Thermal energy is mainly distributed by fluid media to the points of consumption. The energy manager is not only interested in the total energy required, but also in the consumption of individual heat consumers and the flow of energy in the plant in general. The EESIFLO™ EF portable ultrasonic flowmeter with integrated heat quantity calculator has been developed to compliment permanently installed devices.
The flowmeter EESIFLO™ EF is especially appropriate for measurements in large variable supply networks, e.g. to register the heat distribution in a large complex of buildings or to review the heat balances in a process engineering facility. This device is particularly useful in situations where temporary, non-intrusive inspections of heat consumption and distribution need to be made quickly. The advantages of this portable instrument are its flexibility, enabling it to be used in a wide range of applications, and the low installation and running costs.
Principles of Heat Quantity Measurement
The differential method is the basis for the precise measurement of heat quantity. This method considers the enthalpy that enters and leaves a system. The difference between the two values gives the heat consumption. Since the enthalpy difference cannot be measured directly, the value is calculated from the volumetric flow, the inflow and outflow temperatures and the heat coefficient for the medium.
Assuming constant conditions, the heat flow can be calculated with the following formula:
The heat coefficient ki is defined by the specific enthalpy and the density of the heat carrying fluid. These two quantities depend on the temperature and pressure of the medium. In incompressible media however, the variation with pressure is insignificant and can be ignored. Consequently, flowmeters to measure the quantity of heat consist of devices for measuring volumetric flow and temperature. A microprocessor is necessary to compute the quantity of heat flow.

The newly developed flowmeter EESIFLO™ EF incorporates all these features and in contrast to conventional flow meters, it allows the user to measure heat flow and distribution from the outside of pipes without the necessity of disrupting the process in the plant. This is achieved by using a clamp-on ultrasonic flow meter together with two surface temperature sensors.
Temperature Measurement
The EESIFLO™ EF ultrasonic flowmeter features two input channels to connect resistance temperature sensors Pt100 in four wire circuit. This sensor type has been chosen because of its popularity in industrial applications and ready availability in a variety of versions. Two surface sensors are supplied with the unit to measure the temperature of the inflow and outflow. The user may, however, connect other types of sensors of a compatible type according to specific application requirements. This is particularly advantageous where temperature sensors are already installed in the pipe. In such cases, an input correction for each sensor is required to obtain a linear resistance temperature curve. These correction values can be stored in the non-volatile memory of the flowmeter and are therefore always available. When using the supplied sensors, the ability to correct may serve to compensate for the temperature gradient of the pipe.

The so-called energy temperature, which represents the temperature for the transportation of energy, is of special interest for measuring heat flow. According to Adunka[1], this temperature corresponds to the temperature in the middle of the pipe in case of turbulent flow. Under laminar flow conditions, it is more difficult to determine this temperature and the energy temperature is calculated as the mean of the temperatures of the wall and the centre of the pipe.

When using surface temperature sensors, it is the pipe wall temperature which is measured not the energy temperature. In practice however, the temperature difference is important in the calculation of heat flow not the absolute temperatures. The absolute temperatures are only required to determine the heat coefficients. Studies at the University of Rostock[2] showed that the difference between the surface temperatures approximates to the difference between the energy temperatures. The pre-condition is, that the pipe has sufficient insulation to limit the heat loss through the pipe walls. Both the inflow and outflow temperatures should always be measured with the same type of sensor.

These systems are ideal for energy efficiency optimization in industrial sectors and buildings. EESIFLO™ offers a highly accurate, low cost and robust Energy Management Solution.

The BTU (or Energy) Flow measurement systems can be readily configured for almost any size of pipe and are completely non-intrusive, since all the sensors are installed on the outside of the pipes being measured.

Advantages over traditional type flowmeters are seen by the accuracy ,sensitivity and longevity of the meters since they are able to measure both high and low flow rates with the same accuracy, due to the fact that the transit time technology is not dependant on moving parts and frictional wear and tear.
Using two additional clamp on temperature sensors (PT100) or customer temperature inputs , we are ready to establish the quantity of heat by a method known as the Differential Measurement Priniciple.

