FIELD OF INVENTION
The present invention, in general relates to a method of installation of an electrostatic precipitator (ESP) and more particularly, to a method for erecting ESP supporting structures without usage of multi-axis drilling machine.
BACKGROUND OF THE INVENTION
In coal based thermal power plants, the electricity is generated from burning of coal inside a combustion chamber of a boiler. However, a large amount of flue gas containing fine dust particles is produced, which cannot be released to atmosphere directly resulting in intense air pollution. In order to limit the suspended particulate emissions compliant with Ministry of Environment and Forest (MOEF) regulations, electrostatic precipitators (ESPs) are installed for filtering the air pollutants present in the flue gas prior to the discharge of the exhaust gases via chimney at outlet.
The electrostatic precipitator (ESP) is located between the air pre-heater (APH) and induced draft (ID) fan for treating and collecting the dust/ash particles suspended in the flue gas. The working of ESP is based on the principle of electrostatics, with steps of corona generation, particle charging, particle collection and removal. Firstly, the flue gas with ash particles gets ionized by corona discharge inside the ESP, with negative particles being attracted towards the positive collecting plates. Then, the accumulated ash particles are removed through rapping mechanism at a frequent interval, and are collected in a plurality of ESP hoppers. This process is followed by removal of collected particulate matter using ash disposal mechanism.
Generally, four to six numbers of big sized ESP compartments are utilized for filtering of flue gas with the inlet ducting system connecting air

preheater to the inlet of the ESP and the outlet ducting system connecting the outlet of the ESP to the ID fan. The collecting & emitting electrodes are found to be inside the ESP compartment. The flue gas moving from air pre-heater via ESP inlet ducts enters into the ESP chamber through ESP inlet funnel. The equal distribution of flow into each ESP chamber is facilitated with a plurality of flow correction devices such as guide plates, guide vanes, splitters and gas distribution screens. The moving gas molecules contains ash particles which become negatively charged, when the strong negative field applied to the discharge electrode. The negatively charged ash particles migrate to the grounded collecting plates and form a dust layer. The dust layers are frequently rapped with the equipment like tumbling hammers and get collected in the ESP hoppers located at the bottom of the ESP.
Hence, in order to minimize the air pollution caused by release of exhaust gases, proper installation of highly efficient ESPs becomes significant in thermal power plants to safeguard the human health, animals and plantation and the environment. Traditionally, the whole setup of ESP along with its ducting system is supported by trusses, columns, bracing and many other structural components, which are connected with each other through welding joints. These structures are manufactured by units at different location, followed by assembling at power project site for final erection using welded connections. But, as the welding provides permanent joints, they have limitations in dismantling of the structures which may be required during maintenance. Further, the welding process calls for high accuracy, and release harmful welding gases. This disadvantages can be overcome by usage of bolted connections for easier erection of the ESP structural components.

However, bolted connection of L type bracings necessitates usage of multi-axis drilling machine which are very costly with its own limited usage, and also increases the fabrication cost as well as the erection cycle timing. This entails a method for erecting ESP supporting structures involving bolted connection without using multi-axis drilling machine upon implementation of which can lead to process improvement along with reduction in the fabrication cost and timing, maintaining the same performance, and also strictly adhering to the project delivery schedule. Additionally, The L type bracing pattern increases the erection cycle time due to intricate positioning of bolts closer to each other and the torque tightening of the bolts are most difficult and time consuming.
OBJECTS OF THE INVENTION
It is therefore an object of the present invention to solve the aforementioned and other drawbacks existing in the conventional process of erection of ESP supporting structures involving bolted connection.
A primary object of the invention is to provide a method for erecting ESP supporting structures without usage of multi-axis drilling machine.
Another object of the invention is to provide a method for erecting ESP supporting structures without usage of multi-axis drilling machine for reducing the fabrication cost, fabrication cycle timing and erection cycle timing.
Yet another object of the invention is to provide a method for erecting ESP supporting structures without usage of multi-axis drilling machine for reducing skilled manpower and complexities involved and thereby strictly adhering to project delivery schedule.

