Following years of development, knowing that evaporation is key in nutrient management, Daritech introduces the ZND™ system. Utilizing evaporation technology and our patented centrifuge process, you can now remove water from manure with 100% pathogen kill utilizing no chemicals, filters, or membranes
The heart of this modular system is Daritech’s mechanical evaporation unit, with each module producing approximately 20,000 gallons of distillate per day. With the ZND™ system, you can now evaporate water from your manure at a fraction of the cost of a standard evaporation system.
Evaporation Operation Overview
Daritech’s MVR (Mechanical Vapor Recompression) System for dairy manure is designed to efficiently evaporate the water from the manure, resulting in two streams, 1) concentrated nutrients and 2) clear water distillate with a trace of ammonia. With the device operating continuously, the distillate and concentrate are removed, while a steady feed supply of concentrate from a centrifuge is added.
The feed material is preheated and added to a recirculation loop. This material is approximately 200°F as it enters a heat exchanger. In the heat exchanger, vapor gives up its heat to the recirculating material. The manure concentrate then enters a flash vessel tank which is kept under vacuum, reducing the boiling point, creating evaporation. With moisture leaving, the remaining material is now more concentrated due to the water loss. The evaporated vapor is pulled through a blower which is maintaining the vacuum. The blower discharge conveys toward the condensing side of the heat exchanger. Here the vapor condenses and transfers its heat to the recirculating fluid on the opposite side of the exchanger plates. The vapor has now become distillate, and on its way out of the system it is passed through a smaller heat exchanger, pre-heating the feed for maximum efficiency
On most dairies, approximately 80-90% of the manure fed to the system will become distillate. The distillate is overwhelmingly water but also contains some ammonia of the TKN present in the manure. This can give it a slightly cloudy appearance and odor. The ammonia can optionally be removed by the use of aeration or a stripping tower. If recovery is desirable, a scrubbing tower can be added to produce ammonium sulfate.
The remaining sludge nutrients are at a concentration of 10-20% of the initial starting volume. This can be more cost effectively transported over greater distances than would have been required by the original non-concentrated manure.
With the optional 2nd Stage, the evaporator sludge can be sent to a drier to produce SuperO™ organic fertilizer crystals.
Daritech’s Centrifuge is a critical preparatory process to provide high nutrient flow for evaporation. In addition, it removes sand and fiber to decrease wear and tear and allow for less system maintenance. Decanter centrifuges are self-contained machines that use high rotational speed (centrifugal force) to separate solids and liquids, making it an invaluable component of any manure management system.
Autonomous Daily Operation
The Daritech MVR system operations and maintenance is designed for simplicity, ease, efficiency, and autonomous operation. The automation provides remote signaling of system status, alarms, and service requirements ensuring maximum uptime. All operation is controlled via a PLC from which an operator may adjust setpoints as desired to meet the needs of the dairy.