Tower Arrangement Standpipe Arrangement Stock from washers and thickeners fall into special Goulds standpipes that are reverse tapered to prevent stock bridging. Systems include controls for vacuum, dilution, level and flow. Stock from bleach / storage towers falls into Goulds standpipes connected to the tower with expansion joints and valves. Vacuum systems may not be needed as stock levels may be adequate to vent the air. Booster Arrangement Taking stock from standard medium consistency systems, Goulds booster pumps will increase pressures but do not require standpipes or degassing systems as air was removed in the primary pump. Goulds Model 3500 Medium Consistency Pump Systems Capacities to,000 ADSTPD (1850 ADMTPD) @1% O.D. Heads to 50 feet (198 m) 1780 RPM Direct Drive (Most Applications) Consistencies to 1% B.D. High Efficiency Design Pump System Advantages Advantage Efficiency Simplicity of Design Air Extraction System with Patented Secondary Air Separation Device Superior Reliability and Flexibility of External Vacuum Pump Degas System Control Scheme Alarms and Interlocks Technology Development New pump sizes Air handling knowledge Mixing liquid, gas Pipeline pulsation knowledge Successful Installations Selection Commissioning Follow-up Benefit Lower consumed HP Frequently smaller motors Familiarity due to similar design to conventional centrifugal pumps Ease of maintenance when required Simple, effective, no fiber loss Flexible operation Insures long-term pump service Model 3500 uses conventional pump assembly methods. Internal degas designs mounted on the pump shaft require difficult, multiple blind assembly techniques to achieve close internal clearances necessary for operation. The back pull out assembly does not have to be removed from service if the vacuum pump fails Failure of the vacuum pump does not risk production loss Simple level control scheme Effective response to common process changes Advancement of current products New product development Application guidelines and experience Over 100 installations Many repeat customers Applications in key services
Model 3500 Medium Consistency Pump Design Features for Reliable, Efficient Service LABYRINTH SEALS STANDARD Frame is sealed with carbon filled TEFLON labyrinth seals to protect against the harsh environments encountered in pulp mills and bleach plants. BEARINGS Thrust bearing is angular contact PumpPac designed to handle uni-directional thrust leads. Radial bearing is cylindrical roller design to handle high radial loads. Bearings are designed for -year minimum L'10 life with 1-year average life based on maximum loads. DOUBLE CARTRIDGE MECHANICAL SEALS For optimum sealing over full range of operating conditions. Seals from various manufacturers are available. CASING Top centerline discharge. Modified concentric design is key to efficient air removal and allows a wide operating range. LUBRICATION Flood oil is standard with cooling coil in sump. IMPELLER Open impeller with full back shroud. Close front clearance to achieve maximum pump efficiency. Large balance holes to remove air. Step cut design to optimize air separation and fiber retention. DEGASIFICATION NOZZLE Removes air to vacuum system. RENEWABLE SIDEPLATE Easily replaced for extended life. Sealed from pumpage. SECONDARY AIR SEPARATION DEVICE Patented design (U.S. Patent # 5,087,171) assists in minimizing or eliminating fiber pull through vacuum system. RUGGED CAST INDUCER Agitates stock to assist entry into pump. Keeps air well-mixed to assist removal process. CENTRIFUGE Helps separate air from stock and water mixture. Air collects along shaft for removal through impeller balance holes. 3
Standard System Controls, Alarms & Interlocks Standpipe Level/Dilution System DCV-1 DCV- STANDPIPE DC LT LC MODEL 3500 DCV-1UPPER DILUTION VALVE DCV-LOWER DILUTION VALVE LEVEL CONTROL VALVE LT LEVEL TRANSMITTER LC LEVEL CONTROLLER SIGNAL CONVERTER DC DILUTION CONTROLLER Constant standpipe level maintained by LC controlling on pump discharge. Alarms set at 85% and 10% level. Start up Interlock at minimum of 10% level to prevent dry running of pump. Automatic dilution system to assist pumping when standpipe level exceeds its setpoint. Seal & Flush Water System VACUUM PUMP MECHANICAL SEAL FLUSH ALARM FRAME COOLING OUT TO MECHANICAL SEAL IN FRAME COOLING IN VACUUM CHAMBER (STUFFING BOX COVER) 1/" FLUSH WATER INLET (CUSTOMER CONNECTION) Three separate flow meters control flow to: Mechanical seal & bearing cooling coil Vacuum pump make up Vacuum chamber An Alarm sounds if the flow rate drops below 50% of the required value. An Interlock keeps the pump from starting up without minimum seal and flush water flow. Degas System LT STOCK OUT LS LEVEL CONTROL VALVE LT LEVEL TRANSMITTER LC LEVEL CONTROLLER SIGNAL CONVERTER LS LIMIT SWITCH ARV AIR REMOVAL VALVE VR VACUUM RELIEF VALVE PI COMPOUND PRESSURE GAUGE Vacuum pump operates when Model 3500 operates. ARV is open when is open. An Alarm will sound if the vacuum pump shuts down. Closing ARV can isolate air removal system. STANDPIPE MODEL 3500 OPTIONAL FLUSH BY CUSTOMER ARV VR VACUUM PUMP PI SEWER
Air Removal System Model 3500 Without effective air removal, medium consistency pumps will not operate reliably. The efficient air removal system of the Model 3500 and the simple degas system result in easy operation and very low maintenance. 5 3 1 7 1 3 5 7 Induce Flow, Begin Air Separation Centrifuge forms air core along shaft Fiber and water are pumped by impeller vanes Vacuum pulls air with some water & fiber through balance holes Fiber and water pumped to impeller periphery Air with water is extracted past secondary air separation device Air and water are removed through vacuum system Inducer agitates pulp to assist flow into pump inlet. Also inducer action begins to separate air from fiber and water. Centrifuge performs key function of separating air from fiber and water. Fiber and water move to the periphery of the centrifuge, then are picked up by the impeller vanes. The air becomes concentrated in a core along the shaft for removal through the balance holes by the degas system. Fiber and water suspension are subjected to pumping action by impeller vanes. Modified concentric casing design allows for operation over wide flow range. Air and water, plus a small amount of residual fiber, pass through impeller balance holes. The large pump out vanes pump the fiber and water to the periphery of the impeller. Air with water is extracted across the top surface of the patented (US Patent#5,087,171) secondary air removal device into the vacuum system. This device permits separation of any remaining fiber which might be present at this point. Fiber pull through the vacuum system is virtually eliminated. The air and water pulled by the vacuum system is discharged to drain. At high suction standpipe levels and low consistencies, the pump may operate in the self-venting mode without vacuum assist. 5
Hydraulic Coverage Model 3500 CAPACITY 0 500 1000 1500 ADMTPD AT 1% O.D. 0 100 00 300 00 500 00 GPM 700 1780 RPM 00 00 175 TOTAL HEAD FEET 500 00 300 00 3x-1 x8-18h x8- x10-18 x10-h 150 15 100 75 50 TOTAL HEAD METERS 100 5 0 0 500 1000 1500 000 500 0 500 1000 1500 000 CAPACITY GPM 0 ADSTPD AT 1% O.D. Process Opportunities For Mixing In Pump Suction or Standpipe FAS NaOH H O H SO Na S O Steam With Inline Mixer (Model 3501) CIO (liquid) O (gas) Steam