Providing Innovative and Sustainable Solutions in Energy Efficient Surface Aerators

Clarifiers, Thickners, Clariflocculators

Environ High Torque Central Drive Clarifiers, Clariflocculators, High Rated Solid Contact Clarifiers (HRSCC) & Thickners


Environ Clarifiers, described hereunder, are for chemical effluents, various types of industrial processing & even metallurgical processing, where the efficient separation of solids from liquids is the ‘NEED’. Efficient separation of suspended solids or sedimentation is an important and essential aspect in effluent treatment since it not only reduces considerably suspended solids loading, but also helps in reducing the COD / BOD loading, thereby contributing to reducing the sizing of subsequent process viz. that of Biological treatment, etc.

Thus, Clarification / Sedimentation, the process to remove suspended solids, is economical and has become an essential part of effluent treatment plants and raw water treatment plants. Suspended solids removal up to 70% and settleable solids removal up to 90% to 98% and COD removal as high as up to 40% are achievable with the proper design of the clarifier unit.

The process is pure of gravity-separation. This is achieved by the reduction in velocity of the fluid and nearly 180o change in the direction of the flow. The separate solids would flow downward and settle on the tapered floor.

The slow-moving scraper mechanism having scraper arms with neoprene rubber / PP / HDPE / Brass squeegees scrapes the floor and brings the settled sludge (suspended solids) to the central sludge well. The velocity of the movement of scraper arms, squeegees is designed in such a way that the sedimentation process is not distributed at all.

Comparision Between End Drive / Centre Drive Clarifiers

There are two basic types of the clarifier mechanisms which are manufactured.

  • End Drive / Traction Drive type Clarifier with central RCC column for support.
  • Centre Drive Clarifier.

Even though we manufacture both types of Clarifiers at our ENVIRON workshop (having 40,000 sq.ft. area), ENVIRON recommend CENTRE DRIVE Clarifiers to their valued customers & clients for the following reasons :

  • There are two scraper arms in Centre Drive type as compared to one scraper arm only, in End Drive type. So the floor is scraped Twice in one revolution of Centre Drive Clarifier, while in End Drive Clarifier the floor is scraped once only (as there is generally only one hanging scraper arm). Hence scraping efficiency is high in Centre Drive Clarifier.
  • Centre Drive Clarifiers have low running / operating costs, & hence are more economical. For the same diameter of the Clarifier, the HP required for the End Drive Clarifiers is more than HP required for Central Drive Clarifier. For example, in 10 to 15M dia; the Centre Drive Clarifier the motor is of 1HP-1.5HP, while End Drive Clarifier motors are never less than 2HP-3HP. So there is saving in Energy Charges.
  • Centre Drive scraping is ‘POSITIVE TORQUE’ scraping, while in End Drive, since the scraper is hung from the travelling bridge, the factors for the scraping force i.e. the weight of scraper arm and frictional force between the wheel and the end wall top, are too low & becomes ZERO when the wheels start slipping on the wall.
  • From the maintenance point of view, there are more wearing parts in End Drive Clarifier and hence it results in more maintenance expenditure and SUSTAINED PROLONGED DOWN TIMES.

Having more than Thirty years of manufacturing experience in effluent treatment plant machinery and having full-fledged Research & Development Department attached with hydraulic testing facilities up to 150 HP Aerators & having manufacturing facilities of total 40,000 sq.ft. area, we have developed & incorporated following essential cum efficient features in ENVIRON Clarifiers.

Special Features
  • High Torque ‘ENVIRON’ Centre Drive with gears is designed for achieving high scraping efficiency with additional Greaves gears to achieve High reduction ratio.
  • Fixed type full span bridge of Lattice structure suitably designed to take required torque, and having least linear deflection. One meter high double row hand rails is provided.
  • Suitably designed centre drive rotates the heavy mild steel tubular central pipe, having two scraper arms with neoprene rubber / HDPE / PP / BRASS squeegees.
  • SCRAPER ARMS LIFTING DEVICES in two varieties : a) HAND OPERATED SCRAPER ARMS LIFTING DEVICES : This is our standard in-built feature in clarifier. This is provided at NO EXTRA COST. When the scraper arms are embedded, in sludge, due to prolonged stopping of the clarifier, the clarifier mechanism cannot be restarted. The motor will trip, the scraper mechanism gets twisted up and drive gets overloaded and damaged. In such cases the effluent has to be pumped out and settled sludge has to be removed to restart the mechanism. While in our Clarifier there is NO PANIC. Operator has to come on the platform and has to operate the hand wheel. Both the scraper arms are lifted to a maximum height of 200mm. Then the mechanism can be switched on the scraper arms can be lowered down slowly by operating handle in reverse direction. b) MOTORIZED SCRAPER ARMS LIFTING DEVICE : Only 0.5 HP extra electric motor and gearing operate the lifting of the scraper. This feature is provided by us at an EXTRA COST, if asked for.
  • Central sludge well scraper.
  • Overload protection & lifting devices : Electro-mechanical overload protection device has load indicator, Hooter alarm and drive motor cutout switches. In addition to this unique feature particularly for Thickners, Motorized semi automatic or automatic scraper arms lifting devices are also incorporated by us on clients demand. Hand operated scraper arms lifting device are provided with all ENVIRON CLARIFIERS & THICKNERS as a standard feature.
  • Offering Polypropylene (P.P.) Intake Well as standard feature.

Environ Clarifiers Without Bottom Sludge Withdrawal Pipe

For the first time in India, we have Developed & Introduce for minimal maintenance, the ENVIRON Clarifiers without bottom sludge withdrawal pipe. The sludge at 5 to 10mt. total head (pressure) can be obtained at the end of the platform simply by pipe flange connection, this can be taken either to sludge drying beds &/or to aeration tanks for activated sludge plants.

  • Relief from the frequent maintenance of chocking bottom sludge pipe.
  • No separate buying and installing of sludge recirculation pumps.
  • No special construction R.C.C. dry sump for pump.


General arrangement of Clariflocculator

General arrangement of Clarifier

Clariflocculators are generally used for chemical primary treatment for effluent. Instead of separate flocculation & clarification, Clariflocculator is generally used. This results in economical and faster installation of primary treatment. Our Clariflocculators are having high torque center drive with a sludge arm lifting device. We are the only manufacturers to provide this feature as standard. The main feature of Clariflocculator, unlike others, is concentric paddle type Flocculator mechanism which creates the flocs throughout the flocculation zone.

Skimming Device

The skimming mechanism, if required by the client or required for particular applications, can be provided by us. Generally, this mechanism is required to remove floating debris, solids, which floats on effluent surface. It compromises of 1) Rotating Skimmer 2) Scum Scraper 3) Scum Box. Neoprene Rubber wipers are generally provided. The scum scraper collects the scum and drops it in scum box, which is connected to withdrawal piping. A scum skimming arm, supported on one of the scrapper arm, is provided for removal of floating debris, solids. The collected scum is pushed by a level-loaded or spring loaded scraper into a scum box. Through this scum box the scum drains off the paddle and pipe. Thus floating scum is taken out from the clarifier.

Effluent Treatment Plant at M/s. Aurobindo Pharma – Vizag