【Q&A】April 12, 2017
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Question: Explain the principle of the orifice plate flow meter? Answer: When fluid passes through an orifice plate, the flow velocity increases due to the narrowing of the flow channel, which reduces the pressure. Therefore, given a fixed area for the orifice plate, the flow rate can be determined by measuring the pressure drop upstream and downstream of the orifice plate. http://bbs.hcbbs.com/static/image/hrline/4.gif Petrochemical Zone—New Ideas for Energy Saving: The “Creative Thinking” Campaign (Sponsors Wanted; Highest Returns Ever) http://bbs.hcbbs.com/thread-1666758-1-1.html Sponsors are being sought for this campaign; those interested can contact the event coordinator. The Petrochemical Processing Edition—Sharing Pictures of Chemical Equipment has started! A vast amount of wealth, as well as Hchuan coins, are waiting for you to claim them: http://bbs.hcbbs.com/thread-1760733-1-1.html. “Petroleum and Chemicals Section”: Notice regarding the collection of chemical technology materials: http://bbs.hcbbs.com/thread-1614796-1-1.html. http://bbs.hcbbs.com/hcdown/data/attachment/forum/201704/07/123053embbjkok61hz6vvz.jpg.thumb.jpg. [Haixin Chemical Cup ★ Spring has arrived for Hchuan Chemicals] Summary post of the 2017 scenic views sharing event (you can take a look at the local scenery posted by users from various places in your free time): http://bbs.hcbbs.com/thread-1766484-1-1.html
When fluid passes through an orifice plate, the flow velocity increases due to the narrowing of the flow channel, which reduces the pressure; therefore, with the area of the orifice plate fixed, the flow rate can be determined by measuring the pressure drop upstream and downstream of the orifice plate.
As the fluid passes through the orifice plate, the flow velocity increases due to the narrowing of the flow channel, which reduces the pressure. Therefore, when the area of the orifice plate is known, the flow rate can be determined by measuring the pressure drop upstream and downstream of the orifice plate.
When fluid flows through an orifice plate, the flow velocity increases due to the sudden reduction in the flow cross-sectional area, and the static pressure energy decreases. This creates a certain pressure difference before and after the orifice plate; the flow rate can be calculated based on the relationship between this pressure difference and the flow rate
A differential pressure orifice plate flow meter can be roughly divided into three parts: the first is the pressure measurement section at the site, which includes the straight pipe sections before and after the orifice plate, the advanced orifice plate valve, and the pressure guiding tubes; the second is the compensation section for temperature, pressure, and composition, which mainly involves the actual data measured by pressure transmitters, temperature transmitters, and natural gas composition analyzers used on-site; the third is the flow calculation section, which refers to the standard calculation programs installed in specialized flow computers (or calculators). In practical applications, when the fluid filling the pipe flows past a throttling element within the pipe, the flow lines undergo local contraction at that element, resulting in an increase in flow velocity. This leads to a decrease in static pressure, and thus a pressure difference is created before and after the throttling element. The greater the fluid flow rate, the larger the pressure difference generated; this pressure difference is then used as a measure of the flow rate.
The orifice plate flow meter is a differential pressure flow measurement device with a high range ratio, consisting of a standard orifice plate in combination with a multi-parameter differential pressure transmitter. It can measure the flow rate of gases, vapors, liquids, and sludges, and is widely used in process control and measurement across industries such as petroleum, chemicals, metallurgy, power generation, heating, and water supply. A throttling device, also known as a differential pressure flow meter, consists of a primary sensing element and a secondary unit, and is widely used for gases. Flow measurement of steam and liquids. It features a simple structure, easy maintenance, and stable performance
A differential flow meter with a high range ratio, consisting of a standard orifice plate in combination with a multi-parameter differential pressure transmitter (or separate differential pressure transmitters, temperature transmitters, and pressure transmitters), can measure the flow rate of gases, steam, liquids, and natural gas. It is widely used in process control and measurement across industries such as petroleum, chemicals, metallurgy, power generation, heating, and water supply.
As the continuously flowing fluid in the pipe passes through the orifice plate, its cross-sectional area contracts sharply, resulting in high resistance at the pipe wall and a significant decrease in flow velocity. Lower flow velocity leads to higher pressure, while higher flow velocity occurs at the center of the pipe where the pressure is lower. As a result, the fluid experiences acceleration in the radial direction, from the center of the orifice plate toward its edges. Under the influence of this radial acceleration, the flow direction of the fluid particles near the pipe wall is deflected toward the orifice, resulting in a local contraction of the flow bundle. At the center of the orifice in the plate, the flow velocity is high and the static pressure is low, which creates a pressure difference between the fluid before it passes through the orifice and at the moment of throttling. This pressure difference is proportional to the square of the fluid flow rate, and the flow rate of the fluid is calculated based on this proportional square relationship.
The fluid flowing through the pipes passes through a throttling device inside them, causing a local contraction near the throttling element, which increases the flow velocity and creates a static pressure difference on the upstream and downstream sides.
As the fluid flows through the orifice plate, a local contraction is formed at the orifice, causing the flow velocity to increase and the static pressure to decrease; as a result, a pressure difference is created before and after the orifice plate. The greater the flow rate of the fluid, the larger the pressure difference; the flow rate of the fluid is calculated by measuring this pressure difference.