Chain & Flight type Sludge and Scum Collectors

The MD” One Only” collector chain is the latest product development that we launched recently. Unlike
other collector chain designs available in the market, the MD” One Only” collector chain does not
require any pin, locking ring or intermediate bushing. This unique light-weight MD chain is made of advanced
materials and provides durable strength, wear resistance, chemical resistance, and long service life. In
addition, this design enables to meet the specific requirements of each installation, whether for new
construction or when retrofitting existing collector chain, despite of pitch sizes. This is also ideal for
applications with elevated grit levels or sludge loads where a stronger, more robust chain is required.

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System Components

1. Collector chain ME-720S

ME-720S Collector Chain does not require any pin, locking ring or intermediate bushing and it is among the strongest Collector Chains on the market.

The Merdec ME-720S Collector Chain was designed to meet the need for a stronger non-metal chain with excellent chemical and corrosion resistance. The ME-720S Collector Chain is the perfect replacement for any type of collector chains available in the market.

  • No pins and barrels
  • No locking-rings
  • No bushing
  • No separate links

Light weigh

ME-720S collector Chain is manufactured from UV-inhibited acetal polymers for optimal strength. This lightweight chain is designed for easy installation. The lesser weight of the ME-720S chain reduces the additional work associated with installing heavy chains and requires less power for operation. No any tools are required for chain assembly.

Long lasting

Our engineers and technicians have decades of experience designing, developing, and manufacturing of various types of non-metallic chains. They have pioneered the invention, improvement, application, and manufacture of this unique lightweight ME-720S chain. This lightweight chain withstands extremely high sludge loading.

Multi applications

Applications range from any type of primary and secondary applications to any type of industrial wastewater application where sludge loads require strong durable chain.
Through our knowledgeable distributor network, we offer the widest variety of materials, processes, designs and custom services available. We can meet almost any specification or application.

2. Scraper flight ME-E200

Light weight, yet robust

The ME-E200 Flight is pultruded out of UV-inhibited Fiberglass reinforced isophthalic polyester resin (FRP) designed to sweep the sludge and scums effectively across the entire thank floor and the surface. Scraper flights are customer fabricated to suit any application and designed to handle wider tank spans than C-Channel Flights. This unique design gives it exceptional resistance to deflection and twist, ensuring the flights remain strong and stiff throughout their service life. Unlike C-Channel flight, ME-E200 flight design enables to avoid re -circulation of the sludge while turning the scraper flight from bottom to surface.

  • No drilling required
  • No mounting holes required
  • No soaking
  • no sludge re-circulation

Snap lock, multi-position synchronization

The high strength ME-E200 flight can handle heavy sludge loads or be used in tanks over 10 m in width.
One of the unique features of this design is that no drilling (or mounting holes) is required to attached wear shoes and flight attachments on to the scraper flight. This will prevent soaking of the fibreglass resin and allow an additional life span for the flight.
carry wear shoe or wheel options
suitable for all applications
easy and fast installation

3. Carry, return tracks and wall brackets

Return tracks and multi-adjustable brackets
All the return tracks and wall bracket are made of 304 or 316 stainless steels in accordance with customer requirements. They can be used in both new and existing rectangular sludge collectors. The wall bracket is adjustable both vertically and horizontally directions in order to allow accurate wall positioning. The return tracks are easy to fix, easy adjustable, no welding is required.
The return wear shoes of the scrapers which are made of UHMW PE slides against the surface of stainless-steel return tracks which provides low coefficient friction compared to other counterfaces.

Carry tracks (wear strips)
Two option materials are available for the carry tracks (wear strips) in Merdec scraper systems viz. stainless stells and UHMW PE. When the UHMW PE material is used, then the carry wear shoes of the flights will be in stainless steel in order to provide low coefficient friction. Sufficient clearance will be provided for both slotted holes and ends of wear strips to allow thermal expansion.

Eco friendly option
Carry tracks (wear strips) can be replaced with the scraper flight that are equipped with carrying wheels, which will roll on the bottom surface of the tank. This is the more economical option, as it will eliminate entire mounting work of the carry tracks (wear strips). This reduces the costs and the carbon footprint associated with manufacturing and shipping these bulky components.

4. ME-720 series head and idler sprockets

Split design, superior wear resistance

ME-720 series head and idler sprockets are split design, made of UHMW PE material for easy installation and removal. The UHMW PE materials provide a long-lasting wear resistance during operation in a treatment plant’s corrosive environment.

Idler shaft sprockets will rotate freely on bearing sleeves clamped to the static shafts.
ME-720 series head and idler sprockets are applicable in all scrapers systems using 720S chain.
ME-720 series head and idler sprockets are corrosion resistant, abrasion resistant and water

  • Absorption rate not to exceed 0.1% at saturation
  • Split construction
  • Long lasting wear resistance
  • Applicable in all scrapers systems using 720S chain
5. Shaft assembly

Head shaft is the driving shaft of the chain and flight mechanism, with the driven sprocket being driven by chain connected to the drive unit. Generally, the head shaft is subjected to greater forces than the other shafts and is normally the larger in diameter. Head shafts and wall bearing holders are made of 304 and 316 Stainless Steel according to customer requirements, and is virtually maintenance free.
The wall bearings, as well as bearing blocks are made of UHMW-PE and they doesn‘t require any lubrication. All headshaft sprockets are keyed and locked with set screws so that the collector chains are aligned and move together at the same rate. Keyways are machined in such a way so that the sprockets can be adjusted along the shaft for proper alignment. All items on the head shaft are split construction for easy assembly.

Static tensioning shaft assembly

The wall mounting mechanism of the static tensioning shaft is designed in a way that they can be adjusted parallelly on horizontal direction, in order to provided even tensioning force for the collector chain mechanism.

