Tips For Best Control of Low Flow Rates

Low flow measurement and control instrument uses
Coriolis flow measurement sensor.
Image courtesy Brooks Instrument

Coriolis mass flow measurement is the method of choice for applications requiring best accuracy under very low flow conditions. The Quantim Series of mass flow controllers from Brooks Instrument provide indication of fluid flow, density and temperature for applications down to 0.001 Kg/hr. The instrument, in addition to a Coriolis flow sensor, provides digital signal processing, an integral or close coupled control valve, and PID control to deliver a total flow control solution in an integrated package.

Obtaining best available performance on a consistent basis is supported by a well done installation.

• Mount the instrument to a stable surface free from excessive mechanical shock and vibration that might impact performance.
• Locate the device where it can be easily accessed or removed.
• Install an appropriate filter on the fluid inlet side.
• Provide a positive shutoff valve on the downstream side to enable zeroing after installation.
• Make sure the process flow direction matches the required flow direction of the instrument.

The sensor and control valve are designed to function properly when filled with process fluid. This means your installation cannot deliver entrapped gas in a liquid or liquid droplets in a gas. If compressed gas is used to force dosing fluids through a system, it may be necessary to provide a degassing arrangement upstream of the flow controller. Dissolved gas that flashes due to a pressure drop through the instrument can form bubbles that distort sensor and valve performance. 

Little to no maintenance is required after the instrument is installed and zeroed. The inlet filter should be changed at intervals sufficient to assure delivery of clean process fluid to the instrument.

More technical detail on the Quantim Coriolis flow measurement and control instruments is provided in the document below. Whatever your flow measurement or control application, share your challenge with measurement and control specialists, combining your own knowledge and experience with their product application expertise to leverage an effective solution.

Mass Flow Controller - Quantim Series from Miller Energy, Inc.

Yokogawa ROTAMASS "Total Insight" Line of Coriolis Flowmeters

In the last decade, the use of Coriolis flow meters has been changing from general purpose to supporting customer needs in specific applications. While the technological complexity increased, the demand for simple operation and handling also grew.

Yokogawa answers these needs by offering six dedicated product lines with two specialized transmitters allowing the highest flexibility - the ROTAMASS Total Insight.

Total Insight

The ROTAMASS philosophy gives Total Insight throughout the whole lifecycle.

To facilitate the implementation of optimal processes and increase the efficiency of personnel, Yokogawa has placed a strong focus on simplifying fundamental operating concepts with Total Insight. The Total Insight concept is built in to the latest generation of Rotamass transmitters and provides enhanced settings for customized setups, predefined trend views, or multiple configuration sets for fast changeover in batch production.

ROTAMASS NANO - When every drop counts

The world's smallest dual bent tube Coriolis flow meter series for highly accurate measurement at lowest flows.

The dual tube design compensates for fluctuations of density, temperature, pressure and environment conditions. This provides a consistent repeatable and accurate measurement especially for small size Coriolis flow meters.

Typical Applications

• Batching
• Dosing
• Blending
• Chemical injection
• Dosing systems
• High pressure gases
• Liquid and gas low flow measurement
• Precision coatings
• Metering pump control
• Metrology
• R&D laboratory
• Vacuum thin film coating

ROTAMASS Prime - Versatile in applications

The favorably priced and versatile Coriolis flow meter with lowest pressure drop in the market. Ideal for a broad range of standard applications, this series is a flexible and cost effective solution for highly accurate flow and density measurements.
Features such as concentration measurement or the Tube Health Check function allow the meter to be adjusted to customer needs.

• Typical Applications
• Batching
• Blending
• Chemical recovery
• Continuous reaction
• In-line concentration and density measurement
• Catalyst feed
• Filling and dosing
• Mass balance
• Net oil computing
• Palm oil
• Process control

ROTAMASS Supreme - Experience meets innovation

The most accurate Coriolis flow meter with industry’s best zero stability.

The successful Rotamass series has been progressively developed and is also newly equipped with

the latest technology. This meter delivers unsurpassed performance for demanding and critical applications with superior aeration handling and advanced diagnostic functionality.

