Immersion Well Reactors

These reactors are among the most efficient for photochemical reactions since the lamps are effectively surrounded by the solution to be irradiated. The lamps are contained in double-walled immersion wells made of quartz, allowing water cooling and/or filtering of excitation radiation. Various flask designs enable reactions to be conducted under anaerobic conditions at low or constant temperature.

Lamps And Power Supplies

Two basic types of mercury lamps (low and medium pressure) are used.

Low pressure lamps emit over 90% of their radiation at 254nm.

Medium pressure lamps produce predominantly 365-366nm radiation with smaller amounts also in the ultraviolet region at 254, 265, 270, 289, 297, 302, 313 and 334nm.

Significant amounts of radiation are produced in the visible region at 405-408, 436, 546 and 577-579nm.
 

Lamp Model 3006
6 watt low pressure mercury lamp 3006
Lamp Model 3010
125 watt medium pressure mercury lamp 3010/PX0686
Lamp Model 3012
125 watt medium pressure mercury lamp fitted to 400 watt lamp frame 3012/PX0686
Lamp Model 3016
16 watt low pressure mercury lamp 3016
Lamp Model 3040
Medium pressure mercury lamp 3040/PX0686

 
Low Pressure Lamp Characteristics
Nominal Wattage Overall Length (mm) Discharge Length (mm) Diameter (mm) Light outputa Model
6 260 75 15 7 x 1017 3006
16 380 230 15 3 x 1018 3016

 
Medium Pressure Lamp Characteristics
Nominal Wattage Overall Length (mm) Discharge Length (mm) Diameter (mm) Light outputa Model
125 260 30 12 7 x 1018 3010
400 380 110 18 5 x 1019 3040

a Photons/s measured by ferrioxalate actinometery in quartz immersion well

Model 3040 irradiance spectrum
Model 3040 irradiance spectrum

Lamp model 3040 may be operated at 600W output by using power supply Model 3142.  This higher power has proved especially effective when used with the larger flasks volumes 1000ml and 2000ml.

Arc sources possess negative voltage-current characteristics and conventional low-impedance power supplies cannot be used.  Lamps must be operated from reactive-type supplies having a large resistance or inductance in series.  This provides extra power to initiate the arc and reduce the power for continuous operation.  Recommended power supplies for lamps are listed below.  Input voltage 200-240VAC, 50-60Hz.

Power Supply Characteristics
Model Wattage Dimensions (mm) Weight (kg) Lamp Model
L W H
3106 6 240 125 110 1.6 3006
3116 16 240 125 110 2.1 3016
3110 125 240 125 110 3.5 3010
3140 400 280 195 148 8.5 3040
3142 600 280 195 148 9.0 3040

Radiated heat produced by UV lamps

Tests have been carried out to measure the rise in temperature on the surface of the immersion well with the cooling water circulating and a lamp operating.

The cooling water temperature was 20°C in all tests. Ice was introduced into the cooling water, this only lowered the temperature on the surface by 5-10°C.

The low pressure lamps were not tested because of their low operating temperatures.

Lamps Temp Recorded (°C)
125W 3010/PX0686 160
125W lamp fitted to a 400W lamp frame 3012/PX0686 50
400W 3040/PX0686 55
400W 3040/PX0686 operated with 600W power supply 3142/0783 160

Model 3210/3230
Model 3210/3230
immersion well

Immersion Wells

These are double-walled vessels made of quartz glass which house the irradiation lamp.  Inlet and outlet tubes provide for air or water cooling.  A PTFE tube extends to the bottom of the annular space to allow coolant liquid to flow upwards from the bottom of the well.  A space between the walls allows filtering of certain wavelengths with liquids such as cobalt, nickel, copper sulphate, sodium nitrate solutions or gas such as chlorine to reduce secondary photochemical reactions of products.

Immersion Well Characteristics
Overall length (mm) Inside diameter (mm) Outside diameter (mm) Length from top of joint to bottom of well (mm) Joint Model
260 24 38 205 45/40 3210
390 38 58 300 70/50 3230

Reaction Flasks

Model 3309 reaction flask Model 3309 Model 3309
Left: Model 3309 reaction flask. Centre: with immersion well. Right: with immersion well and lamp

Three types of outer reaction flasks are available.  All are made of borosilicate glass and are fitted with one central ground socket to take an immersion well and other smaller sockets for a reflux condenser or drop-in funnel, sampling port etc.  Flasks may be supported by conventional laboratory stands and clamps.

