How The Panaflow Vortex Mass Flowmeter Operates; Velocity Measurement - GE PanaFlow MV80 User Manual

Chapter 1. Introduction

1.2 How the PanaFlow Vortex Mass Flowmeter Operates

PanaFlow MV80 and MV82 Mass Flowmeters (see Figure 1 below) use a unique sensor head to monitor mass flow
rate by directly measuring three variables-fluid velocity, temperature and pressure. The built-in flow computer
calculates the mass flow rate and volumetric flow rate based on these three direct measurements. The velocity,
temperature and pressure sensing head is built into the vortex meter's flow body. To measure fluid velocity, the
flowmeter incorporates a bluff body (shedder bar) in the flow stream and measures the frequency of vortices created by
the shedder bar. Temperature is measured using a platinum resistance temperature detector (PRTD). Pressure
measurement is achieved using a solid-state pressure transducer. All three elements are combined into an integrated
sensor head assembly located downstream of the shedder bar within the flow body.
FLOW
Figure 1: In-Line Vortex Multi-Parameter Mass Flowmeter

1.3 Velocity Measurement

The PanaFlow vortex velocity sensor is a patented mechanical design that minimizes the effects of pipeline vibration
and pump noise, both of which are common error sources in flow measurement with vortex flowmeters. The velocity
measurement is based on the well-known Von Karman vortex shedding phenomenon. Vortices are shed from a shedder
bar, and the vortex velocity sensor located downstream of the shedder bar senses the passage of these vortices. This
method of velocity measurement has many advantages including inherent linearity, high turndown, reliability and
simplicity.
2 PanaFlow™ MV80 & MV82 User's Manual