• Typical Applications
• Batching
• Burner control
• Feed and product control
• Filling and dosing
• Gas void fraction
• In-line concentration and density
• Loss control
• Material and mass balance
• Net oil computing
• Process control
• Solvents
• Water cut

ROTAMASS Intense - Safe under high pressure

The Coriolis meter with the most robust and durable design for precise measurement in high pressure applications.

Safety is always a concern and especially when operating at high pressures. Therefore, this series has been designed to meet the highest safety requirements. Combined with advanced diagnosis such as the “Total Health Check” function, operation is always under secure control.

• Typical Applications
• Chemical injection
• Compressed gases
• Fuels
• Glycol TEG/MEG
• High pressure gases
• Hydraulic oil
• Hydrocarbons
• Liquified gases
• Natural gas hydration
• Offshore and onshore
• Oil refinery processes
• Solvents

ROTAMASS Hygienic - With pure dedication

Specifically designed and certified for food & beverage, biotechnology and pharmaceutical utility applications.

This series is the appropriate answer to the daily constraints of hygienic processes ensuring continuous product quality and minimizing losses. This is made easy by the provided multi-variable measurement and various dedicated features.

• Typical Applications
• Bioreactor feeds
• Bottling
• Carbonation of beverages
• Deionized water
• Fermentation
• Juice processing
• Molasses measurement
• Online sugar concentration
• Raw milk tanker unloading
• Process water reclamation
• Product quality control
• Sugar industry

ROTAMASS Giga - Big in performance

Delivering best in class accuracy and most flexible installation at high flow rates.

The unmatched accuracy at the low end of the measuring range offers maximum flexibility from engineering to final operation. This series unifies a long service life with low maintenance costs and reliable performance.

• Typical Applications
• Bitumen
• Distribution networks
• Drilling mud
• LNG
• Rail car loading
• Ship loading
• Truck loading
• Tar
• Offshore and onshore
• Oil well cementing and hydrofracturing

Essential and Ultimate Transmitters

Future Ready. The ROTAMASS TI product family has a common and unified transmitter platform with two options that provide the highest flexibility and a tailor-made solution. The Essential transmitter is the cost effective solution for general purpose applications, and the Ultimate transmitter provides various additional features for best-in-class measurement.

Essential Transmitter

• Wizard for easy setup and guidance through the main configuration
• “Event Management” as unique and useful support to run the process effectively and safely
• Data mobility provided by microSD card for easy transfer to other devices for fast setup or to pc for in-depth process analysis or remote service
• Widest range of I/O combinations in the market for most flexible adjustment to the existing system periphery
• Universal power supply to install the device anywhere in the world
• HART communication

Ultimate Transmitter

• Patented “Tube Integrity” function and “TotalHealth Check” for inline meter verification without disturbing running measurements
• “Features on demand” for easy expansion of special functions via software activation key
• Batching function combined with multiple configuration sets to support fast changeover
• “Dynamic Pressure Compensation” for consistently accurate and stable measurement even with significant fluctuations in operating pressures
• Inline concentration measurement
• Integrated net oil computing acc. API standard

Share your process flow measurement requirements and challenges with application experts, combining your own experience and knowledge with their product application expertise to develop effective solutions.

Applying Coriolis Flowmeters

Coriolis Flowmeter
Courtesy Yokogawa

Coriolis mass flow meters are widely used throughout the process measurement and control field. Their basic operating principle, combined with modern sensor and signal processing technology, provide a list of potential application advantages.

• Directly measure mass flow based on the principle of measurement.
• No "moving" parts (except the slightly vibrating sensor tubes).
• Coriolis sensors have the ability to measure flow of non-conductive fluids.
• Measure the mass flow rate with high accuracy.
• Instruments can be applied across a wide usable measurement range.
• Deliver density measurement based on oscillating frequency.
• Not materially impacted by fluid viscosity or density.
• Coriolis flow meters also do not need lengthy straight pipe sections upstream or downstream of the sensing unit.

