Calibration of wet gas flow meters, how to read wet gas flow meters

Gas ultrasonic flowmeter is mainly used for the flow measurement of various gases, including natural gas, coal gas, coke oven gas, water gas, coal-to-gas, coalbed methane, gas gas, CNG, LNG, LPG, flare gas, biogas, hydrogen and other combustible gases, and can also reliably measure special gases such as air, nitrogen, and inert gas. If you want to know more about it, you can consult Shanghai Kekun Industrial Science and Technology Development****, thank you!

Accurate measurement of gas flow is of great importance. To ensure the accuracy of the measurement, any flow meter needs to be adjusted or calibrated after a period of use. In this experiment, a standard measuring flask was used to check whether the wet gas flow meter reading was correct, and the volume correction factor of the wet gas flow meter was obtained for use in measuring the gas flow rate.

It is required to master the test method and be able to operate it proficiently. A standard measuring flask is usually used to calibrate the wet gas flow meter. The volume of a standard measuring flask is exactly 1 litre between its scales.

The gas in this volume is passed into the wet gas flow meter, if the pointer of the flow meter is also turned 1 liter, the flow meter reads correctly, otherwise the flow meter should be adjusted or corrected.

The test steps are as follows:

1. Adjust the wet gas flowmeter as required (fill the wet gas flowmeter with an appropriate amount of water and level it).

2. Refer to the calibration system diagram of the wet flowmeter, connect the standard measuring flask, water cup and wet gas flow meter, and add a certain amount of water to the water cup.

3, open the stopcock 5, rotate the stopcock 6, make the air in the standard measuring flask pass into the flowmeter, when the flowmeter pointer just points to the integer value, rotate the stopcock 6 to make the air in the standard measuring flask communicate with the atmosphere.

4, lower the position of the water cup, make the water surface drop, when the water surface descends to the scale, close the 5, make the water surface stop on the scale. Place the water cup back on top of the holder 4.

5. rotate the stopcock 6, make the air in the standard measuring bottle communicate with the flowmeter, and after opening the stopcock 5, the air in the bottle flows into the flowmeter again. When the water surface rises to the scale, close the 5. Take the flow meter reading and fill it in the log sheet.

6. Repeat the above, read the readings of the flowmeter, and fill in the record form. Wait until the flow meter hand turns 1 full turn.

If you find that the flow meter always reads below (or above) the volume of the standard measuring flask, the water level in the wet gas meter is low (or high) and can be adjusted by adding (or subtracting). If it is found that the reading of the flow meter is sometimes lower than the volume of the standard measuring flask and sometimes higher than the volume of the standard measuring flask, it means that the impeller is not uniform, and the correction factor should be calculated and the correction curve should be drawn for use in the measurement.

Read the scales on both sides, multiply the difference by the coefficient is the pressure, if you use alcohol or water in your U-shaped meter, water is yes, alcohol is yes.

There are two types of wet gas flow meters:

One is made of brass.

Material, generally used in the range of non-corrosive gas. The other is made of corrosion-resistant stainless steel.

Corrosive gases can be measured. The LMF LML series wet gas flow meter is one of the commonly used instruments in the laboratory.

Its accuracy when measuring the total volume of gas in the vertical skin.

The higher the flow rate, especially at small flows, it has a small error. It can be used directly to measure gas flow, and can also be used as a standard instrument to detect residual difference and other flow meters.

A cylindrical bowl surrounded by blades is installed in a closed cylindrical housing and can rotate freely around the central axis. The bowl is divided into three to four air chambers by the blades, and each air chamber has a straight slit opening on the inner and outer side walls (the inner side wall opening is the air inlet of the metering chamber, and the outer side wall opening is the air outlet of the metering chamber).

The flow meter housing contains about half of the volume of water or low-viscosity oil as the sealing liquid, and half of the bowl is immersed in the sealing liquid.

How to use: 1. Place the wet gas flow on the workbench and adjust the corner screws to make the level.

The blister is located in the center and is to be maintained for a long time during use.

2. Open the sealing nut of the water level controller.

Pull out the yarn cord inside.

3. In the thermometer.

or in the jack of the pressure gauge, inject distilled water into the gauge.

When the excess distilled water flows from the hole of the water level controller along the yarn rope (a drop flows out for a long time), the yarn rope is put into the sealing nut of the water level controller, and the sealing nut is tightened.

4. Install the thermometer and pressure gauge. (10pa per cell) Connect the air path according to the direction of the inlet and outlet air, and seal it.

5. Open the gas valve to measure the gas.

Legal preparation stove analysis: According to JJF1071-2010 "Rules for the Compilation of National Metrology and Calibration Specifications", the content of this specification includes 9 parts, including scope, reference documents, terms and units of measurement imitation, overview, measurement collapse characteristics, calibration conditions, calibration items and calibration methods, expression of calibration results, recalibration time interval and appendix.

