Eastern Instruments - Solids Mass Flow and Air Flow Measurement Equipment

When it comes to measuring the flow rate of air or gas in a duct, there are many different devices used.  For example, there are thermal sensors, hot wire anemometers, rotating vane anemometers, static pressure drop devices (venturi, orifice plate), and differential pressure devices (pitot, annubar, primary element).  The most widely used and considered a true measurement of the flow is the differential pressure device.  The most widely used differential pressure device is a velocity averaging pitot tube. Velocity Averaging Pitot Tube The velocity averaging pitot tube is a device that when inserted into the air or gas flow stream, provides a high pressure measurement port and a low pressure measurement port.  The high pressure port measures the total pressure created when the air or gas stream impacts the port, where the low pressure port typically measure the static pressure in the duct. VAP³ Velocity Averaging Pitot Tube from Eastern Instruments The dif...

Weigh Belt Feeders have been widely used for many years to measure the flow rate and totalization of solid materials in a process while providing a feed device to move materials through that process.  For some products they can be accurate enough to keep in your process and deal with their calibration issues, but for some products, they can be a maintenance nightmare and something that needs to be replaced.  However, with their large footprint and complex installation, finding a replacement feeder that fits can be a real issue. One way to deal with this maintenance issue but to still have that vital process measurement is to install a flow meter that can be installed at the end of a belt conveyor.  Since the Weigh Belt is in essence a belt conveyor, it would be used as just a material handling device and not a flow meter.  Once such a device that can fit in such a tight space is the CentriFlow Type I meter from Eastern Instruments. CentriFlow Type I Meter ...

Measuring the Mass Flow Rate of a Solid Material can be hard enough, but when a process needs a Controlled Flow Rate as well, this can be really difficult.  Controlling the Flow Rate in a process requires a PID control loop, where the input is an accurately measured flow rate and the controlling device is able to provide a fast change when an input change is noted, without overshoot or undershoot. In most industrial plants, these types of flow controls are typically done by a PLC.  These same PLC's usually take in all of the inputs of the process and compute all of the outputs to all of the devices in the process.  The loads on these PLC's can vary greatly and typically result in a long scan times that can adversely affect the PLC's ability to provide the best PID control loop.  This makes the control of the loop inaccurate, slow, and creates difficulty when trying to tune the loop to obtain the highest degree of control. The best way to get around these issues i...

Measuring the Air Flow in a duct can be difficult enough when the flow profile is not free from turbulence, disturbances, cyclonic flow, and reverse flow, but add to that particulate, ash, dust, or debris in the air, and it can almost be impossible.  So, how do you get accuracy when trying to measure the Air Flow in a duct that has particulate, ash, dust, or debris in the air stream? The traditional way is to use a blast purge or blow back system that will take high pressure compressed air and blow it back through the high and low ports of the air flow pitot or flow element so that any particles, ash, dust, or debris is blown out of the ports on the probe.  This not only uses a lot of compressed air, which needs to be completely dry to work properly, but it also requires a complex system of valves in order for this to be done automatically.  If the blast purge or blow back is not done on a regular basis, and if the particulate, ash, dust, or debris level is high enough ...

A question that we get asked a lot is "why do I need a Solids Flow Meter?" or "how can a Solids Flow Meter help my plant or process?"  To answer these questions, we first will look at what a Solids Flow Meter is and then where/how it can be implemented. CentriFlow Solids Mass Flow Meter from Eastern Instruments DEFINITION OF SOLIDS FLOW METER: Solids Flow Meters can be called many things from Flow Meters, Flow Instrumentation, Process Measurement Devices, or even just Process Meters.  A Solids Flow Meter can be considered an device or point measurement, that when placed in a process, provides a window into what is going on in the process.  It is an instrument that provides vital process flow data like Flow Rate and Totalization/Totalized Weight.  This can be on a continuous process or on a batch process.  The Flow Rate would be in mass units like lb/hr, kg/hr, Ton/hr, MTon/hr, etc, and the Totalization/Totalized Weight would be in mass units like lb, kg...

Measuring the mass flow rate and totalization of a dry solid material can be difficult when that product is a hard to handle powder.  Product characteristics like particle size, cohesiveness, flowability, bulk density can all affect the accuracy of the mass flow measurement of a powder.  Below we will look at these characteristics in more detail and discuss how the CentriFlow Solid Mass Flow Meter is suited to deal with issues from these characteristics, making them non-issues or helping to eliminated/overcome them to get the best accuracy possible. CentriFlow Meter - Type II Configuration Particle Size: Particle size can become an issue when a material's particles get down to the powder regime, around 0.0394" or 1000 microns (18 mesh) and smaller.  The smaller the particle, usually the more trouble it can be to handle and therefore to measure.  However, there are definitely small particles that are not an issue, like sand, which can fall into the 0.0098" or ...

One question that I am asked about all the time is "Why would I need to have a flow straightener and/or flow conditioner to get a good air flow measurement?"  The answer to this questions always comes down to duct configuration or duct arrangement.  If you have a duct that is long and straight, then it is a good bet that there are enough "straight duct runs" to get a decent flow profile in the duct and therefore a good flow measurement.  What most customers find is that these long and straight duct runs just don't exist.  In fact, most customers find that there are more turns, twists, bends, tees, and transitions than the even knew they had. Air/Gas Flow Products & Technology So, how do you know if your flow is turbulent and does not have a good flow profile (i.e. has swirl, reverse flow, cyclonic flow, or flow that is all to one side of the duct)?  For most customers, one way is to go by some guidelines that have been established that give you the ...