The fume cupboards shall be Dynaflow Model  manufactured by: Chemical Fume Handling Equipment 30 Waratah Street, Ermington, N.S.W. 2115.  (Any alternative offered must be strictly subject to clients's approval).  The fume cupboard(s) shall be of aerodynamic bench type and shall be constructed in accordance with this specification and is to comply with the Australian Standard for Fume Cupboards

AS 2243.8, AS 3000, AS2430.3 and AS1482 and shall have been performance tested to Clause 6.1 of BS7258 Part 1 1990.  (Compliance certificate must be supplied).

A SAMPLE FUME CUPBOARD CONTAINING ALL OF THE FEATURES IN THIS SPECIFICATION SHALL BE MADE AVAILABLE BY THE SUCCESSFUL TENDERER FOR INSPECTION.

Dimensions

The fume cupboard shall have the following external dimensions:-

200/1500/2000mm (W) x 890 (D) x 1550mm

The Fume Cupboard

Shall be manufactured from fire retarded glass reinforced plastic and should comply with Australian Standard AS 1530 Part 3 (1973)

Inner Chamber

The inner chamber shall be a one piece moulded, design from chemical resistant glass reinforced plastic with large radiused corners. The roof shall be aerodynamically shaped evenly on three sides towards a flanged rectangle outlet at the rear of the chamber which shall not be less than 45% of the width of the inner chamber and containing no exposed fixing bolts.

(A FLAT NON-AERODYNAMIC TYPE ROOF WILL NOT BE ACCEPTABLE.)

Front Facia

The front facia shall be of the picture frame type manufactured in one piece from chemical resistant glass reinforced plastic and shall extend to the full height of the fume cupboard.  The aerofoil shaped sides and bottom of the facia shall have a minimum width of 100mm at a minimum of 45o to the opening.

Base

The base of the chamber shall contain a full width sump moulded in one piece from G.R.P. and fitted with a waste outlet.  The front shall contain a shaped section inclined towards the sump to assist in the retention of any spillage.  (N.B. A VERTICAL RAISED LIP WILL NOT BE ACCEPTABLE DUE TO THE TURBULENCE AND OBSTRUCTION IT CREATES).

Worktop

The worktop shall be of the removable type, suspended above the full width sump and manufactured from "Trespa" material of not less than 12mm thick.  Drainage shall be achieved via a slot around the removable worktop into the full width sump below.

Additional Sink

* Option

An additional sink shall be supplied measuring      x     x     mm deep moulded into the standard concealed sink/sump.  The worktop is to be cut to expose the additional sink and have a replaceable lid which fits into a rebate in the worktop; retaining the uncluttered work surface.

Sash

The sash shall be of the vertical type, glazed with 6mm armour plate glass and counter balanced by a one piece counter balance weight supported by stainless steel cables running on four ball bearing pulleys.  The bottom of the sash should have a full length aerofoil section and two (2) moulded handles fixed approximately 100mm from the bottom of the sash.The sash runners and channels shall have seals to ensure they are completely airtight and a minimum opening of 50mm should remain when the sash is fully lowered.  (2 separate weights will not be acceptable).

By-Pass

The fume cupboard shall be fitted with a concealed top by-pass system to control the air velocity at the lower sash opening, the by-pass system should be completely sealed off when the sash is fully raised to give all the available extraction through the sash opening for maximum safety.  The extraction rate from the fume cupboard should remain constant, irrespective of the position of the sash.

Baffle

The fume cupboard chamber shall be fitted with a specially designed back baffle manufactured from chemical resistant glass reinforced plastic.  The baffle should ensure the whole of the chamber is scavenged, whether heavy or light corrosive fumes are present and assist in obtaining an even, average, face velocity across the sash.

Lighting

The fume cupboard lighting shall be by a fluorescent light mounted in a purpose made moulded cover and shall provide illumination at the work surface through a sealed armour plate glass panel recessed in the roof of the chamber to avoid disturbing the airflow within the fume cupboard. (A CLEAR P.V.C. PANEL WILL NOT BE ACCEPTABLE.)

Services

The fume cupboard shall be supplied with the following remotely controlled services:-

*Cold water, hot water, gas, nitrogen, compressed air, vacuum, argon, etc. 10 Amp G.P.O.

