Flow measurement in the food industry

In the food and beverage processing industry, accurate measurement and control of raw materials are very demanding. Food grade flow meters Cut costs and increase productivity. Certain processes in the food industry require sanitary conditions. Food industry: dairy products, alcohol, beverages, syrup, chocolate, edible oil, etc.

Food grade oil flow meter

Food grade flow meters can measure edible oil.

There are many steps in the processing of edible oil that require a flow meter to measure the volume and weight of how much oil flows out of the pipeline. Companies that produce and process edible oils need to use flow meters for statistics on the crude oil that is initially refined and the essential oil that is finally refined.

First of all, for oil measurement, electromagnetic flowmeters cannot be selected.

You can choose turbine flowmeters, gear flowmeters, ultrasonic flowmeters, metal rotor flowmeters to measure oil. If you need high-precision measurement. You can also consider mass flow meters.

Extended reading: Sanitary Positive Displacement Flow Meter

Flowmeter used in the beverage industry

An electromagnetic flowmeter is used to measure the volume flow of conductive liquid medium with conductivity greater than 5μs/cm. Electromagnetic flowmeters are usually used to measure the flow of large pipelines. It can be accurately measured in a large beverage production workshop. The minimum diameter of the current electromagnetic flowmeter is 0.1 inches, that is, 2.5 mm, and the maximum diameter can reach nearly 3 meters.

The beverage industry includes beer, fruit juice, etc., and electromagnetic flowmeters could not be better. Generally, the medium is conductive, and it is very good to add ions appropriately. And there is no loss. There is no differential pressure loss or something.

Originally, there are still many ways to protect the electrodes of the electromagnetic flowmeter. We should pay more attention to it in the process of use. Don’t cause the electromagnetic flowmeter to fail to operate normally in the future due to a little negligence.

Flow measurement in Breweries

What kind of flowmeter can be used to solve beer flow measurement? Beer is a conductive medium. Can use electromagnetic flowmeter to measure. When measuring beer, you only need to use stainless steel electrodes and tetrafluoroethylene lining. The electromagnetic flowmeter is a measuring instrument with high measurement accuracy and good stability. It has been widely used in beer flow measurement.

Beer flow measurement. Let’s take a look at how to select a beer electromagnetic flowmeter:

1. Medium
2. Temperature
3. Pressure

When measuring beer flow, you can select according to the above three corresponding parameters to meet the on-site measurement requirements.

Of course, except for electromagnetic flowmeters. The sanitary turbine flowmeter can also be used to measure beer or liquor.

Extended reading: Stainless steel flow meters|304-316 optional

Syrup flow measurement

Food grade flow meters can measure syrup.

High viscosity syrup flow measurement

If the viscosity of the measured syrup is relatively high. Then I recommend using a target flowmeter or an oval gear flowmeter.

The target flow meter is a speed meter. It calculates the flow rate of the medium according to the force of the medium pushing the target. Its intelligent liquid crystal meter head can clearly display the instantaneous flow and cumulative flow of the medium. And output 4-20mA signal. The installation is simple and the maintenance is small. High temperature and high-pressure resistance. Suitable for large, medium, and small pipe diameters. The application range is very wide.

The oval gear flowmeter is a positive displacement flowmeter. It is a mechanical instrument. He calculates the medium flow rate based on the measurement of the rotation of the internal gear. The general configuration is a pointer display type, which only displays the cumulative flow and does not display the instantaneous flow. Therefore, the user needs to explain to the manufacturer when displaying the instantaneous flow rate. The manufacturer will be equipped with a smart meter.

In addition, the output signal is a pulse signal. The user needs a 4-20 mA signal, and the manufacturer also needs to explain it to the manufacturer. Oval gears are relatively bulky. Therefore, it is not suitable for the measurement of large-diameter pipes. Its largest caliber is also smart to 200mm.

Why Generally Choose 4-20ma Output?

In addition to the above two types of vortex, flowmeters are also possible.

Low viscosity syrup flow measurement

If the measured viscosity of the syrup is not very high, an electromagnetic flowmeter or a liquid turbine flowmeter has been used.

Electromagnetic flowmeters are mainly used for the measurement of medicines such as glucose syrup and food syrup. Because medicine and food have higher hygiene requirements. Strict disinfection is required, so clamp-type electromagnetic flowmeters are generally used.

The liquid turbine flowmeter measures low viscosity, and the effect of relatively pure syrup is very good. Responsive, high precision, beautiful and light appearance, installation and maintenance are also very simple. It is suitable for the measurement of small and medium pipelines. Both types of flow meters are smart meters. On-site LCD displays instantaneous flow and cumulative flow. Output 4-20mA signal. The scope of application is also very wide.

