Claims:We claim:
1. A single hopper electrostatic precipitator (101), the hopper electrostatic precipitator (101) consists of:
a plurality of inlet funnels (105) allows entry of flue gas containing dust/ash particles to the electrostatic precipitator (101); 5
a chamber connected with each of the plurality of inlet funnels (105) to ionize the dust/ash particles of the flue gas through corona discharge;
wherein the ionized dust/ash particles get attracted by oppositely charged collecting electrode; 10
Characterized in that
the collected dust/ash particles get frequently rapped from the collecting electrodes and falls into the single hoppers (303, 304) provided per electric field.
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2. The single hopper electrostatic precipitator (101) as claimed in claim 1, wherein width (g) of the hopper (303) for left side bus section is equivalent to width (a+b) of the two hoppers (301) for the left side bus section of double hopper electrostatic precipitator (103).
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3. The single hopper electrostatic precipitator (101) as claimed in claim 1, wherein width (h) of the hopper (304) for right side bus section is equivalent to width (c+d) of the two hoppers (302) for the right-side bus section of the double hopper electrostatic precipitator (103).
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4. The single hopper electrostatic precipitator as claimed in claim 1, wherein width (g) of the hopper (303) for left side bus section of the single hopper electrostatic precipitator (101) is equivalent to width (h) of the hopper (304) for right side bus section the double hopper electrostatic precipitator (103).
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5. The single hopper electrostatic precipitator as claimed in claim 1, wherein the single hopper (303, 304) is provided with a single hopper heater (305).
6. The single hopper electrostatic precipitator as claimed in claim 1, wherein the single hopper (303) has valley angle in range 60 degree to 70 degree. , Description:A SINGLE HOPPER ELECTROSTATIC PRECIPITATOR
FIELD OF INVENTION
[001] The present invention relates to an electrostatic precipitator. The present invention particularly relates to a single hopper structure for higher width electrostatic precipitator for collection of fine and coarse ash particles from the 5 flue gas.
BACKGROUND OF THE INVENTION
[002] In thermal power plants, power is generated by burning coal which generates flue gas with large amount of dust/ ash particles. This dust/ ash laden flue gas is passed across various equipments and finally let out through a tall 10 chimney into the atmosphere.
[003] Before finally escaping in to the atmosphere, flue gas is treated by electrostatic precipitator which captures the dust/ ash particles in the flue gas and the clean dust/ ash free gas finally escape out through the chimney. Electrostatic precipitator works with high level of efficiency in the order of 99.9% in removing 15 dust/ash from the flue gas. This makes the electrostatic precipitator one of the vital equipments in the power plant system which safeguards the human and animal health, plantation and environment and satisfies the Ministry of Environment and Forest regulation.
[004] Electrostatic precipitator works on the principle of Electrostatics. The flue 20 gas from the boiler containing dust/ ash enters into the electrostatic precipitator chamber via duct through inlet funnel. The flow of dust/ ash laden flue gas is equally distributed into each electrostatic precipitator chamber with the help of flow correction device, such as guide plates, guide vanes, splitters and gas distribution screens. 25
[005] The dust/ ash particles in the flue gas are negatively charged with corona discharge by strong negative field applied to the discharge electrode. This negatively charged dust/ ash particles get migrated to the groundless collecting plates and form a dust/ ash layers. The dust/ ash layers are frequently rapped with
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the equipment like tumbling hammers and get collected in the electrostatic precipitator hoppers.
[006] The collected dust/ ash is frequently evacuated through dust/ ash handling system. The collected dust/ ash is removed as quickly as to avoid the packing effect. Hoppers are usually designed with a slope of 60o to 70o to allow free fall 5 of the collected ash via discharge opening at the bottom of the hoppers. Hopper heaters are used to maintain the fluidity of flowing dust/ ash.
[007] Conventionally there are two hoppers per electrical field for each field of electrostatic precipitator. The ionized ash particles get collected into these hoppers after being rapped from the collecting plates through hammers. 10
[008] The collected ash inside the hoppers is to be maintained in hot condition for a continuous period of 8-9 Hours before evacuation in order to maintain the fluidity and flow ability of the ash particles. The hoppers are designed for 8-9 hours of storage capacity and many hopper heaters are provided around each hoper to maintain the hot condition, resulting in more consumption of power. 15
[009] Also this conventional double hopper system involves additional weight due to electrostatic support bearings, deflection plates, casing along with casing columns, hopper approach platform along with floor grills and ash handling system.
[0010] An incorrect hopper design not only affects the performance of 20 electrostatic precipitator but also results in more emission of dust/ ash into the atmosphere than the prescribed standard or the guaranteed parameter.
[0011] There is a requirement for electrostatic precipitator having greater hopper width to cater the need of revised emission norms. Lot of technical and commercial issues are brewed up which lead to difficulty in designing the hopper 25 system with correct valley angle as well as due to other extended dimensions.
[0012] To overcome the above issues faced for electrostatic precipitator with greater hopper, a new structure is disclosed in the present application to replace a double hopper system per electrical field with a single hopper system for the same electric field. This modification leads to enhanced efficiency by reduction in the 30 material and power consumption, while achieving the same performance.
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OBJECTS OF THE INVENTION
[0013] It is therefore an object of the invention to propose a single hopper system per electrical field replacing the conventional two hopper system per electric field.
[0014] Another object of the invention is to reduce the total hopper heaters required, thereby reducing the total power consumption required per electrostatic 5 precipitator.