A still further object of the invention is to provide a method for erecting ESP supporting structures without usage of multi-axis drilling machine for reducing production of harmful welding gases and human errors involved in the conventional welding joint connection method.
Another object of the invention is to provide a method for erecting ESP supporting structures without usage of L-type bracing.
Still another object of the invention is to provide a method for erecting ESP supporting structures without usage of multi-axis drilling machine utilizing straight type bracings.
These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.
SUMMARY OF THE INVENTION
One or more drawbacks of conventional arts for erecting ESP supporting structures during installation of electrostatic precipitator in thermal power plants are overcome, and additional advantages are provided through the present invention as disclosed. Additional features and advantages are realized through the technicalities of the present disclosure.
For trouble free operation and maintenance, proper care has to be taken during ESP erection. In view of this, the present invention provides a bolted connection method for the ESP supporting structures like trusses, columns, bracing. As the conventional method of welding requires higher accuracy and proper alignment, it is replaced by bolted connection

mechanism which simplifies the process of erection, thereby facilitating a reduction in time for ESP installation.
Further, the usage of L type bracing for connecting the two components is replaced by use of straight type bracing without using multi-axis drilling machine. Because, the multi-axis drilling machines are very costly with its own limited usage, which also increases the fabrication cost as well as the erection cycle timing. Hence, the new method of bolted connection with straight type bracing is disclosed for reducing the fabrication cycle timing and erection cycle timing required for a typical project. The reduction achieved in fabrication time is found to be around 10 % along with 30 % in the reception time. The elimination of multi-axis drilling machine also reduces the requirement for skilled manpower and complexities involved.
Various objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description when taken in conjunction with the accompanying drawings in which like parts are designated by like numerals.
It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.
The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of apparatus that are consistent with the subject matter as claimed herein, wherein:
Figure 1 illustrates a three dimensional representation of connection pattern of bracing with the structural column according to an embodiment of the present invention.
Figure 2 illustrates a two dimensional representation of typical ESP bracing connection pattern with the conventional welded field joints.
Figure 3 illustrates an innovative ESP supporting structure bracing pattern with bolted single axis field connection according to an embodiment of the present invention.
Figure 4 illustrates new plates (Hatched) with Bolted single axis field connection along z direction according to an embodiment of the present invention.
The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from 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 INVENTION
While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.
The drawings illustrate only those specific details that are pertinent to understand the embodiments of the present disclosure, so as not to obscure the disclosure with details that will be clear to those of ordinary skill in the art having benefit of the description herein.
The procedure of connection method between different structural components of ESP plays an important role in the establishment of the required objectives. The secondary structure bracing (1), is to be connected to the primary structure column (2) as shown in figure 1. For this, the plate with drilling orientation along axis 1 (3) as shown in Fig 1 is to be connected to plate 2 with drilling orientation along axis 2 (4) as shown in Fig 1, through either welded joint or by means of bolted connections. The welding method requires conventional welding at project site and this is replaced with bolted connection at present. but the present case requires multi-axis drilling machines as both the plates are at different orientation axis 1 and axis 2. The horizontal bracing (5) as shown in Fig 2 and diagonal bracing (6) as shown in Fig 2 are the two dimensional representation of typical ESP bracing connection pattern with conventional Welded field joints.

In the new bolted connection method, a new plate is provided with overlapping bolted joints (9) as shown in figures 3 and 4, connecting two plates from the bracing on the both side. This new plate is locked to the Bolted connections from horizontal bracing (7) as shown in fig 3 and locked to the Bolted connections from diagonal bracing (8) as shown in fig 3 and fig 4. All the bolted connections in both horizontal bracing and diagonal bracing are oriented along single axis which enable the use of single axis drilling machine, thereby eliminating the costliest multi-axis drilling machine as well as achieving the same performance meeting the required design criteria.
LIST OF REFERENCE NUMBERS
1. Secondary structure bracing
2. Primary structure column
3. Drilling orientation along axis 1
4. Drilling orientation along axis 2
5. Horizontal bracing
6. Diagonal bracing
7. Horizontal bracing
8. Bolted connections from diagonal bracing
9. Overlapping bolted joints

We Claim:
1. A method for bolted connection with straight type bracing for Electrostatic
Precipitator (ESP), the method comprising steps of:
- Connecting different structural component of the ESP;
- Connecting new plates which are lying along the orientation axis 1 (3) and orientation axis 2 (4) to a single orientation axis; and,
- Making a new bolted connection with straight bracing;
- Bolting the conventional welding project site; and
- Locking new plate to the bolted connection.

2. The method as claimed in claim 1, wherein the structural component comprises of a secondary structure bracing (1) and primary structure column (2).
3. The method as claimed in claim 1, wherein the conventional welding project site lying along different axes such as horizontal axis (5) and diagonal axis (6).
4. The method as claimed in claim 1, wherein the new bolt connection with straight bracing further provided with new plate having overlapping bolted joints (9) connecting two plates from the bracing on the both side.
5. The method as claimed in claim 4, wherein the new plates are oriented along Z axis.
6. The method as claimed in claim 4, wherein the new plate is locked to the bolted connection from a horizontal bracing (7) and to a diagonal bracing (8), orienting all the bolted connection, lying along horizontal bracing and diagonal bracing, to a single axis along Z direction.