Our systems can calculate the heat flow by taking into account the temperature difference between the inlet and outlet ,the flow at the outlet of the system in conjunction with some other relevant properties of the medium (density and specific heat capacity).


The co-efficents, which the instrument needs to know, in order to measure the heat flow of various media are pre programmed into the flowmeter.In cases where the temperatures of inflow and/or outflow are known , or are constant during the whole measuring period, you may enter these fixed temperatures manually into the instrument.

In these instances, the temperature sensors need not be connected.

the following information is available:
• Volume flow
• Heat flow
• Flow velocity
• Total flow volume or heat quantity (if total counting activated)
• Temperature T1 (inlet temperature)
• Temperature T2 (outlet temperature)
• Temperature difference T1-T2

EESIFLO™ heat meters give the option of displaying two of these measured values (one in each line of the display) and of configuring the display readings according to your requirements.
The flow measurement of the heat carrying fluid is based on the ultrasonic transit time technique. This method utilises the transmission of sound waves in the fluid. Sound pulses are sent alternatively downstream and upstream through the liquid. The ultrasonic signal has different transit times for the two directions comparable to a swimmer in a river who swims faster downstream than upstream. The resolution of the signal time difference is 0.1 ns with a transit time of the sound from 16 µs and 1.6 ms. If these values together with details of the profile of the pipe section are known, the volumetric flow rate can be calculated.


The transducers for coupling the sound signals through the pipe clamp from the outside onto the pipe ensuring that there is no disturbance to the flow nor any expensive installation costs. This method of flow measurement implies that the pipe diameter and tolerances are part of the measuring conditions. Often the inner diameter and wall thickness of the pipe are unknown although this information is required to calculate the volumetric flow from the flow velocity. The input of incorrect pipe parameters will result in measurement errors. For this reason, an device for measuring the wall thickness of the pipe was incorporated into the flowmeter.

Measurement of flow from the outside of a pipe with the EESIFLO™ using magnetic clamps
Heat Quantity Calculation
The microprocessor within the flowmeter computes the heat flow from the measured inflow and outflow temperatures and the volumetric flow rate. The specific enthalpy and the density of the fluid can be internally calculated depending on the measured temperature.

As various liquids may be used as heat carriers, the portable ultrasonic flowmeter EESIFLO™ can be adapted for specific tasks using an in-built database. The database contains information on pipe materials and fluids frequently used and requiring measurement. As well as information on sound velocity and viscosity, the database also stores the coefficients necessary for calculating the heat quantity.

The database can be specifically adapted and extended by the manufacturer to meet specific customer requirements. It is also possible for the customer to enter set-up values and make changes to the stored data. Special software has been designed for use with a Personal Computer to generate the coefficients used for calculating the heat flow and to transfer them via a serial interface to the flowmeter where they are stored in non-volatile memory. These data are available even when the instrument has been repeatedly switched off, the batteries have been changed or a cold start has been performed.
Applications
The EESIFLO™ EF can measure volume flow, flow velocity, mass flow or heat quantity of liquids within a temperature range from -30 °C up to 130 °C. With specially designed high temperature transducers, the temperature range can be extended up to 250 °C, and for short periods up to 300 °C. The ultrasonic sensors are small, lightweight and very robust. Pipe diameters may range from 10 up to 3,000 millimetres.

The instrument can always be used where the pipewall and the liquid to be measured are sonically conductive. This is true for pipewalls consisting of homogeneous material, such as steel, synthetic material, glass or copper, and for liquids which carry not an excessive amount of solid particles or gas bubbles. There is no dependency on electrical parameters of the fluid such as conductivity or dielectric constant.

To assist the user in obtaining a complete profile of the flow conditions in the plant, the EESIFLO™ EF features an in-built data logger which can record up to 150,000 measuring values and up to 15 different sets of site parameters. The data can either be transferred to a Personal Computer (PC) or to a printer as numerical values or in graphic format.

The device allows the operator dialogue in different languages and guides the user through the menus for parameter set-up, measurement or data storage.