The service outlets shall be mounted internally on the side walls of the fume cupboard chamber to preserve the uncluttered work surface.  The outlets shall be finished in electrostatically applied epoxy finish.  The remote control valves and outlets shall be colour coded to the DIN 12920 international standard.  The remote control valves are to be mounted on the sides of the front facia.  The remote control fittings shall be of the Armitage Shanks new "Marklab"range with flow regulating facility.  The fume cupboard shall be totally factory pre-plumbed and pressure tested to ensure no leaks are encountered on site.  (No site plumbing other than the connection of service tails to the main supply shall be carried out on site.)

Fume Cupboard Electrical and Gas Isolation Equipment

The fume cupboard(s) shall be supplied with a Dynasafe Mk 3 Control System.  This Control System is to be an electronic, programmable P.C.B. module containing 40 x 4 character liquid crystal back lit display (LCD) allowing full status display without abbreviation, and all switches, timers and relays to enable the fume cupboard to comply with the Australian Standards, Nos. 2243.8-1992, 3000-1986 and 2430.3-1991 Appendix 'A'.

The Control System shall also have an RS485 multi drop communication channel which will allow the system to communicate with other computers or building management systems over long distances and in electronically noisy environments.  (NOTE: RS232 COMMUNICATION CHANNEL DOES NOT HAVE ADEQUATE NOISE IMMUNITY AND DISTANCE CAPABILITIES AND IS NOT ACCEPTABLE.)

The System is to be complete with a special adjustable flow sensor which allows (in the event of an extraction rate failure) the Control System to activate an 75 DB alarm and graphic warning display on the LCD, and will turn off power and gas supplies via a contactor and solenoid valve.

The module shall also incorporate an internal battery back-up supply to ensure alarm activation and graphicindication when the power supply is lost either by circuit failure or power failure;  as required for compliance to AS2243.8 1992.

The Control System shall be complete with pre-purge, and post purge timers, all graphic indication giving status of fan, light, pre-purge, post-purge, power/gas availability, alarm, alarm mute. (It shall also contain controls for spray bar, fume scrubber pump, Syncroflow Sash System and heat sensor to operate when these are installed).

Fitted on the control module shall be an "Fume Cupboard Emergency Isolator" with graphic indication which when activated will isolate power/gas supplies, but will allow the fan to continue running as required by the Australian Standards.

The unit shall also be programmable by the operator to start or stop the fume cupboard at any preset time, to allow automatic out of hours operation.

 Syncroflow Energy Saving Sash System

The fume cupboards shall be complete with Syncroflow Sash System to control the fume cupboard extraction fan r.p.m.

The system shall be capable of giving an infinitely variable air volume in relation to the sash position whilst maintaining a constant capture velocity of 0.5 m/s across the open sash.  When the sash at its minimum opening of 50mm the extraction rate shall be automatically set to give a minimum of five fume cupboard chamber air changes per minute as required for compliance with AS2243.8-1992.  The system must be capable of giving immediate response to any movement of the sash, therefore limit switches will not be acceptable.

An auto/boost switch shall be incorporated in the fume cupboard control module.  When the boost switch is activated it should override the automatic mode of the controller and instantly provide maximum air quantity from the extraction fan, irrespective of the position of the sash.  When the auto switch is activated the fume cupboard should immediately return to its normal synchronised mode.

Note:

Pre-set multi speeds operated by switches or motorised damper by-pass system or D.C. motors will not be acceptable.

All wiring to the discrete elements of the controller should be provided and installed by the supplier.

Terminals should be provided within the control unit for connection to an incoming single phase 240 volt supply and 3 phase output for wiring to the 3 phase motor fitted to the extraction fan.  All wiring shall comply with AS3000.

An outlet terminal shall be supplied in the discharge duct which acts as a non-return valve which will seal the exhaust system to ensure no fume re-enters the laboratory when the fume cupboard is idle, and to maintain a minimum discharge velocity of 10 m/s.

CONTROL SYSTEM SERIAL COMMUNICATION FOR FUME CUPBOARD AIR FLOW, AIR CONDITIONING AND BUILDING MANAGEMENT SYSTEMS.

A micro processor driven communication system shall be provided which utilises RS485 digital communication channel.

(NOTE: RS232 COMMUNICATION CHANNEL DOES NOT HAVE ADEQUATE NOISE IMMUNITY AND DISTANCE CAPABILITIES AND IS NOT ACCEPTABLE.)

