Biogas Technology EFFICIENT PUMPING AND MIXING TECHNOLOGY FOR BIOGAS PLANTS.

Biogas – it comes naturally With rising energy prices, interest in energy from renewable sources is increasing. Biogas plants are among the few technologies which can be operated both nationally and locally. That’s why, in recent years, not only has the number of installations increased many times over, but so has their output too. By way of comparison, the average output from biogas plants in the year 2000 was 50 kW – today it is up to 400 kW. If a biogas plant is to operate economically, it has to be highly reliable. The complexity of the installation therefore demands high-quality components...

Submersible mixers for an efficient flow High-performance mixers are required in the fermenter (digester), as they maintain the homogeneity of the substrate, help distribute active bacteria and heat, and prevent layers of floating and sinking material. Efficient mixing and the subsequent mixing result depend to a large degree on a strong, effective flow level being generated throughout the tank. The strength of this flow is in turn dependent on the thrust. Factors determining the cost in power consumption of generating the thrust are hydraulic efficiency, speed and the diameter of the propeller....

The low-speed 4460 series Depending on the application, the exceptionally robust design enables continuous operation of up to 180,000 hours between non routine maintenance intervals. The design of the Flygt banana propeller also provides excellent self-cleaning properties, which even prevent clogging in fibrous media. Optimal mixing and surface motion is thus ensured at all times. 1,300 mm and 2,500 mm In order to meet a wealth of different requirements, Flygt banana mixers come with a choice of three different drive units, with propellers available in diameters of 1,300 and 2,500 mm as required....

Optimum positioning In comparison with vertically and diagonally mounted mixers, Flygt banana mixers offer plenty of flexibility in terms of positioning and alignment. The mixer can be optimally aligned, both in height and direction, and adapted to the shape of the tank. The mixer jet thus works over long distances and produces an impressive result. 1 Inner shaft seals Shaft seals between the stator and the gearbox, and between the gearbox and the seal housing. Contains fluid that lubricates and cools the seals whilst acting as an additional leakage barrier. Squirrel-cage induction motor with...

Maximum mixing – minimum investment The compact 4600 series Submersible mixers in the 4600 series can provide far greater flexibility than longshaft mixers in terms of positioning and alignment. The mixer jet can be easily repositioned to work over long distances. For this the mixer position can be adapted to the shape of the tank. This results in an optimum flow level, which in turn produces efficient mixing and low power consumption. The height adjustment feature is particularly useful for preventing and breaking up layers of floating and sinking material. Highly effective in substrate end...

1 Cable entry Compressible bushing and strain relief on the cable prevent leakage into the motor, providing a reliable installation. 2 Oil housing Large barrier fluid volume lubricates and cools the seal and thereby prolongs service life. 3 Monitoring Thermal sensors embedded in the stator windings prevent overheating. Leakage sensors are available as options. 4 Bearings Securely supports the shaft by means of one main bearing at the propeller end and a double bearing at the rear end. 7 Plug-in seal with the Active Seal™ system Offers increased sealing reliability and zero leakage into the motor, thereby...

The configuration of the installed technology is just as mal fermentation, the following factors are essential: important as the quality of the reagents used when it stable temperatures, the exclusion of atmospheric comes to achieving a high gas yield. To ensure opti- oxygen, high activity on the part of the microorgan- 1 Preliminary pit Depending on the amount of straw and feed, the quantity of dry matter in the substrate increases. With Flygt N and F series pumps, the substrate is pumped reliably into the collection pits with virtually no blockage whatsoever. 2) Collection pits The liquid...

isms and, most importantly, good mixing. Flygt mixers and pumps are perfectly suited to the various processes involved in biogas production. Fermenter Flygt 4460 mixers, better known as “banana mixers” ensure the controlled mixing and homogeneity of the substrate, as well as pushing gas bubbles up to the surface. The compact mixers in the 4600 series also prevent the formation of layers of floating and sinking material. Post-fermenter In the post-fermenter, the substrate is more fluid and therefore requires less agitation. The use of the Flygt 4600 series compact mixers and the Flygt 4460 series...

To increase the gas output and thus efficiency, most plants use a mixture of renewable raw materials, solid manure and coenzyme. This increases the levels of dry matter and impurities in the preliminary trench, meaning that pumps and mixers have to be carefully selected. The chopper pumps of the F 3000 series are perfectly suited to pumping media with a high dry matter content. The powerful cutting impellers boast hardened edges and, along with the cutting plate, make light work of long-fibred material such as straw, resulting in a more homogenous medium that is easier to pump. If the risk of...

Cast iron Cast iron without wiper Relief groove Pump housing The improved F series, designed for the toughest jobs, now comes with an even more efficient impeller. This impeller rotates inside a chopping plate and chops all the fibrous elements that pass through into little pieces. This makes pumping easier and prevents the impeller from becoming blocked. The chopper pumps in the F series have been extensively tested in practice and are exceptionally powerful and reliable. With such a high standard of reliability, frustrating and expensive breakdowns are reduced to a minimum. Any foreign bodies...