Helios Infrapro Private Limited

New Alipore, Kolkata, West Bengal

Hopper Heater: The suspended particulate matter (SPM) from the Flue Gas Strem passing through the ESP's are collected in the hoppers below. These are then removed from the ESP and carried by Conveyors of various designs. However, choking and accumulation of this dust sometimes happens in the hoppers due to the presence of moisture and low temperature in the hoppers. This adversely affects the performance of an ESP. As such, hopper heaters are installed in the hopper walls which helps in maintaining the temperature in the hoppers, thereby avoiding any choking or acumulation.Insulator Heaters: The successful performance of an ESP is depending on many factory including the temperature inside the ESP. Air Ingress takes place in the ESP's through the openings of the Insulators. Heaters are installed here to heat the entering air thereby maintaining the temperature within the ESP.

Emitting Electrodes, also knows as Discharge Electrodes is the heart os the ESP. These are High Voltage internal and ionizes the gases and creates the electrical field. When the voltage breaks the gas down at the surface of the electrode, it generates corona power. This leads to creation of corona tufts on the surface of the electrode. Negative polariy voltage is applied to the electrode.The electrode design depends on various factors including the process for which the ESP is installed and the properties and composition of the flue gas.Types of Emitting Electrodes: For the corona generation, initially thin and round wires were installed. In some cases, twisted, barbed or square wires were also used.Nowadays, mostly rigid support frames are used for the electrodes. Frames may consist of spiral-spring electrodes, serrated strips, or needle spikes mounted on a support strip. Rigid type electrodes are also used in some applications, which is made from a single piece of fabricated metal.

For the rapping of the CE and DE, Magnetic-Impulse Rapper (MIGI Rapper) are installed in many designs of ESP's. A current pulse in a coil raises a steel plunger inside the MIGI Rappers. Then by the effect of gravity, the plunger drops back and strikes a rod which is connected to many plates inside the ESP. Frequency and intensity of the rapper are controlled by an electrical controlling system.Therappers for the collecting plates and discharge electrodes are generally mounted on thepenthouse roof for easy maintenance.The collecting plate rappers are mounted at the leading and trailing edge of thecollecting plates.The rapper assembly consists of a 2" diameter solid rod plunger, with a stainless steel tip to eliminate magnetization, which is free to move within a smooth phenolic guide tube around which is wound a copper solenoid type coil. The windings are epoxy encapsulated. A weatherproof metal casingprotects all the components.

For Power Plants, Helios offers the following items required for the operation and maintenance cycles. The supplies are proven in the industry and pass through stringent quality checks at the time of production: -Ceramic Lined Coal Bends, Coal Nozzle Tips etc. Air PreheaterSeals, Speed Reducer Gear Box (5APC, 4APC, 3APC) and its spares, Sector Plates, Tubular Air Preheaters.Forged Shafts, Wheels, Rounds etc.

As dust collects inthe hopper, the weight of the dust pushes down the counterweight of the top flap and dustdischarges downward. The top flap then closes, the bottom flap opens, and the materialfalls out. This type of valve is available in gravity-operated and motorized versions.

esp insulatoris one of the critical parts of an insulator and helios is a proven source for the same. The range of insulators covered by helios includes the following: -

• conical support insulator
• cylindrical support insulator
• shaft insulator
• pin insulator
• wall-through bushing insulator

the porcelain and high aluminainsulator for espmanufactured and supplied by helios ensures: -

• optimum insulating capability at high temperatures.
• high resistance to thermal shock and low thermal expansion thereby avoiding any insulator cracking.
• excellent mechanical strength and impact strength reducing failure due to mechanical stress.
• glazed surface reducing the deposit of dirt and dust.
• suitable for esp's working in temperatures up-to 400c.

normally the clients want the insulators to be supplied immediately as and when the need arises. As such, we maintain a regular stock of the common designs and can supply them at a days notice.

Emitting Electrodes, also knows as Discharge Electrodesis the heart os the ESP. These are High Voltage internal and ionizes the gases and creates the electrical field. When the voltage breaks the gas down at the surface of the electrode, it generates corona power. This leads to creation of corona tufts on the surface of the electrode. Negative polariy voltage is applied to the electrode.

The electrode design depends on various factors including the process for which the ESP is installed and the properties and composition of the flue gas.

Types of Emitting Electrodes:For the corona generation, initially thin and round wires were installed. In some cases, twisted, barbed or square wires were also used.Nowadays, mostly rigid support frames are used for the electrodes. Frames may consist of spiral-spring electrodes, serrated strips, or needle / spikes mounted on a support strip. Rigid type electrodes are also used in some applications, which is made from a single piece of fabricated metal.

Heliosmanufactures and suppliesEmitting / Discharge Electrodesfor Electrostatic Precipitators of all designs and makes. Raw material used for the manufacturing directly impacts the life and durabity of the Electrodes. The finish of the product greatly affects the corona generation and overall performance of the ESP. As such, proper care is taken in the manufacturing of each and everyEmitting Electrodeas well as the packing of the finished materials.

• Spiral Emitting Electrodes
• Pipe and Spike Type Electrode
• Multi-peak Discharge Electrodes
• Straight Round Wires
• Twisted pairs of Wires
• Barbed Discharge Wires
• Rigid masts
• Rigid frames

One electrical field of an electrostatic precipitator is by itself an independent precipitator and within the field, each Gas passage is also an independent ESP. Its operation is governed by the inlet gas and dust conditions, as well as the collecting plate and discharge electrode geometries. As such, creating similar gas and dust conditions in each field and gas passage is of prime importance.Gas Distribution Devicesplay a vital role to achieve this.

Gas Distribution Devices consist ofturning vanes in the inlet ductwork, andperforated gas distribution platesin the inlet and/or outlet fields of the precipitator. These Screens are of modular design manufactured out of Steel sheets and hang within a frame work in the ESP inlet casing to maintain uniform distribution pattern of gas flow throughout the cross section of ESP.

Helios is a preferred source for Gas Distribution Screens required for the ESP's. Apart from the Gas Distribution Screens, Helios is also experienced in carrying ourGas Distribution Teststo understand the present Gas Flow in the ESP with a view to optimize the same to the extent possible.

Collecting Electrodes are the collection surface made of sheet metal on which the particulate mater is collected after being negatively charged within the gas passage of the ESP. Designs of the plates vary from manufacturer to manufacturer. These plates are secured to the ESP shell at ground potential and serve as the positive anode of the gas passage.

General details of the Collecting Plates are given below: -

• Raw Material:Normally the Collecting Plates are made of Carbon Steel. However, for some applications where carbon steel made plates are corroded regularly, these are manufactured with stainless steel or an alloy steel.
• Sheet Thickness:The thickness of the collecting plates range from 0.5 to 2.0mm.
• Spacing:The spacing between the plates vary for different designs of ESP. For example, ESPs with wire type of emitting electrodes, plates are spaced from 150 to 300mm apart. High-efficiency ESPs (using wires) has spacing of 200 to 230 mm. ESPsusingrigid-frameor plate typedischarge electrodeshave a spacing of 300 to 400 mm betwee the plates.
• Height: Collecting Plates are normally 6 to 14M high.