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Muncher protects Thames Water's dewatering system
S EWAGE &
'WASTE WATER
Muncher protects Thames Water's dewatering system O n e o f E u r o p e ' s largest sludge dewatering plants, Thames W a t e r ' s P e r r y Oaks site, is using a n u m b e r o f sludge g r i n d e r s and p r o g r e s s i n g cavity p u m p s from M o n o P u m p s to e n s u r e that all sludge is g r o u n d to t h e correct consistency before e n t e r i n g t h e centrifugal dewatering system. Blockage and clogging of the centrifuges c o u l d b e e x t r e m e l y costly in t e r m s o f d o w n t i m e a n d maintenance. T h e Perry Oaks site receives a p p r o x i m a t e l y 27 000 m 3 o f d i g e s t e d sludge p e r w e e k f r o m Mogden Sewage Treatment Works w h i c h is c e n t r i f u g a l l y d e w a t e r e d and c o n v e r t e d into agricultural fertiliser. Sludge w i t h a solids c o n t e n t o f a r o u n d 2% is p u m p e d from t h e storage tanks to t h e M o n o M u n c h e r . T h e M u n c h e r is a t w i n shaft s l o w s p e e d , high t o r q u e grinder which incorporates a series o f i n t e r l e a v i n g c u t t e r s and spacers giving positive d i s p l a c e m e n t solids grinding. The unique patented cutters pull a n d t e a s e a p a r t f i b r o u s material w h i l e t h e leading e d g e a n d sides o f t h e c u t t e r teeth, c r o p and s h e a r h a r d d e b r i s into small strips, a n d t h e circumferential ' l a n d ' o f t h e c u t t e r c r u s h e s friable o r brittle waste. T h e r e s u l t i n g s l u d g e is p u m p e d b y a M o n o industrial E Range p r o g r e s s i n g cavity p u m p to t h e c e n t r i f u g e s at variable rates o f 35 to 55 m3/hr. C a p a b l e
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of p u m p i n g c a p a c i t i e s u p to 350 m 3 / h r a n d p r e s s u r e s u p to 24 bar, t h e E Range p u m p s incorporate Mono's unique Flexishaft system, which p r o v i d e s a single c o m p o n e n t link b e t w e e n t h e r o t a r y m o t i o n o f t h e d r i v e shaft a n d t h e e c c e n t r i c m o t i o n o f t h e helical rotor. T h e r e d u c e d n u m b e r o f m o v i n g p a r t s in t h e drive train eliminates wear and makes lubrication unnecessary, thus r e d u c i n g the costs and inconvenience of downtime. John Goodman, operations m a n a g e r at t h e Perry, Oaks site c o m m e n t s , "As this site operates c o n t i n u o u s l y t h r o u g h o u t the year, w e require e q u i p m e n t w h i c h can d o t h e same. Since installation in 1994, e a c h p u m p has o p e r a t e d for m o r e t h a n 23 000 hours, m a k i n g a total o f just u n d e r 100 000 hours, w i t h
only o n e m i n o r m a i n t e n a n c e r e q u i r e m e n t in all that time." The positive d i s p l a c e m e n t design o f the M u n c h e r s and t h e E Range p u m p s e n s u r e s an a c c u r a t e f l o w o f sludge to the c e n t r i f u g e s w h i c h is critical to p r e v e n t t h e possibility o f overload. T h e M u n c h e r is s u p p l i e d w i t h a P r o g r a m m a b l e Logic C o n t r o l l e r w h i c h is d e s i g n e d to o p e r a t e in n o r m a l o n / o f f m o d e , to distinguish b e t w e e n an overload w h i c h can b e c l e a r e d by reversing the cutters, and to s h u t - d o w n a n d s o u n d an alarm w h e n t h e system is c o m p l e t e l y b l o c k e d , thus avoiding u n n e c e s sary s h u t d o w n s o r failure. Contact: Mono Pumps, Martin Street, Audenshaw, Manchester M34 5DCL, UK. Tel: +44 161 339 9000; Fax: +44 161 344 0727.
