Mud Tank Agitators: Tank Geometry, Shaft and Impeller Review

Start with a geometry disagreement

Imagine two proposals for the same mud tank. Both name the same motor power, but one includes a longer shaft and additional impeller layer while the other excludes bottom support. The apparent price difference may be a scope difference, not a cheaper equivalent. A useful technical review identifies what each bidder assumes about the tank before comparing the drive packages.

Treat the tank drawing as the common reference. Record the actual compartment boundaries, internal depth, working liquid-level envelope, obstructions and mounting structure. Keep nominal tank volume as context rather than the selection criterion. Two compartments with similar volume can present different mechanical interfaces and unresolved circulation questions. The catalogue evidence retained here does not quantify the resulting mixing performance.

First decision: is the proposed geometry explicit?

Ask each bidder to return an annotated arrangement tied to the same tank drawing revision. The review needs shaft length, impeller layer count, each impeller's diameter and blade description, plus the proposed positions shown as drawing dimensions. These are items for manufacturer engineering approval, not instructions for a buyer to establish installation clearances.

GN's 2019 project discussion links shaft and impeller selection to internal tank dimensions. It also discusses layered impellers and bottom stabilization for taller tanks. That supports asking the geometry questions; it does not establish a universal height threshold, a shaft design limit or an automatic layer assignment for a current G-series model.

Return a proposal for clarification if it names only the motor and a shaft length without defining the submerged arrangement. Conversely, a complete drawing can still leave performance unresolved. Send fluid density, rheology, solids characteristics and the intended suspension or mixing objective for a separate duty assessment. Do not substitute a neat drawing for that assessment.

Second decision: who owns the shaft-support interface?

A bottom support changes the scope shared between the agitator supplier and tank supplier. Require the proposed support arrangement, interface loads, tank attachment responsibility and access requirements to be documented together. Do not assume that an existing tank floor or mounting beam is suitable because an agitator has previously occupied the same location.

For a replacement, identify the installed drive and wet-end parts separately. Preserve the available part numbers and drawings, then ask the proposed supplier to state which components remain and which are replaced. A shaft, coupling or impeller borrowed from an earlier version needs explicit compatibility acceptance; a familiar brand or matching motor power is insufficient.

This review should end with named responsibilities and a controlled arrangement, not a workshop procedure. Shaft fabrication, support installation, alignment and operating practices remain outside this guide and require the responsible parties' approved documentation. No operating speed or installation setting is prescribed here.

Third decision: what does the model row actually prove?

The current GN G-series table pairs GNJBQ075G with 7.5 kW and a 950 mm impeller size; GNJBQ150G pairs 15 kW with 1100 mm. Power and impeller size identify catalogue configurations, but cannot independently establish tank duty, allowable shaft length or the correct layer arrangement. A larger motor is not documentary evidence that a geometrically different proposal meets the same objective.

Keep source versions separate. The GN Solids America page retains a D/DD table. Similar numeric prefixes do not authorize transferring that table's dimensions or layer information to the G/GD series. Ask the bidder to attach the exact offered model's current datasheet and explain any deviation from the retained reference.

Electrical acceptance is another decision. State the actual supply and hazardous-area requirements, then obtain motor and starter identification with the applicable certificate schedules. Check that the documentation covers the offered items and project conditions. A catalogue power entry does not establish supply compatibility or hazardous-area approval.

Close the mass boundary before shipment

The GN catalogue, printed page 39, excludes shaft and impeller from tabulated weight and dimensions. Request complete assembled mass and the shipping-piece schedule separately, including shaft, impellers, supports, spares and packing. Have the supplier identify the basis of any lifting or transport information rather than treating a drive-only figure as the complete package.

Use the mud tank agitator reference to retain model identity during bid review. Submit the reconciled tank drawing, assembly scope and outstanding exceptions through the RFQ Builder. Comparable offers should address the same geometry and responsibilities before delivery terms and price decide the purchase.