Here I simply recommend several flow meters based on the viscosity of the syrup. How to choose specifically. Users need to provide relevant parameters and requirements to make the most suitable and correct choice.

Extended reading: Sludge flow meter for sewage treatment return activated sludge system

Featured Food grade flow meters

Food grade positive displacement flow meter

Positive displacement flow meters, also known as fixed displacement flow meters or PD flow meters, are the most accurate measuring instruments. The oval gear flowmeter is the most typical positive displacement flowmeter.

According to the measuring elements, the volumetric flow plan can be divided into elliptical gear flow meters, double rotor flow meters, disc flow meters, rotary piston flow meters, wet gas meters, and membrane gas meters, etc. The clamp connection oval gear flowmeter has the advantages of a lightweight and convenient connection. Especially in the chemical and pharmaceutical industries, it has a wide range of uses.

Extended reading: Mechanical flow meter types

Sino-Inst offers over 10 Food grade flow meters, with the Best Price. Food grade flow meters are Also called sanitary flowmeters.

A wide variety of Food grade flow meters options are available to you, such as free samples, paid samples.

About 13% of these are magnetic flow meter, 14% are Turbine Flow Meters, 25% are Venturi flow meter, 13% are Handheld ultrasonic flow meter, and others are Liquid mass Flow Meters.

Sino-Inst is Food grade flow meters supplier, located in China. Food grade flow meters products are most popular in North America, Mid East, and Eastern Europe. The United States, and India, which export 99%, 1%, and 1% of Food grade flow meters respectively.

Can rotameter be used for gases?

Rotameter can measure gas.

Rotameter is a variable area flow measuring instrument commonly used in industrial automation process control, which can be used to measure the flow of liquid, gas, and steam.

Rotameters are especially suitable for dry gas and steam measurement. Such as the measurement of nitrogen, air, oxygen and other gases.

It is not applicable if the liquid medium or gas medium contains impurity particles. It will affect the accuracy of the measurement.

If the pressure is relatively large, you can use a metal tube float flowmeter. The metal tube float flowmeter can transmit signals remotely for total accumulation or flow control. You can also customize the remote metal rotor flowmeter according to your needs. Explosion-proof metal rotor flowmeter.

Further reading: Nitrogen(N2) Flow Meter Types

More Featured Gas meters:

Extended reading: Beginner’s Guide: Variable area flow meter

Air Rotameter

Metal tube rotameter can be used to measure air. Because the rotameter is a variable area flow measuring instrument commonly used in industrial process automation control.

Rotameter has the characteristics of small size, large detection range and convenient use. It can be used to measure the flow of liquid, gas and steam. It is especially suitable for medium flow measurement with low flow velocity and small flow. Therefore, there is no problem in measuring air. However, it should be noted that the metal tube rotor flowmeter is only suitable for the flow measurement of small-diameter and low-velocity media within DN200.

Extended Reading: Digital air flow meters

More about Types Of Air Flow Measurement Instruments.

Chlorine Gas Rotameter

Rotameters are used to measure the flow of various small-diameter media. Of course, it is also very reliable when used in the chlorine flow measurement industry.

For the measurement of chlorine gas, the metal tube rotameter can fully meet this measurement requirement. Rotameters are not only made of metal, but also made of glass.

Comparing the two, the metal tube rotor flowmeter has on-site display and intelligent remote transmission functions. The measurement accuracy is high and it is easy to use. And the whole is relatively sturdy and has a long service life.

The glass tube rotameter has a simple structure. There should be no bumps during use. It is fragile and non-explosive, and has a short service life. The metal tube rotameter is superior to the glass tube rotameter when measuring chlorine.

Extended reading: Gas Mass Flow Meter

Nitrogen Gas Rotameter

There are many types of Nitrogen gas flow meters. There are three types of flow meters commonly used to measure nitrogen. Precession vortex flowmeter, gas vortex flowmeter, thermal gas mass flowmeter. When selecting a model, it is necessary to select a suitable model and specification according to the parameters and cost that can be provided on-site.

Of course, the rotameter is also a good choice for measuring nitrogen. Because of the low cost.

Read more anout: Nitrogen Gas-Liquid Nitrogen Flowmeters

Hydrogen Gas Rotameter

There are three types of flowmeters commonly used to measure hydrogen flow: precession vortex flowmeter, gas vortex flowmeter, and thermal gas mass flowmeter. When selecting a model, it is necessary to select a suitable model and specification according to the parameters and cost that can be provided on site. You must communicate well with the sales staff to make the measurement accurate.

Of course, the rotameter is also a good choice for hydrogen measurement. Because of the low cost.