The instrument can feature an integrated measuring point multiplexer which allows for the connection of up to four independent flow sensor sets with one transmitter. EESIFLO™ automatically recognises the connected sensors through Intelligent Sensor Identification. This means that all calibration parameters are stored in the sensor and automatically transferred to the instrument at the time when the sensors are connected.

EESIFLO™ can also be fitted with various process inputs and outputs. The instrument can be equipped with a maximum of four temperature inputs whereby the temperatures can be freely assigned to the available flow channels. This makes it possible to configure, for example, a 3-channel heat flow measuring system with a common inlet temperature and three independent outlet temperatures

Have you ever seen fire ants excitedly swarming over a dropped sandwich? At first glance, you might believe that you were looking at a bunch of ants running around with no organization or direction to their movements. Take another look a few minutes later and you will see that the sandwich is noticeably smaller. Each of those ants has a purpose and an objective. They are working as a team to disassemble and transport the sandwich to a specific place. A unit shutdown has a similar appearance. First glance shows group of workers swarming over a piece of equipment with no organization or direction. But, like those ants, each worker knows what he is expected to do. Many hours of planning and preparation preceded the start of maintenance. By the time the workers swarm the unit, the job has been planned and organized down to the number of man-hours it will take to finish the task.
Although Coriolis mass flow meters are not always included in the planning of a shut down, this may be a good time to perform some preventative maintenance on the critical flow meters. You may have heard that Coriolis meters are so dependable that they should work forever with no attention. In reality, as long as man makes Coriolis meters using man-designed machines there will be a few that perform a little outside factory specifications. Shut downs are an opportunity to check and calibrate your critical flow meters. The best way to calibrate a Coriolis meter is to remove the meter, clean it and send it to a facility that has a gravimetric calibration flow laboratory. In place "proving" may be acceptable for applications that do not require great accuracy, but for a critical measurement, there is no substitute for direct mass-to-mass calibration. Master meter comparators and "inferred-mass" volumetric provers cannot approach the accuracy of a gravimetric facility. Mass Flow Technology in Baytown, Texas has a gravimetric flow calibration laboratory with 0.052% system uncertainty. Some factories have equivalent facilities for calibrating production meters and may provide certified calibration services for customer meters.
If your process fluid is likely to coat or plug, check the meter for internal deposits. Deposits on the inner flow tube walls will degrade meter accuracy. Decontaminate the flow element and use a bore scope to check for deposits inside the flow tubes. If deposits are found, a good hydro-cleaning company can clean the flow tubes. Mass Flow Technology has had considerable success is cleaning Coriolis flow meters that are plugged with set-up concrete.
You don't have to wait for a shut down to keep up with basic and periodic maintenance. Several valuable checks can be made on Coriolis meters during normal operating times. Flow meter zero (the flow meter output during non-flowing conditions) can be checked any time the process flow can be blocked for a few minuets. When process flow is blocked, the flow meter should indicate zero flow. The procedure is simple. Close the upstream and downstream valves and read the flow rate. The best time to check the meter zero is immediately following a batch, not before the batch. The process should be stabilized to operating conditions and entrainment should be purged. Also, make sure any parameters that determine a flow cutoff threshold is set to "0.0" before checking the meter zero. After checking the meter zero, return the original cutoff threshold parameter.
Periodic checks can be a valuable indicator for conditions that gradually grow from nothing into a big problem. Most manufacturers have test points that can be measured and compared to previous checks made under similar conditions. Make a chart for recording these test points and compare the most recent checks to past checks. This may show a trend.

What is the Coriolis Principle?

To some of us the Coriolis Principle is an exact science, but to most of us it is still a black art. Well, imagine a fluid flowing (at velocity V) in a rotating elastic tube as shown below. The fluid will deflect the tube.

