Sludge disposal less is more. Clear solutions for sludge treatment

Transcription

1 Sludge disposal less is more Clear solutions for sludge treatment

2 Alfa Laval has the focus, the technologies and the know-how to deliver the best, most cost-effective solution for modern sludge treatment. Meeting legislative requirements for efficient, environmentally friendly sludge disposal demands new approaches and Alfa Laval delivers. 2 Clear solutions for sludge treatment

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4 We speak sludge disposal Virtually all kinds of industrial activity and urban development result in sludge that needs to be disposed of. The question is how well it can be done, and at what cost. Experience counts Alfa Laval has over forty years of practical experience with sludge treatment. Today, Alfa Laval is involved in the processing of municipal sludge from at least 200 million people. Our solutions are used in more than 1,000 industrial applications, and our systems help produce 1.5 million cubic metres of potable water every day. We deal with all kinds of sludges, whether they come from simple natural sedimentation, secondary biological treatment or advanced tertiary chemical treatment. Experience adds up to savings Alfa Laval G2 decanter centrifuges, spiral heat exchangers and drum thickeners save on more than just the direct costs of sludge disposal. Alfa Laval s expert analyses make sure we provide the most cost-effective solution to specific customer requirements. Process expertise from hundreds of projects all over the world makes a crucial difference in implementing any complex solution that involves the treatment of sludge. A challenge to deal with One characteristic common to all sludges both from industrial sources and from the public sector is that they are normally of little or no commercial value. They therefore represent a challenging disposal problem that is often costly to deal with. Alfa Laval solutions are designed to reduce these disposal costs significantly. Digester heating The Amsterdam WWTP has a capacity of 1.1 million P.E. Alfa Laval supplied six 730-kW ALSHE spiral heat exchangers for the digester heating and four decanter centrifuges for dewatering the digested sludge. The ALSHE copes with high sludge concentrations of up to 6%. The design means only occasional cleaning is required, and the hinged cover makes it easy. All six units are located in the basement, and the compact design means they take up little space. These units were selected for their reliability. We are happy with the installation as it is. Reliability is very important and we trust the Alfa Laval spirals. Mr. R. Ramkisoen, plant manager, the Amsterdam WWTP, the Netherlands

5 Treatment of potable water As part of our dedication to environmental protection, we are very happy with the two Alfa Laval ALDEC 506 decanters for dewatering the sludge. They were chosen mainly because of their automatic control system, which ensures easy, error-free operation. The machinery requires little space compared with belt filter presses, which has made installation a lot easier and given us substantial savings. Wang Wei, Director, Minhang Water Treatment Plant, China For contractors Alfa Laval makes it possible to: reduce the technical uncertainties involved in any tender minimize engineering costs and overall purchasing costs reduce installation and start-up costs boost and strengthen the overall bid due to Alfa Laval s technical capacity For the operator Alfa Laval sludge treatment equipment and solutions add up to: lower polymer consumption, higher cake dryness, clearer effluent and greater capacity lower operating costs due to greater efficiency fully integrated solutions from one single source, guaranteed to work together expert on-the-spot local service, backed by comprehensive maintenance and spare parts services The ideal partner This makes Alfa Laval the ideal partner in any sludge treatment project that focuses on: cost efficiency, both short-term and long-term full compliance with environmental legislation innovative processes that meet and exceed all requirements Minimizing the volume of industrial waste Spanish Recasa, a company specializing in collecting, treating and disposing waste from industrial companies, has installed an Alfa Laval ALDEC G2 decanter to be used in the dewatering process. The decanter produces a sludge cake with a dryness of 35 per cent, and the water is clean enough to pipe to the industrial estate's regular wastewater plant. "Look at the water coming out. It's almost clean enough to drink." Mariano Miguel Arias, General Manager and founder, Recasa, Spain

6 The pressure is on Alfa Laval technology eliminates process bottlenecks Scum dewatering Alfa Laval G2 decanter centrifuges, drum thickeners and spiral heat exchangers are the equipment of choice for use in: Thickening The Alfa Laval thickening system reduces sludge volume by up to 90%. This means significant savings when transporting the sludge elsewhere for further treatment. The digestion process is also optimized due to the longer residence time, which results in better gas yield, improved stabilization and lower heating costs. Use of thickening before dewatering also improves the overall operating economics of the dewatering plant. Influent Screen/Grit removal Dewatering Preheating Primary clarification Effluent cooling Thickening Aeration Return sludge Thickening Dewatering Decanter centrifuges work by multiplying the effects of gravity several thousand times, with centrifugal force separating out the solids in a fraction of the time it would otherwise take. Dewatering is essential to reduce the volume of the sludge as well as to ensure a dry sludge cake. Dewatering reduces transportation and disposal or drying costs, while at the same time limiting any adverse effects on the environment. Digester heating/ Pasteurization Sludge digester Heat recovery Thickening P Preheating Process optimization Process enhancement 6 Clear solutions for sludge treatment