Extended reading: Featured Hydrogen flow meters

Natural Gas Rotameter

The flow measurement of natural gas is currently mainly used in trade settlement and is relatively common. my country’s natural gas trade measurement is based on the volume or energy method under the legally required quality indicators for transfer measurement. At this stage, volume measurement is basically the main method.

At present, the flowmeter products used for natural gas flow measurement generally include: gas waist wheel flowmeter, gas turbine flowmeter, precession vortex flowmeter, vortex flowmeter, ultrasonic flowmeter and orifice flowmeter.

Let’s make a simple comparison on the use of these flow meters.

Extended reading: 5 matters to pay attention to when choosing threaded Vortex Nitrogen Gas Flow Meter

Rotameter Gas Flow Conversion

When measuring gas and liquid media, are the parameters of the rotameter the same?

Metal rotor flowmeter is a variable area flow measuring instrument commonly used in industrial automation process control. When it is measuring liquid and gaseous media, because the density of the two media is different, the material of the rotor of the flowmeter will also be different due to the density of the medium.

Regardless of whether it is measuring gas or liquid, the metal rotor flowmeter is the same in appearance and structure. But because the density of a gas is lower than that of liquid, the density of gas rotor material is smaller than that of the liquid rotor.

Whether the rotameter for measuring gas or liquid, the structure is basically the same, and it is equipped with a rotor in a conical tube. The main differences are as follows:

1. The calculated density of the rotor: the density for liquid is high, and the density for gas is low.
2. Rotor shape: the cross-sectional area of ​​liquid is relatively small, and the cross-sectional area of ​​gas is relatively large
3. Damping device: It is better to use a damping device for liquids and gas, so that the measured value is stable.

Therefore, when we choose the metal rotor flowmeter, we need to clearly describe the real-time conditions of the working conditions with the manufacturer. In this way, we can formulate qualified process and technical parameter models of flowmeters according to the actual requirements of the working conditions. So as to be able to solve the measurement problem more effectively.

Extended reading: Radar level sensor for solids – Dust solid level measurement

Gas Rotameter Calibration

It is not feasible to calibrate metal tube rotameters with conventional methods. This is determined by the structural principle of the transmitter.
Because the rotameter is between the input pressure source and the generated 4-20mA current signal. Besides to machinery and circuits. There are also micro-processing chips that perform calculations on input data. Therefore, the adjustment is different from the conventional method.

In fact, the manufacturer also has instructions on the calibration of metal tube rotameters. A series of transmitters produced by our company. For calibration, there are: “Set range”, “Re-quantity range”, “Fine adjustment” points.

Extended reading: liquid nitrogen level measurement

Among them, the “set range” operation is mainly to complete the configuration work through the number of LRV and URV. The “re-quantity range” operation requires the transmitter to be connected to a standard pressure source. Guided by a series of instructions, the transmitter directly senses the actual pressure and sets the value. The initial and final settings of the range directly depend on the actual pressure input value. But it should be seen that although the analog output of the transmitter has a correct relationship with the input value used. But, the value displayed by the digital readout of the process value will be slightly different. This can be calibrated by fine-tuning items.

Because each part of the metal tube rotor flowmeter needs to be adjusted separately and must be adjusted together. Therefore, the actual calibration can be carried out according to the following steps:

Make a 4-20mA fine-tuning first. It is used to calibrate the D/A converter inside the transmitter. Because it does not involve sensing components.

No external pressure signal source is required.

Do one more full fine-tuning. Make the 4-20mA and digital readings coincide with the actual applied pressure signal. Therefore, a pressure signal source is required.

Finally, do the re-quantification process. Adjust the analog output 4-20mA to match the external pressure signal source. Its function is exactly the same as that of the zero adjustment (Z) and range adjustment (R) switches on the transmitter housing.

Some people think that the range of metal tube rotameter can be changed as long as the HART handheld communicator is used. And can adjust the zero point and span. There is no need to enter a pressure source. But this approach cannot be called calibration, but can only be called “setting range”.

The real calibration requires a standard pressure source to enter the transmitter. The range adjustment (LRV, URV) is not calibration because the standard instrument is not used. Ignore the input part (pressure of the input transmitter) to adjust the output, (transmitter conversion circuit) is not a correct calibration.

Furthermore. The relationship between pressure and differential pressure detection components. A/D conversion circuit. And current output is not equal. The purpose of calibration is to find out the relationship between the three changes.

Extended reading: Cryogenic Flow Meters | Liquid Nitrogen-Liquid Oxygen

Extended reading: How does a rotameter work

Sino-Inst offers over 30 rotameter products. About 50% of these are for liquids. 40% are for gas. At the best price.