SELECTION AND INSTALLATION RECOMMENDATIONS

Some considerations for product selection and installation of Coriolis mass flow meters:

• Rapid temperature changes within the measured medium can impact measurement accuracy.
• Wide ranges of connection types are available, specify the best match for your system.
• Select sensor tube construction material to accommodate media characteristics.
• For liquid measurement, the sensor tube will extend downward from a horizontal pipe run. 
• As with most industrial products, there may be restrictions on where the device may be used. For example, not for use in aircraft. Assure that your application conforms with the intended usage of the instrument.
• Install at least one tight shutoff valve adjacent to the instrument for purposes of zeroing. Isolation valves for inlet and outlet are preferred.
• Follow manufacturer recommendations for pipe supports, if required, at inlet and outlet sides of the unit
• Avoid installation at locations with high levels of vibration or strong electrical fields.
• Locate the sensor unit at the lowest practical level in the piping system. This helps avoid collection of gas bubbles in the sensor tubes.
• Sensor tubes need to be completely filled with subject medium to obtain accurate measurement.
• Avoid the use of flexible connections and reducers at the unit connection points, unless in accordance with specific manufacturer guidelines.

The Coriolis flow meters of different manufacturers may have some particular recommendations, all of which should be followed to insure the best available performance, safety, and longevity of the unit.

Share your process instrumentation challenges and requirements with process measurement specialists, combining your process knowledge and expertise with their product application experience to develop effective solutions.

Save Time And Get The Right Product With Yokogawa Automated Selection Tool

Yokogawa Corporation of America, an industry recognized source for innovative process measurement and control products, has made available an easy to use product selection tool for those navigating through the company's extensive product offering. The Product Finder is a great time saver that enables a user to quickly locate product and technical information on Yokogawa process instrumentation products meeting the user's selected criteria.

Let's step through a quick example. You will see how this quick and easy to use tool saves time by navigating quickly to the website pages detailing products meeting your requirements.

The Product Finder is accessible through a number of links throughout Yokogawa's network of representatives. Clicking the link lands you on the start page of the Product Finder. For this example, I am going to search for a flow meter with the following characteristics:

• Mass flow measurement 
• Non-conductive liquid
• Accuracy of 1%
• Flow measurement device must have an integral transmitter
• Tri-clamp connections

Above, I declared my location as United States. The next step, shown below, is to select "Flow" as the measurement parameter. You will see in the drop down menu that there are many measurement elements that can be selected, with Yokogawa products for each.

My selection of "Flow" from the drop down menu returns all of the company's flow measurement devices, of which there are many (this cropped screenshot, shown below, only shows four, but there were many more) . This is where the selector really helps you. Instead of examining several or many different models, the user can focus the search by adding more product characteristics. You can see the list of prompting questions on the left side of the page. Providing additional characteristics by answering the prompting questions will narrow the search results to the show only the products meeting all the criteria specified by the user.

The next image (below) shows all of my sample product attributes entered on the left column. Note that there is now only a single product that matches all of my sample criteria. The whole process took less than two minutes. By clicking on the "View More Details" button below the product image, I gain access to all of the available technical, support, and product data for my selected flow measurement device.

The process instrumentation specialists at Miller Energy are available to provide additional help in meeting your measurement challenges. Combine their product knowledge and expertise with your process know-how for the best solutions.

Coriolis Mass Flow Meter - Operating Principle, Applications, Advantages

Coriolis Flow Meter - Courtesy Yokogawa

Coriolis mass flow meters are widely used throughout the process measurement and control field. Their basic operating principle, combined with modern sensor and signal processing technology, provide a list of positive aspects.

Directly measure mass flow rate based on the principle of measurement.

Measure the mass flow rate with high accuracy of ±0.1%.

Provide a wide usable measurement range.

Deliver density measurement based on oscillating frequency.

Not materially impacted by fluid viscosity or density.

Coriolis flowmeters also do not need straight pipe sections upstream or downstream of the flowmeter. They also have the ability to measure non-conductive fluids. 

I have included an interesting video, produced by Yokogawa, a world class manufacturer of industrial process measurement and control instrumentation. It provides a clear and insightful illustration of the Coriolis principle and how it is used to provide accurate mass flow measurement.

Share your process measurement and control challenges with an instrumentation specialist. Combining your detailed process knowledge and their product application expertise will yield positive solutions.