- Email: [email protected]
Peristaltic pumps aid groundwater pollution prevention
PPLICATIONS
B
High density solids pump desludges tar lake
It is c o s t i n g t h e L a u s i t z e r Umwelt GmbH DM40 m i l l i o n to r e d e v e l o p two l a r g e t a r lakes, a~pproximately 5 0 0 0 0 m - a-t S c h w a r z e Pumpe, Hoyerswerda (Saxony) in Germany. U s i n g a special floating excavator, s u p p l i e d by Finnish manufacturer Aquam e c / L ~ n n e n , a n d a Putzmeister large volume high density solids p u m p KOS 2180, called the "Dredgemaster", the redev e l o p m e n t c o m p a n y started the desludging a n d disposal work of the t a r deposits. The t a r sludge is fed to a p r e p a r a t i o n p l a n t a n d t h e n delivered to a neighb o u r i n g brown coal power station. The t a r l a k e s h a v e b e e n collecting since 1964 from the p r o d u c t i o n of city gas from brown coal. East G e r m a n y had n e i t h e r the technical n o r the financial m e a n s to dispose of this residue in an e n v i r o n m e n tally-friendly m a n n e r . Now the t a r l a k e s t h r e a t e n to l e a k t h r o u g h to the layers of the deposit leading to the groundwater, affecting t h e d r i n k i n g water supply for a whole region.
The floating excavator a n d D r e d g e m a s t e r r e m o v e u p to 350 t o n n e s daily of the t a r / o i l and solids mix containing phenol. The grab of the excavator first passes the m a t e r i a l to a swinging screen in which any foreign bodies larger t h a n 80 x 80 m m are separated. The t a r sludge is t h e n passed to 3 m capacity m i x e r trough a n d the m a t e r i a l is extensively homogenised. The m i x e r trough is p u t in front of the high d e n s i t y solids p u m p a n d serves as a supply h o p p e r at the same time, i.e. p u m p conveying is c o n t i n u ous even with irregular sludge removal. Due to the p h e n o l v a p o u r s w h i c h rise u p from t h e t a r deposits, the o p e r a t o r c a n n o t work aboard the Dredgemaster. Putzmeister a n d A q u a m e c / I A n n e n have therefore e q u i p p e d the complete system with remote control. The remote control system is carried out via joy-sticks from a central control which is situated on the b a n k of the t a r lake. With the help of two video recorders on b o a r d a n d the c o r r e s p o n d i n g m o n i t o r s on l a n d , t h e p e r s o n n e l c a n m o n i t o r t h e p r o c e s s from a safe distance. The high density solids p u m p , type KOS 2180, has been designed by Putzmeister taking into a c c o u n t the o u t p u t a n d conveying p r e s s u r e in accor-
d a n c e with the c u s t o m e r s ' requests. The m a i n p u m p u n i t consists of a two-cylinder piston p u m p which is hydraulically driven linearly. The conveying p i s t o n s move u n i f o r m l y in a ' p u s h - p u l l ' action, suction a n d pressure stroke alternate. The especially long piston stroke of 2100 m m allows a n o u t p u t of a p p r o x i m a t e l y 130 l / s t r o k e . Putzmeister h a d designed the KOS high density solids p u m p for a c o n v e y i n g o u t p u t of 47 m3/h. An "S" transfer t u b e connects the two delivery cylinders a n d the c o n n e c t e d - u p delivery line. The technical design of the t r a n s f e r - t u b e c o n t r o l l e d KOS p u m p s is based on experience gained by the m a n u f a c t u r e r in conveying high d e n s i t y solids t h a t are difficult to p u m p a n d t h a t are of t o t a l l y d i f f e r e n t c o m p o s i t i o n s , s u c h as filter cake, sludges a n d pastes.
Contact: JQrgen Kronenberg, Putzmeister-Werk, Maschinefabrik GmbH, PO Box 2152, D• 12629 Aichtal, Germany.