If the mass M is guided by Wall A (i.e. the tube), a Coriolis Force will be exerted on the wall as shown below.
CORIOLIS FORCE : Fc = -2 M V W
Now, consider the interior of the RotaMASS sensor
The tube walls guide the process fluid as it flows through the U-Tube pathway. With no fluid inside the tubes the Driver excites the tubes apart at a nominal 150Hz as shown below.
No Flow: Mass Flow:Coriolis Twist
Parallel Deflection

Now imagine fluid of Mass M flowing through and out of the RotaMASS tubes. As the fluid flows down the first half of the U-Tubes it will tend to deflect the tubes in towards each other. Conversely, when the fluid flows up the second half of the U-Tubes it will tend to deflect the tubes out away from each other. This Coriolis Twist action is shown above.

Now the temperature of these tubes dramatically affects their flexibility. So temperature measurement is very critical as follows.


The Mass flow equation for the RotaMASS can be described as follows.


p =Density
fI(20) = Exciting frequency of the empty tubes at 20°C
fv(20) = Exciting frequency of the filled tubes at 20°C
KD = Density calibration constant
fv(20) = fv / (1+FKT (T - 20 °C)) temperature correction
of the actual frequency
FKT = Temperature correction coefficient, depending
on material and size

Molten Sulphur, Bitumen, Pitch, Paint Resins and Liquid Toffee are all hot fluids just so perfect for a Coriolis mass flowmeter. Their fluid properties change wildly with small variances in temperature. The only problem is most meters on the market are literally cooked by these fluids. Not necessarily immediately, but some time in the process the heating medium gets too hot and you soon have the charred remains of a Coriolis in your hands.

Just when the market was about to give up on Coriolis technology, along comes RotaMASS with RCCS sensors that can continuously handle fluid temperatures up to 230°C. And even if your process fluid is hotter than 230°C then contact your local Yokogawa Australia Sales Engineer. Here's how!

Specific materials are selected for the driver and coil components inside the sensor. The electrical design of these components also is critical to successful operation in such difficult conditions. But this is only half the key to Yokogawa's success.

In measuring these fluids it important to maintain their thermal inertia for many reasons as listed below;
- Loss of heat in the fluid can be expensive to restore
- Fluid properties change dramatically and affect the process performance
- Even slight cooling can cause the fluid to stick to the walls, precipitate or bind together.

So to maintain the fluid's thermal inertia, Yokogawa have designed RotaMASS with external process heating as shown below;

Further to this external process heating, Yokogawa provide as a standard factory option the following enclosure of the RotaMASS sensor;

RotaMASS sensor and process heating is contained in a two-part enclosure. Insulation wool is added to fill the void.
The two halves are then riveted together. The terminal box is extended beyond the exterior of the enclosure to allow for field serviceability.

Now the temperature of these tubes dramatically affects their flexibility. So temperature measurement is very critical as follows;

The critical path is to transport the heat from the protection tube to the measuring tubes via the nitrogen. One tube is sufficient to heat the protection tube from only one side. This is because the protection tube is very well insulated by 80mm stone-wool and the heat conductivity is much greater than the nitrogen.
Heat conductivity:
Stainless steel :16 W/(K*m)
Cement :16 W/(K*m)
Nitrogen :0.0025 W/(K*m)

Hot Applications
Below is an application of this technology on hot Bitumen at a Sydney loading terminal. Note the vertical orientation of both of the RotaMASS sensor.

Note only does the thermal enclosure protect the operators from scalding surfaces, it ensures accurate measurement across the meters. If there is a significant temperature difference from the start and end of the U-Tubes this translates into errors in both the flow and density measurements.

New technological breakthroughs have enabled measurements of oil and water mixtures with some gas bubbles or infrequent gas pockets that have traditionally caused damage to other types of inline mechanically driven flow meters. The inline meter may be subject to sand, grit, stones (up to 0.25" diameter), solids and suspensions that could stop and damage other meters. This damage can be caused by close clearances, rotating seals, and stuffing boxes or sensor fouling , depending on the type of intrusive device implemented in the field. Continued or even brief exposure to these elements require removal of the flow meter from the line in question. In an effort minimize downtime, maintenance costs and overall cost of ownership, several oil enterprises have been implementing new technology dual mode clamp on ultrasonic flow meters in these very applications. High speed processors, advanced filtering software and intelligent sensor design have paved the way for a new generation of flow measuring devices currently implemented in oil fields around the world.

