Portable Tank Mixers

Portable tank mixers are submersible mixing units designed for temporary deployment in basins, tanks, or lagoons where permanent mixers aren't installed or are offline for maintenance. You lower the unit into the liquid using a lifting cable or hoist, position it at the desired depth, and connect power via a flexible cord. The mixer's propeller circulates the tank contents to prevent settling, maintain uniform chemistry, or blend new additives. These units typically deliver mixing velocities of 0.3 to 0.5 feet per second in municipal applications. The key trade-off is mobility versus durability—portable units experience more wear from repeated handling, cable flexing, and exposure during moves between tanks compared to permanently mounted equipment, which means you'll inspect seals and cables more frequently than you would with fixed installations.

• Chemical Feed Tank Mixing: Portable mixers maintain polymer solutions in 50-500 gallon day tanks at clarifier and belt press facilities. They prevent stratification and settling that reduces polymer effectiveness by 20-30%. Connected via quick-disconnect flanges, operators move units between tanks as needed rather than installing fixed mixers on every tank.

• Emergency Mixing Operations: During fixed mixer failures, portable units maintain critical processes like lime slurry mixing or alum feed preparation. 5-15 HP units handle most municipal chemical tanks, with deployment within 30 minutes preventing process upsets.

• Temporary Basin Mixing: Construction projects and seasonal lagoon turnover require temporary mixing. Units with 20-50 foot cables reach basin bottoms, providing 0.5-2.0 HP per 1000 gallons for effective turnover in detention basins and equalization tanks.

• Biosolids Holding Tank Mixing: Portable mixers prevent settling in 10,000-50,000 gallon holding tanks before dewatering, maintaining 3-5% solids concentration uniformity essential for consistent belt press performance.

Misconception 1: Portable mixers are simply smaller versions of permanent mixers and can run continuously for months without attention.

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Reality: Portables endure harsher conditions from frequent moves, cable strain, and varied deployment depths, requiring more frequent seal and cable inspections.

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Action: Ask your maintenance team to establish a monthly inspection schedule covering cable integrity and mechanical seal condition.

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Misconception 2: You can use the same portable mixer across any tank size or depth without adjusting placement or runtime.

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Reality: Effective mixing depends on propeller depth, tank geometry, and solids concentration—what works in one basin may create dead zones in another.

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Action: Work with operations staff to document optimal depth settings and observe mixing patterns when first deploying in a new tank.

Propeller generates thrust to move water through the tank by converting shaft rotation into axial flow. Typically cast or fabricated stainless steel with 2-4 blades, sized by diameter to match tank volume and mixing intensity. Blade pitch and diameter determine flow rate—undersized propellers create dead zones while oversized units waste energy and stress the mount.

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Motor provides rotational power to the propeller shaft, usually mounted above the liquid surface on the support frame. Direct-drive or gear-reduced electric motors ranging from 0.5 to 5 HP, with TEFC or explosion-proof enclosures for wastewater environments. Motor selection affects mixing speed and torque—higher speeds suit low-viscosity liquids while gear reduction handles sludge or polymer solutions.

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Shaft connects the motor to the propeller and transmits torque while resisting bending loads from thrust and off-axis forces. Constructed from 304 or 316 stainless steel with length adjustable to tank depth, often with intermediate bearing support. Shaft rigidity prevents wobble that damages seals—longer shafts require larger diameters or support bearings to avoid deflection during operation.

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Mounting frame positions the mixer at the correct angle and depth while supporting motor weight and thrust reaction forces. Typically stainless steel or powder-coated carbon steel with adjustable legs or clamps that hook over tank walls. Secure mounting prevents vibration and maintains propeller depth—loose frames allow the unit to shift and create uneven mixing or surface splashing.

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Seals and bearings isolate the motor from process fluid and support the rotating shaft with minimal friction. Mechanical seals or lip seals at the shaft entry point, with grease-lubricated or oil-bath bearings in the gearbox or motor housing. Seal failure allows water ingress that ruins motors—regular inspection catches leaks before moisture reaches electrical components and causes costly downtime.

Daily Operations: You'll check for unusual noise or vibration during walk-throughs and verify the propeller remains submerged at the target depth. Normal operation shows steady current draw on the motor and visible surface movement without excessive splashing or vortexing. Notify maintenance if you hear grinding sounds, see shaft wobble, or detect a burning smell—these indicate bearing wear or electrical issues requiring immediate shutdown.

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Maintenance: Inspect seals weekly for leaks and check mounting bolts monthly for tightness, wearing gloves and safety glasses when working near rotating equipment. Most plants handle bearing lubrication and seal replacement in-house with basic mechanical skills, but motor rebuilds typically require vendor service. Annual propeller removal for inspection takes 1-2 hours and costs minimal downtime—catching blade erosion or shaft wear early avoids emergency repairs during peak demand.

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Troubleshooting: Excessive vibration usually means a bent shaft or damaged propeller blade, while decreasing flow indicates worn bearings or a loose propeller. Seals typically last 2-3 years in clean water and 1-2 years in grit-laden environments—watch for moisture around the shaft housing as an early warning. You can tighten mounting hardware and adjust depth yourself, but call for help if motor current spikes or the shaft binds—these signal internal damage requiring disassembly and parts replacement.

Portable tank mixer selection depends on interdependent variables including tank geometry, process requirements, and mixing intensity needs. Understanding these parameters helps you ask manufacturers the right questions and evaluate trade-offs during equipment selection.

