- The laboratory fluid bed dryer offers significant advantages over conventional drying techniques:
- The high rates of heat and mass transfer ensure much faster and more homogeneous drying than other methods such as oven and vacuum drying.
- Drying times range from a few seconds to minutes. Complete drying is usually achieved in under 15 mins, the exact time for a given sample, airflow rate and temperature setting being very repeatable. A uniform reproducible moisture content can also be achieved with the appropriate settings.
- Materials with moisture contents from a few per cent to over 80 per cent may be dried.
- The temperature range from ambient to 200°C covers the majority of drying and solvent removal operations. Due to good mixing, the sample temperature is uniform and under close control during drying. This proves advantageous when drying heat sensitive materials or coating particles.
- Among the wide range of materials that can be processed are pharmaceutical, chemicals, minerals, foods, coals, wood chips, plastics, resins, etc. Ask for our specific applications sheet on your material.
- The high performance characteristics of this instrument allow it to be used for many applications in addition to drying, such as:-
- Quick determination of moisture content (eg.coal, tobacco, food products) by correlation with weight loss over 5 mins. using specified drying conditions
- Mixing and blending of solids
- Granulation and agglomeration
- Rough classification of particle size (ie. Stokes law)
TEMPERATURE CONTROL
0 - 200°C. Comprehensive alarm options.
Air flow from the fan passes over a 2 kW electrical heater before delivery to the sample container. The temperature of the heated air is regulated by a closed-loop system that can achieve temperature stability within 1°C. The homogeneity of the fluidising process and the close temperature control are ideal for reproducible and uniform drying.
TIMED CYCLES
0 - 6 hours in six ranges
A timer built into the dryer allows the unit to operate unattended in many routine applications. Drying period is set on a simple analogue dial, time remaining is indicated by a count-down pointer and at the end of the cycle or set temperature point an alarm sounds and the dryer switches off automatically.
AIR FLOW
0.4 - 2.4 m3/min volume ( 0.9 - 5 m/see speed)
Control of fan speed and hence fluidisation velocity is continuously variable over the whose range. Drying is much more rapid than with other methods because of the high mass and heat transfer rates achieved with the fluidising process. Fan speed can be set subjectively by observing the sample behaviour in a glass tub or optimised by calculation using measurements from experiments at a number of different operating conditions.