Peristaltic pumps aid groundwater pollution prevention The ARGE c o m p a n y in Kreuzmont, Austria, is using Waukesha Bredel heavy duty p e r i s t a l t i c p u m p s to h a n d l e Bentonite slurry at a n u m b e r of landfill sites. The p u m p s are used to p r e v e n t p o l l u t i o n of g r o u n d w a t e r a n d to p r o t e c t rivers a g a i n s t c o n t a m i n a t i o n from low level c o n s t r u c t i o n sites. Two m e t h o d s are used to isolate the landfill; the sheet pile wall system in which Bredel S P / 1 0 0 (100 m m i.d h o s e ) p u m p s are used a n d the t h i n wall system in which the p u m p s are type SP/65. P r o g r e s s i v e cavity p u m p s originally u s e d proved expensive to operate in terms of abrasive wear, spares c o n s u m p t i o n a n d downtime. In the sheet pile wall system, a n a r r o w trench or groove is excavated to a d e p t h below the p e r m e a b l e strata, this can be as deep as 50 m. As drilling takes
WORLD PUMPS MARCH 1995
PPLICATIONS
place, t h e t r e n c h is filled w i t h Bentonite which, having an specific g r a v i t y h i g h e r t h a n water, p r e v e n t s g r o u n d w a t e r ingress. As each s e c t i o n of t r e n c h is c o m p l e t e d , art i m p e r m e a b l e m i x t u r e of s a n d c e m e n t , B e n t o nite a n d w a t e r is p u m p e d in. P u m p i n g t a k e s p l a c e from t h e bottom upwards until the trench is c o m p l e t e l y full; t h e B e n t o n i t e is s i m u l t a n e o u s l y p u m p e d away. The final filler is fed as a premix directly to t h e Bredel SP/ 100 p u m p w h i c h is t r o l l e y mounted and r u n s at a speed of 25 r e v / m i n , t h e d i s c h a r g e pressure is 15 bar. In t h e t h i n w a l l s y s t e m , H - s h a p e d p r o f i l e s are d r i v e n into the soil c r e a t i n g grooves a t d e p t h s u p to 35 m. T h e grooves are t h e n filled w i t h a Bentonite mixture containing an isolating compound. The Bentonite h a r d e n s but retains an e l e m e n t of elasticity. B e n t o n i t e is m i x e d on site a n d p u m p e d to a m o b i l e s t o r a g e t a n k by a Bredel S P / 6 5 p u m p . A typical installation involves p u m p i n g o v e r a d i s t a n c e of 800 m t h r o u g h 65 m d i a m e t e r pipe. O u t p u t is 22 m3/h.
Contact: Wim Mantel, Waukesha Bredel Fluid Handling BV, PO Box 47, NL-7490 AA Delden, The Netherlands. Tel: +31 5407 62615; Fax: +31 5407 62605.
B
Elastomer bellows seal increases pump service life
O p e r a t i n g 14 p u m p s t a t i o n s efficiently, a delivery t e r m i n a l a n d 800 miles of 100 m m to 4 0 0 m m d i a m e t e r lines across open countryside distributing s w e e t a n d s o u r crude oil dem a n d s a n intensive a m o u n t of m a i n t e n a n c e effort. P o r t a l Pipe Line, USA, was e x p e r i e n c i n g p r o b l e m s with its s y s t e m a n d one or more seal r e p a i r s were being m a d e weekly. Seals were providing only 5 0 0 h o u r s service before failu r e a n d generally r e m a i n i n g in o p e r a t i o n from between one to t h r e e weeks. To precipitate any seal f a i l u r e a n d downtime, 38 °C warm crude containing h y d r o g e n s u l p h i d e gas w a s p u m p e d i n t o reserve; this led t o p r i m a r y ring corrosion in the seals. Alternative materials were tried including carbon a n d b r o n z e b u t n o t h i n g held u p for m o r e t h a n a couple of months. In addition, other pump c o m p o n e n t s were often found damaged. H y d r o c a r b o n sulphide migrated under and a l o n g t h e seal s h a f t sleeve c a u s i n g p i t t i n g a n d corrosion w h i c h locked the sleeve in place o n t h e p u m p shaft. Crude oil v a p o u r c o n s i s t i n g of hydrogen
