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『Granular Flow Meter Operations: Continuous Weight and Impact Sizing for Powder Industrial Piping』Related information(clamp on meter|electromagnetic meter|venturi meterrotameter|orifice meter|ultrasonic flow meter|mass flow meter|coriolis mass flow meter|coriolis flow meter|magnetic flow meter|magmeter flow meter|magflow flow meter|mag meter flow meter|electromagnetic flow meter|vortex flow meter|turbine flow meter|thermal mass flow meter|thermal flow meter|rotameter flow meter)
Granular Flow Meter Operations: Continuous Weight and Impact Sizing for Powder Industrial Piping
Quick Answer: Granular flow meters combine continuous weight signal and impact force signal for powder in pipes and chutes. For stable powder flow in a closed pipe, choose a continuous weighing meter. For powder that falls freely in a chute or after a pneumatic conveyor, choose an impact plate meter.
Silver Instruments supplies both types for industrial powder lines. The sizing depends on powder density, particle size, pipe angle, and flow range. The article below explains the operation, installation, and sizing choices.
Continuous Weight Measurement in a Closed Pipe
A continuous weighing meter uses a measuring pipe or chute mounted on load cells. The load cells send a weight signal to a transmitter. The transmitter calculates mass flow from the measured weight and material speed. Continuous weight measurement works well for dense phase systems, screw feeders, and short vertical chutes.
A DN80 pipe carrying flour at 6 t/h can use a continuous weighing meter with 0.5% of full scale accuracy. The output can be 4-20 mA HART. The local display shows kg/h and totalized tons.
Impact Sizing for Free Fall and Pneumatic Conveying
An impact flow meter mounts in a dust tight housing. Powder falls onto an angled plate. The impact force is proportional to flow rate. The transmitter compensates for acceleration and sends a 4-20 mA signal. An impact meter is compact and needs less straight upstream pipe than a weight meter.
Force measurement changes with particle velocity. That is why sizing needs the drop height, pipe angle, and airflow. Last year a customer in Vietnam asked Silver Instruments to size a flow meter for limestone powder in a DN80 pneumatic conveying line. Bulk density was 1200 kg/m3. Normal flow was 8 t/h and peak flow was 12 t/h. We recommended an impact plate meter with 4-20 mA HART output and local display. The meter was installed after a bend and before a silo inlet.
Signal Output and Plant Integration
Silver Instruments granular flow meters can output 4-20 mA HART, pulse, or Modbus RTU. The local display can show flow rate, total weight, and alarms. For hazardous areas, ATEX Zone 1 or Zone 21 versions are available. A PT100 temperature input can correct density drift on some powder types.
Most engineers skip this part. The output signal should match the control system input. A 4-20 mA loop is simple. Modbus RTU gives totalizer data and diagnostic bits. Before you order, confirm the maximum flow, minimum flow, and pipeline air pressure.
Sizing Steps for a Powder Line
Send Silver Instruments these values. Powder type, bulk density in kg/m3, particle size in microns, pipe size in DN, angle from horizontal, normal flow in kg/h, peak flow in kg/h, temperature in °C, and pressure in bar. We size the meter plate width and measuring range.
In practice, a DN15 or DN25 meter suits 0 to 100 kg/h for additives and fine powders. A DN50 meter suits 0 to 3 t/h for fine powde
Installation Mistakes We See in the Field
We have seen these problems on customer sites many times. One site installed an impact meter right after a sharp elbow. The powder roped to one side of the plate. The reading was stable but too low. Another site used a weight meter on a vibrating structure. The zero shifted every day.
Use a short straight section before the meter. Mount the unit on a rigid frame. Keep the inlet angle within the range from the sizing sheet. For outdoor cement lines, protect the electronics from rain and direct sunlight. In tropical sites in Southeast Asia, use a sun shield and cable glands with proper sealing.
FAQ: Granular Flow Meter Operations, Weight, and Impact Sizing
What is the difference between a continuous weighing meter and an impact plate meter? A weighing meter measures the weight of powder in a measuring section. An impact meter measures the force of powder hitting a plate. Weighing meters suit dense phase flow. Impact meters suit free fall and dilute phase flow.
Can a granular flow meter handle sticky or abrasive powder? The choice depends on plate material and calibration. For abrasive lime or ash, use a hard facing plate. For sticky powder, avoid impact meters if the material builds up on the plate. Silver Instruments often recommends a continuous weighing meter for sticky food powders.
What pipe size and flow range do we need? Pipe size is not enough. You also need bulk density and flow range. A DN80 line at 2 t/h and a DN80 line at 20 t/h need different measuring ranges. Send the actual flow data.
What output signals can Silver Instruments provide? Standard options include 4-20 mA HART, pulse, and Modbus RTU. The display shows flow rate and total. Alarm relays can warn when flow is below a set point.
Can one meter work after a pneumatic conveyor and a free fall chute? The same meter can work only if velocity and impact angle stay inside the range. In many plants, the pneumatic line and free fall chute have different velocities. Silver Instruments sizes two meters or one meter with multirange calibration.
How to Send a Sizing Request to Silver Instruments
Send Silver Automation Instruments your powder type, bulk density in kg/m3, particle size in microns, pipe size in DN, normal flow in kg/h, peak flow in kg/h, temperature in °C, and pressure in bar. We will recommend a continuous weighing meter or an impact plate meter and a specific measuring range.
Tel: +86-25-68650347. Whatsapp: +86-25-52155837. WeChat: +86 15365082610. For liquid and gas lines in the same plant, Silver Automation Instruments also supplies Coriolis, electromagnetic, ultrasonic, vortex, oval gear, and thermal mass flow meters. Send your fluid, pressure, temperature, and line size. Silver Automation Instruments website is flow-meter.com.au.