SLURRY WATER CIRCUIT | CONCENTRATION MEASUREMENT
Differential Pressure Concentration Meter
Concentration measured from twin-flange differential pressure across a fixed vertical separation. No insertion element sits in an abrasive stream, the range reaches 0 to 4 g/cm³, and the installed cost is materially lower than an insertion tuning-fork probe.
0 – 4 g/cm³
Range
0.1%
Linearity
0.2 seconds
Response Time
1.3 – 3 m/s
Working Velocity
DEFINITION & OVERVIEW
What is a Differential Pressure Concentration Meter?
A differential pressure concentration meter works out how much solid is in a slurry from pressure alone. Two flanges sit a fixed distance apart on a vertical section of line, and the difference in pressure between them rises with the density of what is flowing through. No element reaches into the stream.
That is the reason to choose it for abrasive duty. Slurries with a high solids content wear and clog anything placed in the flow, which limits the instruments that can be used on them. With the sensing done at the flanges, there is nothing in the stream to erode, and the installed cost is materially lower than an insertion probe.
John Finlay's unit covers 0 to 4 g/cm³, twice the range of our Tuning-Fork Concentration Meter (0 to 2 g/cm³), with 0.1% linearity and a 0.2 second response. It outputs 4–20 mA two-wire with HART and runs on 12–45 V DC. The tuning-fork probe is the higher-precision option. This meter is the engineered alternative where abrasion, installed cost or a range above 2 g/cm³ decides the selection.
The same twin-flange principle is described in more detail, with construction and display options, on our Differential Pressure Density Meter page.
Nothing in the Stream
Twin-flange sensing at a fixed vertical separation means no insertion element to wear or clog in an abrasive slurry.
Wider Range
0 to 4 g/cm³, against 0 to 2 g/cm³ for the insertion tuning-fork probe.
Lower Installed Cost
A materially lower installed cost than the insertion tuning-fork instrument.
Parameter | Value |
|---|---|
Measuring Principle | Twin-flange differential pressure across a fixed vertical separation |
Range | 0 – 4 g/cm³ (the insertion tuning-fork probe covers 0 – 2 g/cm³) |
Accuracy | ±0.002 g/cm³ |
Linearity | 0.1% |
Response Time | 0.2 seconds |
Working Velocity | 1.3 – 3 m/s |
Output | 4–20 mA two-wire with HART |
Power Supply | 12–45 V DC |
KEY FEATURES
Key Features & Performance Highlights
Differential Pressure Concentration Meter
No Insertion Element in an Abrasive Stream
Sensing happens at two flanges on a fixed vertical section, so there is no probe or fork in the flow to erode or clog. On dense, abrasive underflow that is the difference between an instrument that lasts and one that needs regular replacement.
0 to 4 g/cm³ Range, 0.2 Second Response
Covers dense suspensions beyond the 2 g/cm³ ceiling of an insertion tuning-fork probe, and responds in 0.2 seconds, fast enough for control loops and not just trending.
Standard Two-Wire Integration with HART
A 4–20 mA two-wire output with HART on a 12–45 V DC loop supply wires into existing control systems like any other loop-powered transmitter.
WORKING PRINCIPLE
How the Differential Pressure Concentration Meter Works
Concentration is calculated from a pressure difference between two fixed points, with nothing placed in the flow.
Twin Flanges on a Vertical Section
The meter mounts on a vertical section of line with two flanges a fixed distance apart, at a working velocity of 1.3 to 3 m/s.
Pressure at Each Flange
Each flange senses the process pressure at its position in the line.
Differential Pressure Tracks Density
Because the vertical separation is fixed, the pressure difference between the flanges is a direct function of the density of the slurry between them.
Concentration Calculation
The transmitter converts that pressure difference to a concentration reading.
Signal Output
A 4–20 mA two-wire signal with HART carries the reading to the plant control system.
TECHNICAL SPECIFICATIONS
Differential Pressure Concentration Meter | Full Specification
Parameter | Value |
|---|---|
Measuring Principle | Twin-flange differential pressure across a fixed vertical separation |
Range | 0 – 4 g/cm³ |
Accuracy | ±0.002 g/cm³ |
Linearity | 0.1% |
Response Time | 0.2 seconds |
Working Velocity | 1.3 – 3 m/s |
Output | 4–20 mA two-wire with HART |
Power Supply | 12–45 V DC |
COMPARISON
Differential Pressure vs. Insertion Tuning-Fork Concentration Measurement
Differential Pressure Concentration Meter
Insertion Tuning-Fork Concentration Meter
Applications of the Differential Pressure Concentration Meter
Where concentration has to be measured in a stream that would wear out an insertion probe, or where the range or the installed cost rules the probe out.
Thickener Underflow Concentration
Underflow is dense and abrasive. Twin-flange sensing keeps the instrument out of the stream.
Dense Suspensions Above 2 g/cm³
The only one of our two concentration instruments that reaches 4 g/cm³.
Abrasive Slurry Lines
Any line where solids content wears or clogs anything placed in the flow.
Multi-Point Installations
Where several concentration points are needed, the lower installed cost counts at every point.
Thickener Instrumentation Systems
One of the concentration options in our complete thickener instrumentation system.
About John Finlay
Concentration Measurement Instrumentation Supplier in India
Why John Finlay?
0 – 4
g/cm³ Accuracy
Twice the range of an insertion tuning-fork probe, with a 0.2 second response.
130+
Coal Washery Projects
Completed EPC projects worldwide, including Asia’s largest coking coal washery at 30 MTPA.
EPC
Full Circuit Supply
Supplied as part of a complete instrumentation and automation offering across the coal preparation flowsheet.
IN
India-Based Support
Manufactured at Hefei John Finlay Mining Equipment Co., Ltd. and supported locally in India for installation, commissioning, spares and service.
Differential Pressure Concentration Meter | Frequently Asked Questions
Common questions from coal washery process engineers choosing a concentration instrument for slurry.
Two flanges sit a fixed distance apart on a vertical section of line. The pressure difference between them rises with the density of the slurry, and the transmitter converts that difference to a concentration reading. Nothing is inserted into the flow.
Choose it when abrasion, installed cost or a range above 2 g/cm³ decides the selection. The tuning-fork probe is the higher-precision instrument at ±0.001 g/cm³, so choose that when the extra precision matters. See our Tuning-Fork Concentration Meter.
0 to 4 g/cm³, with 0.1% linearity and a 0.2 second response.
They use the same twin-flange measuring principle and share the same range, response and signal specification. The Differential Pressure Density Meter page describes construction and display options in more detail.
4–20 mA two-wire with HART, loop powered from 12–45 V DC.
A working velocity of 1.3 to 3 m/s through the measuring section.
Measuring concentration in a stream that wears out probes?
Our engineers can help you choose between insertion and differential pressure concentration measurement for each point in your circuit.
Talk to an ExpertRelated Equipment
Instrumentation Hub
All packaged instrumentation systems, grouped by process area.
Instrumentation Hub
All packaged instrumentation systems, grouped by process area.
Thickener Instrumentation System (S2)
This meter is one of the instrument options in the full thickener system.
Differential Pressure Density Meter
The engineered alternative has a wider 0–4 g/cm³ range, no insertion element, lower installed cost.