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Liquid flow meter is an instrument that measures the flow rate and/or the total amount of fluid over a selected time interval. It is an instrument used to measure the liquid flow in a closed pipe or open channel.
Liquid flow meter is to measure liquid in a closed pipe or open channel
Due to the different measuring principles, each liquid flow meter has its most applicable working conditions and unique installation requirements. In the actual application of flow meters, in order to achieve excellent measurement results, it is necessary to select the appropriate liquid flow sensor, and also take into account that the installation location of the flowmeter must meet the measurement requirements of the selected meter.
Differential pressure flowmeters, vortex flowmeters, electromagnetic flowmeters,turbine flow meter and mass flowmeters are some of the more commonly used flow meters in petrochemical plants.
Orifice Plate –DP flow meter
DP flowmeter is a huge family of flowmeters. According to different throttling device forms, it is divided into a variety of different flowmeters, such as orifice plate, venturi tube, nozzle, balance flowmeter, wedge flowmeter Meters and so on , using the same measurement principle, but according to the different forms of the throttling device for the needs of different working conditions. Differential pressure flow meters are widely used in petrochemical plants because of their strong adaptability, wide range, stable operation, low failure rate and basically no maintenance. Differential pressure flowmeter is a traditional liquid flowmeter, often used to measure water, diesel, gasoline and other liquid.
Vortex flowmeter has a wide adjustable range and can be used to measure the flow of various process media, such as water, alcohol, milk, diesel, kerosene, etc. However, because the Karman vortex needs to be generated at a certain speed, the vortex flowmeter has a high zero cut-off point. The minimum flow that a vortex flowmeter can measure is limited by the Reynolds number, the flow rate of the fluid, and the signal-to-noise ratio (frequency disturbance). Vortex flowmeters are sensitive to fluid oscillations and mechanical vibrations. If the frequency of vibration enters the measurement frequency range of the flowmeter, systematic and random errors will occur.
Magnetic flow meter to measure clean or dirty liquid
Electromagnetic flowmeter is produced according to the principle of electromagnetic induction. Magmeters are suitable for flow measurement of most conductive liquids, but not for gases and steam. It is digital liquid flow meter, It can be used for the measurement of dirty, greasy liquid and untreated sewage, pulp, mud liquid flow, and can also be used for the measurement of corrosive chemicals, such as used as hydrochloric acid flow meter, sulfuric acid flow sensor, sodium hydroxide flow transmitter, chlorine water flow gauge, tap water flow instruments, aluminum chloride solution flow meter, sodium chloride solution flow meter, silver nitrate, ferric chloride solution and other conductive liquids.,etc.
The following factors should be considered when using an electromagnetic flowmeter:
(1) Consider the conductivity of the liquid. The required minimum conductivity should refer to the manufacturer's recommendations, generally requiring a conductivity of 0.05 to 20μS/cm; therefore, liquids with relatively low conductivity are not suitable, such as deionized water, pure water, etc.
Consider the conductivity of the liquid when considering magmeter
(2) The choice of lining material, generally there are several optional materials such as PTFE, PFA and rubber.
(2) The choice of lining material, generally there are several optional materials such as PTFE, PFA and rubber.
PTFE is the most commonly used lining material. Because it cannot be glued to the inside of the shell, it is not suitable for vacuum conditions.
PFA lining can be used for the measurement of hygienic liquids, such as drinking water, milk, juice, etc., and can withstand higher liquid temperature;
Rubber, neoprene or natural rubber are the cheapest linings, with better wear resistance, and can be used for slurry or water measurement.
(3) When choosing the electrode material of the electromagnetic flowmeter, not only the corrosion resistance to the measured liquid should be considered, but also the avoidance of the electrode surface effect.
Electrodes of electromagnetic flow meter
Coriolis Mass flow meter is suitable for all liquids , especially suitable for complex liquids such as resins, syrups, mortars, etc.
Coriolis Mass flow meter - all liquid measurement
The mass flow meters discussed in this article refer to Coriolis mass flow meters. It can be used for almost all kinds liquid flow measurement. The viscosity change of the fluid does not affect the measurement of the mass flowmeter, so it can be applied to the flow of mud and emulsifier, measuring chemical injection and oil blending. Within the allowable density range of the instrument, the change in density does not affect the measurement of the mass flowmeter. The flowmeter has no moving parts and is not easily damaged.
