Overview
Ratio control blenders are suitable for any liquid hydrocarbon blending application where the quality of the feedstock is consistent and known. The final blended product is produced to an extremely accurate component ratio determined by the flow meters, the efficiency and linearization of the control system. Accuracy of better than +/- 0.25% over the full metering range can easily be achieved.
The component ratio is maintained at all times during the batch by the closed loop control between the flow signals from the field equipment (flow meters, pressure and temperature sensors) and the control signals from the controller back to the field equipment.
The field equipment
The field equipment (valves and meters etc) enable the components to be simultaneously metered into the lend header to produce the final blended product. Products normally exit the blend header through a mixer to ensure that a homogenous product is delivered at all times. This also provides an ideal location for an automatic sampler. The field equipment for every blender is selected to ensure minimal pressure drop and maximum reliability.
The control system
The real-time control system monitors the outputs from the field equipment (flow rates, etc), performs calculations for meter linearization, temperature compensation, etc. and feeds back appropriate control signals to the field equipment to maintain the blending process within the required parameters (i.e. closed-loop control).
The controller has unique self-learning control algorithms that instantly respond to changes in process conditions and the components are continuously measured and adjusted during the batch to ensure optimum quality and minimum give-away.
Blended products are volume corrected to standard conditions using API 2540 / IP 200. Loading and blend documentation can be automatically produced in volume or mass units by the controller.
Our systems are designed to ensure consistent quality throughout the batch even during tank changes, feedstock starvation, loss of power or the unlikely failure of a system component. All of our viscosity trim blenders are supplied fully skid mounted, piped, wired and tested ready for installation at your site and guaranteed to perform to your specifications.
All Sensia's ratio control blenders are supplied fully skid mounted, piped, wired and tested ready for installation at your site and guaranteed to perform to your specifications.
