Modular 88MLV series is based on up-to-date high output amalgam lamps and is intended for use in open channels systems for wastewater disinfection.
A module’s lamps are arranged in several staggered arrays installed vertically, perpendicular to water flow.
Each lamp is enclosed by a protective sleeve of quartz glass with high UV radiation transmittance.
Application
Disinfection of secondary and tertiary treated wastewater effluents in municipal and industrial WWTP plants with medium and large flow capacities.
Uses in combined sewer overflow and rain water disinfection systems.
Advantages
·State-of-the-art high output low-pressure amalgam lamps with prolonged working life;
·Safe, simple and quick maintenance of vertical lamps without lifting the module out of the water;
·Vertical design provides semi-turbulent plug flow ensuring that all water receives maximum exposure to germicidal UV light;
·Absence of detachable bases immersed in water ensures high reliability throughout the UV equipment’s working life;
·Vertical configuration provides a high capacity UV systems with much more compact footprint;
·The series is equipped with PLC based monitor and control system providing control of each lamp in the UV system;
·New electronic ballasts significantly reduce power consumption and increase overall system efficiency;
·UV sensors provide greater operational security;
·The 88MLV series is equipped with both chemical and mechanical high efficacy cleaning systems.
Components description
UV Modules
LIT 88MLV UV Disinfection Systems have modular design for flexible design, easy system integration, installation and operation. The key component of the 88MLV series UV system is the 88MLV-36A module consisting of 36 high power amalgam lamps. The UV lamps are vertically installed in protective quartz sleeves and arranged in four parallel rows, each row with 9 lamps. The quartz sleeves with lamps are fixed in the 88MLV module, and placed perpendicular to the flow in the UV channel. The modules can be installed in the channel separately or can be grouped in series and/or in parallel. A group of UV modules is referred to as an UV bank. All electrical lamp connections of the 88MLV module are above the waterline. The lamps can be accessed through a quick-release cover that allows the lamps to be checked or replaced without having to remove the module from the water flow or disturb the quartz sleeve seals. UV modules can be removed from the UV bank independently from each other using a lifting device.
Ballast cabinets
The UV lamps are powered by Electronic ballasts. The high efficient electronic ballasts are fitted inside the ballast cabinets. The ballast cabinets are installed near each UV bank over the channel. Each UV module is connected to the electronic ballast cabinet by a pair of waterproof connector plugs. Each cabinet has a display to provide status information about the UV Bank, the individual modules and the respective individual UV lamps.
Power supply cabinets
The LIT UV 88MLV systems for Large-scale UV plants with multiple UV channels the power supply of the UV system is provided through a separate Power Distribution Cabinet. This cabinet contains a main power switch, electrical overload protection, ground fault interrupter and electrical breakers for each UV bank. The electricity requirements for UV system are 380 V / 3 phase / 50 Hz. The power distribution cabinet provides electrical connections to the UV system components like ballast cabinets, water level control system, the sluice gate motors and the cleaning system.
Operating and Control system
A Control Cabinet controls and operates the UV plant. The cabinet front door contains a control display with a graphical user interface for the UV system monitoring and control. The UV system can be operated in either automatic or manual modes. The control system is using an industrial PLC system; optionally this allows transmitting all operational data from the UV system to the main WWTP control centre usingstandard industrial fieldbus communication. The Control System incorporates a data logging function that records all operating parameters and the alarm history.
UV sensor
Each bank in the UV plant is equipped with two UV intensity sensors. The UV sensor measures the UV intensity inside the UV bank, the analogue signal is transmitted to the UV system Control cabinet. The UV intensity is continuous monitored and referenced against the minimum required UV intensity necessary for proper disinfection. The UV intensity can drop below the minimum required levels due to fouling of the quartz sleeves or aging of the UV lamps. When this occurs the UV system controller generates an LOW UV intensity alarm.
Automatic level control system
The LIT UV 88MLV disinfection system supply includes an automatic water level control device. This automatic water level controller consists of motorized slide gate mounted at the UV channel outlet, PLC controller and ultrasonic water level sensor. The water level control system maintains a constant water level inside the disinfection channel at all flows up to the design peak flow. It prevents the overflow of the UV system and guarantees that all water will be disinfected properly.
Chemical cleaning system
The 88MLV chemical cleaning system consists of a concrete or stainless steel tank, a water pump and a set of pipes. The reservoir is used for dissolving the cleaning solution. The water pump circulates the water / cleaning solution mixture through the chamber. A 0.2% aqueous solution of citric or oxalic acid is used for routine cleaning of the disinfection system (once every 2- 3 months). This chemical cleaning method provides effective removal of fouling from quartz sleeves and requires minimum labour and material resources.
Mechanical cleaning system
Depending on the level of suspended solids and the hardness of the treated wastewater, an automatic mechanical wiping system can be supplied as an option for 88MLV UV modules. This cleaning system maintains the quartz sleeves clean without having to remove the UV modules from the channels. The automatic mechanical cleaning prevents quartz sleeve fouling during UV system operation and it removes deposits from quartz sleeve surface using mechanical wipers which are periodically moved along quartz tubes. The cleaning frequency can be adjusted through the UV system control cabinet. The mechanical cleaning device is driven by pneumatic cylinders which are connected to an air compressor with reservoir.
Additional components
·UV Module Service Rack 11MLP UV system includes a mobile frame to hold modules that are extracted during servicing (e.g. lamp replacement). Each frame is designed to support 2 lamp modules for repair, cleaning or storage.
·Flow Distribution Baffles Where space is limited or when the channel length is restricted, stainless steel perforated baffle plates are inserted at the inlet of each UV channel, providing enhanced flow distribution and optimize mixing across the UV channel.
·Channel Cover Plates Under operating conditions, the channels with UV banks are covered by profiled zinc galvanized iron plates.
Series description