Thermal mass flow meter

About: Thermal mass flow meter is a research topic. Over the lifetime, 1759 publications have been published within this topic receiving 21878 citations.

Understand two-phase flow in process piping

Abstract: Two-phase flow often presents design and operational problems not associated with liquid or gas flow. For example, several different flow patterns may exist along the pipeline. Frictional pressure losses are more difficult to estimate, and, in the case of a cross-country pipeline, a terrain profile is necessary to predict pressure drops due to elevation changes. The downstream end of the pipeline often requires a separator to separate the liquid and vapor phases, and a slug catcher may be required to remove liquid slugs. Static pressure losses in gas-liquid flow differ from those in single-phase flow because an interface can be either smooth or rough, depending on the flow pattern. Two-phase pressure losses may be up to a factor of 10 higher than those in single-phases flow; in the former, the two phases tend to separate and the liquid lags behind. Most correlations for two-phase pressure drop are empirical and, thus, limited by the range of data for which they were derived. Mathematical models for predicting the flow regime and a procedure for calculating pressure drop in process pipelines are presented.

Lithographic apparatus and a method of measuring flow rate in a two phase flow

Abstract: A lithographic apparatus is disclosed that includes a conduit for two phase flow therethrough. A flow separator is provided to separate the two phase flow into a gas flow and a liquid flow. A flow meter measures the flow rate of fluid in the gas flow or the liquid flow.

Measuring mass flow rates of fluid flows

Abstract: Apparatus for measuring the mass flow rate of a fluid flow utilises a pair of conduits (102, 104). The conduits (102, 104) are wound about a common centre line (106) to form a spiral coil having a mid cross-over point and a cross-over point on either side of the mid cross-over point. A driving mechanism (48) is connected between the conduits (102, 104), at their mid cross-over point, for applying transverse oscillations to the conduits at a selected frequency. The fluid whose mass flow rate is to be measured is divided roughly equally and supplied through the conduits (102, 104). A motion sensor (56) at the cross-over point upstream of the driving mechanism (48) and another one (58) at the cross-over point downstream of the driving mechanism (48) produce signals which have the same frequency as the driving frequency but which lead or lag the driving frequency with regard to phase. This difference in phase is a measurement of mass flow rate. The use of a spiral coil arrangement of the conduits (102, 104) provides self compensation for changes in temperature and/or thermal gradients.