Design

Slow-running submersible mixer with two-stage planetary gear reduction

Application

• Energetically optimized mixing and circulation of activated sludges
• Generation of flow rates in circulation channels

Type key

Special features/product advantages

• Efficient energy usage.
  The innovative blade geometry and energy-efficient IE3/IE4 motors ensure the best possible specific thrust coefficient. At the same time, this reduces your energy and operating costs.
• Consistently reliable.
  The low-wearing GFK/PA6 propeller is durable and scores with its self-cleaning effect.
• Smooth running thanks to the balanced propeller load, even in high thrust ranges and when incoming flow conditions are unfavourable.

Technical data

• Mains connection: 3~400 V, 50 Hz
• Submerged operating mode: S1
• Protection class: IP 68
• Max. fluid temperature: 40 °C
• 2-stage planetary gear with an exchangeable 2nd planetary gear
• Mechanical shaft seal with SiC/SiC pairing
• Permanently lubricated roller bearings
• Max. immersion depth: 20 m

Equipment/function

• Installation with stand allows free placement in basin
• Flexible installation
• Two-stage planetary gear with exchangeable second planetary stage

Materials

• Housing components: EN-GJL-250
• Propeller blades: GRP vinyl ester; TRE 312: PA 6C
• Propeller hub: EN-GJS-400
• Screwed connections: Stainless steel 1.4571
• Seal bushing: Stainless steel 1.4571
• Gear shaft: Stainless steel 1.4462

Description/design

Propeller

2- or 3-bladed propeller in sandwich-style construction with a nominal propeller diameter of 1200 mm to 2600 mm.

TRE 312: 3-blade, solid-material propeller with a nominal propeller diameter of 1200 mm.

All propellers have an clogging-free design made possibly by backward-curved flow edge.

Motor

Wilo-submersible motor of the T-series (surface-cooled motor) with standard connection for an easy and efficient adaptation of the motor power. The motor heat is given off directly to the fluid via the housing. The winding is equipped with a temperature monitor. Large-sized inclined and grooved ball bearings ensure long service life of the motor bearings.

TRE units are equipped with high-efficiency TE motors which meet the IE3/IE4 classification (derived from IEC 60034‑30).

Seal

Sealing is achieved through the use of a 3-chamber system (pre-chamber, gear chamber and sealing chamber). The large-volume pre-chamber and sealing chamber collect leakage from the mechanical seal. If desired, the pre-chamber can be equipped with an external sealing chamber electrode. The sealing between the fluid and the pre-chamber, as well as between the gear and sealing chamber are realized by a corrosion-resistant and wear-proof mechanical seal made of solid silicon carbide material. The sealing between the pre-chamber and gear chamber as well as between the sealing chamber and motor are realised by radial sealing rings. A seal bushing ensures long-term corrosion-protected fit of the mechanical seal.

Gear

2-stage planetary gear with exchangeable transmissions. The gear bearings are dimensioned so that the resulting mixing forces are absorbed and are not transferred to the motor bearings.

Cable

The power cable is a type NSSHÖU cable for heavy mechanical loads. The power cable enters the motor housing through a water pressure-tight cable inlet with strain relief and bend protection. The individual wires as well as the cable sheath are additionally sealed to keep out fluids.

Configuration

A separate configuration must be carried out for each application to ensure optimum generation of fluid current. Carefully follow the instructions for the supplied configuration when installing the units.

Commissioning

Immersed operating mode S1:

The unit can be used immersed in continuous duty. Surfacing the propeller or motor is strictly prohibited. In the case of fluctuating fluid levels, the system should switch off automatically if the degree of water submersion drops below the minimum level.

When installing the power cables, make sure that they are not drawn into the propeller by the fluid current.

Options

• Special voltages
• PTC thermistor sensor
• External sealing chamber control
• Ceram coating C0
• Ex-rated to ATEX or FM

Accessories

• Stand for free positioning of the units in the basin
• Auxiliary lifting device
• Special fastening pieces for the use of an auxiliary lifting device for multiple units
• Additional rope anchoring
• Fixation sets with anchor bolts

Scope of delivery

• Submersible mixer with cable per customer request
• TR 212 and TRE 312: Propeller completely pre-assembled
• TR(E) 216, 221, 226-3, 316, 321 and 326-3: Propeller blades - delivered loose, installation on-site
• Accessories according to customer request
• Operating and maintenance manual