1、 Overview of Balanced Flow Meter

ARSPH balanced flowmeter, also known as porous orifice flowmeter, has made significant improvements to traditional throttling devices using fluid dynamics research results, and has significant characteristics of balanced flowmeter rectification. Traditional throttling devices only have one flow aperture, which causes the fluid to lose its ideal state after throttling; The balanced flow meter has multiple functional apertures, which can maximize the rectification of the flow field into an ideal fluid, thus fully utilizing the advantages of differential pressure flow meters. Balanced flow meters are almost applicable to all fluid measurements and represent a revolution in fluid measurement technology. Currently, balanced flow meters have been widely used in industries such as petroleum, chemical, metallurgical, power, natural gas, and water treatment.

2、 Characteristics of Balanced Flow Meter Products

ARSPH balance flowmeter has high linearity and good repeatability. The balanced flow meter flow sensor has the characteristics of a symmetrical porous structure, which can balance the flow field, reduce eddy currents, vibrations, and signal noise, greatly improve the stability of the flow field, and increase linearity by 5-10 times compared to orifice plates. The repeatability is increased by 54%, which is 0.15%. From its comprehensive performance, the balanced flow meter belongs to the high-end flow meter category.

5: When the range ratio is 1, the linearity can reach ± 0.3%;

7: When the range ratio is 1, the linearity can reach ± 0.5%;

10: When the range ratio is 1, the linearity can reach ± 1.0%;

Low requirements for straight pipe sections. Due to the stable flow field and twice the speed of pressure recovery compared to orifice plates, the balanced flowmeter flow sensor greatly reduces the requirements for straight pipe sections. The front and rear straight pipe sections are generally 3D in front and 1D in back, with a minimum of less than 0.5D, thus eliminating a large number of straight pipe sections, especially those made of special and expensive materials.

Reduce permanent pressure loss. The porous symmetrical balanced flowmeter design reduces turbulent shear forces and vortex formation, reduces kinetic energy loss, and reduces permanent pressure loss by 2.5 times compared to orifice plates under the same measurement conditions, thereby saving considerable operating energy costs. It is an energy-saving instrument that is worth promoting extensively.

Resistant to dirt and not easily clogged. The design of a porous symmetrical balance flowmeter reduces turbulent shear forces and vortex formation, greatly reducing the formation of dead zones, ensuring the smooth passage of dirty media through multiple holes, and reducing the chance of fluid holes being blocked.

Can directly replace orifice plates. It has the same usage method and appearance as the orifice plate, so it can be directly replaced without any changes in piping or related instruments. It is very suitable for the energy metering EMS transformation of the entire plant to replace the orifice plate with a balanced flow meter.

Wide flow measurement range. According to the experimental results, balance the performance of the flowmeter so that its flow rate can range from the minimum to the speed of sound; Its minimum Reynolds number can be lower than 200, and its maximum Reynolds number is greater than 107; The beta value can be selected from 0.25 to 0.90.

Long term stability is good. Due to the significant reduction in turbulent shear force, the direct friction between the medium and the throttling element is greatly reduced, and its β value remains unchanged for a long time. The entire instrument has no movable components, so it can maintain stability for a long time.

Can measure high temperature and high pressure media. Like orifice plates and other throttling devices, the working temperature and pressure depend on the material and grade of the pipeline and flange. The working temperature can reach 650 degrees Celsius and the working pressure can reach 42 megapascals.

Capable of measuring media under complex working conditions. Due to its unique structural design, it has special properties and can handle gas-liquid two-phase, various mixed gases (such as gas, biogas, coal gas, etc.), various low-temperature gases (such as LNG, liquid oxygen, liquid nitrogen, liquid argon, liquid hydrogen, liquid chlorine, liquefied ethylene, liquefied petroleum gas, etc.), slurries, multiphase water flow, vibrating water flow, electromagnetic interference media, and bidirectional flow (because the balance flowmeter is completely symmetrical on both sides)

3、 Working principle of balanced flowmeter

ARSPH balance flowmeter is a revolutionary differential pressure flow meter, which works on the same principle as other differential pressure flow meters, based on the energy conversion principle in sealed pipelines: under ideal fluid conditions, the flow rate in the pipeline is proportional to the square root of the differential pressure; According to the Bernoulli equation, the flow rate in the pipeline can be calculated based on the measured travel pressure value. The balanced flow meter flow sensor is a porous disc throttling rectifier installed on the cross-section of the pipeline. The size and distribution of each hole are customized based on special formulas and test data, known as function holes. When the fluid passes through the function hole of the disk, it will be rectified by the balance flowmeter, and the vortex will be minimized, forming an approximate ideal fluid. Through the pressure measuring device, a stable differential pressure signal can be obtained, and the volume flow rate and mass flow rate can be calculated according to the Bernoulli equation.