A wide variety of Gas Rotameter options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Gas Rotameters, located in China.

The top supplying country is China (Mainland), which supply 100% of the Float Flow Meter respectively.

Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Gas Rotameter products are most popular in Domestic Market, Southeast Asia, and Mid East.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

How does a float flow meter work?

Float Flow Meter is also called rotor flow meter. It is mainly used for small and medium caliber flow measurement. It can measure liquid, gas, steam, etc. The product series have complete specifications and are widely used.

Extended reading: Gas Rotameter Tips

Float Flow Meter working principle

Float Flow Meter consists of two parts. One of the rotameter is a tapered tube that gradually expands from bottom to top. The other is a rotor that is placed in the tapered tube and can move freely up and down along the centerline of the tube.

When measuring the flow of fluid, the measured fluid flows in from the lower end of the tapered tube. The flow of fluid impacts the rotor and produces a force on it. The magnitude of this force varies with the flow rate.

When the flow is large enough, the generated force will lift the rotor and raise it.

Extended reading: Fluid flow meter types

At the same time, the measured fluid flows through the annular section between the rotor and the tapered tube wall. At this time, there are three forces acting on the rotor. The dynamic pressure of the fluid on the rotor, the buoyancy of the rotor in the fluid, and the gravity of the rotor itself.

When the flowmeter is installed vertically, the center of gravity of the rotor coincides with the axis of the tapered tube. The three forces acting on the rotor are all along the direction parallel to the axis of the tube.

When these three forces reach a balance, the rotor floats smoothly on a certain position in the cone tube.

For a given rotameter, the size and shape of the rotor have been determined. Therefore, its buoyancy in the fluid and its own gravity is known to be constant. Only the dynamic pressure of the fluid on the float changes with the flow rate of the incoming flow.

Therefore, when the flow rate of the incoming flow becomes larger or smaller, the rotor will move up or down. The flow cross-sectional area of ​​the corresponding position also changes. Until the flow rate becomes the corresponding speed when the flow rate becomes balanced, the rotor is stable in the new position.

For a given rotameter, the position of the rotor in the cone tube is in one-to-one correspondence with the flow rate of the fluid flowing through the cone tube.

In order to prevent the rotor from touching the tube wall when moving up and down on the centerline of the tapered tube, two methods are usually used.

One is to install a guide mandrel in the center of the rotor to keep the rotor moving up and down on the centerline of the tapered tube.

The other is a chute on the edge of the rotor disc. When the fluid flows through the rotor from bottom to top, one side bypasses the rotor. At the same time, it passes through the chute to generate a reverse thrust. The rotor keeps rotating around the centerline. . It can keep the rotor from touching the pipe wall when working. The rotor material of the rotameter can be made of stainless steel, aluminum, bronze, etc.

Extended reading: Micro flow meters for low flow liquids

Types of Float Flow Meter-variable area flowmeter

Float type water flow meter

Rotameters can be used to measure the instantaneous flow of water. There are many flow meters for measuring water. Almost all flow meters that measure liquids can be used to measure water.

The original rotameter used to measure water is now used to measure the flow rate of gasoline. Is the reading correct?

Certainly not. Rotameter measuring liquid is most affected by liquid density and viscosity. It is recommended to find the manufacturer to tell them the parameters of your gasoline. It should be able to help you convert and tell you the true flow rate when the current scale is used to measure gasoline.

Rotameters measure different liquids. How to convert?

Rotameter display value correction. The fluid and state when the flowmeter is in use are generally different from the fluid and state when the flowmeter is scaled. Therefore, the value of the flow meter reading during use is not the real flow through the flow meter. The indicated value must be corrected according to the fluid and state in use. In order to get the correct flow.

The flow meter produced by Sino-Inst is calibrated with water for measuring liquid. The flowmeter for measuring gas is calibrated with air. The indicated value is scaled according to the volume flow rate of the standard state (water at 20°C; air at 20°C, 101.325KPa). Therefore, all corrections are based on the standard state index.

Extended reading: Beginner’s Guide: Variable area flow meter

More Featured Water Flow Meters:

Float air flow meter

Metal tube rotameter can be used to measure air. Because rotameter is a kind of variable area flow measuring instrument commonly used in industrial process automation control.

It has the characteristics of small size, large detection range, and convenient use.

It can be used to measure the flow of liquid, gas and steam. It is especially suitable for medium flow measurement with low flow rate and small flow, so there is no problem in measuring air.

However, it should be noted that the metal tube rotor flowmeter is only suitable for the flow measurement of small-diameter and low-velocity media within DN200.

