Application
Disinfection of secondary and tertiary treated wastewater effluents of
municipal and industrial WWTP plants of medium and large flow capacities.
Applications in combined sewer overflow and storm water disinfection
systems.
88MLV series advantages
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State-of-the-art high output low-pressure amalgam lamps with prolonged
operating lifetime;
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Safe, simple and quick maintenance of vertical lamps without lifting the
module out of water;
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Vertical design provides semi-turbulent plug flow ensuring that all water
receives maximum exposure to germicidal UV light;
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Absence of detachable bases immersed into water provides high reliability
throughout service life of the UV equipment;
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Vertical configuration provides a high capacity UV systems with much more
compact space layout;
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The series is equipped with PLC based monitor and control system providing
control of each lamp in the UV system;
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New electronic ballasts significantly reduce power consumption and increase
overall system efficiency;
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UV sensors provide greater operational security;
System Description and Components
UV Modules
LIT 88MLV UV Disinfection Systems have modular design for flexible, easy
system integration, installation and operation. The key component of the 88MLV
series UV system is 88MLV-36A module consisting of 36 vertically placed lamps.
Lamps are arranged in four parallel rows of 9 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 quick-attachment cover lid that allows the lamps to be
checked or replaced without having to remove the module out of the water flow or
disturb 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.
Power supply cabinets
For large-scale UV systems incorporating multiple UV channels the power
supply of the UV system is realized through separate Distribution Power Supply
Cabinet. In the cabinet there are overcurrent protection fuses, main power
switch and power switches for each UV bank. The electricity requirements for UV
system are 380 V / 3 phase / 50 Hz. From the distribution power supply cabinet
there are electrical connections to the electronic ballast cabinets, water level
control system, motor drives of the shut-off sliding gates and cleaning system.
Operating and Control system
Control and operation of the UV plant is provided through a Control Cabinet.
On a front door of the cabinet there is a control panel with graphical user
interface to control the UV system. The UV system can be operated both in
automatic and manual modes. The control system is implemented on the base of
industrial PLC system. There is an optional possibility to transmit all
operational data from the UV system to the main WWTP control centre through the
standard industrial serial bus. The Control System incorporates the data logging
function for recording all operating parameters as well as alarm history. The
minimum capacity of the log register is 1 year.
UV sensor
Each bank of UV plant is equipped with two UV-radiation intensity meters. The
UV sensor measures the UV intensity inside the UV bank, converts the analog
signal to digital form and transmits it to the Operating and Control system.
Automatic level control system
Each disinfection channel is equipped with automatic level control system. It
consists of motorized sliding gate mounted at the channel outlet, PLC controller
and ultrasonic and/or variable-capacitance water level sensor. A level control
system maintains proper water levels inside the disinfection channel at 0-100%
flow variations. It prevents overflows and guarantees that all water will be
treated properly without bypassing the UV modules.
Chemical cleaning system
88MLV UV system is provided with a chemical cleaning system for the quartz
sleeves in each channel without removing lamp 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 washing solution
preparation, circulation pump, system of pipes from stainless still and
switching valves.
Mechanical cleaning system
At high levels of suspended solids in treated wastewater an optional
automatic mechanical wiping system can be supplied with 88MLV UV modules for
quartz sleeves cleaning without removing 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
PLC control unit supplied for the entire wiping system. The pneumatic/hydraulic
cylinders are powered by air compressor with receiving tank.
Additional components
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UV Module Service Rack
88MLV UV system includes a mobile frame to fit the
extracted modules during service works (e.g. lamp replacement). Each frame is
designed to support one module for repair, cleaning or storage.
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Flow Equalizing Gratings
At space limited 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.
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