4、 Balance flowmeter measurement system

Selection calculation

Before manufacturing, each balance flowmeter needs to be selected and calculated based on process parameters to determine the opening position and size, thereby determining the design performance of the meter. The calculation has determined the differential pressure value, measurement range, measurement accuracy range, pressure loss, and recommended beta value.

check

Each balanced flowmeter undergoes real flow calibration before leaving the factory. If real flow calibration is not carried out, simulation calibration must also be carried out. Our unit can accurately provide the flow coefficient value based on years of data.

Component material

The materials of the components used in the balanced flowmeter are strictly screened and qualified products, ensuring the continuous and accurate operation of the flowmeter over a long period of time.

Valves and three valve groups

A balanced flowmeter is a throttling device, which includes a primary valve, a three valve group, a drain valve, etc. in its system; It is convenient for system debugging and maintenance. Valves and three valve groups shall be equipped with materials in accordance with the contract requirements.

Differential pressure transmitter and flow processing system

Differential pressure transmitter is a throttling device for differential pressure measurement, which converts the differential pressure signal into an electrical signal for output. The flow processing system converts the electrical signal of the differential pressure transmitter into a flow signal for display, recording, and output through software calculation.

safety requirements

Anyone installing, inspecting, or maintaining a balanced flowmeter must have a clear and correct understanding of the structure of the pipeline and the pressure and temperature of the system. Be careful when lifting and installing instruments, as improper lifting and installation may damage the instruments.

When calibrating instruments, appropriate and correct tools must be used.

When adjusting and disassembling instruments, it should be ensured that there are no situations in the pipeline that pose a threat to personal safety.

Before driving, it is necessary to check whether all connections are firm, whether the sealing meets the design requirements, and maintain a certain safe distance from the flow meter to avoid accidents.

Unpacking and verification

After the arrival of the flow meter, an open box inspection should be carried out to prevent damage or loss of the flow meter or accessories during transportation. If there is a problem with the random file or flow meter, please contact us promptly.

Flow meter installation and positioning

Each balanced flow meter must be installed in accordance with the requirements for pressure tap installation. There is a difference in pressure tapping between horizontal and vertical installation of throttling components, and attention should be paid to the arrangement of pressure pipes for balanced flow meters.

Piping requirements

It is recommended to install a balanced flowmeter with an upstream straight pipe section greater than 3D and a downstream straight pipe section greater than 1D, where D represents the nominal diameter of the installed pipeline. Due to the inherent characteristics of balanced flow meters, the accuracy of the flow meter is not affected when it is located adjacent to one 90 degree bend or adjacent to two 90 degree bends that are not in the same plane. When installing with variable diameter, pay attention to the straight pipe section.

Orientation of the pressure port

For horizontally installed flow meters, for gas measuring media, the pressure tap is located above the pipeline; For liquid or vapor media, the pressure tap is located on the side of the pipeline at 3 or 9 o'clock on the clock. When installed vertically, there is no requirement for the orientation of the pressure tap.

Pressure pipe

Install the pressure pipe as much as possible, so that no differential pressure signal will be generated when there is no medium circulation. Please refer to the installation diagram for details.

Attention: If the medium is gas or steam, it may condense in the impulse pipe. Please note the following two points:

The pressure pipe should be horizontally spaced to ensure sufficient distance between the vertical line and the instrument, and to ensure that there is no steam in the vertical pipeline.

For vertical installation sites, the installation of pressure pipes should comply with the requirements for the layout of pressure pipes in throttling devices.

Compensation demand

In the measurement of gases, vapors, and liquids with large density changes, the system needs to increase temperature and pressure compensation. The temperature is generally between 7-10D at the throttle element, and the pressure is between 3-5D at the throttle element.

Key points for installation inspection

Whether the full range of the differential pressure transmitter meets the design requirements of the flowmeter.

Whether the zero point of the differential pressure transmitter meets the requirements.

Is the connection between the differential pressure transmitter and the accumulator correct, and are the parameters of the accumulator set correctly.

Has the pressure pipe been purged.

Is there any leakage in the pressure pipe.

Whether the valve group is closed as required.

5、 Balanced flowmeter spectrum