Coriolis flow meter sensor without moving parts
Coriolis mass flowmeter is a high-precision mass flowmeter that was popularized and used internationally in the late 1980s. The electronic flowmeter is an instrument that uses the Coriolis force generated when the fluid flows through the moving tube to measure the mass flow of the fluid. It can simultaneously measure the instantaneous mass flow and temperature of the liquid and can accumulate the total mass flow. The biggest advantage of this digital liquid mass meter is that it can measure the mass flow, density, and temperature parameters of the liquid at the same time, and it is not affected by the fluid temperature, pressure, viscosity, conductivity, and fluid state.
Coriolis flow meter is with best accuracy in the world.
Coriolis flow meter can be used for following liquid measurement: Lubricating oil, high viscosity oil, syrup, peanut oil, gasoline, diesel oil, toothpaste, yogurt, edible oil hydraulic oil, rubber, paraffin, paint, high viscosity oil, thickener, asphalt, thickener, etc.
Coriolis flow meter is measuring alcohol mass flow
As the fluid flows through the turbine flowmeter, the fluid rotates the rotor. The rotational speed of the rotor is related to the velocity of the fluid. The flow or total is derived from the average flow rate of the fluid felt by the rotor. Turbine flow meters accurately measure clean liquids.
The filtered liquid cannot have impurities and must be equipped with a filter, liquid turbine flow meter can measure pure water, mineral water, ethanol, beer, mineral water, RO water, deionized water, diesel, kerosene, alcohol and other pure liquids.
Liquid turbine flow meter is used to measure clean liquid
Micro flowmeters are widely used for accurate measurement of low flow in various industries, such as automotive, aviation, mining, power, paint and petroleum, etc. Applications include fuel, fuel oil lubricants, alcohol, bio, ethanol fuel, grease, binders, inks, pesticides and pumped or gravity fed non-conductive liquids. Quantitative addition, robot glue, hydraulic pressure, large motor, oil injection.micro liquid flow meter can be with ml/min flow unit, it is ml/min or cc/min liquid flow meter.
The selection of flow meters should comprehensively consider a variety of factors, generally in the following aspects:
(1) To ensure the correct selection of the flowmeter, a variety of process parameters should be comprehensively considered, such as fluid state, flow rate, pressure, temperature, density and viscosity under minimum, normal and maximum design conditions. Also consider changes in operating modes and abnormal operating conditions, such as start-up, commissioning and process conditions in emergency situations;
(2) Whether there are special process requirements, such as whether there is multiphase flow, special fluid composition, corrosion, erosion, whether the liquid contains solid particles, etc.;
Liquid composition should be provided to silverinstruments.com
(3) The liquid flow sensor installed in the pipeline is a part of the process pipeline system, so it must meet the material and grade requirements of the pipeline, and the pressure loss of the flow meter should be less than the maximum pressure loss allowed by the process pipeline;
Users need to confirm pressure loss of the flow meter
(4) The measurement accuracy requirements of the instrument. Usually the flow measurement accuracy and stability of the instrument are proportional to the price of the instrument. Not all flow measurement in the process device requires high accuracy. Selecting the appropriate flow metering instrument according to the accuracy requirements is an effective means to improve the cost performance;
Coriolis flow meter is the most accurate flow meter but also the most expensive one.
(5) Installation requirements of the instrument. Different types of liquid flowmeters have different installation requirements, such as straight pipe section requirements, pipeline vibration, fluid flow direction, etc.
Most liquid flow meters require sufficient straight pipe sections, such as electromagnetic flow meters, turbine flow meters, vortex flow meters, variable area flow meters, etc. However, Coriolis flow meters and PD flow meters do not require straight pipe sections.
Most flow meters needs straight pipelines for installation
This article briefly discusses some type’s liquid flow meters, such as differential pressure flowmeters, vortex flowmeters, electromagnetic flowmeters, turbine flow meter, and mass flowmeters for various liquid measurements. In addition, ultrasonic flowmeters, rotor flowmeters, ml/min liquid flow meter, micro liquid flow meter, positive displacement flowmeters.,etc. are also frequently used liquid flow measurement instruments.
In practical applications, there are many types of liquid flow meters, each of which has its own performance characteristics, applicable working conditions and installation requirements. Factors such as process conditions, use occasions, installation conditions and cost-effectiveness should be comprehensively considered in the design of flow meters.
