Title of Invention	"AIR HEATER FIRE MONITOR."
Abstract	The invention relates to an air heater fire monitor comprising a flanged alloy steel pipe (1) filled with insulation (2) material and a tube (3) is provided co-axially at the centre (4) of the said alloy steel pipe (1) and the thermocouple wires are provided through the centre (4) of the said tube (3) and the said thermocouple is connected to an alarm set point characterized in that during operation the insulation maintains a temperature difference between thermocouple and operating temperature and in case of fire, the insulation is burnt and the thermocouple sets the alarm.

Title of Invention

"AIR HEATER FIRE MONITOR."

Abstract

The invention relates to an air heater fire monitor comprising a flanged alloy steel pipe (1) filled with insulation (2) material and a tube (3) is provided co-axially at the centre (4) of the said alloy steel pipe (1) and the thermocouple wires are provided through the centre (4) of the said tube (3) and the said thermocouple is connected to an alarm set point characterized in that during operation the insulation maintains a temperature difference between thermocouple and operating temperature and in case of fire, the insulation is burnt and the thermocouple sets the alarm.

Full Text	The invention relates to an Air Heater Fire Monitor, In the regenerative air Pre Heater there is possibility of fire at the time of operation. The process uses oil as fuel which is fired and the hot gas is carried to the air pre-heater. During initial stages of firing due to incomplete combustion, the unburnt oil along with gas reaches the Preheater. This oil settle on the air heater basketstand which may lead to air heater fire. It tis essential to detect the fire in the initial stages itself, and fire put under control so that damages to the air heater can be avoided. At present there are two systems to detect the fire during operation of the regenerative air preheater. They are : 1. Infra red fire sensing device. 2. Thermocouple temperature comparison fire sensors. The infra red optical device detects the flame and gives a signal to electronic panel kept in the control cabinet. To have a clear view an air jet is kept in the infra red device to avoid settling of dust particals. To keep the device cool a circulating water system is also provided. The device is hinge mounted at the top so that it can swing out for inspection and cleaning during shut-down of the air heater. In the second system an indigenous thermocouple temperature comparison devices is used. The thermopcouple temperature sensed are compared within themselves and the differences are identified. This checking is done in the electronic control panel. If there is a fire there will be high temperature difference between the thermocouples which gives the signal about the fire. The thermocouples are kept in the gas and air path. There are disadvantages associated with the present system of fire monitoring . One of the main disadvantages of the existing infra red fire servicing device is that the device is is very sophisticated requiring expensive components. Another disadvantages if the existing infraved fire sensing device is that due to the use of many intricate components chances of breakdown is very high if any one of the component is malfunctioning. Yet another disadvantage of the existing thermocouple temperatures comparison fire sensors is that the device is expensive. Still another disadvantage of the existing thermocouple sensors is that of high erosion of the thermocouple due to high ash particles in the gas. The thermocouple requires regular replacement. Therefore the main object of the present invention is to provide a simple and fullproof device for detection of the air heater fire which is also not expensive. Another object of the present invention is to provide foradevice for the control where in case of fire in the air heater, the thermocouple directly faces the high temperature to operate the alarm. Yet another object of the present invention is that by keeping the fire monitor at different places above and below the air heater baskets, the exact location of the fire can be identified. Still another object of the present invention is that the device is fool proof and avoids the air heater damage and production loss. A further object of the present invention is to protect the thermocouple from gas erosion during the operation. According to this invention there is provided an air heater fire monitor comprising a flanged alloy steel pipe filled with insulation material and a tube is provided co-axially at the centre of the said alloy steel pipe and the thermocouple wires are provided through the centre of the said tube and the said thermocouple connected to an alarm set point. Characterised in that The during operation insulation maintains a temperature difference between thermocoupleends and operating temperature and in case of fire, the insulation is burnt and the thermo-couple sets off "the alarm. The nature of the invention, objective and further advantage residing in the same will be apparent from the to following description made with reference to non limiting exemplary embodiments of the invention represented in the accompanying drawing . BIG.1. Show a sectional view of the air heater fire monitor. In accordance with the present invention the device comprises a flanged alloy steel pipe (1) filled with insulation (2) material is above and below the baskets. A tube (3) provided at the centre of the pipe. (1) The thermocouple wires are provided through the centre (4) of the tube.(3) The quality of the insulation is such that when the gas temperature reaches 1OOCabove the operating temperature the insulation burnts completely. The insulation (2) thickness is such that during operation the thermocouple shows 50.C below the operating temperature. The thermocouple is connected to an alarm set point. When there is a fire in the air heater the insulation in the pipe burnts completely. The thermocouple faces the high temperature and gives an alarm. By keeping this air heater fire monitor at different places above and below the air heater baskets, the exact location of the fire can be identified. This system avoids damage to the air heater and production loss. One of the advantages in this system is that the thermocouple is saved from gas erosion during operation. This is a simple and easy system to detect the air heater fire. The invention described hereinabove is in relation to a non-limiting embodiment as an defined the accompanying claims. CLAIM; 1. An air heater fire monitor comprising a flanged alloy steel pipe (1) filled with insulation (2) material and a tube (3) is provided co-axially at the centre (4) of the said alloy steel pipe (1) and the thermocouple wires are provided through the centre (4) of the said tube (3) and the said thermocouple is connected to an alarm set point characterized in that during operation the insulation maintains a temperature difference between thermocoupleends and operating temperature and in case of fire, the insulation is burnt and the thermocouple sets off the alarm. 2. The air heater fire monitor as claimed in claim 1 wherein the alloy steel pipe is provided with a flange for fixing in to the baskets. 3. The air heater fire monitor as claimed in claim 1 wherein the insulation material thickness is such as to maintain a temperature difference of 50°C between the operating temperature and thermocouple. 4. The air heater fire monitor as claimed in claim 1, wherein the insulation material burns off when operating temperature exceeds by 100°C. 5. An air heater fire monitor as herein above described and illustrated.