sulphide a n d other trace hydrocarbons, also proved a p o t e n t i a l h a z a r d by f o r m i n g a v a p o u r cloud around leaking seals which could easily ignite. Portal called i n J o h n Crane to e x a m i n e the problem. The r e c o m m e n d a t i o n was a J o h n Crane Type 1B elastomer bellows s e a l w i t h a t u n g s t e n carbide mating ring and a silicon carbide p r i m a r y ring. The seal is self-aligning with automatic adjustment to c o m p e n s a t e for a b n o r m a l shaft end play. Incorporating a n o t c h e d drive b a n d t h a t prev e n t s u n d u e stress on the elastomer bellows it e l i m i n a t e s slippage p r o t e c t i n g the shaft a n d sleeve from wear. N o n - c l o g g i n g is a c c o m p l i s h e d t h r o u g h a single-coil spring design. The seal can be used with t e m p e r a t u r e s from -40 to + 200 °C, a n d accommodate pressures to 1200 psig. To meet Portal's need for p u m p s t a r t - u p s d u r i n g cold weather periods, Buna-N m a t e r i a l was specified for the O-rings a n d elastomer bellows as it is designed for temperatures to -40 °C. The first Type 1B seal was sized for 76 m m s h a f t a n d installed for testing. The tests proved successful with the p u m p s staying on-line w i t h o u t interruption. Recently new seals have been i n s t a l l e d a c r o s s a r a n g e of s h a f t s f r o m 63 to 90 m m . mechanical Company supervisors have reported several of the p u m p s operating c o n t i n u o u s l y for m o r e t h a n 20 000 hours since initial installation.
Contact: The Market Development Group, John Crane UK, Crossbow House, 40 Liverpool Rd, Slough, SL1 4QX, UK. Tel: +44 1753 224000; Fax: +44 1753 224422.
B
Mobile Bredel pump unit
WORLD PUMPS MARCH 1995
Variable s p e e d drives simulate water flow
ABB I n d u s t r i a l S y s t e m s a.c. drives have been installed at the new UK Coastal Research
B
High density solids pump desludges tar lake
It is c o s t i n g t h e L a u s i t z e r Umwelt GmbH DM40 m i l l i o n to r e d e v e l o p two l a r g e t a r lakes, a~pproximately 5 0 0 0 0 m - a-t S c h w a r z e Pumpe, Hoyerswerda (Saxony) in Germany. U s i n g a special floating excavator, s u p p l i e d by Finnish manufacturer Aquam e c / L ~ n n e n , a n d a Putzmeister large volume high density solids p u m p KOS 2180, called the "Dredgemaster", the redev e l o p m e n t c o m p a n y started the desludging a n d disposal work of the t a r deposits. The t a r sludge is fed to a p r e p a r a t i o n p l a n t a n d t h e n delivered to a neighb o u r i n g brown coal power station. The t a r l a k e s h a v e b e e n collecting since 1964 from the p r o d u c t i o n of city gas from brown coal. East G e r m a n y had n e i t h e r the technical n o r the financial m e a n s to dispose of this residue in an e n v i r o n m e n tally-friendly m a n n e r . Now the t a r l a k e s t h r e a t e n to l e a k t h r o u g h to the layers of the deposit leading to the groundwater, affecting t h e d r i n k i n g water supply for a whole region.
