Water and Wastewater Technology

EDUR-pumps guarantee the efficient operation of applied water and wastewater technologies. The requirement to not only conserve water, but also return it to natural water recources in cleaned quality after use, holds enormous innovation potential for reducing the impact on the environment.

Centrifugal Pumps in the Field of Water- and Wastewater Technology

Application of EDUR-Centrifugal Pumps in Water and Wastewater Technology

EDUR-centrifugal pumps are used in various areas within water and wastewater technology. The advantages of EDUR-centrifugal pumps lie in the robustness and durability of the pumps as well as in the special capability of the multiphase pumps to supply fluid-gas mixtures. At the same time EDUR offers a wide range of torque flow pumps for the supply of contaminated water, which is pervaded with large particles.

Typical applications of EDUR-pumps range from water supply to treatment and disinfection for process water. Due to special properties of the gas conveying capability and the self-priming behaviour, the pumps are also used in critical areas, for example, in the food and pharmaceutical industries.

Multiphase Pumps in Flotation Plants

Efficient wastewater treatment comprises the recovery and reuse of nutrients and valuable substances. This is achieved by various cleaning steps by means of mechanical, biological and physical-chemical processes. In wastewater technology, flotation as a physical-chemical process is a proven efficient method worldwide.

Flotation Plant with Centrifugal Pumps

Our multiphase pumps are used in flotation plants all over the world. With dissolved air flotation, a return flow of the clear water is saturated with air under pressure and then reduced to atmospheric pressure again. The micro bubbles that become free during the pressure release accumulate on the suspended solids and carry them to the surface, from where they are skimmed or skimmed off. Typical fields of application include the treatment of liquids with suspended solids such as oil-water emulsions, fat separations, phosphate and heavy metal precipitations, biological wastewater treatment plants and many more. In this context hazardous wastes are treated within multistage flotation plants. The pump hydraulics of EDUR-multiphase pumps are specially developed for this process allowing throttled operation on the suction side without sucking additional compressed air gas from the environment. These special pumps ensure a reliable supply of liquids with gas proportions of up to 30% at a pressure of usually 4 to 7 bar. When using the EDUR-multiphase pump in a flotation plant according to VDMA standard sheet 24430, direct addition of the gas into the suction line takes place thus allowing a reduction of plant components compared with systems of conventional type: Compressor, pressure tank, elaborate control unit and various valves are omitted.

Self-Priming Centrifugal Pumps for Water Supply

For water supply, self-priming centrifugal pumps are often used. Prior to being taken online for the first time, the pump itself must be filled with the operating medium, which remains in the pump and cannot be levered out due to the nozzle facing upward. With water in the pump body, the pump generates negative pressure on the suction side. The air column is thereby pulled out of the suction line, thus pulling up the water column. As soon as sufficiently filled, the pump starts the normal supply. The sucked air must be discharged on the pressure side via a venting valve. Self-priming EDUR-pumps are classic centrifugal pumps and have a better efficiency than side channel pumps. The advantage of self-priming pumps is that a foot valve is not needed at the end of the suction line. Foot valves are often a weak point in water-supplying plants since they may be prone to clogging, calcifying or wear and tear in case of sediment load and can subsequently fail unnoticed. In these cases, “pouring” is not possible, because the water escapes through the defective foot valve. With pumps that rely on a permanent liquid column due to their functionality, this can lead to damages and malfunctions.

By means of performances of up to 300 m³/h and heads of up to 16 bar, the self-priming EDUR-pumps can be used very well for the feeding of elevated tanks, for instance.

Centrifugal Pumps in Process Water Supply

Process water networks for cooling processes in industrial companies are often fed from rivers. Self-priming centrifugal pumps are suitable for process or raw water extraction. In contrast to well pumps or submersible pumps that are immersed into the fluid, self-priming centrifugal pumps are installed dry and within easy reach. As a result, they offer advantages in terms of maintenance. With correspondingly high capacities, submersible pumps that are equally powerful are extremely heavy and hard to handle accordingly.

Centrifugal Pumps in Industrial Water Treatment

Industrial Water Treatment: Cleaning with Centrifugal Pumps

To treat water from rivers and streams for industrial purposes, EDUR provides the right pump solution. Due to mechanical water treatment via use of centrifugal pumps with the special properties of a flotation pump, suspended solids such as algae can be removed to obtain clear water.


Centrifugal Pumps for the Treatment of Drinking Water

Apart from general water pumping, EDUR-centrifugal pumps have special properties to transport media containing gas proportions of up to 30% of the volume flow rate to be supplied. The pumps can convey these liquids saturated with gas without being damaged during the process. Users often take advantage of this in the treatment of drinking water for disinfection or for drinking water treatment by introducing ozone into the water for sustainable disinfection. The ozone introduced into the water quickly decomposes to oxygen again. A similar application is additional dosing of carbon dixoide (CO2).

Centrifugal Pumps for the Treatment of Slaughterhouse Wastewater

In the meat processing industry, such as in slaughterhouses, fat rendering plants, animal carcass treatment facilities et cetera, operating companies experience considerable savings in energy costs and use of chemicals with simultaneously improved discharge values by using EDUR-centrifugal pumps in flotation plants. This applies to both brand-new plants and existing old plants after corresponding retrofitting. Operating companies of those slaughterhouse have reported that energy costs, for example, could be considerably reduced since EDUR-multiphase pumps operate with almost half the installed drive power of flotation systems with two side channel pumps. When compared to side channel pumps, EDUR-multiphase pumps set themselves apart through their stable flow characteristics, low-wear operation and high energy efficiency. Plant manufacturers report savings both in terms of investment volume and running operating costs which, depending on the type of plant, lie within 30 and 50 per cent compared with conventional plants.