Full Text

The invention relates to an Air Heater Fire Monitor,

In the regenerative air Pre Heater there is possibility of fire at the time of operation. The process uses oil as fuel which is fired and the hot gas is carried to the air pre-heater. During initial stages of firing due to incomplete

combustion, the unburnt oil along with gas reaches the Preheater. This oil settle on the air heater basketstand which may lead to air heater fire. It tis essential to detect the fire in the initial stages itself, and fire put under control so that damages to the air heater can be avoided. At present there are two systems to detect the fire during operation of the regenerative air preheater. They are :
1. Infra red fire sensing device.
2. Thermocouple temperature comparison fire sensors.
The infra red optical device detects the flame and gives a signal to electronic panel kept in the control cabinet. To have a clear view an air jet is kept in the infra red device to avoid settling of dust particals. To keep the device cool a circulating water system is also provided. The device is hinge mounted at the top so that it can swing out for inspection and cleaning during shut-down of the air heater.
In the second system an indigenous thermocouple temperature comparison devices is used. The thermopcouple temperature sensed are compared within themselves and the differences are identified. This checking is done in the electronic control panel. If there is a fire there will be high temperature difference between the thermocouples which gives the signal about the fire. The thermocouples are kept in the gas and air path.
There are disadvantages associated with the present system of fire monitoring .
One of the main disadvantages of the existing infra red fire servicing device is that the device is is very sophisticated requiring expensive components.
Another disadvantages if the existing infraved fire sensing device is that due to the use of many intricate components chances of breakdown is very high if any one of the component is malfunctioning.
Yet another disadvantage of the existing thermocouple temperatures comparison fire sensors is that the device is expensive.
Still another disadvantage of the existing thermocouple sensors is that of high erosion of the thermocouple due to high ash particles in the gas. The thermocouple requires regular replacement.
Therefore the main object of the present invention