More Featured air flow meters:

Extended reading: Integral DP Flow Meter|Gas, liquid, steam|Compact structure

Sino-Inst offers over 30 Float Flow Meter products. About 50% of these are for liquids. 40% are for gas. At the best price.

A wide variety of Float Flow Meter options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of Rotameter flow meters, located in China.

The top supplying country is China (Mainland), which supply 100% of the Float Flow Meter respectively.

Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Float Flow Meter products are most popular in Domestic Market, Southeast Asia, and Mid East.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

Sino-Inst supplies GTL/C powder flow meter. The intelligent electrostatic powder flow meter continuously measures bulk solid materials in a process. The ring sensor is used. It is suitable for the measurement of solid mass flow in a wide range of metal-enclosed pipelines from kgh to th. The system is suitable for online monitoring of solid flow such as powder and dust conveyed by pipeline pneumatic conveying. Also known as pipeline solid flowmeter, solid powder flowmeter, intelligent electrostatic powder flowmeter, solid dust flowmeter, microwave solid flowmeter, etc. Applicable to: coal powder, mineral powder, lime, cement, flour, petroleum coke powder, etc.

How Do You Measure the Flow of Solids?

The Solid Flow Meter is based on the theory of contact electrification of solid materials. The powder material will accumulate a certain degree of electric charge during the process of pneumatic conveying or free fall.

Solid Flow Meter uses today’s advanced ring sensor. It can effectively capture every charged powder particle signal that passes through the ring sensor. It is amplified, shaped, and filtered by an amplifier circuit, and then processed by a high-speed processor. The final output is linear with the powder flow The standard current signal of the relationship.

The GTL/C powder flow meter is suitable for the measurement of solid mass flow in metal-enclosed pipelines with a wide range from kg/h to t/h. The system is suitable for online monitoring of the flow of solids such as powder and dust conveyed by pneumatic conveying. It can be widely used in electric power, metallurgy, cement, pharmaceutical, chemical, food manufacturing, and other industries.

Solid Flow Meter Selection Guide

When looking for a solid flow meter suitable for your process, Sino-Inst recommends that you make the best choice based on the following conditions:

• Maximum flow
• Material particle size
• Material temperature
• Bulk density/bulk density

After finding a solid flow meter suitable for your process according to the application conditions and material characteristics, you should also consider the following influencing factors:

• Wear: Wear will affect the life of the measuring piece. It is worth noting that changes in material flow will also cause significant wear.
• Adhesion: Materials should not adhere or accumulate on the surface of the measuring piece, as this will cause calibration deviations due to the buffering effect of adhered or accumulated materials.
• Corrosive: Corrosive materials will damage the flowmeter components. Corrosive gases are also worth noting.
• Airflow: Unstable and unpredictable airflow will affect the accuracy of airflow.
• Unsteady material flow: For uneven material flow, please choose a displacement sensor type solid flowmeter. Because the displacement sensor type solid flowmeter has the characteristics of mechanical hydraulic buffering.

Selection of the capacity of solid flowmeter draft tube:

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

Impact Plate Solid Flow Meter

Impact Plate Solid Flow Meter is used for metering equipment for powdery and granular materials with strong fluidity. Mainly suitable for closed material flow. Installation is restricted. Other occasions where similar products cannot be adapted. It is widely used in building materials, cement, chemical industry, coal, mining, ceramics, glass, metallurgy, grain, fertilizer, feed, port, electric power, coking, environmental protection and other industries.

Flow Meter Selection Guide 101: Find the Perfect Fit for Your Application

Microwave Solid Flowmeter-Gas Powder Explosion-Proof

The microwave solid flow meter uses the latest microwave technology. It is suitable for the measurement of solids in metal pipes.
Online flow measurement. All powder, dust, crumbs, and particulate matter can be measured repeatedly. The measurement range is as small as kilograms per hour and as large as tons per hour.
A microwave solid flowmeter is suitable for online measurement during pneumatic conveying or free fall. Therefore, it is an alternative product of a cost-effective weighing system.
MONITOR level monitor and display can be used on various occasions to detect the flow/non-flow state of powder and solid particles. Choose SFD-2 solid level monitor or SFI solid level display. Mainly based on the output type (relay or analog Quantity) requirements.

More Featured Flow Meters:

You may like:

Sino-Inst offers over 50 flow meter for flow measurement. About 50% of these are differential pressure flow meters, 40% is the liquid flow sensor, and 20% are Ultrasonic Level Transmitter and mass flow meter.

A wide variety of flow meters options are available to you, such as free samples, paid samples.

Sino-Instrument is a globally recognized supplier and manufacturer of flow measurement instrumentation, located in China.

The differential pressure flow meter consists of a primary device and a secondary device.

