MACE Flow Training Course

Transcription

1 MACE Flow Training Course ABOUT MACE MACE is a family company founded in With a core team of research and development engineers MACE continue to design and manufacture electronic monitoring instrumentation including ultrasonic flow meters, data loggers and controllers for the agricultural, industrial and environmental markets. The current Series 3 meter (or XCi Device) with its plug-in card design enables the user to connect single or multiple sensors, and third party sensors such as soil moisture, weather stations, water quality and even pump engine monitoring quickly and easily. This offers the customer a highly flexible, cost effective water monitoring solution. FLOW FUNDAMENTALS Q = V x A Page 1 of 21

2 Irrespective of the flow technology used, there are some fundamental basics that apply to every installation. To accurately and repeatedly measure water flow we want a uniform, Laminar flow condition, or as close as possible. For this reason every meter specifies straight pipe run both upstream and downstream of the meter. The rule of thumb is 10 straight diameters upstream and 5 straight diameters downstream. MACE Doppler sensors require 6 upstream and 2 downstream. Insert magmeters require 40 straight pipe diameters upstream and 15 diameters downstream. Page 2 of 21

3 The velocity profile in a pipe should be uniform and can best be displayed with concentric rings, with each ring a little slower as we get closer to the pipe wall. However, due to pipe joins, corrosion, differences in wall thickness, build-up of silt, mineral deposits and vegetation etc. it is rarely that straight forward. Near to a pump or a gate, the turbulence is excessive and it is next to impossible to get reliable or repeatable readings. Obviously as the gate opening changes the velocity profile and turbulence changes. The same with a variable speed pump, and on the ramp up or ramp down of a fixed speed pump. For this reason we generally stipulate a minimum of 20 diameters between the gate or pump and the water meter. The MACE Doppler ultrasonic velocity sensors transmit an ultrasonic (sound) wave into the flow. This sound wave is reflected by acoustically reflective particles (e.g. air bubbles, suspended solids) and the instrument detects the reflected frequencies. The difference between the transmitted frequency and the received frequencies is directly proportional to the velocity of the stream flow. Page 3 of 21

4 In full or partially full pipes, the velocity of the stream flow varies markedly across the crosssection of the pipe. Typically, velocity is zero along the wall of the pipe and increases to a maximum at or about the centre of the pipe. MACE Doppler ultrasonic velocity sensors receive reflected frequencies from particles moving at these different velocities. The greater the area of flow moving at a particular velocity, the greater the number of reflections with the respective frequency shift. The average velocity of the stream is therefore calculated by averaging those frequency reflections received across the whole stream profile. Area Velocity sensors are typically used for all environmental, stream, channel and sewer flows. They are suitable for both Non-Full and Full flowing channels. The sensor directly measures the fluid Velocity AND the fluid Depth. Knowing the channel shape and size, we have the wetted area and using the Q = V x A formula we know the flow. The Area Velocity sensor is typically mounted at the bottom of a channel or pipe, with the sensor generally facing upstream. This enables the sensor to measure the Velocity in a section of uniform flow, upstream of any turbulence that may be created by the sensor. The Depth is measured using a built-in ceramic pressure transducer, that is fairly impact resistant, and unlike diaphragm type transducers, is not subject to drift and constant recalibration. MACE have a range of adjustable poly ZX SnapStraps and poly mounting plates for positioning and fixing the sensor in place. Page 4 of 21

5 Insert transducers are used in full pipes where the use of straps is restricted or impractical. They can be installed by the hot tap method which means a ball valve is attached to the pipe and the insertion transducer can be introduced to, and removed from, the flow through the ball valve without stopping the flow. (See figure 5.9). Insert transducers usually require full pipe. Strap mounted transducers are used where the body of the pipe is easily accessed. The transducers are strapped onto the outer wall of the pipes. Can be used with full or partially full pipes. Flow does not need to be stopped to install these transducers. Straps can be made of a variety of materials including plastic or stainless steel. This type of meter is not suitable for use on pipes of non-continuous materials such as reinforced concrete. There are a multitude of Flow measurement technologies available, each with their own pro s and con s. For Liquid flow monitoring the main options are: Doppler Magnetic Transit Time Non-Contact Radar or Laser Clamp-on Ultrasonic Mechanical Weirs & Flumes Weirs and Flumes are a structural device installed in a stream, that provide a unique velocity coefficient. The flow is channelled through this structure and by measuring the level of the fluid passing through, it is a simple equation to determine flow, The theory behind these devices dates back to Roman times, so it is fairly well proven and understood. Whilst simple in theory, the accuracy is fairly rough in practice as the results are dependent upon the precision of the manufacture of the weir or flume, plus the errors of installation, coupled with the accuracy of the level measuring device. In reality, the accuracy is around the +/- 15% mark. Page 5 of 21