Chinese plant receives axially split p u m p s from Newark
T h i r t e e n LNN a x i a l l y split casing p u m p s from IngersollDresser Pumps have been i n s t a l l e d in a n e w £ 1 8 . 8 m water treatment plant at Liuzhou in s o u t h e r n C h i n a . T h e p u m p s w e r e o r d e r e d as p a r t of c o n t r a c t w o n b y Purac Limited f r o m t h e client, t h e Liuzhou Water Supply Company. The w a t e r t r e a t m e n t w o r k s is n o w
WORLD PUMPS JANUARY 1998
in its c o m m i s s i o n i n g p h a s e and is d u e to deliver w a t e r before t h e e n d o f O c t o b e r 1997. M1 o f t h e LNN p u m p s w e r e p r o d u c e d at Ingersoll-Dresser Pumps' Newark manufacturing facility in N o t t i n g h a m s h i r e , England. Purac s e l e c t e d four 515 k W 600LNN950 p u m p s as intake w a t e r p u m p s , w h i c h are individually capable of
p u m p i n g u p to 4~()0 m3Alr o f w a t e r to p r o v i d e a total s u p p l y o f 800 million litres a day. The p u m p s are h o u s e d in a 40 m high intake tower situated m o r e than 30 m b e l o w g r o u n d level. T h e r e are also t w i n sets of LNN p u m p s for b a c k w a s h applications comprising two 37 k W 350LNN475 units and
'WASTE WATER
Muncher protects Thames Water's dewatering system O n e o f E u r o p e ' s largest sludge dewatering plants, Thames W a t e r ' s P e r r y Oaks site, is using a n u m b e r o f sludge g r i n d e r s and p r o g r e s s i n g cavity p u m p s from M o n o P u m p s to e n s u r e that all sludge is g r o u n d to t h e correct consistency before e n t e r i n g t h e centrifugal dewatering system. Blockage and clogging of the centrifuges c o u l d b e e x t r e m e l y costly in t e r m s o f d o w n t i m e a n d maintenance. T h e Perry Oaks site receives a p p r o x i m a t e l y 27 000 m 3 o f d i g e s t e d sludge p e r w e e k f r o m Mogden Sewage Treatment Works w h i c h is c e n t r i f u g a l l y d e w a t e r e d and c o n v e r t e d into agricultural fertiliser. Sludge w i t h a solids c o n t e n t o f a r o u n d 2% is p u m p e d from t h e storage tanks to t h e M o n o M u n c h e r . T h e M u n c h e r is a t w i n shaft s l o w s p e e d , high t o r q u e grinder which incorporates a series o f i n t e r l e a v i n g c u t t e r s and spacers giving positive d i s p l a c e m e n t solids grinding. The unique patented cutters pull a n d t e a s e a p a r t f i b r o u s material w h i l e t h e leading e d g e a n d sides o f t h e c u t t e r teeth, c r o p and s h e a r h a r d d e b r i s into small strips, a n d t h e circumferential ' l a n d ' o f t h e c u t t e r c r u s h e s friable o r brittle waste. T h e r e s u l t i n g s l u d g e is p u m p e d b y a M o n o industrial E Range p r o g r e s s i n g cavity p u m p to t h e c e n t r i f u g e s at variable rates o f 35 to 55 m3/hr. C a p a b l e
[]
of p u m p i n g c a p a c i t i e s u p to 350 m 3 / h r a n d p r e s s u r e s u p to 24 bar, t h e E Range p u m p s incorporate Mono's unique Flexishaft system, which p r o v i d e s a single c o m p o n e n t link b e t w e e n t h e r o t a r y m o t i o n o f t h e d r i v e shaft a n d t h e e c c e n t r i c m o t i o n o f t h e helical rotor. T h e r e d u c e d n u m b e r o f m o v i n g p a r t s in t h e drive train eliminates wear and makes lubrication unnecessary, thus r e d u c i n g the costs and inconvenience of downtime. John Goodman, operations m a n a g e r at t h e Perry, Oaks site c o m m e n t s , "As this site operates c o n t i n u o u s l y t h r o u g h o u t the year, w e require e q u i p m e n t w h i c h can d o t h e same. Since installation in 1994, e a c h p u m p has o p e r a t e d for m o r e t h a n 23 000 hours, m a k i n g a total o f just u n d e r 100 000 hours, w i t h
only o n e m i n o r m a i n t e n a n c e r e q u i r e m e n t in all that time." The positive d i s p l a c e m e n t design o f the M u n c h e r s and t h e E Range p u m p s e n s u r e s an a c c u r a t e f l o w o f sludge to the c e n t r i f u g e s w h i c h is critical to p r e v e n t t h e possibility o f overload. T h e M u n c h e r is s u p p l i e d w i t h a P r o g r a m m a b l e Logic C o n t r o l l e r w h i c h is d e s i g n e d to o p e r a t e in n o r m a l o n / o f f m o d e , to distinguish b e t w e e n an overload w h i c h can b e c l e a r e d by reversing the cutters, and to s h u t - d o w n a n d s o u n d an alarm w h e n t h e system is c o m p l e t e l y b l o c k e d , thus avoiding u n n e c e s sary s h u t d o w n s o r failure. Contact: Mono Pumps, Martin Street, Audenshaw, Manchester M34 5DCL, UK. Tel: +44 161 339 9000; Fax: +44 161 344 0727.
Chinese plant receives axially split p u m p s from Newark
T h i r t e e n LNN a x i a l l y split casing p u m p s from IngersollDresser Pumps have been i n s t a l l e d in a n e w £ 1 8 . 8 m water treatment plant at Liuzhou in s o u t h e r n C h i n a . T h e p u m p s w e r e o r d e r e d as p a r t of c o n t r a c t w o n b y Purac Limited f r o m t h e client, t h e Liuzhou Water Supply Company. The w a t e r t r e a t m e n t w o r k s is n o w
WORLD PUMPS JANUARY 1998
in its c o m m i s s i o n i n g p h a s e and is d u e to deliver w a t e r before t h e e n d o f O c t o b e r 1997. M1 o f t h e LNN p u m p s w e r e p r o d u c e d at Ingersoll-Dresser Pumps' Newark manufacturing facility in N o t t i n g h a m s h i r e , England. Purac s e l e c t e d four 515 k W 600LNN950 p u m p s as intake w a t e r p u m p s , w h i c h are individually capable of
p u m p i n g u p to 4~()0 m3Alr o f w a t e r to p r o v i d e a total s u p p l y o f 800 million litres a day. The p u m p s are h o u s e d in a 40 m high intake tower situated m o r e than 30 m b e l o w g r o u n d level. T h e r e are also t w i n sets of LNN p u m p s for b a c k w a s h applications comprising two 37 k W 350LNN475 units and