The primary device is called the flow measuring element. It is installed in the pipeline of the fluid to be measured. It produces a pressure difference proportional to the flow (velocity). It is used for the secondary device to display the flow.

The secondary device is called a display instrument. It receives the differential pressure signal generated by the measuring element and converts it into the corresponding flow rate for display. The primary device of the differential pressure flow meter is often a throttling device or a dynamic pressure measuring device (pitot tube, velocity tube, etc.).

The secondary device is a variety of mechanical, electronic, and combined differential pressure meters equipped with flow display instruments. The differential pressure-sensitive components of differential pressure meters are mostly elastic components.

Since the differential pressure and the flow have a square root relationship, the flow display instruments are equipped with a square root device to linearize the flow scale.

Most meters are also equipped with flow totalizers to display the cumulative flow for economic accounting. This method of using differential pressure to measure flow has a long history and is relatively mature. Countries around the world are generally used on more important occasions. It accounts for about 70% of various flow measurement methods.

Extended Reading: Differential Pressure (DP) Flow Meters Technology

Extended reading: What Is Flush Diaphragm Pressure Sensor?

Featured Differential Pressure Flow Meters

Extended reading: ​Solid flow meter | For bulk solids-powder-soybean-cement 

Differential pressure flow meter calculation

Calculation formula 1: Conversion of differential pressure and flow rate of differential pressure flow meter

The differential pressure of a differential pressure flow meter is proportional to the square of the flow, or the flow is proportional to the square root of the differential pressure. Expressed by the following formula:

The scale unit of the flow meter is the flow percentage, and when the lower limit range of the differential pressure is 0, we get:

In the above formula:
△P is any differential pressure;
Q is any flow;
△Pmax is the upper limit of differential pressure;
Qmax is the upper limit of flow;
n is any percentage of flow

Extended reading: Measuring Flow With Pressure Sensors

[Calculation example 1]

The range of a certain differential pressure transmitter is 0-40kPa. The corresponding flow rate is 0-1603/h. The output signal is 4-20mA. What is the flow rate when the output current of the differential pressure transmitter is 8mA? What is the differential pressure?

Solution:

①Calculate the flow rate of the differential pressure flow meter according to the flow calculation formula

When the output is 8mA, the flow rate is 80m3/h.

②When the differential pressure transmitter is known to output 8mA. The flow rate is 80m3/h. The flow rate is 50% of full scale. Calculate the differential pressure value of the differential pressure transmitter according to the flow calculation formula

When the output current is 8mA, the differential pressure is 10kPa.

Extended reading: Industrial Pressure Transmitters|Buy from the manufacturer

Calculation formula 2: Conversion of volume flow in standard state and working state

The conversion formula of volume flow between standard state and working state is as follows:

In the formula,

qv is the volumetric flow rate under working conditions, in m3/h;
qn is the volume flow under standard conditions, in m3/h;
P is the absolute pressure under working conditions, the unit is Pa;
Pn is the absolute pressure in the standard state, in Pa;
T is the thermodynamic temperature under working conditions, in K;
Tn is the thermodynamic temperature in the standard state, in K;
Z is the gas compression coefficient under working conditions;
Zn is the gas compressibility coefficient under standard conditions;

Extended reading: how to calibrate a pressure transmitter

[Calculation example 2]

The design range of an airflow meter is 0-2000m3/h (at 20℃, 101.325kPa state). The pressure under working conditions is 0.5MPa. The temperature is 60°C. Find the volume flow under working conditions.

Solution: Substitute the data into the formula to calculate the volume flow under working conditions

The volume flow range of this flow meter is 0-460m3/h under working conditions.

Extended reading: Vortex Steam Flow Meter

Calculation formula 3: Calculation of changing range of standard orifice plate

Sometimes it is encountered in the field that the measured flow exceeds the maximum range of the orifice plate, or the flow is too small and can only be displayed below 30% of the maximum range. The emergency can be met by expanding or reducing the differential pressure range. The basis for changing the range is the formula. The maximum differential pressure and maximum flow rate of the flow meter in use are known. With these two parameters combined with the flow calculation formula, the calculation work for changing the range can be carried out.

Extended reading: wireless pressure transmitter working principle

[Calculation example 3]

There is an orifice flow meter, the original design differential pressure range is 0-60kPa. The flow range is 0-10000kg/h. The process flow of the expansion of production scale has exceeded the maximum flow of the orifice, and the range is planned to be expanded to 0-15000kg/h.

Solution: Calculate the corresponding maximum differential pressure according to the formula

The differential pressure value simply calculated above will have a certain error and is not a trade settlement. It can be used in general production sites. Uncertainty will not be a problem, but the pressure loss will increase. When changing the range of the orifice plate, the influence of many parameter changes should be considered comprehensively, and the iterative calculation method should be selected for the formal.