Although more durable designs and more cost-effective inline meters are being produced to work with dirty process fluid or where the risk of overspeeding is a potential problem, there are reasons that have persuaded certain groups of users to lean towards using newer digital based clamp on technology. The main criteria being the total cost of ownership. Although the initial costs of other inline devices are more attractive in the initial stages, there are long term and immediate expenses which have to be accounted for. Some of the problems associated with traditional methods are:

1. Continual re-calibration of flow devices due to mechanical wear and tear
2. Direct Damage to flow elements due to gas pockets , grit or other materials causing calibration deviations or complete failures within days, weeks or months.
3. Cost of installations , re-installations and manpower
4. Remote locations of these devices are a major source of frustration due to the distance involved and the need for continual maintenance and checking

Advantages of a clamp on design are evidenced by

1. Lower cost of ownership (no maintenance required, no moving parts)
2. Non-intrusive designs considerably speed up installation time
3. Re-calibration is not a continual requirement and does not require removal of elements from the line
4. Clamp on Flowmeters are immune to gas pockets , sand and grit since there is no contact with the process media
5. Reynolds compensation factors can be implemented in the software design to improve accuracy on liquids with fixed kinematic viscosities.

The following shows typical flow data gathered on a 10 inch crude oil line in the liquid phase with a fixed kinematic viscosity and density. It is important for the user to input viscosity and density parameters so that the change of state from laminar to turbulent flow can be predicted . The accuracies normally achieved are withing 1% of rate if pipe conditions are acceptable and correct process and pipe data are entered into the flow computer. Like many other types of meters, clamp on flowmeters require fully formed axially symmetric flow profiles, so reasonable lengths of straight pipe are required for more accurate flow measurements. Below is typical data gathered from the crude oil measurement over several hours

In this case, Transit Time methods are being used since Doppler methods cannot measure accurately at low flow rates due to limitations on the dependency of particles or gas bubbles in the line which may not even be present

Transit time meters work on the principal that the time of flight from the downstream transducer to the upstream during flow will always be greater than the upstream to downstream time. This is measured in milliseconds and can be correlated to flow velocities

Successful measurements require the user to input the pipe wall thickness, outer diameter, liquid kinematic viscosity and density if the fluid is an unkown type. This information can normally be obtained from an experienced laboratory or from previous analytical data.

DIFFICULT APPLICATIONS

The following is a typical case study on a difficult application where economics played a major role in technology consideration . We can consider this application as a “worst case” implementation where the meters were operating on their technological limits. Test locations where the flow was always in a liquid state have not presented problems for the technology with steady readings and accurate data measurements and clamp on flowmeters are accepted as an alternative means to accurate flow measurements.

EESIFLO does not claim to measure three phase flow regimes but the data gathered by the devices in these applications have proved useful to oil well planners. Some level of accuracy is achievable depending on pipe and liquid conditions. This application is of interest to users who cannot justify the purchase of full blown inline multiphase flowmeters that claim to accurately measure oil , liquid and gas ratios. In this instance, it was important for the client to obtain non-intrusive information from a well and from subsequent other wells. It was known that the flow maintained a liquid state for the most part but previous inline devices suffered continual damage and another solution was of most importance.

It was the intention of EESiFlo to work cooperatively with X oil company to solve the flow measurement problems experienced at various oil well locations which were predominantly oil based liquids containing mixtures of water for the most with intervals of high aeration and GVF at particular times of the day. Although it was impossible to measure the gas phases, the meters produced results that gave operators important information on the production of their wells which enabled them to plan for further courses of action

Following are observations from data gathered on a 4 inch carbon steel pipe flow applicaton

Above is a graphical representation of the Volumetric Flow (in barrels per hour) recorded during the initial installation at POV location. Note that a cyclic “noise” phenomenon occurred at approximately 3 to 4 hour intervals.

Below is a short section of data displaying numerous accurate flow values between 9.5 and 10.5 barrels per hour. Near the end of this period, note a period of erratic data which continued for ½ hour, until the data signal was eventually lost. This Lost Data period continued for approximately ½ hour when the signal returned. The reason for this (and subsequent) lost data is unknown, and is discussed later.

