Static Probes
Static Probes
Can anyone tell me the function of static probes?How these works?
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Imran.Idris
- Core Member
- Posts: 59
- Joined: 16 Mar 2010, 04:22
- Area of interest: Chemical Engineering
Re: Static Probes
Pitot - Static probes sense total and static pressures at the same point in a moving fluid.
These measurements are often sufficient for calculating flow velocity and weight flow rate if the density is known. As a fluid's density is often a function of its temperature, it may be necessary to measure temperature in addition to velocity pressure. Pitot - Static probes may standardly be equipped with a thermocouple for simultaneous temperature measurements at the same point in the fluid stream as pressure measurements.
This is used as flow measuring element in relatively cleaner and less viscous fluids, mostly gases.
It works on the principle of velocity head conversion to pressure head.
These measurements are often sufficient for calculating flow velocity and weight flow rate if the density is known. As a fluid's density is often a function of its temperature, it may be necessary to measure temperature in addition to velocity pressure. Pitot - Static probes may standardly be equipped with a thermocouple for simultaneous temperature measurements at the same point in the fluid stream as pressure measurements.
This is used as flow measuring element in relatively cleaner and less viscous fluids, mostly gases.
It works on the principle of velocity head conversion to pressure head.
Re: Static Probes
Thanks Imran, please guide me further.
Actually, the undersigned static probes are required for the gas reactor (This gas reactor will be the part of polyethylene Pilot Plant) .The bottom portion of Gas Reactor equipped with distributor plate (will be placed inside of reactor) on which catalyst will be placed. The process gases will be passed through reactor from bottom side with the help of cycle gas compressor. Now, I have taken some references from already running Polyethylene pilot plants and going through these references, I understand that static probes will be used for measuring catalyst carryover. (Please correct me if I am at wrong side).Moreover, please explain why catalyst carryover needs to be measured and how static charge measured by static probes interpret catalyst carryover.
The below are some references.
1-Recycle line static Probe
One recycle line static probe will be located in a part of the recycle line close to the inlet of the recycle line at the top of the reactor before the compressor. The probe tip may be a carbon steel rod (or other materials) and may extend approximately to the centre of recycle line. As recycle gas and entrained solid particles (resin and/or catalyst/support particles) flow past the probe, some of the solid particles strike the rod and transfer charge. Current from the at least one recycle line probe may be + - 0 to 50 nano amps per sq cm.
2-Distributor plate Static probe
There will be as a minimum distributor plate static probe which represents another means of measuring the carryover static. The distributor plate probe comprises a metal cap placed above one or more of the holes in the distributor plate. The caps are insulated from the plate and connected to a current meter by means of an electric conduit. The probe measures current transfer due to the impact of catalyst and/or resin fines on the metal cap or caps.
The distributor plate static probes (caps) may be constructed of carbon steel or other conductors to simulate the charge transfer that occurs with all of the other (non-instrumented) caps on the distributor plate. Ideally, these distributor plate probes (caps) are constructed from the same material as the distributor plate and caps. Current measured in the at least one distributor plate probe may range from + - 0 to 50 nano amps per sq cm.
Thanks.
Rana Ghulam Rasool
KSA
Actually, the undersigned static probes are required for the gas reactor (This gas reactor will be the part of polyethylene Pilot Plant) .The bottom portion of Gas Reactor equipped with distributor plate (will be placed inside of reactor) on which catalyst will be placed. The process gases will be passed through reactor from bottom side with the help of cycle gas compressor. Now, I have taken some references from already running Polyethylene pilot plants and going through these references, I understand that static probes will be used for measuring catalyst carryover. (Please correct me if I am at wrong side).Moreover, please explain why catalyst carryover needs to be measured and how static charge measured by static probes interpret catalyst carryover.
The below are some references.
1-Recycle line static Probe
One recycle line static probe will be located in a part of the recycle line close to the inlet of the recycle line at the top of the reactor before the compressor. The probe tip may be a carbon steel rod (or other materials) and may extend approximately to the centre of recycle line. As recycle gas and entrained solid particles (resin and/or catalyst/support particles) flow past the probe, some of the solid particles strike the rod and transfer charge. Current from the at least one recycle line probe may be + - 0 to 50 nano amps per sq cm.
2-Distributor plate Static probe
There will be as a minimum distributor plate static probe which represents another means of measuring the carryover static. The distributor plate probe comprises a metal cap placed above one or more of the holes in the distributor plate. The caps are insulated from the plate and connected to a current meter by means of an electric conduit. The probe measures current transfer due to the impact of catalyst and/or resin fines on the metal cap or caps.
The distributor plate static probes (caps) may be constructed of carbon steel or other conductors to simulate the charge transfer that occurs with all of the other (non-instrumented) caps on the distributor plate. Ideally, these distributor plate probes (caps) are constructed from the same material as the distributor plate and caps. Current measured in the at least one distributor plate probe may range from + - 0 to 50 nano amps per sq cm.
Thanks.
Rana Ghulam Rasool
KSA