Clamp-On Doppler Ultrasonic Flowmeter QWUS-DP1000 DN25-DN2000 For Slurry Sludge Tailings
Product Details
| Measurement Principle: | Doppler Frequency Shift With Spectral Peak Tracking | Pipe Size Range: | DN25-DN2000 (OD 32-2000 Mm) |
|---|---|---|---|
| Minimum Solids Content: | 100 Mg/l Suspended Solids Or 2% Volumetric Air | Accuracy: | +/-2% Of Reading After Site Calibration |
| Velocity Range: | 0.3-12 M/s Bidirectional | Fluid Temperature: | -20 To +80 C Standard, 150 C Optional |
| Compatible Pipe Materials: | Steel, Stainless, Ductile Iron, PVC, HDPE, Cement-mortar And Rubber Lined, GRP | Transducer Protection: | IP68 Potted, Stainless Clamp Bands |
| Outputs: | 4-20mA, Pulse, Relay Alarm, RS485 Modbus RTU | Power Supply: | 24 VDC, 220 VAC Or Battery Pack |
| Highlight |
Clamp-On Doppler Ultrasonic Flowmeter,High Suspended Solids Slurry Measurement,Non-Intrusive External Pipe Mounting |
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Product Description
The failure is rarely a manufacturing defect. It is a mismatch. A transit-time meter needs a clear liquid path for sound to cross, and the moment that path is filled with 3 % sand, pulp fibre or digested sludge, the signal attenuates and the reading collapses to zero or drifts to a nonsense figure. Magnetic meters cope with the solids but need a conductive liquid, a full bore, and a spool cut into the line, which is exactly what a running tailings main and an existing HDPE discharge cannot offer.
What the plant actually needs is an instrument that treats the particles as the measurement mechanism rather than as an obstacle. Three conditions define that duty:
- The pipe is already built. Large-diameter welded, concrete-lined, cement-mortar or HDPE pipe cannot take a spool without a crane, a shutdown and a week of welding.
- The fluid is opaque and abrasive. Sand, ore pulp, lime slurry and paper stock wear out anything that sits in the flow path, so insertion probes become a quarterly maintenance item.
- The measurement is commercial or regulatory. Tailings balance, effluent load charges and dredging volumes are reported figures; an estimated flow rate is no longer accepted by auditors or regulators.
| Service condition | What the site normally sees | Commercial consequence | How the Doppler meter responds |
|---|---|---|---|
| High-solids slurry 2–15 % by weight, sand and ore fines, DN300–DN900 steel line |
Transit-time meter loses signal and reads zero or drops out; magnetic liner wears through in 12–18 months; insertion probe erodes and blocks | Tailings mass balance is estimated rather than measured; liner replacement means an unplanned outage on the whole beneficiation circuit | Uses the suspended particles as acoustic reflectors; clamped entirely outside the pipe, so abrasive wear cannot touch the sensor |
| Sludge and effluent 1–4 % dry solids, rag, grit and grease, buried or ductile iron main |
Mechanical and vortex meters plug; the pipe is often buried, so no spool option exists; existing meters read low as solids build on the internals | Effluent load charges are calculated on suspect data; blocked meters cause pumping overflows and consent breaches | No obstruction and no wetted parts, so grease and rag pass through; the external transducer is serviceable without breaking containment |
A Doppler meter sends a continuous ultrasonic beam into the pipe at an angle and listens for what comes back. Particles moving with the flow reflect that beam at a slightly different frequency, and the size of that shift is directly proportional to how fast the reflectors are moving. Because every suspended solid and every entrained air bubble acts as a reflector, the meter does not need a clear liquid — it needs something to bounce off, and dirty service always supplies that.
- Reflector-based, not path-based. A transit-time meter measures the whole liquid column; a Doppler meter measures the moving reflectors and applies a profile correction, which is why it works precisely where the clear-liquid instrument gives up.
- Minimum solids threshold matters. Reliable operation starts around 100 mg/l of suspended solids or 2 % volumetric air. Below that, a hybrid instrument or a transit-time unit is the correct choice, and we will tell you so before you order.