6 Mechanical meters have obvious limitations, such as very easy to tamper with, high maintenance, and poor accuracy due to wear. Clamp-on Ultrasonic meters are great in theory, as they simply clamp around an existing pipe with no flanges or inserts into the fluid being measured. On new, clean pipes of a single material e.g. poly pipes they work fairly well so long as the fluid makeup is constant, and the setup and alignment is correctly carried out. However, on older pipes, the wall thickness will not be constant, there is usually a build-up of ferric or carbonate material inside the pipe, there could be reinforcing inside the pipe or it could be lined with another material. Any of these issues will affect the ultrasonic signal as it passes through the pipe wall (or walls) through the fluid and again back through the pipe to the receiving transducer. Page 6 of 21

7 Non-Contact Radar and Laser flow measurement systems are similarly great in theory. The devices sit under the manhole cover and send a radar or laser beam down to the surface of the flow stream. However they only measure the surface flow and cannot penetrate into the stream. In sewers where there are lots of solids, fats, grease and suspended solids, the surface flow does not equal the average stream flow. Also both systems cannot handle submerged conditions and are usually offered with an additional Area Velocity sensor. Transit Time meters give fairly good results provided they offer multiple cross path readings, and the beams are properly aligned. The down side is that the path alignment is critical and requires a lot of time to correctly setup. Also the pipe or channel must remain full with a consistent velocity profile. Entrained gases and/or suspended sediment affect the acoustic signal strength and Too much aeration or turbulence can destroy the signal. Transit Time meters cannot handle changing velocity profiles. Page 7 of 21

8 Magflow meters also give fairly good results, but the installation cost is often prohibitive. Different size meters are required for each pipe size. The pipe must be cut; flanges fitted to the existing pipe and the meter bolted into place. Magflow meters are a huge chunk of metal a 300mm mag weighs around 70Kg which means multiple people to install the meter along with a sling or a crane. If the pipe is above ground, the meter must be supported. If the pipe is buried, the ground will need to be excavated. Doppler sensors provide very accurate and repeatable results along with enormous cost benefits. They measure the true average Velocity in a channel or pipe and are suitable for channels up to 3 metre diameter. MACE sensors are suitable for all pipes and channels from 150mm to 2500mm diameter, and if there are 2, 3, or 4 river pumps side by side, or multiple inlets into a sewer pipe, up to 4 sensors can be connected to the one meter. MACE Doppler sensors accurately measure even with changing velocity profiles. Pulse Doppler sensors send multiple Velocity beams into or across a channel. They are ideal for very large channels, rivers and even harbour applications. However in smaller channels and pipes, the multiple beams often miss the velocity profile giving false and erroneous flow data. Page 8 of 21

9 SITE SELECTION Physical access to site Security of site & Equipment Pipe / Culvert / natural channel Full or non-full pipe flow Gravity or Pumped Flow Surface or Ground water Flow Range Other equipment Power supply Telemetry Doppler ultrasonic flow measurement is generally unsuitable for use in: Very Clean water such as potable water or ground water High pressure applications Very small pipes and channels The FloPro is our logging flowmeter. It features: Weatherproof & Lockable enclosure Can be mounted on a pole, a wall or hang from a ladder in a manhole Internal rechargeable 12 VDC battery Can be AC powered or solar panel powered at permanent sites LCD display and front panel buttons to scroll through totals Large internal data logging function Modular and flexible design with plug-in boards Can have multiple flow sensors connected Accepts inputs from other sensors Range of output options 3G telemetry option Very simple setup and configuration Page 9 of 21

10 The HVFlo is an IP68 submersible version of the FloPro with an external IP68 connector for an Area Velocity sensor with mating IP68 connector. It is purpose built for below ground sewer applications. It has one (1) only Doppler card for one (1) only sensor. The internal 12 VDC rechargeable battery will adequately power the system for 3 to 4 months depending upon logging intervals and any outputs or telemetry. The HydroMace is our economical, NON-FLOW METER data logger. It features everything the FloPro does except that it does NOT support the flow sensors. Page 10 of 21

11 Applications Sewer Inflow & Infiltration studies Capacity Monitoring Trade Waste Proving / Testing of new subdivisions Sewer Pump Stations Page 11 of 21

12 Sewerage Treatment Plants Mace Flow Training by Arthur Brien Generally older or smaller rural plants with concrete channels. Page 12 of 21

