LDE-80 electromagnetic flowmeter use in the process of A/D saturation solution

Case introduction

LDE-80 electromagnetic flowmeter in the application of A/D saturation, usually caused by improper installation of electromagnetic flowmeter layout or pipeline medium mixed with foreign objects, etc. LDE-80 electromagnetic flowmeter quality mixed with foreign objects in the treatment: 1, cavities formed by the failure of the liquid mixed with gas (bubbles) 3. abrasion and deposition of fouling 4. condensate in the gas Electromagnetic flowmeter improper installation layout Mainly in the following areas: upstream disturbance source and downstream disturbance source, upstream of the disturbance source of spiral welded pipe and various types of flow-retarding fittings (such as bends, reducers, branches and valves), according to the type of disturbance flow is divided into two categories, type 1 velocity distribution distortion and secondary flow; type 2 in addition to the velocity distribution distortion and control of the secondary flow, and vortex. Various types of pipe fittings encountered more than bends and various combinations of bends (such as flat double bends and three-dimensional double bends). Various types of flow instrumentation on the upstream flow perturbation sensitivity, and therefore to propose their own installation requirements. Downstream disturbance sources are mainly bends, valves, etc. on the formation of fluid flow disturbance will be propagated upstream, can affect several times the length of the pipe diameter at a distance. In most cases 5 times the diameter of the downstream straight section is already enough; some may have to be a little longer, but it can be considered 10 times the diameter of the downstream straight section, can reliably cope with any downstream pipe fittings generated by the disturbance. If the length of the straight pipe section does not meet the requirements and the measurement accuracy is to be ensured, one of the following two alternatives can be taken 1) calibrated under field installation conditions, or in the same as the field installation conditions of the perturbation flow stopper together with the instrumentation, control engineering network, calibrated in the laboratory on the real-flow calibration device. 2) Installation of the flow adjuster upstream of the instrumentation as described in the following section. 1. Sealing gaskets are eccentric (not centred). 2) Installation of the flow adjuster upstream of the instrumentation as described in section 1.1. ). The sealing gasket is installed off-centre, obscuring part of the flow area and making the velocity distribution severely distorted and asymmetric. As asymmetric flow occurs in the flow sensor inlet, that is, the length of the upstream straight pipe section, will be on the differential pressure, turbine, vortex, acoustic, target, electromagnetic and other instruments to bring the measurement error. For example, DN50mm electromagnetic flowmeter liner eccentricity 10mm, the measurement error is as high as 4% ~ 10%. 2. standard orifice plate sharp angle is not installed in the flow-facing surface 3. instrumentation and pipeline sealing liner between the inner diameter Dg is smaller than the pipeline inner diameter Dp and the instrumentation of the inner diameter of the Dm and the production of the beam flow. Dg should be slightly larger than, for example, Dg 4. will be sensitive to vibration interference instrumentation is installed in the pipeline there is a vibration of 5. the lack of the necessary Lack of necessary protective fittings6. The flow meter is in the wrong flow direction. Sealing gasket inside diameter is too small or installation of eccentric although on the volumetric, float type, Coriolis mass type instrument flow value has no effect or small effect, but will increase the additional pressure loss.