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Form V372, Rev. 12 

- 4 - 

12/18, ECN4334 

 

Total Rotamix

TM

 flow is determined in consultation with Vaughan Co. Sales Engineering. The total flow 

is calculated based on your storage tank (or digester) volume and consideration of your tank geometry. 
Once you know total system flow, you can determine best sizing for suction and discharge piping. 
Vaughan Co. will help you with piping sizing recommendations. 

Nozzle sizing for the nozzle assemblies is also determined at the beginning of the Rotamix

TM

 project in 

consultation with Vaughan Co. Proper sizing for the nozzles is critically important in making the system 
work efficiently. 

 

Follow all confined space entry procedures when entering an enclosed tank. 

Nozzle aiming is performed once nozzle assembly installation is complete but before the storage or 
digester tank is closed up. Proper nozzle aiming is critically important and is performed by your 
Vaughan Co. representative. Please contact your representative to schedule this very important 
operation before closing the digester or storage tank. 

Finally, location of the nozzle assemblies within the digester is determined in consultation with Vaughan 
Co. In a cylindrical tank (such as a digester) the floor-mounted nozzles are typically mounted on a circle 
whose diameter is defined by Vaughan Co. based on the diameter of your storage tank. Also, the 
nozzle angles are determined by Vaughan Co. The positioning and angles of the nozzles in your 
digester or storage tank are defined on a Rotamix Nozzle Location Plan drawing specific to your 
project. This drawing will always be included in the custom Installation, Operation and Maintenance 
Manual for your particular Rotamix system. 

Vaughan Foambuster: 

The Vaughan Foambuster is a patented nozzle and splash plate combination that sprays sludge 
droplets over a large area at the upper surface of a digester to break down and suppress foam. In some 
cases, digester mixing systems are purchased with the addition of the Foambuster because of the risk 
of foaming, particularly in activated sludge plants. The Foambuster nozzle must be mounted above 
liquid level. Only a few inches of distance is enough to allow the Foambuster to work. Also, the 
Foambuster needs about 4 ft. of headroom above the height of the nozzle to allow the spray to cover as 
much of the tank surface as possible. The Foambuster works best with a fixed cover. Finally, the 
Foambuster is designed to be aimed radially inward toward the center if the Foambuster if located near 
the outer walls, or aimed radially outward toward the outer walls if the Foambuster is located at the tank 
center. When the Foambuster is used with the Rotamix system, Rotamix rotates the liquid in the tank 
below the Foambuster. In this way, one Foambuster can cover all the surface area of the tank as it 
rotates below the Foambuster. 

Vaughan Co. recommends that the Foambuster operates whenever the Rotamix system operates. By 
taking this approach, if foaming should occur, the Foambuster will always be operating to keep the level 
of foam broken down and under control. If foaming is allowed to take place when the Foambuster is not 
operating, foam may adhere to the tank walls, preventing the surface from rotating. If the upper surface 
does not rotate, the Foambuster will not be effective at controlling foam over the entire upper surface. 

System Venting: 

 

Explosions can kill or injure! Mixing may liberate gases of decomposition which are highly 
flammable or explosive. Do not use an open flame or non-explosion-proof equipment in areas 
where gas is present. Follow all plant safety procedures for hazardous areas. 

Sludge pumping systems are likely to generate gases of decomposition and these gases are likely to 
collect in either the suction piping or in the chopper pump casing. Should this occur, the pump would 
not work properly when started, since the impeller, when rotating, will collect gas and not be able to fill 
with the sludge to be pumped. So gas buildup in the system may keep your pump and Rotamix system 
from working properly. This can be particularly troublesome if your system operates intermittently. Gas 
binding is also much more common if your pump has other than a top discharge on the pump casing. 

Summary of Contents for ROTAMIX SYSTEM

Page 1: ...STALLATION OPERATION MAINTENANCE INSTRUCTIONS VAUGHAN CO INC 364 Monte Elma Road Montesano WA 98563 Phone 1 360 249 4042 Fax 1 360 249 6155 Toll Free Phone US only 1 888 249 CHOP 2467 Web Site www chopperpumps com Company E mail info chopperpumps com ...

Page 2: ...Form V372 Rev 12 10 18 ECN4334 This manual is for all Vaughan Rotamix Systems NOTE The pump for your Rotamix System will require an additional IO M manual ...

Page 3: ... A Receipt Inspection B Storage Considerations C Installation I Vaughan Foambuster II Roof Mounted Nozzles III System Venting D Nozzle Aiming Instructions 4 STARTUP INSTRUCTIONS Page 7 5 NORMAL OPERATION Page 12 A Digester Mixing B Sludge Tank Mixing C Blend Tank Mixing 7 SHUTDOWN INSTRUCTIONS Page 13 8 MAINTENANCE Page 13 A Routine Maintenance B Corrective Maintenance 9 TROUBLESHOOTING Page 14 10...

Page 4: ...of low voltage poor ventilation overloaded lines etc These motors can restart automatically as the motor cools down DO NOT work on the pump or motor without first disconnecting and locking out the power supply Enter tanks or pits with extreme caution and only after an instrument check of the pit tank has been completed to verify the absence of dangerous gases and the presence of safe levels of oxy...