Reaction Flask Details
Reactant Capacity (Nominal) (ml) Central joint Flask type
Standard Gas inlet Flow through
Model Nos.
75 45/40 3299 3311
100 45/40 3301 3312 3321
150 45/40 3303 3313
200 70/50 3315
300 70/50 3307 3325
400 70/50 3317
1000 70/50 3309
2000 70/50 3310
 
Standard flask         Model 3309 flask         Model 3310 flask
Left: standard flask. Centre: Model 3309 1000ml flask. Right: Model 3310 2000ml flask

Standard Flasks

These are cylindrical flasks with a partially flattened bottom for a magnetic stirrer bar.

They are provided with one angle socket (10/19) and one vertical socket (14/23).  PTFE tubing for gaseous agitation may be led through the 10/19 socket.  This type of flask may be immersed in a container of liquid ice slush, etc. for low/constant temperature irradiations.

Larger Capacity Standard Flasks

The 1000ml and 2000ml flasks are fitted with one angle socket B14/23, one vertical socket B19/26 and SQ18 screw thread for gas agitation of reactant.

Gas inlet flask             Flow through flask
Left: gas inlet flask. Right: flow through flask

Gas Inlet Flask

These are similar to the standard flasks but have a sintered glass disc (medium porosity) fitted to the bottom of the flask to permit gas agitation and allow the reaction mixture to be kept under an inert or reactive atmosphere.

A glass-PTFE stopcock is attached at the bottom.

Flow Through Flask

This type of flask is provided with two vertical sockets (14/23 and 10/19) and upper exit tube fitted with glass-PTFR stopcock.

Two tubes are fitted at the base, one with sintered disc and glass-PTFE stopcock for use as a liquid entrance tube and drain tube.

The inert pump used for the thin film reactor may be used with a reservoir to pump liquid through this type of reaction flask.

Cutting off Radiation below 300nm

Small quartz immersion well reactor components RQ125: Use small borosilicate glass immersion well 3220.

Large quartz immersion well reactor components RQ400: Use glass filter sleeve 3408

Full details of liquid cut-off filter solutions are supplied with instruction manuals.

Reflux Condenser

A double-surface reflux condenser, overall length 275nm with 14/23 cone joint, prevents “reactant creep” and loss of vapour when low boiling point liquids are used.  This will fit all types of reaction flasks, excluding 1000 and 2000ml capacities.

Immersion Well Reactor Components

The following lists describe a number of reactor components, the combination included in each model having proved effective since the models RQ125 and RQ400 were introduced in 1976.

Quartz Immersion Well Reactor RQ125 Components
6 watt low pressure mercury lamp Model 3006
6 watt power supply (fitted with a safety RCD-protected plug) Model 3106
125 watt medium pressure mercury lamp Model 3010
125 watt power supply (fitted with a safety RCD-protected plug) Model 3110
Small quartz immersion well Model 3210
75ml gas-inlet reaction flask Model 3311
Glass filter sleeve Model 3404
Reflux condenser, connecting tubing for water cooling
RCD-protected safety power break socket (for non-UK customers)
UV protection goggles/spectacles
Support stand complete and instruction manual
 
Options:
75ml standard reaction flask Model 3299
100ml standard reaction flask Model 3301
100ml gas-inlet reaction flask Model 3312
150ml standard reaction flask Model 3303
150ml gas-inlet reaction flask Model 3313
100ml flow-through reaction flask Model 3321
 
Immersion well reactor RQ400
Model RQ400 immersion well reactor
Quartz Immersion Well Reactor RQ400 Components
16 watt low pressure mercury lamp Model 3016
16 watt power supply (fitted with a safety RCD-protected plug) Model 3116
400 watt medium pressure mercury lamp Model 3040
400 watt power supply (fitted with a safety RCD-protected plug) Model 3140
Large quartz immersion well Model 3230
200ml gas inlet reaction flask Model 3315
Glass filter sleeve Model 3408
Reflux condenser, connecting tubing for water cooling
RCD-protected safety power break socket (for non-UK customers)
UV protection goggles/spectacles
Support stand and instruction manual
 
Options:
300ml standard reaction flask Model 3307
400ml gas inlet reaction flask Model 3317
300ml flow through reaction flask Model 3325
1000ml standard reaction flask Model 3309
2000ml standard reaction flask Model 3310
125 watt medium pressure mercury lamp fitted to 400 watt lamp frame Model 3012
125 watt power supply (fitted with a safety RCD-protected plug) Model 3110
 
Quartz Immersion Well Reactor RQ600 Components
400/600 watt medium pressure mercury lamp Model 3040
600 watt power supply (fitted with a safety RCD-protected plug) Model 3142
Large quartz immersion well Model 3230
1000ml standard reaction flask Model 3309
Glass filter sleeve Model 3408
Reflux condenser, connecting tubing for water cooling
RCD-protected safety power break socket (for non UK customers)
UV protection goggles/spectacles
Support stand and instruction manual
 
Option:
2000ml standard reaction flask Model 3310

Flasks with larger volumes are available on request.