● Three Modes of Pool Boiling Observed Easily
● Allows Safe Investigation into the Normally Dangerous condition of Film Boiling
● Safe and Suitable For Unsupervised Student
● Operation Ozone Friendly, Low Pressure, Non-toxic Working Fluid
● Responds Rapidly to Control Changes
● Negligible Operating and Maintenance Costs
● Two year Warranty
Introduction
Boiling and condensation are vital processes in the transfer of heat from a hot to a colder region in numerous applications, e.g. power generation, refrigeration, refining, heat transmission, etc.
Three distinctive modes of pool boiling occur: convective, nucleate and the potentially dangerous film boiling. Student engineers need to be aware of the boiling mode characteristics if they are to be involved in the design, operation or service of any heat transfer process.
The Hilton H656 Boiling Heat Transfer Unit is bench mounted, fully instrumented and operates from a simple mains electric and water supplies.
The unit will be of particular interest to those studying:
Mechanical Engineering
Chemical Engineering
Plant and Process Engineering
Engineering Physics
Marine Engineering
Nuclear Engineering
Control and Instrumentation
Building Services
Experimental Capabilities
Visual demonstration of convective, nucleate and film boiling.
Study of the heat flux and surface heat transfer coefficient at constant temperature.
Investigation of the effect of pressure on critical heat flux.
Study of filmwise condensation and condenser overall heat transfer coefficient.
Investigation of the pressure- temperature relationship of a pure substance, and the effect of air in a condenser.
Demonstration of:
o Liquid carry over or priming in boilers.
o Law of partial pressures
Description
A glass reinforced plastic panel supports a vertical glass cylinder containing a horizontally mounted heating element immersed in the liquid. The heat input can be varied to control the heat flux and hence the mode of boiling.
At the top of the cylinder is a coil through which cooling water flows. This condenses the vapour produced by the heat input and the liquid formed returns to the bottom of the cylinder for reevaporation. Control of the cooling water flow maintains a constant pressure during an experiment.
The standard instrumentation consists of a surface temperature thermocouple plus four glass thermometers, wattmeter, pressure gauge and water flowmeter. These enable all relevant heat transfer calculations to be made.
For student safety, the unit is fitted with both overload and residual current circuit breakers. A high pressure cut out and internal safety valve prevents a safe pressure being exceeded. The heating element is protected by a high temperature switch.