All Merdec sludge scraper systems are provided with smart synchronised surface tension mechanisms. As an option Merdec also provided smart G-force auto tensioner which will keep actual required tensioning force constantly during the operation.

6. Drive assembly
Merdec provides standard stainless-steel chain, drive and driven chain sprockets and float tensioner to meet any application requirements. Stainless steel chain can maintain accurate average transmission ratio, high transmission efficiency, strong overload capacity can work better at low speed and heavy load. This chain has good corrosion resistance and can adapt to higher or lower temperature working environments. The float type chain tensioner and due to its’ unique design, that allows it to slide up and down the drive chain wherever there is slack. Its reliability and lack of needed maintenance make it the tensioner of choice.
As an option to stainless steel chain and chain sprockets, Merdce provides 78 non-metallic drive chain, drive and driven sprockets and float tensioner. Injection moulded from reinforced nylon, 78 chain is strong, lightweight, and resistant to corrosion and chemicals. This non-metallic chain is simple to install and maintain. The float type chain tensioner or similar device will provide for chain tensioning. The 78 series none metallic chain, sprockets and other associated components can be retrofitted or interchangeable with any reputable sludge collector manufacturer’s parts and components.
Drive and overload protection
All the gear motors used in Merdec scrapers systems are from world-class suppliers. These gear motors are applicable in almost every working environments. To protect the entire scraper system, Merdec provides electronic over and under load duel limit monitor which measures motor power, kW[%], with both over- and underload detection. This device will provide is an accurate and linear motor load value across the whole load range. Drive unit will have its own protection cover made of AISI304.
7. G-force smart tensioner

Smart G-force tensioner

Smart G-force tensioner Correct operating tension is an important factor in the satisfactory performance and life of chain collector system. As chains wear, they elongate, which results in sway, slap and this puts undue jolt into the scraper mechanism resulting an excessive wear and tear. In addition, as the chain elongates, it "crawls" out of the sprocket teeth resulting sever damage to the scraper system.

To avoid excessive wear and tear, Merdec has developed Smart G-force tensioner to provide constant amount of tension force to the collector chains, increasing life span of the entire system. Economical, easy to install, maintenance free, the Smart G-force tensioner is the answer to the problem of controlling collector chain tension.

Real-time data such as functional status can be sent to any mobile device via HMI/SCADA user interface, depending on plant operating platform and requirements. This Cloud-based HMI user interface is available as an option.

Provides synchronised optimum tensioning

The functions of the Smart G-force tensioner based on gravity force and it constantly synchronised the optimum amount of tension force to the collector chain in accordance with sludge loading. This Smart G-force tensioner can be retrofitted to any manufacturer’s sludge collector system.


Optical control of chain elongation

  • The tensioning force is providing an ideal, smooth operating movement.
  • Not in ideal operating mode, precautions needed in near future.
  • Collector chain is exceeded maximum allowable elongation and needed to take off one link of the collector chain and readjust the Smart G-force tensioner to optimum position
8. System control

For the automatic control of the Merdec Chain and Flight Scraper systems, each sludge collector will be equipped with local control panel which is capable of operating locally or /auto/remote modes. Real-time data such as functional status
can be sent to any mobile device via HMI/SCADA user interface, depending on plant operating platform and requirements. This Cloud-based HMI user interface is available as an option.

1. Local control panel
2. Gear motor (over and underload protection)
3. Drive chain motion detector
4. Flight monitoring device
5. G-force tensioner
6. Scum pipe actuator (timer-based control)

9. Scum troughs, power skimmers

Simple and economical
The removal of scum during clarification is a necessary step to decease organic loadings and scum build-up in the treatment processes. From a design point of view, a Rotary Skimmer is the most economical and most common type of surface scum skimmer. It effectively removes sewage scum and floating materials from sedimentation tanks and discharge it into scum through. Meredc scum troughs are available in a range of pipe diameter 200mm – 400mm and maximum span tank width 12m. The scum troughs are fabricated of AISI306 or 316 material depending on site

  • Available in different diameters
  • Length of the pipe up to 12m
  • Manual or auto functions

Cross Collectors
Chain and Flight as well as Screw Conveyor type Cross Collectors are available with all ancillary components. A Screw Conveyor Cross Collector may be used as an alternative to Chain and Flight Cross Collectors. It serves the same purpose of concentrating the sludge into a sump pit.

Power skimmers
Merdec also provide chain and flight type power skimmers in 2 or 3 shaft designs. These power skimmers are ideal for the removal of heavy floating materials such as grease, scum etc. These floating materials discharge into scum pit over the beach plate. All these components are made of non-metallic and stainless-steel materials. Different operating methods e.g. manual hand lever, hand wheel, worm gear, electric actuators etc. are available.

  • Zero lubrication
  • Corrosion free
  • Easy and fast installation


Potable water

To remove heavy sludge (slit and mud) from the sedimentation tank required strong and reliable sludge removal systems. We at Merdec have the capacity and know-how to do this job. Being as a pioneering engineering company with vast experiences in this field, Merdec always provides the best.


Domestic wastewater

Merdec “one only” Sludge and Scum collectors are ideal for primary and secondary applications where sludge loads require strong wear and tear resistance. We provide durable solutions for extremely wider and longer as well as multi-deck sedimentation tanks.


Industrial wastewater

The “one only” Sludge & Scum Collectors are applicable in various industrial wastewater applications, such as API, Desalination, Pulp & Paper etc. as well as grit and grease chambers.

Merdec Sludge & Scum Collector components comprised of the finest quality components available in the market and all submerged components are non-corrosive.