Equipment for clarifiers

Bar Mixer

Tha bar mixer is intended for intensification and increase of the thickening process in sludge thickeners.

Main elements of default design:

  • 1) Bridge with hand rails (aluminium alloy)
  • 2) Bar frame (stainless steel)
  • 3) Rotating frame (stainless steel)
  • 4) Driven trolley
  • 5) Electrics
  • 6) Supporting column for clarifiers with diameter more than 15 m (stainless steel)

Additional equipment:

  • 7) Sludge collection unit (stainless steel)
  • 8) Floating solids collection unit (stainless steel)
  • 9) Discharge tank (stainless steel)
  • 10) Gutter weirs – type OSO
  • 11) Wastewater supply unit (option a or b) (stainless steel)
  • 12) Supports for sludge thickener covering (aluminium alloy)
  • 13) Central deflector–type KWd

Proposal request should include:

  1. Additional equipment list
  2. Tank dimensions (diameter, wall height, bottom inclination angle, bridge sizes)
  3. Clarifier wastewater level and clarifier ledge level difference
  4. Wastewater supply and discharge method
  5. Wastewater overflow parameters

When placing an order, drawings with THE correct dimensions of the tank, delivery- and lateral pipelines should be provided.

Схема стержневой мешалки с центральным приводом для гравитационного уплотнителя тип MPRst

Bar mixer scheme

1. Bridge and safety handles with entrance stairs

Bridge and safety handles with entrance stairs (picture 1 on the scheme) are manufactured from aluminium alloy, which has a high strength index and corrosion resistance. Due to this, there is no need for expensive painting.

The bridge is a supporting structure and working elements are hung from it. For clarifiers with diameter larger than 15 m, it is propped up by a supporting column (position. 6). It is possible to install supports underneath the sludge thickener cover as an option (position 12). For this, an additional agreement with the cover supplier has to be made. By default, the handles are mounted on the bridge so as not to limit the access to the drive unit chamber.

2. Bar frames

Two bar frames, each equipped with mixing bars, (position 2) are the main working elements of the mixer. Their shape, as well as the distance between them, are designed to create drain channels in the sludge through the motion. This separates pore water and gases from the sludge.

In addition, bar frames can be equipped with one or two sludge collection units (position 7). Steel scrapers equipped with a rubber attachment is a working element of this unit.

3. Trolley

Thickener frames (position 2) are connected to the rotary frame (position 3) with a toothed crown wheel of the support rotating device. The crown wheel is driven by a toothed gear fitted on the geared motor's shaft.

4. Electrics

The electric control cabinet (position 5) and light bulbs are mounted on the platform of the scraper. The cabinet allows the operator to switch the scraper on and off; both manually or remotely (remote Start-Stop), as well as to indicate equipment status with an alarm.The mixer is supplied with variable speed drive which allows adjustment of the scraper speed.

5. Floating solids removal

This unit consists of the scraper (position 8), that moves floating solids out of the clarifier, and an additional scraper that removes floating solids directly to the bunker (position 9). The bunker is equipped with a nozzle that allows connection to the discharge system.

6. Overflow tray system

This system (position 9) can be manufactured in the following options:

  • Trays with double ended trapezoidal weirs on the inside and outside walls of the overflow) with or without deflectors.
  • Trays with weirs on the outside of the wall, with the inside wall submerged under the wastewater level. In this case the outside wall acts as a deflector.

One of the tray segments acts as a connector with the withdrawal system at the same time.

7. Wastewater supply unit

Wastewater is supplied by a pipeline, situated under the bottom of the tank (position 11b) or mounted under the bridge (position 11a).

  • The stirrer is made of corrosion-resistant materials ensuring the long-term service life of equipment
  • The form of stirring pickets and the distance between them a such that drainage channels are generated in the sludge when they mowe; void water and gases are extracted from the sludge by means of pickets
  • Equipment is controlled from an electrical control cabinet. This allows switching on or off a scraper in a remote manner and send a signal of operation or failure