The floating excavator a n d D r e d g e m a s t e r r e m o v e u p to 350 t o n n e s daily of the t a r / o i l and solids mix containing phenol. The grab of the excavator first passes the m a t e r i a l to a swinging screen in which any foreign bodies larger t h a n 80 x 80 m m are separated. The t a r sludge is t h e n passed to 3 m capacity m i x e r trough a n d the m a t e r i a l is extensively homogenised. The m i x e r trough is p u t in front of the high d e n s i t y solids p u m p a n d serves as a supply h o p p e r at the same time, i.e. p u m p conveying is c o n t i n u ous even with irregular sludge removal. Due to the p h e n o l v a p o u r s w h i c h rise u p from t h e t a r deposits, the o p e r a t o r c a n n o t work aboard the Dredgemaster. Putzmeister a n d A q u a m e c / I A n n e n have therefore e q u i p p e d the complete system with remote control. The remote control system is carried out via joy-sticks from a central control which is situated on the b a n k of the t a r lake. With the help of two video recorders on b o a r d a n d the c o r r e s p o n d i n g m o n i t o r s on l a n d , t h e p e r s o n n e l c a n m o n i t o r t h e p r o c e s s from a safe distance. The high density solids p u m p , type KOS 2180, has been designed by Putzmeister taking into a c c o u n t the o u t p u t a n d conveying p r e s s u r e in accor-
d a n c e with the c u s t o m e r s ' requests. The m a i n p u m p u n i t consists of a two-cylinder piston p u m p which is hydraulically driven linearly. The conveying p i s t o n s move u n i f o r m l y in a ' p u s h - p u l l ' action, suction a n d pressure stroke alternate. The especially long piston stroke of 2100 m m allows a n o u t p u t of a p p r o x i m a t e l y 130 l / s t r o k e . Putzmeister h a d designed the KOS high density solids p u m p for a c o n v e y i n g o u t p u t of 47 m3/h. An "S" transfer t u b e connects the two delivery cylinders a n d the c o n n e c t e d - u p delivery line. The technical design of the t r a n s f e r - t u b e c o n t r o l l e d KOS p u m p s is based on experience gained by the m a n u f a c t u r e r in conveying high d e n s i t y solids t h a t are difficult to p u m p a n d t h a t are of t o t a l l y d i f f e r e n t c o m p o s i t i o n s , s u c h as filter cake, sludges a n d pastes.
Contact: JQrgen Kronenberg, Putzmeister-Werk, Maschinefabrik GmbH, PO Box 2152, D• 12629 Aichtal, Germany.
Peristaltic pumps aid groundwater pollution prevention The ARGE c o m p a n y in Kreuzmont, Austria, is using Waukesha Bredel heavy duty p e r i s t a l t i c p u m p s to h a n d l e Bentonite slurry at a n u m b e r of landfill sites. The p u m p s are used to p r e v e n t p o l l u t i o n of g r o u n d w a t e r a n d to p r o t e c t rivers a g a i n s t c o n t a m i n a t i o n from low level c o n s t r u c t i o n sites. Two m e t h o d s are used to isolate the landfill; the sheet pile wall system in which Bredel S P / 1 0 0 (100 m m i.d h o s e ) p u m p s are used a n d the t h i n wall system in which the p u m p s are type SP/65. P r o g r e s s i v e cavity p u m p s originally u s e d proved expensive to operate in terms of abrasive wear, spares c o n s u m p t i o n a n d downtime. In the sheet pile wall system, a n a r r o w trench or groove is excavated to a d e p t h below the p e r m e a b l e strata, this can be as deep as 50 m. As drilling takes
WORLD PUMPS MARCH 1995
PPLICATIONS
place, t h e t r e n c h is filled w i t h Bentonite which, having an specific g r a v i t y h i g h e r t h a n water, p r e v e n t s g r o u n d w a t e r ingress. As each s e c t i o n of t r e n c h is c o m p l e t e d , art i m p e r m e a b l e m i x t u r e of s a n d c e m e n t , B e n t o nite a n d w a t e r is p u m p e d in. P u m p i n g t a k e s p l a c e from t h e bottom upwards until the trench is c o m p l e t e l y full; t h e B e n t o n i t e is s i m u l t a n e o u s l y p u m p e d away. The final filler is fed as a premix directly to t h e Bredel SP/ 100 p u m p w h i c h is t r o l l e y mounted and r u n s at a speed of 25 r e v / m i n , t h e d i s c h a r g e pressure is 15 bar. In t h e t h i n w a l l s y s t e m , H - s h a p e d p r o f i l e s are d r i v e n into the soil c r e a t i n g grooves a t d e p t h s u p to 35 m. T h e grooves are t h e n filled w i t h a Bentonite mixture containing an isolating compound. The Bentonite h a r d e n s but retains an e l e m e n t of elasticity. B e n t o n i t e is m i x e d on site a n d p u m p e d to a m o b i l e s t o r a g e t a n k by a Bredel S P / 6 5 p u m p . A typical installation involves p u m p i n g o v e r a d i s t a n c e of 800 m t h r o u g h 65 m d i a m e t e r pipe. O u t p u t is 22 m3/h.
