Four Ways To Measure Steam Flow

People have been showing more interest in energy production and use for the last few years. The increasing price of crude oil has affected all areas of the economy and has led to increased fuel prices and heating oil costs. To produce electricity, we use steam as a source of power. Therefore, steam flow measurement technologies have become important.

We get heat for a power plant from many sources like fossil fuels (coal, natural gas, or oil), nuclear fuel, waste fuels, solar energy, and geothermal energy. These sources release heat through combustion or a similar process, and we transfer this heat to water to make steam with the help of boilers. This steam usually drives an electric generator.

Due to the increasing cost of energy, many manufacturers are finding ways to improve power generation efficiency. Therefore, it has become essential to measure steam flow.

In the flowmeter market of $4.5 billion, 6% revenue is achieved through sales of flowmeters used for steam flow measurement.

There are types of flowmeters to measure steam flow with different working principles, but most of the flowmeters use DP or steam vortex flow meter technology.

Steam flow meter price

• Steam Flow meter price is determined by many factors, the main factors are
• a. Steam flow meter types, different steam flow meter working principles, different price, the main types are vortex flow meter, DP flow meter, VA flow meters.,etc. For example , one inch digital vortex flow meter for steam can be as low as USD 300.
• b. Steam flow sensor size, normally the larger the size , the higher the cost. However we have insertion steam flow meter using vortex technology for large size vapor pipe lines, the price can be around  500 $ for pipe lines around 10” or 12 inches.
• c. Steam Flow meter functions, steam flow meter with HART protocol, RS485 will cost more.
• d. Steam Flow meters from China or India flow meter manufactures have very low price and competitive cost. Anyway steam flow measurement technology is a very mature technology and has very reliable measurement technology, even the price is low, and China steam flow meter still has reliable performance.

Steam Flow Meter Selection

1.  Differential-pressure (DP) flowmeters to measure steam flow rate

Disadvantages

• Pressure drop
• Interference with the flow stream
• Wear and tear with time
• Limited range
• Rely on square root method to calculate flow

Advantages

• Relatively cheaper
• Easy installation
• Most studied and best understood way to measure flow
• Multivariable DP flowmeters can measure multiple process variables like differential pressure, process pressure, temperature, and mass flow.

Primary Elements

The effectiveness of a DP flowmeter depends on the primary elements.

• Flow nozzles
• Orifice plates
• Pitot tubes
• Venturi tubes
• Wedge elements
• V-Cone Flow meter
• 
  
• Out of the above, flow nozzles are the best because they can easily handle high temperatures and pressure.

2.  Vortex flowmeters to measure steam

These flowmeters are better than other flowmeters of the latest technology:

• Coriolis meters - recently being used to measure gas flow and steam flow measurement has just started
• Ultrasonic meters - used for measuring gas flow for many years, but now being used for steam flow measurement
• Magnetic flowmeters - Cannot measure gas flow or steam flow
• Multivariable DP flowmeters - Can measure liquid, gas, and steam. They have more significant pressure drop due to primary elements when compared to vortex

It is challenging to measure fluids like steam due to high pressure and high temperatures. Moreover, the measurement parameter changes with the steam type (wet, saturated, or superheated). We usually measure steam coming from a boiler in power plants and process plants.

Vortex shedding flow meters can tolerate vapor high pressure and temperatures. They also offer wide rangeability, which means that we can measure steam flow at changing velocities.

STLU-VFN series steam flow meter is from China steam flow meter factory at low price cost , it can have built-in temperature and pressure compensation , the steam flow meter has LCD display to show steam pressure , temperature, volumetric flow and steam mass flow.

It can be used as a very economical steam flow totalizer . Steam flow measurement units can be t/h, kg/hr.

3.  Rotameters or Variable-area flowmeters

They have limited use for steam flow measurement because they do not have an output signal, and we need to read them manually. This makes rotameters worthless for automated power plants. However, some companies have been able to develop rotameters with output signals or transmitters.

Secondly, rotameters are less accurate with a tolerance of 5% to 10%, which is not acceptable in process & power plants. Even if a user wants to use a low-cost meter, he would prefer to use a DP flowmeter. Since rotameters are low-cost, they are suitable for non-critical applications where high accuracy is not required.

4.  Target flowmeters

We can use target meters for liquid, gas, or steam flow measurements. Still, they are generally used for measuring steam flow (both superheated and saturated). We can recalibrate them to compensate for wear and tear. They do not have moving parts and can bear pressures up to 15000 PSI and temperature up to 500 degrees F. These meters can fit in lines of more than 3/8 inches.

They are mechanically manufactured since 1950 are therefore known as conventional flowmeters. They are similar to vortex meters in many aspects. Thus many companies are not supplying them anymore. Vortex meters use bluff bodies and count vortices to measure steam flow. Target meters depend on a body inserted into the flow stream and measure the force applied on the target by fluid or steam.

Vortex Flow meter Offers a Safety Net

Some suppliers have included vortex to the range of flowmeters like Turbine, Coriolis, and Ultrasonic. This provides their user with another choice if they face difficulty measuring steam in any of these technologies. The vortex steam flow meters are becoming popular as a backup or safety net because companies may find some technologies difficult to apply. They may want to try new technologies to measure steam flow.

Vortex flow meters are quite reliable because they can handle high pressure and temperatures and the pressure drop is also minimal. Suppliers will get encouraged to develop and promote alternative technologies. After all, they can rely on vortex flow transmitters as a backup or safety net.