Low pressure steam boiler BAHR’UNO (STD-HPO-HP)

Low pressure steam boiler, three pass reverse flame, with efficiency from 91% up to 97%(1) according the installed smoke tube (STD, HPO, HP).

BAHR’UNO is a family of packaged smoke tube steam boilers, three pass reverse flame, wet back. Standard safety pressure up to 0.98 bar and output from 140 to 3000 kg/h. It can be operated with liquid or gaseous fuels. Every model is complete with regulations and safety accessories for automatic operation and easy commissioning.

In compliance to the current laws, each steam boiler undergoes a conformity assessment, carried out by a Notified Body. The conformance to the essential safety requirements demanded by the European Pressure Equipment Directive 2014/68/UE (PED) is guaranteed by the CE mark.

Design features

By means of the reverse flame principle the smoke gases in the combustion chamber are diverted to the front, then reversed again to the smoke tube sections and discharged through the chimney connection. The appliance is designed to ensure low heating loads in the combustion chamber and low superficial loads.

• Boiler body: is made up of a cylindrical shell and a wet back furnace, made of high quality steel. All the materials have certificates attesting their chemical and mechanical characteristics, the controls are carried out during each production stage, and, theirs suitability for use as well. The welding seams are carried out by qualified personnel in compliance to certified procedures and are subjected to Non Destructive Tests, in accordance to an internal “Manufacturing and Control” program. Once the boilers have been manufactured they are subjected to hydraulic testing in accordance to the requirement 7.4 – Annex I, laid down in the Directive 2014/68/UE (PED).
  
• Smoke tubes: made of high quality steel, are welded to tube plates. Pipes are equipped with steel turbulators or fitted with aluminum and/or steel inserts according the installed smoke tube.
• Front door: is built in welded steel plate, completely cladded internally with a layer of insulation material and with a layer of high density refractory material. The door is fitted with hinges which enable it to be easily adjusted and quickly opened. Moreover, the door is fitted with a self-cleaning sight glass for combustion control during boiler operation.
• Rear smoke-box: is built in welded steel plate and fixed on to the tube plate by nuts for an easy access to it. It is fitted with a small door for cleaning purposes and the horizontal flue connection (vertical on request), with a diameter sized to the boiler’s output. The rear smoke-box is pre-arranged for the installation of an integral economizer.
• The base: is built with a steel frame, welded to the tube plates and closed with steel plates. 
• Walkway: positioned on the top part of the boiler, is made of steel, covered with chequered plate and completed; on request with handrail and access ladder.
• Insulation: the shell is thermally insulated with a 100 mm rock wool cladding binded with high density, thick thermosetting resins, suitably supported and covered externally in 10/10 thick enamelled aluminum. The frontal parts of the boiler are also insulated with rock wool and covered externally with a metallic box.

Standard equipment (2)

• Steam main globe valve.
• 2 spring loaded safety valves.
• 2 reflecting level indicators, with flanged connections, purging and cut-off cocks.
• 1 large manometer with 3 way cock for manometer calibration.
• 1 safety pressure switch with manual reset onto the board panel, CE PED certified.
• 1 limit working pressure switch.
• 1 regulation pressure switch for two stages burners or probe for modulating burners.
• 2 safety minimum level switches, with manual reset CE certified.
• 2 water level probes for ON-OFF pump regulation.
• Feeding group complete with 2 centrifugal pumps.
• Valve assembly for feeding circuit, with relevant pipes already fitted.
• Automatic group for level control.
• 1 manual bottom blowdown valve.
• Man-hole on top and hand-hole on water side.
• Integral steam drier for high steam quality.
• Blind burner plate.
• Turbulators (STD version) or special high efficiency pipes fitted with inserts (HPO, HP versions).
• Lifting lugs.
• Control board panel IP55 400V - 3+N - 50Hz
• Document folder enclosing:
• - Manufacturer's Declaration of Conformity in compliance with the Annex VII of the European Directive 2014/68/UE (PED)
• - Installation, operation and service manuals.
• - Certificates of safety components.
• - Control board’s electric schemes and related Declaration of Conformity.
• - Water characteristics: requirements concerning the quality of water supply, the water in the boiler, frequency and type of sample tests to do.

Options

• Spring actuated safety valve 
• Kit of “Second boiler water feeding pump” 
• Kit of “maximum safety level”
• Kit TDS (Total Dissolved Salts)
• Kit of “Automatic de-sludging” (Blow down)
• Kit of “72 hr exemption” for standard steam boiler *
• Pre-drilled burner plate
• Oil or gas fired burner 

    * Supplied with electronic board panel Unical, model IML (Industrial Multi Logic)

Special versions

• BAHR’UNO 72 hr - Equipped with either "IML" or "IMC board panel” and “Kit 72 hr” to obtain:
  
• the certification for operation “without continuous surveillance” for model until 2000 kg/h
• the certification for operation “without continuous surveillance” up to a maximum of 72 hr for model over 2000 kg/h.
• EC / HPOEC / HPEC versions - To increase more the already high steam boiler efficiency, without influencing the dimensions the boilers are already preset to fit, on request (in the factory or later, on the field), the economizer Kit EC, which is specific for each model and is available for both, gas and oil versions.
  

(1) This value is intended with economizer and may change according working pressure and load conditions.

(2) The quantity and the model may vary according to the configuration.