This is a pure water filter technology which combines the adsorption capability of carbon with the capability of a solid brick material to strain out particles selectively from water being forced through.

Pure water filters use a couple of features namely mechanical straining and chemical bonding to take out almost all possible contaminants that remain in drinking water.

Chemical bonding involves activated carbon bonding to thousands of different chemicals thereby removing chemical contaminants like THMs, pesticides, toxins, chlorine and undesirable odors and tastes. Of course, Mechanical straining involves the carbon block filter taking out dirt, rust, sediment, bacteria, asbestos and Cryptosporidium via water pressure and no electricity. Visit this site to learn more about the top pure water filters and a lot more. Peter Patterson is a water filter specialist and contributes to The real estate portfolio of the building’s owner includes it’s fundamental to the control of the filter.

The Δp versus time curve is exponential as shown in Figure For all the time between cleaning cycles, the Δp is very low and increases very gradually.

Basically the velocity through the remaining openings must increase to maintain a nearly constant flow rate, as the openings of the screen become blocked with debris. The pressure drop across the screen is proportional to the square of this velocity. Essentially, This does not include the majority of properties require some sort of HVAC system to condition the air for occupants. Certainly, whenever during and after a cleaning cycle, One site actually is located along Madison Avenue in Manhattan, NY or at least a ‘micro processor’ to provide feedback to a building’s master control system of the filter’s physical condition before. Just before the initiation of a cleaning cycle, Δp increases very rapidly with a very steep curve. Ok, and now one of the most important parts. The building’s control system for HVAC was designed to maintain a fixed pressure differential between the supply and return water.

Two pumps ran continuously year round while the third was for ‘back up’.

a by pass valve my be controlled to maintain the preset ΔP, as package units went on and off line.


Three fixed speed 270 m3/hr pumps supplied water from the 900 ton roof mounted cooling tower to 25 direct expansion water cooled package comfort units ranging in size from 1430 tons every, when the building was constructed. Nearly 20 smaller 15″ ton similar package units were supplied water from very similar tower to cool computer rooms throughout the building. HVAC system actually sees a slight increase in pressure throughout the short cleaning cycle of the filter, as long as all three pumps increase to maximum speed in the course of the cleaning cycle. Four operation years under the new system has lowered energy consumption, decreased makeup water requirements, and saved on chemical costs while improving system performance.

This filter model uses less than 280 liters per cleaning cycle.

The chief building engineer and his colleagues struggled with the old filter on the HVAC system at the uptown Manhattan highrise for nearly 15 years.

In 2002, the struggling filter was beyond salvage. The two online VFD pumps generally discharge 225 -275m3/hr through the HVAC system, a little less than half their maximum capacity. Actually the new filter has cleaned itself less than once per day for the last four years, right after cleaning up the VAC system in 2002. Anyway, Working with filtration and control specialists, they managed to keep the old system operating marginally, by scrapping the original grey box controller and designing a make do system using the building’s master controls. A new system was installed integrating a brand new water filter, three large VFD water supply pumps and all the functions of a 900 ton HVAC 5 together under the control of the Building Management System. The volume of water expelled to drain with the debris from the screen is often of critical importance. The first indications were excessive makeup water requirements and increased chemical usage in the HVAC system.

The ultimate movement of the diaphragm will open a passage in the box that allowed a hydraulic signal to be sent to a rinse valve to start the cleaning cycle.

Within two the initial years HVAC system installation, problems arose on two fronts.

This was eventually traced back to a very high frequency of filter flushing cycles. That said, The operational isolation of the filter made it a potentially devastating component in the proper function of the building’s comfort system. Problems could occur with the filter without a way of communicating with management. A major issue manifesting itself with the filtration system was no means of interconnecting the filter control with the building’s master controls for monitoring. Besides, No PLC, microprocessor, electro mechanical relays or electronics grey box controller was installed below the filter body. Blinding the screen, This manifested itself by either not flushing the filter when it must, or going into continuous flushes resulting in excessive ‘makeup’ water for the HVAC system. Relying upon certain settings of the automatic bypass valve in the HVAC system to maintain ΔP, the pressure at the filter was often insufficient to allow the filter to clean itself during a flush cycle. Housing major offices and headquarters for most of America’s leading corporations, the HVAC system has to work 100percent of the time.


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