/inspection opening for horn type 230

3) Mounting brackets for solenoid, air and electric unit

Installation requirements:

1) Power supply for electric unit (220V/30VA)

2) Compressed air supply (7bar) ½”

2. Installation and guidelines.

-Horns consist of 4 parts. Compression driver (sound generator), elbow piece,

intermediate horn and final horn.

-Final horn is the one that should be mounted on the inspection door. Considering

dimensions of final horn (type 230: external diameter 325mm, overall length 310mm,

type 360: ext. diameter 175mm, overall length 370mm), inspection opening must have

adequate Location and dimensions so the door together with the welded horn can be FREE OPEN CLOSE or REMOVE complete.

Therefore opening must be at least 340mm and 200mm wide respectively. The door

itself must have a round hole of 200mm for type 230 and 140mm for type 360.

The final horn must be fitted into this hole and welded forming together with the door one piece. The rest of the parts are mounted on the final horn one after the other.

-For exhaust gas boilers, acoustic horn type 230 Aluminum is much stronger than

Horn 360 and must be fitted before the tubes (gas inlet side) and type 360 just after

(gas outlet side).

For optimum operation of acoustic cleaner the horns must can be mounted on about

0.5m – to 2.0 meters away from the tubes. Increasing this distance greatly

compromises cleaning effect.

Boiler exhaust inspection doors can be used for this purpose provided those are placed

as close to the tubes as required above.

-It is essential that horns must be positioned horizontally in way that

compression driver must on the top.  This is to ensure longer MTBF of the latter by preventing building up particles on the horn itself.

It is recommended that a protective bracket is fitted in order to protect the horn from accidental contact during normal operation/overhauling especially if they are fitted in way of a passage. Bracket could be welded on the door itself so it protects the horn even on case of door withdrawal and placed on the floor.

-Mounting bracket is suggested to be fitted next to inspection door in a way that the

air and electric unit are protected against any possible damage during normal

operation and standard overhauling of vessels appliances nearby, including also

maintenance of boiler itself. As there is manometer on the filter element must be

placed in a height that an average person can read (1.5-1.7 m).

- Air and power supply is to be permanently provided to the air and electric unit. Air

supply must be of no smaller than 1/2” steel pipe and electric power cable to be

protected as per project specification. Valve must be placed just before air unit

enabling system isolation in case of malfunction.

-Air connection between horn and solenoid valve is to be made by flexible hose ¼”of

adequate length in order to allow safe withdrawal of inspection door but no longer

than 0.7 meter. Flexible hose is to be removed from the horn in case of inspection

door withdrawal.



Pneumatic installation. Applies for both types of horns.

Pneumatic installation





Horn type 230. Assembled on the inspection door. Please note that protective

supporting bracket is not included. This must be designed so as to match specific

installation. It is suggested that compression driver is protected by this bracket.