Legal basis: JJF1071-2010 "Rules for the Preparation of National Metrology and Calibration Specifications" Article 1 The content of this specification includes 9 parts, including scope, reference documents, terms and units of measurement, overview, measurement characteristics, calibration conditions, calibration items and calibration methods, expression of calibration results, recalibration time interval and appendix.

In general, there are two types of calibration of flowmeters; i.e. calibration and non-calibration. **Calibration: Do not need to remove the flowmeter to achieve**Calibration in the flow state, this method is not too accurate, but the calibration can probably be done with an ultrasonic flowmeter.

Calibrate it. The verification and calibration of flowmeters are carried out in accordance with the verification regulations of various flowmeters promulgated by the National Bureau of Metrology. At present, the flowmeter used, except for the standard throttling device, which does not need to be verified by the experiment, almost all the other flowmeters must be verified when they leave the factory.

Calibration should also be performed frequently during the use of the flow meter. The calibration methods of liquid flowmeters mainly include volumetric method, mass method, standard volume tube method and standard flowmeter comparison method. The calibration methods of gas flowmeters mainly include the sonic nozzle method, the servo standard flowmeter comparison method and the bell method.

Flow is the amount of fluid passing through a pipe or a cross-section of equipment per unit of time. This quantity is expressed in terms of quality and is known as mass flow.

Expressed in volume, it is called volumetric flow; Expressed in terms of weight, it is called the gravimetric flow. Because the density of the fluid varies with the state parameters of the fluid, the state of the fluid must be indicated at the same time as the volume flow rate is given. In particular, the density of gases varies significantly with pressure and temperature, and in order to facilitate the comparison of the volume flow rate, the volume flow rate in the working state is often converted to the standard state.

Volumetric flow rate (temperature of 20 and absolute pressure of 101325pa). Commonly used flow measurement methods include velocity flow measurement method, volumetric flow measurement method, and direct or indirect measurement of the mass of fluid flowing through a pipe section per unit time.

In the above method, the velocity flow measurement method instrument is widely used. At present, the flowmeter used, except for the standard throttling device, which does not need to be verified by the experiment, almost all the other flowmeters must be verified when they leave the factory. Calibration should also be performed frequently during the use of the flow meter.

First, convert the operating condition range to the Reynolds number range.

Secondly, the calibration equipment selected should conform to the specified Reynolds number range.

It is then calibrated under different pressure conditions or with different gases. Within a certain accuracy class, the Reynolds characteristics of standard differential pressure gas flow meters are well known. Similarly, the characteristics of certain types of turbine gas flow meters are known.

In some cases, it may be necessary to perform several tests before proceeding with the final calibration to verify that the gas flow meter is operating in accordance with the Reynolds calibration factor.

When the gas flowmeter is calibrated, it is calibrated with air under standard conditions, and it must be calibrated under working conditions. The standard condition is a flow rate of about 20 degrees at a standard atmospheric pressure and a temperature; The operating condition refers to the flow rate in the operating condition.

There are two types of wet gas flow meters: one is adopted, which is generally used in the range of non-corrosive gases. On the other hand, it is made of materials that can measure corrosive gases.

The LMF LML series wet gas flow meter is one of the commonly used instruments in the laboratory. When measuring the total volume of gas, it has a high accuracy, especially at small flow rates, and its error is small. It can be used directly to measure gas flow, and can also be used as a standard instrument to verify other flow meters.

The body of the integrated vapor flowmeter can be made into two structural forms: flange type and flange clamp type. The vortex flowmeter is mounted on the pipeline to be tested by means of a flange or clamp flange. For small pipe diameters, threaded connection type and pipe welded type can be made.

The fluid flow part of the meter body is processed into a measuring tube with a nominal diameter of d, which provides a channel for the measured fluid to pass through the instrument. The measuring tube is installed with the generator and the detection element, the generator is perpendicular to the axis of the measuring tube, it can be welded in the meter body, Jiangxi vortex street flow meter business, can also be installed in the meter body through the seal, its main function is to produce Carmen vortex. The detection element is also installed in the meter body, which can be a variety of thermal elements, ultrasonic, strain, capacitance, magnetism, pressure, using optics, etc., for detecting eddy current signals.

The detection element can be mounted on or downstream of the generator and can be detached from the measuring tube.

Gas flow meter model parameters.

Product parameters: Measuring medium: gases, liquids and vapors.

Diameter selection of flange clamping method.

Selection of the caliber of the flange connection.

Flow Measurement Range: Normal Measurement Flow Rate Range: Reynolds Number; gas 5 50m s; The normal measurement flow range of liquids is shown in Table 2. The vapor flow range is shown in Table 3 for the measurement accuracy level.

Medium temperature to be measured: room temperature 25 100

High temperature 25 150 -25 250

Output Signal Impulse Voltage Output Signal High Level 8 10V Low Level Pulse Duty Cycle is about 50%, and the transmission distance is 100m

The pulse current remote transmission signal is 4 20mA, and the transmission distance is.

Instrument ambient temperature: -25 +55 Humidity: 5 Shanghai Cixi Instrument****.