Hrs Unicus - Multi effect evaporation with unicus scraped surface evaporators

HRS Unicus In this video we explain how HRS applies its scraped surface technology for environmental waste concentration. Evaporation is an effective way of reducing the volume of environmental waste streams. Often, these waste streams cause fouling of process equipment when they are heated up. To overcome this problem, HRS developed a self cleaning heat exchanger called the Unicus. This evaporation process comprises the following stages: - Preheating. - First stage evaporation. - Second stage evaporation. - Separation of steam. - Condensing of evaporated steam. - Recovery of the final concentrated product. The hot energy of the condensate water is used to heat up the incoming product. This way the products temperature is brought closely to the evaporation temperature. A concentric tube in tube heat exchanger with corrugated inner tubes are applied. The corrugation profile creates extra turbulence and breaks up the fluid boundary layer. This results in higher heat transfer rates and a better resistance against fouling. The first evaporation step consists of a scraped surface heat exchanger which evaporates part of the product, a pump which recirculates at high speed, and a vapor separator tank with cyclone shape. Inside each inner tube of the evaporator a scraper bar is fitted. The movement of the scrapers cleans the heat transfer surface in a continuous way. Therefore the evaporation process does not have to be stopped for cleaning up the evaporator when it is fouled. The scrapers also act as static mixers. This helps to keep the heat transfer high. Inside the cyclone separator the flow is introduced sideways, creating a centrifugal flow, this helps to separate the lighter fluid, the vapor, from the heavier fluid, the liquid product. The product drops to the bottom from where it returns to the recirculation pump and steam leaves the cyclone evaporator through the top. The steam goes to a condenser where is condensed to water. This condenser is a corrugated tube heat exchanger which uses cooling water for the process. The condensed water is pumped to the preheater to heat up the incoming product. A pump is used to transport the product from the first to the second evaporation stage. This phase acts the same way as the first: the process works continuously recirculating the product at high speed and separating the vapors using centrifugal force. The evaporated steam from the cyclone separator is sent to the shell side of the first evaporator as thermal energy source. During the evaporation process the product increases in dry matter concentration and density. A density measuring device is used to control the final product concentration. Multi stage evaporation with HRS Unicus scraped surface evaporators: An energy efficient way of concentrating effluents. No downtime for cleaning the evaporators for fouling. HRS Heat Exchangers is an innovative company in the creation of new sustainable technologies which guarantee the highest quality service to our customers. For more information, visit us at www.hrs-heatexchangers.com