88-MLV Series

Series description

Modular 88-MLV series are based on state of the art high intensity amalgam lamps and are designed for applications in open channel wastewater disinfection projects. The lamps in the modules are arranged in staggered arrays that are installed in a vertical position, perpendicular to the water flow. Each lamp is placed in a protective quartz sleeve with high UV transmittance.

Application

The LIT UV 88-MLV series are developed to disinfection of secondary and tertiary treated wastewater effluents of municipal and industrial WWTP plants of medium and large flow capacities. The vertical open channel system design is applied to comply with various standards for surface water discharge and re-use of waste water. Nowadays also the 88-MLV systems find their application in combined sewer overflow and storm water disinfection systems.

88-MLV series advantages

  • State-of-the-art high power, high intensity amalgam lamps with prolonged operating lifetime;
  • Safe, simple and quick maintenance of the lamps without lifting the module out of the water;
  • Vertical design provides a semi-turbulent plug flow ensuring that all water receives maximum exposure to germicidal UV light;
  • Compact size through vertical configuration;
  • Equipped with PLC based monitors and control systems controlling of each UV lamp;
  • Electronic ballasts significantly reduce power consumption and increase the overall system efficiency;
  • UV sensors provide greater operational security;
  • The series is equipped with effective chemical and mechanical cleaning systems

System Description and Components

UV Modules

The LIT 88-MLV UV Disinfection System has a modular design for flexible, easy system configuration and. Key component of the 88-MLV series UV system are the 88-MLV-24A module consisting of 24 vertically placed lamps and the 88-MLV-36A module, consisting of 36 vertical lamps. The lamps are arranged in four parallel rows of six, respectively nine lamps in each row. The modules can be installed in the channel separately or can be grouped in series and/or in parallel. Each module has a quick-access-cover that allows dry access to the UV lamps to check or replace, without having to remove the module out of the water flow, or breaking the quartz sleeve seals.

Ballast cabinets

Electronic ballast cabinets are installed near each UV bank above the channel. Each UV module is connected to the electronic ballast cabinet through a pair of waterproof plugs. High efficiency electronic ballasts are installed inside the cabinets. Each cabinet has a small LCD display to provide the information about UV module and UV lamp status in each respective UV bank. The ballasts are designed to comply with various electrical power distribution networks and have a high power factor..

Operating and Control system

The operation of the UV plant is guided through a Control Cabinet on basis of an industrial PLC system. The front of the cabinet is equipped with a graphical user interfaces to control the UV system, which can be operated both in automatic and manual modes. All operational data from the UV system can be transmitted to the main WWTP SCADA using standard industrial field bus communication. The Control System incorporates a data logging function for recording all operating parameters.

UV sensor

Each bank of UV plant is equipped with two UV-radiation intensity sensors. The UV sensor measures the UV intensity inside the UV bank, converts the analogue signal to a UV intensity value which is transmitted to the Operating and Control system.

Automatic level control system

Each disinfection channel is equipped with an automatic level control system. It consists of a motorized slide gate mounted at the channel outlet, PLC controller and ultrasonic and/or variable-capacitance water level sensor. The level control system assures proper water levels are maintained inside the disinfection channel at 0-100% flow variations. It prevents overflow and guarantees that all water will be treated properly without by-passing the UV modules.

Chemical cleaning system

The 88-MLV UV system is provided with a chemical cleaning system for the quartz sleeves in each channel without the necessity to remove the UV modules from the channels. All lamps in a channel being treated are cleaned simultaneously. During the cleaning period a UV channel is closed and water effluent passes through the remaining channels. The cleaning system consists of a tank, for preparation of the cleaning solution, a circulation pump, a system of stainless steel pipes and switching valves.

Mechanical cleaning system

Due to the nature of the application the treated water contains relative high levels of suspended solids, therefore the 88-MLV is equipped with an automatic mechanical wiping system. This system is cleaning the quartz sleeves without having to remove the UV modules from the channels. Such cleaning prevents quartz sleeve fouling during UV system operation, it removes deposits from the quartz sleeve surface by mechanical wipers which are moved periodically along quartz tubes. The wiping frequency can be adjusted through UV system control. The pneumatic cylinders are powered by air compressor with receiving tank.

Additional components

  • Flow Equalizing plates
    At limited space conditions, when the channel length is restricted, stainless steel gratings with profiled holes can be installed at each channel entry to provide better water flow mixing and distribution across channel.
  • Channel Cover Plates
    when operating, the channels with UV banks are covered by profiled zinc galvanized iron plates.