For the remainder of this data set, data appeared very accurate in three or four hour groups, at the end of which some undefined interference caused flow data to become erratic, and eventually the signal was lost. This loss of signal appears below on repetitive 3 to 4 hour cycles.

Loss of Signal

In addition to recording flow velocity (shown red below) the EESiFlo “Series” product line are capable of recording the signal strength of each data transmission. This signal strength is represented by a black line in the graph below. Note that prior to the loss both flow values and signal strength remain acceptable. As signal strength values dropped considerably, the flow values became erratic. Once signal strength returned to an acceptable level, flow values also became valid.

In addition to flow volume and signal strength, EESiFlo “Series” products are capable of measuring and recording the changing Speed of Sound of the medium, which is represented below by a blue line. Again, when flow data appeared normal, the signal strength and speed of sound all appeared normal. However, when the physical properties of the medium changed, all three signals became erratic until both speed of sound and flow values where finally lost. As soon as the properties returned to normal values, both speed of sound and flow rates returned to normal.

The Problem:
Rotameter RAMC is often used in critical applications where safety is paramount. RAMC has the option of low flow alarm outputs. A low flow contact is set and an alarm is activated if flow drops below the minimum level. But what happens if the float is mechanically blocked? The meter works wrong and the blocked float cannot be seen through the solid S.S. tube !!

Under normal flow conditions the guided float tumbles round its center of gravity. This generates small movements of the pick up magnet. This fluctuation is measured by the Microprocessor. Below are typical fluctuations

The mechanically blocked float does not generate small movements of the pick up magnet. These Zero -fluctuations are measured by the Microprocessor. If these are under a certain level, the alarm current is set. The level is determined during an Autozero adjustment.

The Zero-fluctuations are recorded under no flow condition when the float is at the rest point (Autozero). A level for minimum fluctuations including a safety factor is generated.

Gill Instruments Ltd, the world leader in the design and production of ultrasonic meteorological anemometers, has now successfully applied the same technology to the demanding medical fields of anaesthesia and ventilation monitoring. The Spirocell uses proven ultrasonic techniques to measure gas flow reliably and accurately with no moving parts. Compared with existing technology the Spirocell provides extended functionality, reduced lifetime costs and improved reliability. It can measure from extremely low flow rates up to its maximum with no change in its configuration. Together with its high sample rate this gives the speed of response and accuracy to produce detailed information on very small changes in the gas flow. Unlike other measurement devices the Spirocell retains its accuracy despite the presence of moisture and the rapid changes in temperature and humidity that are found in patient respiration. This robustness of operation also means that the user is not required to perform any calibration on the unit. Along with these benefits the Spirocell is also easy to use. It is simple to install, has output via a serial link and requires no regular maintenance. Safety is a key factor in the design of the Spirocell so the unit has extensive error checking and diagnostic routines to ensure that only reliable data is collected. The ultrasonic sensors can be easily detached from the unit to allow sterilisation. The unit complies with all relevant US FDA recommendations. Gill Instruments Ltd is very experienced in designing and manufacturing products to the highest standards and can provide expert support to allow easy integration into other systems.

PRINCIPLE OF OPERATION
The Spirocell uses ultrasound to measure the velocity of gas travelling through the device. Bursts of ultrasound are transmitted upstream and downstream in the gas flow between the two sensors. The time of flight in both directions is measured and the distance between the sensors is known. Therefore, by using the equation opposite, the flow rate of the gas can be calculated. The tube in which the gas is flowing has a known cross sectional area, so for a given period of time the volume of the gas flow can also be measured. The speed of sound in a gas is dependent on factors such as temperature, pressure, humidity and composition. As can be seen, by using the difference in the times of flight, the equation used to calculate the flow rate becomes independent of the speed of sound. This means the measurement is unaffected by changes in these factors. This makes the Spirocell simple to use and removes the need for any time consuming calibration procedures to correct for environmental changes.