Page 5: ...wn from the pump as a projectile All pumps must be run with suction and discharge piping in place or blind flanges installed on suction and discharge connections Blind flanges should be vented to avoid pressure build up Note that cast rotating parts could break if metal to metal contact occurs while the pump is running dry Shut pump off when adjusting fittings to avoid being sprayed with pumpage P...

Page 6: ... the crating is damaged look for cracked fittings and clamps or damaged paint report damage to your carrier Vaughan Co can also work with you to provide replacement fittings as needed B STORAGE CONSIDERATIONS The epoxy paint on the nozzle assembly is susceptible to damage from prolonged UV exposure If nozzle assemblies are to be stored for more than two weeks prior to installation they must be eit...

Page 7: ...ming particularly in activated sludge plants The Foambuster nozzle must be mounted above liquid level Only a few inches of distance is enough to allow the Foambuster to work Also the Foambuster needs about 4 ft of headroom above the height of the nozzle to allow the spray to cover as much of the tank surface as possible The Foambuster works best with a fixed cover Finally the Foambuster is designe...

Page 8: ...st approach b You can use a solenoid controlled valve 2 is best controlled by a timer in your control panel which would open this valve prior to each startup of the pump Based on experimentation you can determine how long it takes to vent the gas from the system to completely fill the pump casing before the pump starts You can then set the timer to this setting Again run the piping either to a dra...

Page 9: ...egree mark on the protractor See your Nozzle Layout drawing for the proper angles to set your nozzles Moving the lower nozzle will tend to move the protractor also Be sure to recheck the zero point before tightening the lower nozzle clamp STEP 4 To aim the upper nozzle tie the plumb bob string to the bolt on the nozzle clamp as shown Make sure that it hangs from the the center of the nozzle Loosen...

Page 10: ...o mixing at allSee the pump IO M Manual for pump startup and operating instructions Vaughan Co requires the Startup Certification Checklist pages with the job specific Vaughan Rotamix tank drawing marked up with nozzle locations nozzle angles nozzle elevations and confirmation of all bolt torques to be sent to Vaughan Engineering If the job specific tank drawing is not available please contact Vau...

Page 11: ...rmation of all bolt torques to be sent to Vaughan Engineering All verified dimensions should be indicated by a circle or check mark on that dimension Rotamix Drawing No _____________________________ Is drawing attached Yes ____ No ____ Is drawing marked up to show each verified nozzle location Yes ____ No ____ Is drawing marked up to show each verified nozzle angle Yes ____ No ____ SYSTEM DATA Tan...

Page 12: ..._____ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ ___________________...

Page 13: ...f maintaining continuous mixing during foaming or RVE events is that pockets of feed sludge are continuously mixed with the rest of the digestate spreading out gas generation over a maximum time period to minimize sudden bursts of liberated gas By maintaining continuous mixing at lower speeds the gas generation and therefore the foam generation is kept more under control Reduced energy mixing for ...

Page 14: ...working order and that the nozzles are still properly aimed Whenever you check the nozzle system inspect the nozzle opening to make sure that the glass coating is still intact If the glass coating and ductile iron metal is worn away replace the nozzle For polyurethane nozzles measure the discharge diameter to make sure that it is no more than 15 larger than it was when new For example a new 2 00 d...

Page 15: ...ump speed For example if 100 speed is at 60 Hz on your VFD do not run the VFD at less than 45 Hz Too slow of a speed reduces pump and system pressure and can result in nozzle plugging 2 Troubleshooting the nozzles A Historically about of 1 of Rotamix systems experience a plugged nozzle so while blockage can occur it s not a common problem Nozzle blockage may show up as reduced mixing within your d...

Page 16: ...sentatives is required and can head off problems with installation of incorrect nozzle size D A worn nozzle may show up as increased mixing within your digester or storage tank Other symptoms of a worn nozzle could be higher than normal mixing pump electric motor power requirements higher amps and lower pump discharge pressure compared to your recorded readings at startup You may also hear pump ca...

Page 17: ... VSR and this means that more gases of decomposition methane and carbon dioxide are generated We want high VSR for better digestion and we want more gas for cogeneration of electricity However generating too much gas in a digester over too little time can lead to foaming RVE issues and possible digester overflows Digester overflow means bad odors a big cleanup and complaints from residential neigh...

Page 18: ... start If foaming occurs after startup of the mixing system and a Foambuster has not been installed with the system the recovery costs for installing a Foambuster are much higher D Poor mixing can result if the viscosity of the mixed sludge is too high This situation can occur when mixing very thick TWAS thickened waste activated sludge Once TWAS gets up to the range of 6 7 solids mixing may be di...

Page 19: ...le parts are repaired or replaced by anyone other than Vaughan Co or its duly authorized representatives Vaughan Co assumes no liability for consequential damages of any kind and the purchaser by acceptance of delivery assumes all liability for the consequences of the use or misuse of Vaughan Co products by the purchaser its employees or others Vaughan Co will not be held responsible for travel ex...

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