what is the difference of KBD submersible pump and KBZ submersible dewatering pump?

The primary difference between the KBZ Series and the KBD Series lies in their intended application, slurry handling capability, and internal mechanism.

In short: The KBZ series is a heavy-duty dewatering/drainage pump, while the KBD series is an agitator slurry pump built upon the KBZ design.

Core Differences Overview

Feature / Aspect	KBZ Series (Dewatering Pump)	KBD Series (Agitator Slurry Pump)
Primary Function	Dewatering and drainage of water containing solids/sand	Pumping heavy, high-concentration slurries and sediment
Base Design	Standard heavy-duty cast iron dewatering pump platform	Built using the KBZ series structure as its foundation
Agitator Mechanism	❌ No built-in mechanical agitator	✅ Equipped with a shaft-mounted agitator
Slurry/Solids Handling	Suitable for suspended sand, silt, and small particles	Fluidizes settled sludge, mud, and heavy solids for smooth suction
Impeller Material	High-chrome alloy semi-open impeller with ductile iron wear plate	High-chrome alloy impeller combined with high-chrome wear plate
Power Range	1.5 kW (2 HP) up to 22 kW (30 HP)	1.5 kW (2 HP) up to 5.5 kW / 22 kW depending on model frame
Max Capacity / Head	Up to 240 m³/h	Head up to 72 meters

Detailed Breakdown

1. Built-in Agitator vs. Standard Suction

KBD Series: Features an integrated bottom agitator attached to the extended motor shaft. The agitator mechanically stirs up settled mud, sand, bentonite, and heavy sediments at the bottom of a pit, suspending them in liquid so they can be smoothly pumped without clogging the volute.
KBZ Series: Relies on passive liquid suction without a mechanical agitator. It is designed to pump water and liquid mixture containing suspended solids, but cannot easily break up or fluidize thick, compacted sediment beds.

2. Shared Structural & Design Advantages

Because the KBD series is derived from the KBZ base frame, both series share TUSSU’s core heavy-duty engineering features:

Cast Iron Construction: Motor casing and pump body are made of high-rigidity cast iron for extreme durability in aggressive environments.
Side-Flow & Top-Discharge Channel: The discharge fluid passes through a cooling channel surrounding the motor housing before exiting through the top outlet. This design ensures effective motor cooling even when operated partially exposed in shallow water or tight sumps.
High-Pressure Mechanical Seal: Enhances allowable submersion depth (up to 25 meters deep).

3. Application Scenarios

Choose the KBZ Dewatering Pump for:
- General construction site dewatering and groundwater management.
- Mining, quarrying, and coal ore water transfer.
- Sewage treatment plant bypass and general high-head drainage.
Choose the KBD Slurry Pump for:
- Heavy sand and gravel pits, dredging, and bentonite slurry handling in foundation works.
- Sludge pit cleanout and settling basin maintenance where solids settle at the bottom.
- Environments where heavy solids require continuous agitation to prevent pump inlet blockages.