The Spirocell uses extensive self diagnostic routines which ensure a higher data integrity than any other technology. The results from these tests along with the flow data is output on the RS232 serial link. For example, if the unit fails any of its start up tests then no data will be transmitted and an error message will be sent. The Spirocell disassembles easily to allow the appropriate components to be sterilised. The unit is compatible with chemical and steam sterilisation for 15 to 30 min at 121°C.

Introduction

The Auper flow meter was originally design specifically to be used in draft beer. Three years of R&D were necessary to originally design this flow meter which has remained unchanged (and copied) since its release on the market in 1985. Auper was the first company to manufacture such a flow meter in North America. Tens of thousands are in use all over the world in all kinds of draft beer dispensers. It is used to monitor other products too, such as soft drink, juice, coffee, oil, water etc... We use standard Hex nut, washers and draft beer tailpieces to adapt to all plastic beverage tubing. The internal diameter of the tubing may vary from 3/16" (4.7mm) to 1/2" (13 mm). Tailpieces are available in chrome plated brass or stainless steel.

Operation

Liquid flowing into the flow meter (turbine) causes the propeller located inside the flow meter to spin. The internal diameter of the turbine and the design of the passageway allows a liquid to circulate normally, without cavitations or blockage. A flow meter is selected according to its typical flow rate specifications. At equal pressure, a liquid with a low viscosity (beer, water) flows more easily and at a faster rate within the same line than a thick viscose liquid like syrup. We are never concerned with the type of liquid we are measuring but by the speed at which it is dispensed. The Auper flow meter is made of Delrin for its durability, its low friction properties (close to Teflon) and extremely low absorption. It is covered with rubber to protect it from moisture and water. The flow meter does not require any power from the electronics it is connected too. An accidental short-circuit would not damage it. The signal generated by this flow meter is totally independent from the type of product it is measuring; viscosity or dark products would not block the passage of an infra-red beam for instance.

The Auper flow meter model 50-316 has an operating curve which was designed for standard draft beer dispensers. This model operates very well on beer lines with an internal diameter between 3/16" (4.76mm) and 3/8" (9.25mm) with an average flow rate between 1 and 2.5 oz/sec (1.5 and 4 l/min). Some products such as the Guinness beer or carbonated water are often running at slower speed and will require a model with a slower typical flow rate (50-018). Ask you Auper representative for guidance before you order.

Model	Application	Pulse/oz	ml/pulse	Typical flow rate
50-018	Guinness/Soft drink/Soda	30	1	1 Oz/sec	30 ml/sec
50-316	Draft beer/Wine/Soda	15	2	2 Oz/sec	60 ml/sec
50-332	Alcohol/Syrups	45	0.6	<>	<>
50-114	Fast flow applications	7	4.25	4 Oz/sec	120 ml/min

Installation

The flow meters are usually mounted in the storage room above the keg, on top of the wall bracket. It is inserted in the rigid tubing and secured to the wall using a plastic bracket when necessary. If FOB detectors (also called empty keg detectors) are used, the flow meter should be installed after this device. The FOB will prevent the flow meter from ever being in contact with foam or air rushing up the line.Each product line has to have a flow meter. Each flow meter is wired out of the storage room to either one of the Auper electronic controllers. Each flow meter is identified by line number, brand name and destination.

Beer Line Cleaning

The norms for beer line cleaning will vary from one country to another. Most beer line cleaners use a caustic solution (bleach) to clean and disinfect the lines and then rinse using soft water. The turbine should remain connected to the line in order to benefit from the line cleaning. When ever lines are cleaned, the meters should be read before and after or the system could be disabled by the manager. In certain countries, norms require that a sponge be used during the procedure. The turbine would have to be removed from the line since it will block the passage to the sponge or the sponge would block the flow meter. The company responsible for the line cleaning must be warned that flow meters have been installed in the beer lines and you must request that they use chemicals instead of sponges. Beer line cleaning should take place at least every 4 to 6 weeks.

