Coriolis
Hot Applications
Molten Sulphur, Bitumen, Pitch, Paint Resins and Liquid
Toffee are all hot fluids just so perfect for a Coriolis
mass flowmeter. Their fluid properties change wildly with
small variances in temperature. The only problem is most
meters on the market are literally cooked by these fluids.
Not necessarily immediately, but some time in the process
the heating medium gets too hot and you soon have the
charred remains of a Coriolis in your hands.
Just when the market was about to give up on Coriolis
technology, along comes RotaMASS with RCCS sensors that
can continuously handle fluid temperatures up to 230°C.
And even if your process fluid is hotter than 230°C
then contact your local Yokogawa Australia Sales Engineer.
Here's how!
Specific materials are selected for the driver and
coil components inside the sensor. The electrical design
of these components also is critical to successful operation
in such difficult conditions. But this is only half
the key to Yokogawa's success.
In measuring these fluids it important to maintain
their thermal inertia for many reasons as listed below;
- Loss of heat in the fluid can
be expensive to restore
- Fluid properties change dramatically and affect
the process performance
- Even slight cooling can cause the fluid to stick
to the walls, precipitate or bind together. |
So to maintain the fluid's thermal inertia, Yokogawa
have designed RotaMASS with external process heating
as shown below;
Further to this external process heating,
Yokogawa provide as a standard factory option the following
enclosure of the RotaMASS sensor;
RotaMASS sensor and process heating is contained in
a two-part enclosure. Insulation wool is added to fill
the void.
The two halves are then riveted together.
The terminal box is extended beyond the exterior of
the enclosure to allow for field serviceability.
Now the temperature of these tubes dramatically
affects their flexibility. So temperature measurement
is very critical as follows;
The critical path is to transport the
heat from the protection tube to the measuring tubes
via the nitrogen. One tube is sufficient to heat the
protection tube from only one side. This is because
the protection tube is very well insulated by 80mm
stone-wool and the heat conductivity is much greater
than the nitrogen.
Heat conductivity:
Stainless steel
Cement
Nitrogen |
:16 W/(K*m)
:16 W/(K*m)
:0.0025 W/(K*m)
|
Hot Applications
Below is an application of this technology on hot
Bitumen at a Sydney loading terminal. Note the vertical
orientation of both of the RotaMASS sensor.
Note only does the thermal enclosure
protect the operators from scalding surfaces, it ensures
accurate measurement across the meters. If there is
a significant temperature difference from the start
and end of the U-Tubes this translates into errors
in both the flow and density measurements.
For a more detailed analysis of your requirements
contact your local Yokogawa Australia Sales Engineer
|