is to provide a simple and fullproof device for detection of the air heater fire which is also not expensive.
Another object of the present invention is to provide foradevice for the control where in case of fire in the air heater, the thermocouple directly faces the high temperature to operate the alarm.
Yet another object of the present invention is that by keeping the fire monitor at different places above and below the air heater baskets, the exact location of the fire can be identified.
Still another object of the present invention is that the device is fool proof and avoids the air heater damage and production loss.
A further object of the present invention is to protect the thermocouple from gas erosion during the operation.
According to this invention there is provided an air heater fire monitor comprising a flanged alloy steel pipe filled with insulation material and a tube is provided co-axially at the centre of the said alloy steel pipe and the thermocouple wires are provided through the centre of the said tube and the said thermocouple
connected to an alarm set point. Characterised in that
The during operation insulation maintains a temperature
difference between thermocoupleends and operating temperature
and in case of fire, the insulation is burnt and the thermo-couple sets off "the alarm.
The nature of the invention, objective and further
advantage residing in the same will be apparent from the
to following description made with reference to non limiting
exemplary embodiments of the invention represented in the accompanying drawing .
BIG.1. Show a sectional view of the air heater fire monitor.
In accordance with the present invention the
device comprises a flanged alloy steel pipe (1) filled with insulation (2) material is above and below the baskets. A tube (3) provided at the centre of the pipe. (1) The thermocouple wires are provided through the centre (4) of the tube.(3) The quality of the insulation is such that when the gas temperature reaches 1OOCabove the operating temperature the insulation burnts completely. The insulation (2) thickness is such that during operation the thermocouple shows 50.C below the operating temperature. The thermocouple is connected to an alarm set point.
When there is a fire in the air heater the insulation in the pipe burnts completely. The thermocouple faces the high temperature and gives an alarm. By keeping this air heater fire monitor at different places above and below the air heater baskets, the exact location of the fire can be identified. This system avoids damage to the air heater and production loss. One of the advantages in this system is that the thermocouple is saved from gas erosion during operation. This is a simple and easy system to detect the air heater fire.
The invention described hereinabove is in relation to a non-limiting embodiment as an defined the accompanying claims.

CLAIM;
1. An air heater fire monitor comprising a flanged alloy steel pipe (1)
filled with insulation (2) material and a tube (3) is provided co-axially
at the centre (4) of the said alloy steel pipe (1) and the thermocouple
wires are provided through the centre (4) of the said tube (3) and the
said thermocouple is connected to an alarm set point characterized in
that during operation the insulation maintains a temperature difference
between thermocoupleends and operating temperature and in case of fire, the insulation is burnt and the thermocouple sets off the alarm.
2. The air heater fire monitor as claimed in claim 1 wherein the alloy
steel pipe is provided with a flange for fixing in to the baskets.
3. The air heater fire monitor as claimed in claim 1 wherein the
insulation material thickness is such as to maintain a temperature
difference of 50°C between the operating temperature and
thermocouple.
4. The air heater fire monitor as claimed in claim 1, wherein the
insulation material burns off when operating temperature exceeds by
100°C.
5. An air heater fire monitor as herein above described and illustrated.

Documents:

633-del-1997-abstract.pdf

633-del-1997-claims.pdf

633-del-1997-correspondence-others.pdf

633-del-1997-correspondence-po.pdf

633-del-1997-description (complete).pdf

633-del-1997-drawings.pdf

633-del-1997-form-1.pdf

633-del-1997-form-19.pdf

633-del-1997-form-2.pdf

633-del-1997-form-3.pdf

633-del-1997-gpa.pdf

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Patent Number

214726

Indian Patent Application Number

633/DEL/1997

PG Journal Number

09/2008

Publication Date

29-Feb-2008

Grant Date

14-Feb-2008

Date of Filing

14-Mar-1997

Name of Patentee

BHARAT HEAVY ELECTRICALS LTD.

Applicant Address

BHEL HOUSE, SIRI FORT, NEW DELHI 110049, INDIA.

Inventors:

#	Inventor's Name	Inventor's Address
1	RAMALINGA NARAYANASWAMI	BHARAT HEAVY ELECTRICALS LTD., HIGH PRESSURE BOILER PLANT, TIRUCHIRAPALLI TAMILNADU, 620014, INDIA.

PCT International Classification Number

G08B0 17/06

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA