The following models
of Jerguson /Jacoby Tarbox eductors can be used as heating devices
using a pressurized liquid as the motive force for the process:
MLH, MLE, ULJ. These units operate over a variety of conditions.
The models MLE and MLH will pull more steam for a given set
of pressure conditions. They require a larger pressure drop
through the eductor, but it results in a higher temperature
rise through the eductor per pass. These units are generally
used when the system requires a single pass through the eductor.
If they are operated intermittently, the pressure drop will
increase when the steam is shut off. When using low pressure
steam for heating, it is recommended that the motive liquid
temperature in these units not exceed 100°F. Higher incoming
temperatures should be thoroughly evaluated to avoid objectionable
noise and water hammer. To determine the actual operating parameters
of each unit, refer to the performance table for that unit.
The model ULJ generally requires a steam pressure greater
than the liquid pressure being used. It also produces less
pressure drop on the liquid, but there is a lower temperature
rise for the liquid medium, as the lower steam flows contain
less total BTUs. These models are designed so that they can
be used on a multiple pass system. Many times these units are
used to heat jackets on reactors or other systems where low
pressure drops in the liquid lines are required or where a
small temperature increase per pass is required. The lower
amount of steam injected per pass allows these units to heat
to higher final temperatures. Also, the liquid pressure drop
remains small in these units when the steam flow is shut off.
The units, listed in general order of largest to smallest
temperature rise and pressure drop, are: MLE, MLH, ULJ. These
units are available for use to heat in-line, producing hot
liquids for spray cleaning operations, heating liquids for
jacketing on reactors or heat exchangers, cooking or sterilizing
in-line.
When used with a temperature probe and a steam control valve,
the eductor will result in an almost instant temperature adjustment.
The lag time of the temperature probe and valve will affect
the performance of the system lag more than the eductor itself. |