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Impeller Diameter (inches) determines the zone of influence and mixing energy distribution within the tank. Municipal portable tank mixers commonly use impellers between 12 and 36 inches in diameter. Larger impellers create broader flow patterns suitable for bulk blending in storage tanks, while smaller impellers concentrate energy for localized mixing in process tanks or when solids suspension is critical.

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Motor Power (horsepower) drives mixing intensity and determines electrical service requirements at temporary installation points. Municipal portable tank mixers commonly operate between 0.5 and 5 horsepower. Higher power delivers the velocity needed for dense slurries or rapid blending, while lower power suffices for gentle mixing in chemical feed tanks or situations where you want to avoid shearing biological flocs.

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Shaft Length (feet) must reach the optimal mixing zone while providing structural stability during operation. Municipal portable tank mixers commonly feature shafts between 3 and 12 feet long. Longer shafts accommodate deeper tanks but require more robust mounting hardware to prevent deflection, while shorter shafts simplify setup and reduce vibration concerns in shallow basins.

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Impeller Speed (rpm) controls shear forces and flow velocity throughout the mixing zone. Municipal portable tank mixers commonly rotate between 400 and 1,750 rpm. Higher speeds generate turbulence for difficult mixing tasks but may damage fragile flocs, while lower speeds provide gentle turnover suitable for blending without disrupting biological processes or settled solids.

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Mounting Configuration affects installation flexibility and operational stability across different tank geometries. Municipal portable tank mixers commonly use clamp-on bridge mounts or weighted base designs. Bridge mounts offer precise positioning and stability for rectangular tanks, while weighted bases provide quick deployment in circular tanks without permanent modifications.

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All values are typical ranges—actual selection requires manufacturer consultation and site-specific analysis.

What mixer mounting configuration fits your tank access and structural constraints?

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• Why it matters: Mounting method determines installation complexity, required structural modifications, and operational flexibility.
• What you need to know: Tank diameter, wall thickness, access points, overhead clearance, and existing structural supports.
• Typical considerations: Bridge-mounted units span tank diameter and distribute load but require overhead support structures. Deck-mounted configurations attach to tank walls or internal columns, minimizing overhead work but concentrating loads. Wall-mounted designs suit tanks with limited top access but require reinforced attachment points and careful alignment.
• Ask manufacturer reps: What mounting hardware and structural load calculations do you provide for our tank configuration?
• Ask senior engineers: Have you encountered installation challenges with this mounting type in similar tank geometries?
• Ask operations team: How often do you need to remove or reposition mixers during maintenance activities?

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How will you balance mixing intensity against solids settling and energy consumption?

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• Why it matters: Insufficient mixing causes settling and process failures; excessive mixing wastes energy and damages floc.
• What you need to know: Process requirements, solids concentration, desired velocity gradient, acceptable power density, and operational flexibility needs.
• Typical considerations: Equalization and blending applications tolerate higher intensity mixing with fewer settling concerns. Flocculation and biological processes require gentler mixing to preserve particle structure while maintaining suspension. Variable speed capability allows operators to adjust intensity for changing influent conditions or seasonal variations.
• Ask manufacturer reps: What impeller options provide the velocity gradient range our process requires without oversizing?
• Ask senior engineers: What mixing intensity has worked in similar applications at other facilities you've designed?
• Ask operations team: Do current process conditions vary enough that speed adjustment would improve performance?

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What sealing and corrosion protection matches your water chemistry and maintenance capabilities?

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• Why it matters: Seal failures cause downtime and contamination; inadequate materials corrode prematurely in aggressive environments.
• What you need to know: Water pH, chloride content, temperature ranges, presence of abrasives, and maintenance staff experience level.
• Typical considerations: Mechanical seals handle most municipal applications but require periodic replacement and proper lubrication. Oil-filled housings protect bearings in corrosive environments but need monitoring for leaks. Material selection balances corrosion resistance with cost—stainless steel wetted parts suit most conditions while specialized coatings address extreme chemistry.
• Ask manufacturer reps: What seal configuration and materials do you recommend for our specific water chemistry profile?
• Ask senior engineers: What seal types have required the least maintenance in facilities with similar conditions?
• Ask operations team: What seal maintenance tasks can your team handle versus requiring contractor support?

Lead Times: 6-12 weeks for standard portable units; custom shaft lengths or explosion-proof motors extend to 16 weeks. Important for project scheduling—confirm early.

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Installation Requirements: Adequate deck space or tank access for mounting hardware; 120V or 480V power within 50 feet of mixer location; lifting equipment for units over 150 pounds.

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Coordination Needs: Coordinate with electrical for power drops and disconnect switches. Coordinate with structural for deck loading and anchor bolt embedments. Coordinate with process for mixer placement to avoid short-circuiting inlet/outlet flows.

Hayward Gordon – Portable and permanent tank mixers with clamp-on and flange mounting—known for municipal lagoon and equalization basin applications.

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Landia – Submersible mixers and chopper pumps for wastewater—specializes in high-solids environments and septage receiving.

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Grundfos (Flygt brand) – Portable and fixed submersible mixers—extensive municipal installed base with rental fleet availability.

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This is not an exhaustive list—consult regional representatives and project specifications.

• Fixed Submersible Mixers - Preferred for permanent installations, 20-30% lower lifecycle cost but require basin modifications ($15K-25K vs $8K-15K portable)

• Surface Aerators - Better for oxygen transfer applications, similar capital cost but higher energy consumption

• Jet Mixing Systems - Effective for deep basins >15 feet, higher installation cost but no moving parts in basin, preferred where maintenance access is limited