Multiphase Pumps in Fuel Production

During fuel production from regenerative energy sources (e.g. wood, calorific waste components, animal meal or biodiesel) carbon dioxide (CO2) is washed out of the synthesis gas. For this purpose, the gas is pressed by means of a compressor into an absorption container where it flows upward through a packed bed. At the same time, the filling is sprayed from above by an EDUR-multiphase pump with water which thus accumulates carbon dioxide (CO2) from the synthesis gas and degasses for the most part in a desorption tank. During the repeated suction process, gas bubbles occur due to complete saturation of the water, which are brought back in the solution seamlessly due to the special hydraulics of the EDUR-multiphase pump.

Centrifugal Pumps for Gassing Flotation in the Oil and Gas Industry

Centrifgal Pumps for Gassing Flotation in the Oil and Gas Industry

In the oil and gas industry, gassing flotation for the separation of oil-water mixtures is a proven concept. Therefore, during crude oil production in specially designed flotation plants, natural gas from existing deposits is fed. Here, EDUR-multiphase pumps replace conventional systems on many oil fields worldwide. During the process, multiphase pumps function as the gas dosing facility instead of conventional systems, which operate with jet nozzles, pressure tanks and compressors. At the same time, EDUR-pumps act as dynamic mixers due to the specially designed impellers in open design. In combination with the diffuser blade device, high shear forces generate a considerably improved dispersion of gas proportions in comparison to traditionally used static mixers with standard pumps.

Centrifugal Pumps for the Treatment of Cooling Lubricants

In the metal processing industry, contaminated cooling lubricants of the production have to be treated in order to be reused in the process. This water-oil mixture is fed into a removal pool and is then supplied into a sedimentation basin via a collection basin with sludge collector. EDUR-multiphase pumps transport the fluid, which is correspondingly dosed with chemicals into flotation plants within the circuit.

Centrifugal Pumps for Raw Material Extraction

Origins of dissolved air flotation can be traced back to mineral enrichment processes during ore production more than 100 years ago. Supplied crude ores are ground and fed into flotation plants where the mineral particles float to the water surface due to micro bubbles and are kept in a kind of foam cover, the so-called flotate. To do so, flotation additives are dosed to the water-air mixture generated by the EDUR-multiphase pumps. Ore concentrates obtained in this way are smelt in subsequent processes.

Centrifugal Pumps for Cleaning Agent Preparation

Oil residues arise from the cleaning of parts and the surface treatment of components following mechanical machining, for example in the automotive industry. Cleaning agents, which are supplied in a closed circuit, absorb these oil residues and are subsequently treated again in a flotation process.

Centrifugal Pumps in Ammonia Stripping Units

In fertilizer production, for example, nitrogen content and the chemical oxygen demand (COD) must not exceed legal limits. Therefore, a downstream stripping unit is installed. Wastewater is introduced at the height of the tank bottom and is then conveyed by EDUR-multiphase pumps. Atmospheric air is automatically sucked in and brought into the solution under pressure. After releasing to atmospheric pressure, the water-air mixture generated is led back into the tank via a nozzles system. Due to this special type of sprinkling, ammonia (NH3) in the wastewater is released and fed back in gaseous state into the process of fertilizer production upstream.

Centrifugal Pumps in the Paper Industry

Centrifugal Pumps in the Paper Industry

Calcareous deposits from the circuit water in the paper industry within system components such as heat exchangers, pipes and cooling systems can be prevented using lime traps. In this way freshwater consumption is significantly reduced and both plant reliability and process sustainability as a whole are improved. Also, a reduction in repair and maintenance costs of the systems is achieved. Due to the EDUR-multiphase concept, energy costs can be reduced by more than 65% compared to conventional systems. Maintenance and cost-intensive components such as compressed air chambers and compressors are omitted completely.

Centrifugal Pumps in Cooling Water Treatment Using Ozone

Biofouling is a term from the heat exchanger technology. Marine biofouling is one main problem for materials which are in permanent contact with seawater. Seawater organisms deposit in heat exchangers, filters and piping and thus influence the reliable function of drive motors and other facilities on board seagoing vessels, which require reliable cooling.

EDUR-multiphase pumps have been nominated for participation at the 7th Framework Program of the EU for research and technological development. The EU project included the development of a procedure for avoiding marine biofouling. EDUR-multiphase pumps with ozone-intake to the water improve the seawater quality for cooling marine motors significantly. Moreover, the cost-intensive use of chemicals is avoided and a reduction of repair costs is obtained.

Centrifugal Pumps for Filter Backwashing

In drinking water production, filters are backwashed with compressed air, whereby the rinsing effect is improved. However, the rinse waters are provided with an increased gas proportion, which can lead to problems with a normal volute housing pump. The gas conveying capability of EDUR-pumps, however, allow them to supply the fluid without any problems with gas accumulations in the sealing area thanks to the special design in the mechanical seal chamber of the block machine.

Centrifugal Pumps for Pressure Boosting

EDUR delivers the corresponding pumps in horizontal and vertical design or self-priming pumps for special pressure boosting systems.