Contact: Wim Mantel, Waukesha Bredel Fluid Handling BV, PO Box 47, NL-7490 AA Delden, The Netherlands. Tel: +31 5407 62615; Fax: +31 5407 62605.
B
Elastomer bellows seal increases pump service life
O p e r a t i n g 14 p u m p s t a t i o n s efficiently, a delivery t e r m i n a l a n d 800 miles of 100 m m to 4 0 0 m m d i a m e t e r lines across open countryside distributing s w e e t a n d s o u r crude oil dem a n d s a n intensive a m o u n t of m a i n t e n a n c e effort. P o r t a l Pipe Line, USA, was e x p e r i e n c i n g p r o b l e m s with its s y s t e m a n d one or more seal r e p a i r s were being m a d e weekly. Seals were providing only 5 0 0 h o u r s service before failu r e a n d generally r e m a i n i n g in o p e r a t i o n from between one to t h r e e weeks. To precipitate any seal f a i l u r e a n d downtime, 38 °C warm crude containing h y d r o g e n s u l p h i d e gas w a s p u m p e d i n t o reserve; this led t o p r i m a r y ring corrosion in the seals. Alternative materials were tried including carbon a n d b r o n z e b u t n o t h i n g held u p for m o r e t h a n a couple of months. In addition, other pump c o m p o n e n t s were often found damaged. H y d r o c a r b o n sulphide migrated under and a l o n g t h e seal s h a f t sleeve c a u s i n g p i t t i n g a n d corrosion w h i c h locked the sleeve in place o n t h e p u m p shaft. Crude oil v a p o u r c o n s i s t i n g of hydrogen
sulphide a n d other trace hydrocarbons, also proved a p o t e n t i a l h a z a r d by f o r m i n g a v a p o u r cloud around leaking seals which could easily ignite. Portal called i n J o h n Crane to e x a m i n e the problem. The r e c o m m e n d a t i o n was a J o h n Crane Type 1B elastomer bellows s e a l w i t h a t u n g s t e n carbide mating ring and a silicon carbide p r i m a r y ring. The seal is self-aligning with automatic adjustment to c o m p e n s a t e for a b n o r m a l shaft end play. Incorporating a n o t c h e d drive b a n d t h a t prev e n t s u n d u e stress on the elastomer bellows it e l i m i n a t e s slippage p r o t e c t i n g the shaft a n d sleeve from wear. N o n - c l o g g i n g is a c c o m p l i s h e d t h r o u g h a single-coil spring design. The seal can be used with t e m p e r a t u r e s from -40 to + 200 °C, a n d accommodate pressures to 1200 psig. To meet Portal's need for p u m p s t a r t - u p s d u r i n g cold weather periods, Buna-N m a t e r i a l was specified for the O-rings a n d elastomer bellows as it is designed for temperatures to -40 °C. The first Type 1B seal was sized for 76 m m s h a f t a n d installed for testing. The tests proved successful with the p u m p s staying on-line w i t h o u t interruption. Recently new seals have been i n s t a l l e d a c r o s s a r a n g e of s h a f t s f r o m 63 to 90 m m . mechanical Company supervisors have reported several of the p u m p s operating c o n t i n u o u s l y for m o r e t h a n 20 000 hours since initial installation.
Contact: The Market Development Group, John Crane UK, Crossbow House, 40 Liverpool Rd, Slough, SL1 4QX, UK. Tel: +44 1753 224000; Fax: +44 1753 224422.
B
Mobile Bredel pump unit
WORLD PUMPS MARCH 1995
Variable s p e e d drives simulate water flow
ABB I n d u s t r i a l S y s t e m s a.c. drives have been installed at the new UK Coastal Research