7 Total solution Novozymes, the world s largest producer of industrial enzymes, is extending the number of ALDEC decanters installed in its treatment plant to dewater the biomass by-product. Alfa Laval delivers a complete system, with guaranteed compatibility between sludge unloading systems, lime silos, polymer equipment, controls, pumps, valves and decanters. Alfa Laval is very familiar with our needs and our production processes, and knows that our ability to handle the specific quantities of liquid waste on time depends on everything being fully optimized at all times. Niels-Viktor Nielsen, Process Manager, Novozymes, Denmark reheating Secondary clarification Direct dewatering Preheating Dewatering Final effluent Sludge preheating Preheating the sludge to 60 C or higher before dewatering alters the sludge characteristics and makes it easier to dewater. Using Alfa Laval spiral heat exchangers means that cake dryness can be increased by up to 6% by preheating. In cases where dryness is already sufficient, preheating can save up to 40% on polymer consumption. Sludge pasteurization Environmental legislation all over the world sets limits on the quantities of pathogens and microbes that are permitted to be present in the sludge before disposal. These limits can be adhered to effectively by pasteurization, which involves heating the sludge to 70 C for thirty minutes. Using Alfa Laval spiral heat exchangers to do this makes it possible to exceed even the most stringent standards for the elimination of pathogens, at the same time as saving energy by recovering heat between two sludge flows. Digestion heating Because digesters operate most efficiently above ambient temperature, heating is required. Alfa Laval spiral heat exchangers are the most efficient way to do this, heating the sludge in a smooth, well-controlled way in a recirculation loop. This improves the digestion process, and gas production increases when the digesters are maintained at a stable temperature. Effluent cooling In some industrial waste treatment processes, it can be necessary to reduce the temperature of certain waste streams, as high temperatures can impair the efficiency of the subsequent treatment stages. Alfa Laval spiral heat exchangers provide a reliable, efficient way of doing this. Dewatering Clear solutions for sludge treatment 7

8 Good results the sum of many parts Alfa Laval providing technologies developed specifically for sludge treatment Alfa Laval high-performance solutions are built around quality products: ALDEC G2 decanter centrifuges ALDRUM drum thickener systems ALSHE spiral heat exchangers All products are available in a wide range of different versions designed to meet individual customer requirements. These cover the entire spectrum, from straightforward configurations with prime focus on the initial purchase price, to state-of-the-art installations with unbeatable life-cycle costs. built using a flexible, modular approach that can meet even the toughest challenges. This means that each and every component and assembly can be configured to meet individual needs, from the basic high-performance units upwards. With Alfa Laval equipment, you only pay for what you really need nothing more. Value for money Alfa Laval sludge treatment equipment provides every customer with value for money, because it is all designed and 8 Clear solutions for sludge treatment

9 Advantages in common All the equipment supplied by Alfa Laval be it a decanter centrifuge, a drum thickener or a spiral heat exchanger has important characteristics in common. The processing sections are fully enclosed. This ensures maximum protection of staff from risks associated with exposure to chemical and biological aerosols. The equipment takes up only a fraction of the floor space needed for alternative technologies. An Alfa Laval solution thus boosts plant capacity without additional construction costs. They are easy to operate, supervise and service, thereby reducing costs still further. Sludge in any form is abrasive. In Alfa Laval equipment, the critical parts are therefore made of wearresistant material. Alfa Laval has developed unique feed zones that ensure superior performance in centrifuging, filtering and heating processes. These advantages are available in the form of separate units, packages of components, pre-engineered modules or turnkey plants. Thickening for improved dewatering The CCM Brewery Group in Mexico produces many well-known beers, including SOL. The Group successfully tested the ALDRUM drum thickener and subsequently purchased the module for their factory in Guadelajara. We were impressed with the simplicity and the efficiency of the ALDRUM. The thickening process is ideal both for improving the effectiveness of the digester, and in preparing for dewatering with our ALDEC decanter. Alfonso J. Cantu Q., Environment Manager, CCM Group, Mexico

10 Nonstop Performance A lifetime commitment For us at Alfa Laval, our obligation to you as a customer does not stop short at delivery. Our Parts & Service organization is there to ensure that your process always runs at peak performance. This is a commitment that extends throughout the lifetime of the system. We call it Nonstop Performance. Nonstop Performance is based on our global network of experts, who are always on standby to provide you with genuine spare parts on site, in more than 50 countries, 365 days a year, right around the clock. In terms of service, we speak your language. Alfa Laval service is based on a profound insight into the needs of the sludge treatment industry. We see every product as part of a process and understand the role it plays within that process. We can therefore work in close collaboration with you to tailor an individual service package that matches your requirements perfectly. Service must result in bottom-line benefits. We therefore help you to calculate the savings that will result from any proposed service package, and the real-term benefits it will provide. Challenge us to show you! 10 Clear solutions for sludge treatment

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12 Alfa Laval in brief Alfa Laval is a leading global provider of specialized products and engineered solutions. Our equipment, systems and services are dedicated to helping customers to optimize the performance of their processes. Time and time again. We help our customers to heat, cool, separate and transport products such as oil, water, chemicals, beverages, foodstuffs, starch and pharmaceuticals. Our worldwide organization works closely with customers in almost 100 countries to help them stay ahead. How to contact Alfa Laval Up-to-date Alfa Laval contact details for all countries are always available on our website at PEE00041EN 0610