- Frequency tracking rejects noise. The DP1000 filters pump and valve noise by tracking the spectral peak of the returning signal, so a slurry line with a running centrifugal pump does not produce a wandering reading.
- Velocity, then area, then volume. The converter knows the pipe inside diameter from the site survey, converts average velocity into volumetric flow, and totals it with sign so backwash and reverse pumping are counted separately.
The structural argument for clamp-on hardware is not accuracy — it is that the meter never becomes part of the process. Nothing is wetted, nothing obstructs, and nothing has to be isolated for service. On a large slurry main, that difference shows up as a fraction of the cost of the alternative.
This is where most clamp-on projects succeed or fail, and it is decided before the order rather than at commissioning. The four variables that must be captured on the survey are pipe outside diameter, wall thickness, pipe material and the expected solids concentration. Velocity should then be checked: below 0.3 m/s the reflector signal weakens and accuracy degrades, while above 8 m/s abrasion and aeration both increase, so a line running at design 1.5–3 m/s is the comfortable band.
| Industry | Mining and mineral processing |
| Site and region | Copper concentrator, Atacama Desert, Chile |
| Application point | Tailings transport line from thickener underflow to the disposal dam, two parallel trains |
| Fluid and temperature | Tailings slurry, 8–12 % solids by weight, 18–28 °C |
| Line size and flow range | DN500 rubber-lined carbon steel, 320–780 m³/h per train |
| Measurement challenge | Magnetic meter liners had been replaced twice in three years and the pipeline runs continuously, so no shutdown window was available for a spool change |
| Configuration supplied | QWUS-DP1000 clamp-on set, DN500, high-temperature transducers, 30 m cable, solar-tolerant 24 VDC converter in IP66 enclosure |
| Accuracy achieved | ±2 % of reading, verified against the plant's ultrasonic level-based volumetric check |
| Commissioning time | Five hours per train, no production interruption, no hot work permit required |
| Verified result | Tonnes-to-dam reporting moved from estimate to continuous measurement; two pump-speed setpoint corrections reduced specific power consumption by 6 % |
| Industry | Palm oil milling / agro-industrial effluent |
| Site and region | Palm oil mill, Johor, Malaysia |
| Application point | Final discharge main from the anaerobic pond series to the receiving watercourse |
| Fluid and temperature | Palm oil mill effluent (POME), 2–4 % dry solids, 35–45 °C |
| Line size and flow range | DN250 ductile iron with cement-mortar lining, 60–260 m³/h |
| Measurement challenge | Regulatory discharge reporting required continuous flow; the existing flume had silted and the pond level was the only reference the mill could produce |
| Configuration supplied | QWUS-DP1000 clamp-on, DN250, cement-lined pipe compensation, 4–20 mA plus pulse to the SCADA logger |
| Accuracy achieved | ±2 % of reading after calibration against the mill's volumetric tank test |
| Commissioning time | Three hours, mounted on the existing pipe bridge with no civil work |
| Verified result | Monthly discharge volume is now logged automatically and accepted by the local environment authority; one grease-related dropout was cleared with a couplant change |
| Pipe size range | DN25 – DN2000 (outside diameter 32 – 2000 mm) |
| Measurement principle | Doppler frequency shift, continuous wave, with spectral peak tracking |
| Minimum solids content | 100 mg/l suspended solids, or 2 % volumetric entrained air |
| Accuracy and repeatability | ±2 % of reading after site calibration; repeatability ±0.5 % |
| Velocity range | 0.3 – 12 m/s bidirectional; best accuracy band 0.8 – 6 m/s |
| Fluid temperature | −20 °C to +80 °C standard; to +150 °C with high-temperature transducer set |
| Compatible pipe materials | Steel, stainless, ductile iron, cast iron, PVC, HDPE, cement-mortar lined, rubber lined, GRP |
| Transducer protection | IP68 potted, stainless clamp bands, encapsulated cable gland |
| Outputs | 4–20 mA, pulse, relay alarm, RS485 Modbus RTU, data logger option with SD card |
| Power and display | 24 VDC, 220 VAC or rechargeable battery pack; LCD with signal strength and SNR diagnostics |
The deciding variable is what is inside the liquid. If the stream carries more than roughly 100 mg/l of suspended solids or about 2 % entrained air — slurry, sludge, pulp, dredging spoil, raw sewage — a Doppler meter is the sound engineering choice and its reflectors guarantee a returning signal. Below that threshold the reflectors are too few and a transit-time instrument performs better, because it needs a clear acoustic path rather than particles. Where the process swings between both states, a hybrid converter that switches between the two principles covers the whole range. Give us the fluid description, typical solids concentration and pipe material, and we will name the correct principle in writing before you commit to a purchase order.
