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.

Air flow rate meter

Abstract: A flow rate meter for determining the mass or flow rate of flowing air, having a temperature-dependent measuring resistor disposed in an air bypass conduit. The air bypass conduit has a convergent portion in the region of the measuring resistor in which the air flow is accelerated. As a result of the air flow the effects of any air disturbances upon the measuring element are reduced. The following geometric relationships are advantageous: l 1 /l s >3.8, l 1/2 >1.5, l 1 /1 3 >2.0, l 1/4 >9.0, l 5 /l s >1.5, l 5 /l 6 =1.7 to 1.9, b 1 /b s >40.0, b 1 /b 2 >2.0, l 1 /b 1 >3.5, and l 5 /b 3 =5.5 to 6. The air flow rate meter is especially suitable for determining the mass or flow rate of aspirated air in mixture-compressing engines with externally supplied ignition as well as air-compressing, self-igniting engines.

Improved design of a proportional flow meter

Abstract: Conventional flow meters have several drawbacks which were overcome in the improved design. Geometry of the control section of the flow meter was determined theoretically in order to maintain normal depth—discharge relation upstream. Model dimensions were computed from prototype canal with a scale of 1:30. The improved flow meter has high modular limit and nearly constant coefficient of discharge under free flow condition. Conventional expansive transition provided at the outlet of the flow meter was replaced by straight expansion. Studies were made with four different lengths of expansion governed by side splays 0:1, 1:1, 2:1 and 3:1. With level bed, the hydraulic performance of expansions defined in terms of efficiency (η0) and Coriolis coefficient (α2) were found to be extremely poor. Separation of flow occurred right from the entry of the expansions resulting in highly non-uniform velocity downstream. By providing adverse slopes to the expansion floor, performance of the flow meter was found ...

Determination of Steam Quality and Flow Rate Using Pressure Data From an Orifice Meter and a Critical Flowmeter

Abstract: A method for measurement of steam quality and flow rate has been developed, laboratory tested, and packaged for thermal EOR applications. The method consists of an orifice flow meter in series with a critical flow meter. The flow through the orifice is subcritical. The critical-flow meter can be a static choke, a venturi, a nozzle, or a thick orifice, etc. Steam flow rate equations for orifice flow and for critical flow were established with empirically derived constants. These two equations were combined and solved to determine the steam quality and flow rate. The basic mechanical parts of the measurement system are rugged and inexpensive. The pressure transmitters and flow computer are portable and can be used for spot checks or for continuous monitoring. The steam quality and flow rate information obtained make it possible to evaluate the performance of steam distribution systems and thus to identify where modifications to the distribution system piping are needed.

Coriolis-type flow meter and method for measuring the mass flow rate of a gaseous or vaporous fluid

Abstract: The accuracy of this method is comparable to that of the measurement of liquids. The fluid flows through at least one flow tube (4) of a mass flow sensor (1) of a Coriolis mass flow/density meter, which flow tube vibrates at a frequency f being equal to or in the vicinity of the instantaneous mechanical resonance frequency of the flow tube (4) having a vibrator (16). A first and second vibration sensor (17, 18) are attached to the flow tube, deliver a first and a second sensor signal (x17, x18), and are positioned at a given distance from each other in the direction of flow. The flow tube (4) is surrounded by a support frame or a support tube (15) or held by a support plate so as to be capable of vibrating. The sensor signals (x17, x18) have a phase difference from which a signal qf is formed; it is multiplied by a function f(c) dependent on the speed of sound c in the fluid which can be approximated by a function f(Tm) dependent on the current temperature Tm of the flow tube (4).