Cole Parmer FSB-200 Series, Инструкция по эксплуатации

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PRINCIPLE OF OPERATION
Figure 1: Schematic of the FSB-200-P-AC
Control for temperature and a flow meter are mounted on a recessed panel on the front of the unit together
with on-off switches for the power supply and the dust extraction system. The inner container is well insulated
and the outer case is vented so that it remains safe and cool to the touch even when the bath is operating at its
maximum temperature. The inner container is filled from the top with alumina. When fluidized, the alumina is
heated by the four immersion heaters close to the inner container outer wall with the control thermocouple
giving excellent temperature control.
The heater elements are protected from excessive surface temperatures by a pressure switch operated by the
fluidized air and the power supply is removed if the air supply to the unit is disrupted. The unit also has an over-
temperature cut-out fitted to protect the heater element in the event of an over temperature fault (limit set to
730°C).
Air supplied to the unit passes through two filters to remove oil and moisture from the system. A pressure
regulator is also fitted to set the correct pressure for the cyclone extraction system and for optimum fluidization.
An automatic fluidizing air control system is fitted which adjusts the air flow rate accordingly to suit the set
temperature of the bath. The fluidized air passes through a flow meter then to a plenum chamber fitted under
the fluidized bath which evenly distributes the fluidized air evenly across the bath inner chamber.
Dust extraction is carried out by ambient air being drawn down (venturi effect) past the probe plate and through
a peripheral slot around the top edge of the inner container. The air then passes through a cyclone to separate
and remove any alumina particles which are collected in a glass collection jar and then passes through the
exhaust filter. Entrained alumina removed by the cyclone and collected in the collection jar, which is accessible
from the front of the unit, can be re-used and simply emptied back into the bath.
This model is specially designed to allow the operating temperature of the fluidized bath to be adjusted from a
remote source while the bath is unsupervised. Basic control programmes are set by the operator allowing for the
control of set temperature, incremental temperature steps, dwell times and control of dead bed state.
Where an ultra-stable temperature condition is required a “dead bed” state can be programmed into the control
system. During this “dead bed” condition the air and electrical supply to the fluidized bed are switched off. For a
period of up to 8 minutes, the fluidized bed becomes an isothermal mass without heat input and very low heat
loss. Under these conditions the stability at the centre of the aluminium oxide is ±0.01°C over the range of the
unit.