COMBO FILTER FOR INDUSTRIAL FLUE GAS CONTROL

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International Journal of Advances in Engineering Research http://www.ijaer.com (IJAER) 2016, Vol. No. 11, Issue No. V, May e-ISSN: 2231-5152, p-ISSN: 2454-1796

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INTERNATIONAL JOURNAL OF ADVANCES IN ENGINEERING RESEARCH

COMBO FILTER FOR INDUSTRIAL FLUE GAS

CONTROL

MULAGALA SRINIVAS RAMA KUMAR (M.S.RAMA KUMAR)

RAMA KUMAR.M.S1 M.Tech (P.E) Thermax Enviro Division

Thermax Enviro ltd, Midc, Bhosari, Pune,India-411026.

ABSTRACT

While strong environmental restrictions are requiring power companies to reduce SOx , NOx

and Mercury emissions, deregulation pressures are simultaneously necessitating improvements in the thermal

efficiency of all coal-fired & Other plants. SOx, NOx, and Mercuryhave become serious air pollutant such as

photochemical smog .Coal-fired power plants represent a significant fraction of the anthropogenic emissions

of mercury into the atmosphere along with SOx and NOx. In spite of an attempt to reduce the amount of SOX,

NOx and Mercury emitted the density of SOx , NOx and Mercury in the atmosphere has remained on a stable

level, or even become worse. Here, we designed a novel type of COMBO FILTER (Combination of E.S.P

& Bag Filter) which is used for reducing SOx, NOx, and Mercury along with other pollutants in the flue gases.

Key Terms : E.S.P,BAG-FILTER,COMBO-FILTER,SOLENOID VALVE.

COMBO FILTER (Combination of E.S.P & Bag Filter):

E.S.P: An electrostatic precipitator (ESP) is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

ESP Electrodes

This section will discuss two types of electrodes in the ESP, the discharge electrode and the collection electrode (sometimes referred to as the collection plate)The purpose of the discharge electrode is to produce the corona which ionizes the surrounding air, thus charging and driving particulate to the collection plate. Discharge electrodes have changed over the years, starting out as a thin wire design. More recent electrodes fall into several construction types including stringing wires, thin metal strips, roll formed masts, and the pipe and spike arrangements.

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length of the precipitator column. Optimum corona dispersion results in uniformly charged particles giving the best collection performance. In gas passages, the electrodes are typically spaced.. These applications tend to be used in high corrosive environments and require stainless steel. In these cases, a conductive composite rod electrode would be of tremendous cost advantage, lighter, and perform for a longer period of time.

BAG-HOUSE: Bag-houses are incredibly versatile and can be engineered for almost any dust producing application by varying size and bag types. They are very efficient when properly maintained and are also rugged enough to handle rough applications. However, they typically require a lot of maintenance and a relatively dry environment to operate effectively. Their use is also limited to certain operating temperatures and chemical conditions.

Pulse controller is the main control unit Pulse bag filter cleaning system, the control pulse signal output from the solenoid valve it is blowing compressed air circulation filter bag cleaning, dust resistance is maintained at the set range inside, in order to ensure the efficiency of processing power and dust precipitator. Pulse jet control device output electrical signal of a sustained period, the pulse width. Output time between the two signals, called pulse interval. The controller outputs an electrical signal needs time to complete a cycle, called the pulse period.

Terminology in Compressed Air Calculations :

i) Return Trip Time (RTT) :It is the time required to complete pulsing cycle in minutes. In other

words, it’s the time span between two successive pulses from the same valve measured in minutes.

Return trip time isselected on the basis of total inlet dust load. RTT is comparatively high for low

dust loads and low for high dust loads. If we are firing more than one PSV at a time in that case we consider all of the PSVs As single unit for time span calculation only. For air volume calculation we have to consider

All PSVs individually.

ii) On Time The time for which valve is in ‘Open’ condition for a single pulse. It is measured in Milliseconds generally.

iii) Off Time

It is the time span between two successive pulses of two different valves in the same RTT. Generally it is measured in seconds.

Advantages of Dual-Action Filter systems :

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longer time. Because the Bag Filter’s load is shared with the ESP, filter bags last longer ensuring the efficiency of your system;

Retrofit solutions : Effective Dual-Action Filter retrofit solutions can extend the life of your existing plant while ensuring compliance with emissions regulations.

The novel feature of the current-fed converter combined with an input chopper is its performance under abnormal operating conditions. Transformer T1, IGBT’s Q1 through Q5, and diodes D1 through D8 can all operate in a shorted state with system level protection. Under such conditions, the rate of rise of current is a function of the applied voltage across inductor L1 divided by its inductance. Inductor L1 is typically sized to maintain a peak to peak ripple current within a fraction of it maximum value. As long as system shutdown occurs within the switching period of the chopper, peak currents are well controlled. Permitting an extended fault detection period allows fault protection circuitry to be well filtered enabling robust, nuisance free tripping operation in high electrical noise environments.

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converter stage can be protected with the chopper shutdown and a fault in the chopper stage can be protected with the current-fed converter shutdown.

The previous constraints placed on the switching states of the current-fed converter can be circumvented with the introduction of catch diode D16. This component provides a current return path for IGBT’s Q1, Q3 or Q2, Q4 when the devices are turned off. Diode D16 clamps the maximum off state voltage of the H-bridge to the voltage across capacitor C1.

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INTERNATIONAL JOURNAL OF ADVANCES IN ENGINEERING RESEARCH Application : Combo filter for 2*66 TPH Coal fired plant .

Turbine load : 3.18 mw.

APPLICATION Combo filter FOR 2 ᵡ 66 TPH BOILER(/COAL

FIRED)

FUEL USED

Imported Coal

S.NO PARAMETER

E.S.P

BAG

FILTER UNIT DESIGNED MEASURED

1 No of mechanical

/Electrical fields

Two

Fields No.

2MECH 42ELECTRICAL

2MECH/2 ELECTRICAL

2 Gas Flow At Inlet (Total) AM3/HR 147600 150295

A Gas Flow Per Pass AM3/SEC 41 27.483

B Gas Flow At Outlet AM3/HR 95000 98940.48

3 Gas Temp At Inlet (Operating) DEG C 200 200

3a Gas Temp At Outlet DEG C 175 175

4 Moisture % v/v 16.06 14.85

5 Inlet dust load GMS/NM3 77.63 77.63

6 Emission guarantee MGMS/NM3 15 5.3

7 Collection efficiency % 99.87 >100

8 Plate area (total) M2 4320 4320

A Plate area (per pass) M2 4320 4320

9 SCA M2/M3/SEC 105.37 130.37

10 Velocity M/SEC 0.57 13.29

11 Migration velocity (wd) CM/SEC 5.51 7.418

Treatment time SEC 21.1 8.126

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13 Pressure drop across

The esp(top entry) MM OF WC 25-30 9.2

14 Esp penhouse temp ıC 90-110 100

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