The system is to allow the fume cupboard's Dynasafe Mk3 Control Systems and Syncroflow Sash Systems to communicate their air flow status, as well as operation and alarm status, to a central Syncroflow Management Module mounted in the mechanical plantroom.

The Syncroflow Management Module is to provide a single analogue output to allow the air conditioning system to immediately adjust to the fume cupboard operation and exhaust air flow demand, as well as allow for provision of alarm status for the Building Management Control System.

Extraction Fan

The Chemical Fume Extraction Fan shall be Pifan Series II expressly suitable for the purpose of corrosive fume extraction.  The casing should be moulded in one piece with no seams or joints from chemical resistant reinforced plastic.  The fan should be suitable for connection to a 420 volt 3 phase power supply.  The fan should be capable of providing a velocity rate of not less than 0.5 m/s across the open face of the fume cupboard, after taking into consideration the pressure losses throughout the extract system.

Prewiring of Fume Cupboard

The fume cupboard manufacturer shall completely pre-wire the fume cupboard including all lights, G.P.O., solenoids, relays, timers and alarm system.  Terminals shall be provided for site wiring by others for the electrical supply to fume cupboard and for wiring to extraction fan.

Spray Bay

A spray bar is to be fitted behind the back baffle which shall have a remote control valve for shutting off when not required, together with the auto and manual operation incorporated into the control module.

Support Cupboard

The support unit shall be designed to support the fume cupboard and should provide cupboard space complete with doors, handles and adjustable shelf.  There should be a removable internal back for access to any services running on the wall behind. Where Perchloric Acid fume scrubber/mist eliminators are installed, the support cupboard shall be adapted to house the recycle neutralising tank, chemical pump, valves and pipework, etc.

Perchloric Acid (or other) Fume Scrubber

The fume scrubber shall be a Dynaflow M/E.  This combination fume scrubber and mist eliminator shall be fitted directly to the outlet of the fume cupboard capable of removing 98% of Perchloric Acid fumes by weight.  The unit shall be moulded in one piece from chemical grade glass reinforced fire retarded plastic incorporating eliminator pads and spray jet section.  It shall be fitted with a clear inspection panel to monitor the operation of the spray section and be removable for maintenance.  (As required by AS2243.8 - 1992).

The fume scrubber recycle neutralising tank and chemical pump for scrubber shall be fitted in the support cupboard beneath the fume cupboard and be supported on a spillage tray with raised edges to assist in containing any accidental spillage.

The recycle tank is to be fitted with a sight glass, overflow pipe, connection for water supply and a drain controlled by a P.V.C. valve for connection to main drain.

The fume scrubber system, recycle tank, chemical pump, spray pipe, drains and overflows shall be provided pre-plumbed and left for easy connection to water and drain supply by the site plumber.

Note:  The fume scrubber must be accessible for maintenance without disturbing the interior of the fume cupboard chamber.

Note:  Any alternative offered must strictly be subject to client's approval.

All tenderers shall supply a copy of certified independent test report by an approved testing authority, with their tender as proof of the efficiency of the fume scrubber/mist eliminator.  Failure to do so will prejudice acceptance of the tender.

The fume scrubber shall be a Dynaflow S/C. The fume scrubber is to be a self contained unit combining a scrubber section and neutralising tank in a one piece moulded GRP unit.

The scrubber section is to contain scrubbing and elimination pads, removable spray section, and have a clear observation window to monitor spray operation and pads. (As required by AS2243.8 - 1992).

Fixed to a purpose made moulded recess, for protection, is to be a magnetic drive, leak proof, polypropylene centrifugal chemical pump, coupled to a totally enclosed motor and equipped with thermal overload protection and having a ceramic spindle supported both ends in P.T.F.E. fluorocarbon bearings. The pump is to be correctly sized to pump water or neutralising agent from the sump tank to spray section in scrubber and be suitable for connection to a 240 volt single phase supply.

All necessary pipework is to be completed from pump to spray section and points are to be provided for the site plumber to connect a water supply and drain valve to main services.

Note:  Any alternative offered must strictly be subject to client's approval.

All tenderers shall supply a copy of certified independent test report by an approved testing authority, with their tender as proof of the efficiency of the fume scrubber/mist eliminator.  Failure to do so will prejudice acceptance of the tender.

Operator's manual - 2 copies are required.

Acceptance