What is the difference between iterative calculation and simple calculation? The following is a comparative example

Extended reading: Liquid Bitumen/Asphalt Flow Meter

[Calculation example 4]

The original maximum flow rate of a certain steam flow meter was 70,000 kg/h, and the maximum differential pressure was 100 kPa. Because the actual flow is too small, the proposed maximum flow is 35000kg/h. The result of iterative calculation by computer is 35000kg/h, and the corresponding maximum differential pressure is 24.837kPa.

Solution: According to the formula, use a simple method to calculate the maximum differential pressure corresponding to 35000kg/h as 25kPa

If the result of the iterative calculation is taken as the standard value, the error of the simple calculation is:

Compared with the two methods, the error generated by the simple calculation method is 0.656%. Many production sites are still acceptable, especially for emergencies. Because the replacement of the orifice plate needs to be ordered and stopped. In order to reduce errors, some parameters (such as outflow coefficient, expansion coefficient, fluid density, etc.) can be indirectly corrected in the flow totalizer or DCS.

Change the range of the standard orifice plate by yourself, and first calculate it according to the flow calculation formula. Then set the range of the differential pressure transmitter according to the calculation result and calibrate it. Set the new parameters of the flow totalizer and DCS, then it can be put into use.

Changing the range of the orifice plate by yourself is restricted by conditions, that is, the newly changed range cannot exceed the 3:1 adjustable range of the standard orifice plate. The iterative calculation method is used when conditions permit. Or redesign the orifice plate.

Extended reading: Food grade flow meters for Food & Beverage industry

You may like:

Extended reading: extrusion melt pressure transducer

Sino-Inst, Manufacturer for differential pressure flow meter. Including an Orifice plate, Venturi, Annubar, etc. Suitable for liquid, gas, and steam flow measurement.

Sino-Inst’s differential pressure flow meters, made in China, Having good Quality, With a better price. Our flow measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

Sludge treatment (sludge treatment) refers to the reduction, stabilization, and harmless processing of sludge such as thickening, tempering, dewatering, stabilization, drying, or incineration. The higher the degree of sewage treatment, the more sludge residues that need to be treated.

Why use an electromagnetic flowmeter to measure the sludge flow rate?

The main reason for using an electromagnetic flowmeter to solve the flow of sludge is its low cost, high measurement accuracy, and good stability. Many flows measuring instruments can meet this requirement.

Featured Sludge Flow Meters

Read more about: Different Types of Flowmeters – Technical and Application Analysis

Return Activated Sludge

The wastewater treatment plant uses a secondary treatment process called activated sludge. This process converts non-sedimentable substances into biological flocs. This substance is produced in the aeration tank and settled in the final sedimentation tank.

Activated sludge is an aerobic process. It can promote the health of microorganisms and ensure effective treatment. The balance between food and oxygen and microorganisms must be maintained for optimal treatment. An element of maintaining biomass is to return a part of the sedimentation sludge from the final sedimentation tank to the aeration tank to maintain the balance of the biological system. This part of activated sludge is called RAS (Returned Activated Sludge).

The RAS is returned to the aeration tank via a variable-speed centrifugal pump. Accurate flow rate measurement is essential to ensure that the proper ratio of “food to microorganisms” is maintained. The RAS flow rate is determined by a microbiological health laboratory analysis, and the flow rate is adjusted accordingly.

Extended reading: Insertion Ultrasonic Water Flow Meter – Designed for Agricultural Irrigation, Garden Management

Sludge Flow Measurement of Return Activated Sludge Pipe

1 Project background

• DN 400mm stainless steel pipe;
• Full tube
• High pollution load, suspended solids content as high as 1%.

2 Measurement requirements

• Trouble-free and stable measurement of the horizontal conveying pipe of the return sludge conveyed by the screw pump lifting equipment;
• Due to high pollution load and gas load. The two existing measurements. Electromagnetic flowmeter + external clamp ultrasonic time difference method. Neither can work reliably or at all;
• The installation cost is low.

3 Solution

• Use NFP type cross-correlation flow measurement system;
• A hole was drilled upstream of the existing electromagnetic flowmeter. The NFP mounting piece was welded to the existing pipeline;
• Install a ball valve that can remove the sensor during operation, adjust and fix the cross-correlation sensor.

4 Advantages

• Simple and fast upgrade and transformation of existing facilities;
• The old flow measurement equipment does not necessarily need to be dismantled;
• Although the concentration of suspended solids in the water is high, the flow measurement is still reliable.