[0015] Another object of the invention is to reduce the overall structural columns and other electrostatic precipitator supporting structure requirements.
[0016] A still another object of the invention is to reduce the number of dust/ ash handling system required for modified single hopper system. 10
[0017] A still another object of the invention is to reduce the emission of plant by properly utilizing the electrostatic precipitator hoppers and avoiding re-entertainment of the flue gas.
SUMMARY OF THE INVENTION:
[0018] The present invention provides a single hopper system replacing the 15 conventional double hopper system for achieving the same performance. The arrangement of hopper along the width of the electrostatic precipitator plays an important role in the establishment of the above stated objectives.
[0019] The present subject matter discloses a single hopper system per electric field or total of two hoppers along the width of electrostatic precipitator for higher 20 width electrostatic precipitator.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0020] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally 25 effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and
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components. Some embodiments of system or methods in accordance with embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0021] Figure 1a illustrates isometric view of conventional double hopper system;
[0022] Figure 1b illustrates isometric view of single hopper system per electric 5 field according to present invention;
[0023] Figure 2a illustrates side view of a conventional double hopper system;
[0024] Figure 2b illustrates side view of a single hopper system according to present invention;
[0025] Figure 3a illustrates side view of conventional double hopper system with 10 dimensions;
[0026] Figure 3b illustrates side view of a single hopper system with dimension according to present invention;
[0027] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from 15 the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF THE CURRENT INVENTION
[0028] It should be noted that the description and figures merely illustrate the 20 principles of the present subject matter. It should be appreciated by those skilled in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not 25 explicitly described or shown herein, embody the principles of the present subject matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be 30 construed as being without limitation to such specifically recited examples and
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conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. 5
[0029] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the 10 principles of the present subject matter and are included within its scope.
[0030] The present invention proposes a single hopper electrostatic precipitator (101) having single hopper electric field or total of two hoppers (102) along the width of electrostatic precipitator (101) to make the width of the single hopper electrostatic precipitator (101) greater than the conventional double hopper 15 electrostatic precipitator (103).
[0031] Reference may be made to figure 3a wherein the dimension “a” and “b” indicate the width of each hopper (301) for left side bus section for a double hopper electrostatic precipitator (103) and the dimensions “c” and “d” indicate the width of each hopper (302) for a right-side bus section for a double hopper 20 electrostatic precipitator (103). The double hoppers (301, 302) of the double hopper electrostatic precipitator (103) is replaced by single hopper (303) having dimension “g” indicating the width of each hopper for left side bus section of the single hopper electrostatic precipitator (101) and the dimension “h” indicating the width of each hopper (304) for a right side bus section for a single hopper 25 electrostatic precipitator (101).
[0032] The ratio to be followed in designing the single hopper system is in such a way to conserve the dimensions, i.e., a+b = g, c+d = h and g=h. The width (g) of single hopper (303) of single hopper electrostatic precipitator (101) is equivalent to the width (a+b) of double hoppers (301) of double hopper 30 electrostatic precipitator (103). Also, the width (h) of the single hopper (304) of
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the single hopper electrostatic precipitator (101) is equivalent to width (c+d) of the double hopper (302) of double hopper electrostatic precipitator (103). Further, width of single hopper (303) is equivalent to width of single hopper (304) of the single hopper electrostatic precipitator (101).
[0033] The flue gas containing dust/ ash particles flows from APH outlet (104) to 5 the chamber of the single hopper electrostatic precipitator (101) via inlet ducting system. Each single hopper electrostatic precipitator contains two bus section or two inlet funnels (105) through which the flue gas enters the single hopper electrostatic precipitator (101) before encountering corona discharge. When high voltage is applied corona discharge occurs around the discharge wires to generate 10 ions. The dust/ ash particles contained in the flue gas guided through the air intake port collide with the ions to get charged. The charged dust/ ash are attracted by the oppositely charged collecting electrode and form some layers over it. The collected dust/ ash layers are frequently rapped with the equipment like tumbling hammers and falls into single hoppers (303, 304) provided per electric field. The 15 collected dust/ ash inside the single hopper electrostatic precipitator (101) are kept under hot conditions for 8-9 hours to maintain their fluidity and flow ability. Hopper heaters (305) are provided around each hopper to maintain hot conditions. The storage capacity is kept suitable to accumulate dust/ ash for 8-9 hours.
[0034] The single hopper system (303, 304) in single hopper electrostatic 20 precipitator (101) results in reduction in material consumption occurs for mechanical items like hopper supporting structures, insulation wool, electrostatic precipitator support bearing, cladding, hopper heater panels, ash handling system and civil foundation. The present single hopper system in electrostatic precipitator results in overall reduction of ten percent in material consumption. 25
[0035] In an aspect of the present invention, the single hopper 303 has valley angle in range 60 degree to 70 degree.
[0036] As the number of hoppers is reduced by fifty percent in single hopper system in electrostatic precipitator there is also reduction in hopper heaters required, which leads to reduction in power consumption by nearly twenty five 30 percent.
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[0037] As two hoppers are replaced by one hopper, the one hopper has greater width than the previously used hopper. This greater width of the single hopper helps in caters the need of revised norms proposed by the Ministry of Environment and Forest regulation.
[0038] Although embodiments for the present subject matter have been described 5 in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/component of the present invention will be apparent to those skilled in the art, and thus it is 10 intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.