More Than
5,000 Filters and Centrifuges Dewater Municipal Wastewater Sludge in the U.S.
Most of the 16,000 publicly
owned wastewater treatment plants in the U.S. are small and do not
mechanically dewater sewage sludge. Nevertheless more than 5,000 filters and
centrifuges are in use at the larger plants.
A new online database compiled
by the McIlvaine Company provides details on belt filter presses, centrifuges,
vacuum filters, and plate and frame or recessed chamber filter presses
installed in U.S. municipal wastewater treatment plants. Plants smaller than 5
MGD nearly all use belt filter presses. The majority of the largest plants on
the other hand use centrifuges. The development of centrifuges to achieve dry
solids content of more than 30% has led to the selection on this type of
dewatering device where the sludge is incinerated or where sludge would
otherwise have to be thermally dried.
Not surprisingly the most
populous states have the most installations. In New York for example there are
130 facilities utilizing 300 belt filter presses, 27 facilities utilize
centrifuges. However these 27 facilities produce 133,000 dry tons of sludge
per year vs. 185,000 tpy for facilities with belt presses. New York City alone
operates more than 50 centrifuges. 13 facilities in New York State operate
plate and frame filter presses and only 6 facilities have vacuum filters.
The largest supplier of
centrifuges in the U.S. is Alfa Laval (including the former Sharples). This
company has nearly 600 units in service in U.S. municipal wastewater plants.
Eimco (including the former Bird and KHD) and GEA (Westfalia, Centrico) round
out the top three suppliers in the U.S.
Ashbrook and Andritz are the
two top suppliers of belt filter presses. USFilter and Eimco are the top
suppliers of plate and frame and recessed chamber filter presses for municipal
applications.
U.S. Municipal Wastewater Treatment Plant Database includes plant size, location, addresses, description of unit processes, names of dewatering equipment suppliers and equipment size and model numbers. Click here for more information on this online database.
