Whether for industrial processes, biogas plants, sewage treatment plants, or when using hydrogen, gas volume measurements are carried out in all these areas of application. For many years, machine and plant manufacturers as well as customers from the process industry have been extremely satisfied with the range of reliable and durable instrument devices from the factories of KOBOLD Messring.
For many years, KOBOLD Messring has had an oscillation flow meter in its range, namely the DOG-4, however, after extensive revision the design has evolved to the latest version with a clear classification and new possible uses. This latest version is the DOG-6.
DOG-4 and DOG-6 for a variety of uses
The previous model, the oscillating flow meter DOG-4, is only suitable for dry gases. In addition to this, the development of the DOG-6 oscillation flowmeter provides the capability to measure both dry and moist gases.
Due to a special device design, it offers clear advantages over the previous model DOG-4, especially when used with damp media, for example with natural condensate drainage. Thanks to its robust sensor, it is ideally suited for such applications. The DOG-6 is also equipped with an optional shut-off valve, calibration software and a flow computer. Depending on customer requirements, the DOG-6, for which there is of course an individual calibration protocol for each device, can be manufactured as an individual custom-made product. Its areas of application are extremely extensive because it is suitable for dry gases and mixed gases as well as for gas mixtures and moist gases.
What happens with the oscillation measuring method?
With this flow measurement, a partial flow of the medium is routed through a bypass into the flow oscillator. In the oscillator, the actual measuring cell, the medium flows through a chamber with two flow channels. A bluff body directs the flow either to the left or to the right. A channel on the side of the bluff body connects both sides. The flow creates positive pressure on one side and negative pressure on the other. The pressure difference redirects the media flow to the other side. The flow begins to oscillate between the two sides and causes the medium in the connecting channel to oscillate.
The frequency of the oscillation is a measure of the flow velocity. A platinum hot-wire sensor detects the oscillation in the connection channel and converts it into an electrical signal. The signal is processed in the downstream electronics and displayed or output.
What is the new DOG-6 suitable for?
The DOG-6 oscillation flowmeter shows what it can do, especially in tough industrial applications. A key advantage is that it is designed without moving wear parts and its sensor easily withstands aggressive media, moisture and dirt particles. The installation position can be selected as desired, however, in the case of condensate in the gas, Kobold recommends horizontal installation. This is because the construction of the device leads to the drainage of the condensate from the oscillator, which is further optimized by the inclined measuring head.
The latter is required, for example, when biogas is generated naturally in the fermenter. This makes the DOG-6 particularly suitable for biogas plants, especially as it is also resistant to Sulphur. Another advantage: it also works at low operating pressure, with only small pressure losses, typically less than 30 mbar.
The DOG-6 is available in a stainless steel flange design with a wide range of nominal diameters up to DN 200. A wide range of custom-made products are also available. In addition to biogas plants, the DOG-6 oscillation flowmeter can also provide excellent service in sewage treatment plants, in industrial processes, and in hydrogen applications.
Furthermore, measurements can be carried out for various gases such as compressed air, natural gas, biogas, hydrogen, digester gas, various gas mixtures or for medical or technical gases such as propane, argon or similar.
Other advantages of the DOG-6 Oscillation Flow Meter
The device is characterized by a selection of several measuring ranges per nominal width, high measuring accuracy and long-term stability. It has ATEX/IECEx approvals for potentially explosive areas of application from zone 0. Since the device is extremely insensitive to contamination and works wear-free, its use is also almost maintenance-free, however, if the device sensor needs to be replaced, this can be accomplished on site without interrupting the process. This is ensured by optional shut-off valves. With this service process, a recalibration is not necessary.
The large measuring range and diverse, individually programmable electronics options ensure that the DOG-6 can handle a wide range of gases, including promising energy sources such as biogas and hydrogen. External influences such as pressure and temperature changes, the DOG-6 easily withstands changes. Individual evaluations are made possible in particular by using the flow computer. In addition to instantaneous and cumulative flow rates, temperature and pressure can be evaluated via separate inputs in order to output standard units. In addition, data storage and communication can be implemented via numerous output options.
With all these advantages, the DOG-6 offers an impressive number of possible uses, durability, and accuracy in the measurements - and at an unbeatable price. A comparable price-performance ratio is unattainable for the alternative ultrasonic technology.