Merdec One Only Chain Scrapers

Chain & Flight type Sludge and Scum Collectors

Merdec

With over 30 years’ experience in chain and flight collector systems design and manufacturing has given us a solid base to bring a new updated system to the market. During the designing of this system, Merdec has carefully taken into account all the most important factors for the benefit of the customer.

The "One Only" Merdec chain scrapers are suitable for various types of rectangular settling tanks and our components can also be used in many existing systems in the market. Our chain scrapers can be provided as top, bottom, 4-shaft, 3-shaft or multi-layer scraper systems for many types of applications such as wastewater treatment, DAF, desalination or water treatment.:


  • Most Merdec Chain scraper components are suitable in almost all existing systems.
  • Suitability in wide range of applications and operation conditions
  • One piece chain link and other carefully designed features ensure the system is easy to install and maintain
  • Long service life and low operating costs (minimal water absorption, changing most of components without emptying the tank, design solutions to allow for minimal wear and tear)
  • Cost-effective price structure (Quick ROI)
  • High quality construction materials and components


Scraper component sales


Additionally, to complete systems, Merdec provides components for almost all existing chain scraper systems in the market whether it’s spare parts or for refurbishing. Our components are compatible with most of non-metallic Chain and Flight Collectors. We also provide and design complete systems to customers by supplying the complex parts while designing some parts for the customer to be produced locally (e.g. stainless steel shafts and rails). When heavy and bulky parts such as stainless-steel components are produced locally avoiding transfer through sea, it saves both the customers’ money and the environment!

Applications

Potable water

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

Domestic wastewater

Merdec chain scrapers are ideal for primary and secondary settling applications where sludge loads require strong wear and tear resistance. We provide durable solutions for wide and long as well as multi-deck sedimentation tanks.

Industrial wastewater

Merdec chain scrapers are applicable in various industrial wastewater applications, such as API, Desalination, Pulp & Paper etc. as well as grit and grease chambers. Our components are supplied according to the many material standards required by each application..

System Components

Chain and flight scrapers system components - Merdec Oy
Collector chain ME-720S - Merdec Oy
  • 1. COLLECTOR CHAIN ME-720S

    ME-720S Collector Chain does not require any pin, locking ring or intermediate bushing and it is extremely simple and fast to assemble.


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


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

    LIGHT WEIGHT

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


    LONG LASTING

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


    MULTI APPLICATIONS

    Applications range from any type of primary and secondary applications to any kind 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.

Scraper flight ME-E200 - Merdec Oy
  • 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 tank floor and surface. Scraper flights are customer fabricated to suit any application and designed to handle wider tank spans. 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 avoids 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

    FAST LOCK, MULTI-POSITION SYNCHRONIZATION

    The high strength ME-E200 flight can handle heavy sludge loads or be used in tanks over 10m 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 fibre-glass resin and allow an additional life span for the flight. Carry wear shoe or wheel options suitable for all applications, easy and fast installation.

Carry, Return tracks and wall brackets - Merdec Oy
  • 3. CARRY, RETURN RAILS AND WALL BRACKETS

    RETURN RAILS AND MULTI-ADJUSTABLE BRACKETS

    All the return rails and wall brackets are made of AISI 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 in both vertical and horizontal directions in order to allow accurate wall positioning. The return rails are easy to fix, easy to adjust and no welding is required. The return guiding shoes of the scrapers which are made of UHMW PE slide against the surface of stainless-steel return tracks which provide low coefficient friction compared to other counterfaces.


    CARRY RAILS (WEAR STRIPS)

    Two option materials are available for the carry rails (wear strips) in Merdec scraper systems viz. stainless steel and UHMW PE. When the UHMW PE material is used, then the carry guiding 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.


    OPTION!

    Carry rails (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 rails. This reduces the costs and the carbon footprint associated with manufacturing and shipping these bulky components.

ME-720 series head and idler sprockets - Merdec Oy
  • 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 resistant.


    • Absorption rate not to exceed 0.1% at saturation
    • Split construction
    • Long lasting wear resistance
    • Applicable in all scrapers systems using 6" pitch chain
Shaft assembly - Merdec Oy
  • 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 larger in diameter. Head shafts and wall bearing holders are made of AISI 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 don‘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 provide 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 provides smart G-force auto tensioner which will keep actual required tensioning force constant during the operation.

Drive assembly - Merdec Oy
  • 6. DRIVE ASSEMBLY

    METALLIC (STAINLESS STEEL)

    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 due to its’ unique design 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.  


    NON-METALLIC

    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 molded 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 be provided 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 environment. To protect the entire scraper system, Merdec provides electronic over and under load dual limit monitor which measures motor power, kW[%], with both over-and underload detection. This device will provide an accurate and linear motor load value across the whole load range. Drive unit will have its own protection cover made of AISI304.

G-force smart tensioner - Merdec Oy
  • 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 in 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 are based on gravity force and it constantly synchronizes 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

    Once the tension of the collector chain is set, the elongation of the chain will be followed optically


    • At green, no measures required.
    • At yellow, preparing for future maintenance procedure
    •  red, maintenance procedure to be done at a certain timeframe 

    After this point the collector chain has reached its maximum allowable elongation and it is required to take off one link of the collector chain and readjust the Smart G-force tensioner to initial position.

System control - Merdec Oy
  • 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)
Scum troughs, power skimmers - Merdec Oy
  • 9. SCUM TROUGHS, POWER SKIMMERS, CROSS COLLECTORS

    SIMPLE AND ECONOMICAL

    The removal of scum during clarification is a necessary step to decrease 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 trough. Merdec scum troughs are available in a range of 200mm – 400mm pipe diameter and maximum tank width of 12m. The scum troughs are fabricated of AISI 304 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 provides 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

Example of MERDEC Scum skimmer

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