MR-WL 225 Heat Transfer In The Fluidised Bed Didactic Equipment Teaching Heat Transfer Lab Equipment
Fluidised beds are used in a broad range of applications, e.g. for industrial drying, fluidised bed combustion or heat treatment of materials. Bulk solids are transformed from a fixed bed into a fluidised bed when fluids pass through them. In terms of fluid mechanical and thermodynamic properties, the fluidised bed behaves like an incompressible fluid.
The heat transfer between hot fluid and a fixed bed occurs mainly through heat conduction. Due to the movement of the particles, the fluid and the particles are very well mixed in the fluidised bed. This enables optimum heat transfer between fluid and particles and ensures an even temperature distribution in the reactor.
The core element in WL 225 is a backlit glass reactor which enables students to observe the fluidisation process. Compressed air flows upwards through a porous sintered-metal plate. On the sintered-metal plate is a fixed bed. If the velocity of the air is less than the so-called fluidisation velocity, the flow merely passes through the fixed bed. At higher velocities the bed is loosened to such an extent that individual solid particles are suspended by the fluid and form a fluidised bed. The air escapes through a filter at the top end of the glass reactor.
The air flow rate is set via a valve. A submersible heating element in the reactor enables examination of the heat transfer in the fluidised bed.
Sensors record the pressure at the inlet into the reactor and in the fluidised bed, the air flow rate, the heating power, pressure and temperatures at the air inlet of the reactor, on the surface of the heating element and in the fluidised bed. The measured values can be read on digital displays. At the same time, the measured values can also be transmitted directly to a PC via USB. The data acquisition software is included.
Aluminium oxide in various particle sizes is included in the scope of delivery as bulk solid.
1.examination of the fluidised bed formation and the heat transfer in the fluidised bed
2.fluidised bed of compressed air and aluminium oxide, particle sizes either 100µm or 250µm
3.glass reactor, backlit
4.glass reactor with sintered-metal plate at the inlet and air filter at the outlet
5.heating element, submersible and with adjustable power output
6.manual setting of the air flow rate via valve and flow meter
7.sensors with digital displays for temperature at heater, air inlet, in fluidised bed, pressure upstream of the reactor and in the fluidised bed, air flow rate, heating power
8.steel rulers for measuring the immersion depth of the heating element and the height of the fluidised bed
9.safety valve, temperature switch at the heater, air filter at the outlet
10.GUNT software for data acquisition via USB under Windows 8.1, 10