Trouble shooting foamy draft beer

Draught beer is a sensitive product which requires a certain number of parameters to be just right :Temperature, pressure, propellant and good beer system design. The Auper flow meter (turbine) is guaranteed not to make beer foam. However, the installation of flow meters into your beer lines will not solve the foaming problems. It would only tell you how much is wasted. Before you proceed with the installation of the flow meters, take a good look at the dispenser itself and ask a few questions. Test the system in the morning before the bartenders start using it.

1. Does the serving temperature correspond to the brewers norms ?

North America: 38F(3.3C) & 42 F(5.5C)
Europe: 43F(6C) & 48F(9C)

Pour a glass and insert a thermometer immediately in the freshly poured beer. If the temperature in the glass is outside these norms, it is quite possible that your refrigeration system is defective or needs adjustment. Too high a temperature will increase the risk of excessive foaming. If too cold, the beer is not foamy enough and bartenders usually serve more in each glass. In either case, you should be concerned that the pour cost will probably be too high.

2. Is the flow rate between 2.5 and 3.5 l/min (Aprox: 2 oz/sec) ?

If the flow rate is too slow, it is probably due to a lack of pressure in the system. The C02 gas can separate from the beer while in the line causing the beer to foam at the tap. The color of the beer will change a few seconds after the tap is opened, passing from a clear and golden color to white. A gas leak will have the same effects.

3. Check the propellant ! Is the beer flat or over carbonated ?

Any beer system with a distance between the kegs and the faucet greater than 10 feet (3 meters) should be pressurized using a mixture of air or nitrogen (70 %) and CO2 (30 %). Straight CO2 can be used for direct draw systems and very short runs (less than 10 feet or 3 M). Clean straight air can be used if the sales volume per day is very high. Otherwise, it will either contaminate the beer (think of where the air is pumped from) or it will make the beer flat. The wrong choice of propellant will either make the beer foam, make it flat or change the taste. In either case you will be wasting product thus increasing your pour cost . Get a qualified technician to look at the problem !

Non-refrigerated kegs (Europe)

Temperature is one of the elements that will affect draft beer along with pressure, the type of gas, the line design and the product itself. When kegs are stored in a non-refrigerated room, an increase in the store room temperature will have an effect on the way the product pours at the faucet. The higher the storage temperature is, the more gas pressure will be required to dispense the beer properly. When kegs are kept in a cooler, the external temperature will not have an effect on the draft beer since everything is under a controlled environment. With this type of installation, pressure settings are often kept to a minimum. The smallest change in temperature will have an effect and may cause foaming. Before you proceed with the installation of the flow meter, check if you can dispense draft beer for 15 seconds with the beer retaining its golden color when coming out of the faucet. If after a moment, it turns white, the pressure is too low. Inserting a flow meter will only make things worse. Increase the pressure by 2 PSI (14 KPa) and try again. Repeat this procedure until you can pour beer properly for at least 15 seconds. When inserting a flow meter in the beer line, the additional friction may have to be compensated by increasing the pressure settings. Once the flow meter is in place, do the same test and follow the same procedure.

Soft drink and Juice

Pre-Mix
Whether it is wine, juice, or soft drink, if it's ready to serve it’s Pre-Mix. As with draught beer, one flow meter per line will be necessary.

Post-Mix
For Post-Mix dispensers you have the choice of measuring the syrups or the carbonated water. If you are only interested in the total amount of soft drink dispensed , you will only need one flow meter connected to the carbonated water line (soda).

1. Measuring carbonated water

The ratio of the mixture (or “Brix”) is usually the same or very close for all the syrups (5:1). By installing the flow meter in the carbonated water (soda) line you will register the total amount of soft drink served through the dispenser. Since one carbonator unit can feed multiple dispensers, it is possible to install the flow meter closer to the carbonator just before the line splits to each dispenser, to monitor the total soft drink dispensed . If you want to monitor each dispenser separately, then the one flow meter per dispenser is installed, after the split, closer to the dispenser.

2. Measuring syrups.

If you want to know the quantity of each flavor served, you will need to install a turbine on each of the syrup lines. For this application it is necessary to use the turbine with model number 50-032 (slower flow rate).