13 StormWater Page 13 of 21

14 Catchments Page 14 of 21

15 Mining Page 15 of 21

16 Environmental Flows Baseline Studies Environmental Impacts Water Resources Environmental Protection Sediment & Runoff Studies Nutrient Monitoring Water Quality Assessment Page 16 of 21

17 FLOPRO Packages Mace Flow Training by Arthur Brien Water Sampler + FLOPRO In-Situ Troll 600 water quality + FLOPRO Weather Station + FLOPRO Complete monitoring Package MACE FloPro flow meter with Area Velocity Sensor Automatic water sampler In-Situ Troll 600 with Turbidity & Conductivity Weather Station Telemetry with SMS / Alarms HYDROMACE PACKAGES In-Situ Troll 600 water quality + HydroMace In-Situ LEVEL Troll 500 water Level + HydroMace Weather Station + HydroMace Complete monitoring Package MACE HydroMace Data Logger Automatic water sampler In-Situ Troll 600 with Turbidity & Conductivity Weather Station Telemetry with SMS / Alarms Page 17 of 21

18 OPPOSITION HACH o Sold through Pacific Data in Qld, they have Area Velocity and a Radar Flow system. The Radar looks good to sewer operations staff, because there is no need to enter the manhole and worry about confined space entry etc. However, the radar does NOT penetrate into the flow stream and measures the surface flows only. All sewer flows have solids and the heavier the solids, these tend to travel along the bottom of the channel which makes the flow slower as you look deeper into the stream. ISCO o Offer both an Area Velocity sensor + a Laser Flow device which is expensive and like the Radar sensors only measures the water surface. They try and push a system using BOTH the Laser and the Area Velocity!! ADS o Use an Area Velocity sensor for Sewer applications ONLY. ADS offer the complete installation + monitoring + Reporting package. They will sell their flow meters if pushed! StarFlow o SDI-12 Area Velocity sensor prone to water ingress. Uses Unidata loggers and telemetry. Sontek o The IQ series is Sontek s attempt to measure in small channels, creeks and pipes with a pulse Doppler sensor. However the sensor is very big, uses an ultrasonic depth sensor which means it must be mounted at the 6.00 o clock position and can be covered in silt and debris, and the velocity beams miss the majority of the stream. Page 18 of 21

19 Customers Water Authorities o Sewer Operations o Sewerage Treatment Plants o Trade Waste o Stormwater officers o Catchment Management Councils o Stormwater o Wastewater Government Departments o EPA o Water Resources Universities o Environmental Schools o Geography o Water resources o Agricultural Studies Industry o Trade Waste o Stormwater o Any site Discharge Environmental Consultants Engineering Consultants Forestry o Gov. Forestry Departments o Logging Contractors o EPA Mine sites o Underground o Open Pit Page 19 of 21

20 PART NUMBERS for MACE FLOPRO Description Item Notes FloPro Logging Flow meter Doppler Card One (1) card required per sensor Area / Velocity Sensor with 10m Cable 20 and 30m cable sensor options available Sensor Mounting Plate - Poly For pipes use ZX SnapStraps Solar Panel (12V/5W) VAC mains Power Pack Mounting Kit - Device & Solar Panel (5W/10W) USB External Comms Lead SDI-12 Card connects SDI-12 devices to FloPro I/O Card Analogue + Digital Inputs & Outputs x 4 to 20mA Inputs; 2 x voltage inputs or 0-30VDC; 2 x Frequency inputs; 2 x counter inputs; 2 x 4 to 20mA outputs; 2 x Digital / Pulse outputs WebComm Card - 3G Telemetry Includes antenna - requires SIM Card and suitable Data Plan WebComm - SIM Card Only WebComm - Data Plan - 10MB/Month, paid yearly in advance Mb and 50Mb plans available Page 20 of 21

21 PART NUMBERS for MACE HYDROMACE Description Item Notes HydroMace Data Logger Does NOT support any MACE Flow Velocity sensors Sensor Mounting Plate - Poly For pipes use ZX SnapStraps Solar Panel (12V/5W) VAC mains power pack Mounting Kit - Device & Solar Panel (5W/10W) USB External Comms Lead SDI-12 Card connects SDI-12 devices to FloPro I/O Card Analogue + Digital Inputs & Outputs x 4 to 20mA Inputs; 2 x voltage inputs or 0-30VDC; 2 x Frequency inputs; 2 x counter inputs; 2 x 4 to 20mA outputs; 2 x Digital / Pulse outputs WebComm Card - 3G Telemetry Includes antenna - requires SIM Card and suitable Data Plan WebComm - SIM Card Only WebComm - Data Plan - 10MB/Month, paid yearly in advance Mb and 50Mb plans available Page 21 of 21