Yes, with the right preparation. HDPE carries sound well but attenuates it, so the survey must confirm wall thickness and the transducer spacing must be calculated from that figure rather than defaulted. Cement-mortar and rubber-lined pipe are two-layer walls, and the converter needs the lining thickness entered separately so the acoustic path is computed through both materials. Very rough or highly porous concrete scatters the beam and may need a smoother mounting pad or a different frequency transducer. The practical test is a survey: sound velocity, pipe geometry and a signal sample at the proposed mounting point. We ask for one or two photographs of the pipe alongside the measurement data, because that single step removes most clamp-on installation surprises.
For slurry, sludge and effluent duty it is normally the realistic figure and is well inside most regulatory reporting tolerances, which typically sit at ±5 % or ±10 % for discharge volume. Inline meters reach ±0.5 % but require a spool in an abrasive, often unavailable section of pipe, and their liners wear, which means the installed accuracy degrades over time in a way a clamp-on transducer never does. The comparison to make is installed accuracy over five years, not catalogue accuracy on day one. Where a fiscal figure is involved we recommend a periodic site calibration against a volumetric or level-based reference and a documented correction factor in the controller.
Installation needs a clean bare-metal patch at the mounting point, couplant, two transducers on clamp bands at the calculated spacing, and cable to the converter. No hot work, no shutdown and no permit-to-drain. The survey figures — outside diameter, wall thickness, material, solids load — determine the spacing before anyone climbs the pipe. Ongoing maintenance is limited to refreshing couplant every twelve to twenty-four months, checking signal strength in the diagnostics menu, and re-tensioning straps if the pipe expands thermally. Because the meter reports signal-to-noise ratio continuously, degraded coupling appears as a falling number on the display long before the totaliser goes flat, which turns a surprise outage into a planned ten-minute task.
Tell us the pipe outside diameter, wall thickness, material and solids load
We will confirm the principle, calculate transducer spacing and send a clamp-on quotation with survey guidance.
Doppler measurement lives on the particles in the stream. Below about 100 mg/l of suspended solids there is nothing to reflect the beam and a Doppler reading becomes unreliable, so the honest answer for clean water is a different principle. Where the fluid is clean enough for a clear acoustic path, a transit-time spool piece ultrasonic flowmeter delivers 0.5 % of reading instead of 2 % and needs no reflectors at all. Where solids exceed that threshold, or where the line is welded, buried or lined and cannot be cut, this clamp-on Doppler ultrasonic flowmeter for slurry is the correct and often the only practical choice.
Related flow measurement options
- Transit-time spool piece ultrasonic flowmeter with 0.5% accuracy
- Ultrasonic open channel flowmeter for weir and flume discharge
- Portable Doppler ultrasonic flowmeter for survey work
- Hybrid ultrasonic flowmeter with automatic mode switching
- Cross correlation clamp-on ultrasonic flowmeter
- Industrial non-invasive ultrasonic flowmeter for clean liquids
Product Highlights
Clamp-on Doppler ultrasonic flowmeter for slurry, sludge, tailings and effluent with suspended solids above 100 mg/l. Mounts outside DN25-DN2000 steel, HDPE, ductile iron or lined pipe with no cutting and no shutdown, delivering 2% of reading with continuous signal diagnostics and IP68 potted transducers.
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