Read more about: Shop 101: Key Factors In Selecting A Pipe Flow Meter

Extended reading: Micro flow meters for low flow liquids

Advantages of electromagnetic flowmeter in sludge measurement

1. The electromagnetic flowmeter has no mechanical inertia. Responsive. Can measure instantaneous pulsating flow. It can also measure the flow in both directions.
2. The output of the electromagnetic flowmeter is only proportional to the average flow rate of the measured medium. It has nothing to do with the flow state (laminar or turbulent) under symmetrical distribution. Therefore, the electromagnetic flowmeter has a very wide range. The measurement range can reach 100:1, and some even reach the operable flow range of 1000:1.
3. The sensor structure of the electromagnetic flowmeter is simple. There are no moving parts in the measuring tube, nor any throttling parts that hinder fluid flow. So when the fluid passes through the flow meter, it will not cause any additional pressure loss. It is one of the flow meters with low energy consumption in the flowmeter.
4. The industrial electromagnetic flowmeter has a very wide caliber range. From a few millimeters to a few meters. Moreover, there are real-flow calibration equipment with a diameter of 3m in China. Laid a foundation for the application and development of electromagnetic flowmeters.
5. The electromagnetic flowmeter is a volume flow measuring instrument. During the measurement process, it is not affected by the temperature, viscosity, density and conductivity (in a certain range) of the measured medium. Therefore, the electromagnetic flowmeter only needs to be calibrated by water. It can be used to measure the flow of other conductive liquids.
6. It can measure the flow of dirty medium, corrosive medium and suspended liquid-solid two-phase flow. This is because there are no obstructing flow parts inside the meter measuring tube. The fluid to be measured is only in contact with the inner lining of the measuring tube and the electrode, and the material can be selected according to the nature of the fluid to be measured.

For example, use polytrifluoroethylene or polytetrafluoroethylene as the lining. It can measure various corrosive media such as acid, alkali and salt. The use of wear-resistant rubber as the inner lining is particularly suitable for measuring liquid-solid two-phase flows such as mineral slurry and cement slurry with solid particles and greater wear, as well as various suspended liquids such as fiber-containing liquids and pulps.

Extended reading: Orifice Plate Flow Meter

Can electromagnetic flowmeter measure sludge fluid with 85% moisture content?

Yes, there is no problem at all. I am the technology of the electromagnetic flowmeter manufacturer, and the measurement is no problem. It is only when the density of the sediment particles reaches a certain level. There will be peak fluctuations. However, the measurement is no problem.

Extended reading: ultrasonic sludge level meter

Which lining material electromagnetic flowmeter is used for sludge flow meter?

What kind of flowmeter can be used for sludge flow measurement. According to the characteristics of the sludge medium, the flow rate of the sludge can be measured by using an electromagnetic flowmeter. The electrode material uses tantalum electrode, and the lining material uses ceramic material or tetrafluoroethylene. In this way, the sludge flow measurement conditions can be solved.

More about:

Learn More about Sludge Treatment

Before sludge treatment, we must first understand the classification of sludge:

1. Treatment of physicochemical sludge discharged from sedimentation tank or thickening tank of waterworks. It is a medium and fine-grained organic and inorganic mixed sludge. The compressibility and dehydration performance are average.
2. The remaining activated sludge discharged from the secondary settling tank of the domestic sewage plant is hydrophilic, fine-grained organic sludge, with poor compressibility and poor dehydration performance.
3. Treatment of physicochemical and biochemical mixed sludge discharged from the thickening tank produced by industrial wastewater treatment. It is a medium-fine-grained mixed sludge. The dewatering performance of the fiber-containing body is better. The other compressibility and dewatering performance are average.
4. The physical and chemical fine-grained sludge produced by the physical method and chemical method discharged from the thickening tank from the industrial wastewater treatment. It belongs to the fine-grained inorganic sludge. The compressibility and dewatering performance are general.
5. Physical and chemical precipitation of coarse-grained sludge produced by industrial wastewater treatment. It belongs to coarse-grained hydrophobic inorganic sludge. It has good compressibility and dewatering performance.

Extended reading: Stainless steel flow meters|304-316 optional

You may like:

Extended Reading: Special Magnetic Flowmeter Installation situation

Sino-Inst offers Sludge flow meter products. About 85% of these are Magnetic flow meters, 3% are Ultrasonic water meters. A wide variety of Sludge flow meter options are available to you, such as free samples, paid samples.

The top-selling countries or regions are China, India, and Israel, which supply 99%, 1%, and 1% of sewage flow meter respectively. Sludge flow meter products are most popular in Domestic Market, Mid East, and North America. You can ensure product safety by selecting from certified suppliers, with ISO9001, and Other certifications.

Request a Quote