JPS5935722A - Method of igniting gas heating device - Google Patents

Abstract

PURPOSE:To carry out ignition of a gas furnace safely and positively by firstly igniting a pilot burner while supplying preheated air from a main burner, adding thereto a combustion gas at a point in time where the preheating temperature of air reaches a set value, and supplying the combustion gas as a geseous mixture from the main burner. CONSTITUTION:Air is discharged at a predetermined flow quantity from the main burner 4 into the furnace 1 through an air pipeline 10, air pipes 8, 7 and a main mixer 5 by the command from a controller 19, and is heated by a preheater 6 when air passes through an air pipe 7. Then, a sensor 18 detects that the temperature of air within the gas furnace 1 has reached a set temperature, an air pipeline 16 and a gas pipeline 17 of a pilot burner system are opened, and a gaseous mixture of the pilot burner 14 is ignited by means of a heater or the like. Here, when the sensor 18 confirms the ignition of the pilot burner 14, a control value 12 of a gas pipeline 11 of the main burner system is gradually opened by the command of the controller 19, and the gas is sent into the gas pipeline 11 and the main mixer 5 and a gaseous mixture mixed with air preheated in the main mixer 5 is supplied from the main burner 4 into the gas furnace 1.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a method of igniting a gas heating device for high temperature heating.

[Technical background of the invention]

For example, in the manufacturing process of high-melting-point materials such as tungsten wire, a main burner that spews out a mixed gas is installed as a heating device to heat the wire, and the mixed gas from the main burner is completely combusted to raise the furnace wall temperature to a high temperature. The radiant heat is used to heat the wire as it moves through the furnace.

However, when using this gas furnace, the method of igniting all the mixed gas ejected from the main burner is to use an ignition source (spark rod, pilot gas, electric heat Since it is difficult to install all the heaters, a method of igniting them from outside the furnace is used.

The conventional ignition method is to first open the gas system valve, release only the main burner gas into the furnace, and then use the gas that fills the furnace and flows out of the furnace through the opening of the furnace body. The worker manually ignites the ignition. The gas is mixed with the air outside the furnace and burned, and while watching the flames, the worker operates the main burner's air system valve in the fully open direction, mixing them with the gas-air mixer. Gradually increase the amount of air.

Then, with the mixed gas supplied from the main gunner,
When the ratio of air and gas filling the furnace reaches the flammability limit, the flame outside the furnace entrance is drawn into the furnace, and the mixed gas filling the furnace is instantly ignited, causing a kind of explosion-like phenomenon. With great effort, the mixed gas supplied from the main burner in the furnace is fully ignited.

[Problems with background technology]

However, the process is carried out manually (mulberry production is very difficult) by gradually opening the pulp in the air system and supplying air from the main burner while monitoring the state of the flame of the burning gas outside the furnace inlet. , Skilled operation is required.Also, since the mixed gas in the furnace burns in an explosive-like state,
Not only is the work dangerous, but the ignition source metal may be blown out, making it difficult to ignite the main burner, or even damaging the furnace and reducing its durability (2. It is conceivable to use a venturi mixer or pressure equalization valve to control the flow rate by keeping the mixing ratio of the mixed gas discharged from the burner constant, but automatic ignition may be possible. Automatic ignition of a gas furnace is difficult because the temperature inside the furnace is high and it is difficult to install an ignition source and sensors.

[Purpose of the invention]

The present invention provides a method for igniting a gas heating device that can reliably and safely ignite a gas furnace, and can also be ignited by automatic control.

[Summary of the invention]

The method of igniting the gas heating device according to the present invention is to first ignite the pilot burner while supplying all preheated air from the main burner, and when the preheated temperature of the air reaches the set point, combustion gas is added to the main burner. The mixed gas is supplied as a mixed gas, and the mixed gas in the furnace is ignited by a pilot burner.

[Embodiments of the invention]

An embodiment of the present invention illustrated in the drawings will be described below.

Fig. 1 shows a gas furnace for heating wire and a mixed gas supply system as an example of a heating device for carrying out the ignition method of the present invention. A main burner 4 is provided inside the gas furnace 1, and the main burner 41d is connected through a main mixer 5 to an air pipe 7 equipped with a preheating heater 6f such as a sheathed heater. The gas furnace 1 is provided with an exhaust pipe 9, and an air pipe 8 surrounding the exhaust pipe 9 is provided with an air and flow meter 13 interposed therebetween, and a gas pipe 1 of the main burner system.
1 is connected to the main mixer 5 with a control valve 12 and a flow meter 13 interposed therebetween.

In order to carry out the ignition method of the present invention, a pilot burner 14 for igniting the main burner is prepared outside the gas furnace 1.・Mother Ilotpana 14 is pilot mixer 1
5 to the air piping 16 and gas piping 17 of the Noguirotpana system. Air piping 16 and gas piping 17 are connected to air piping 10 and gas piping 11 of the main burner system. Further, a sensor 18 such as a temperature detector or a flame detector is installed outside the gas furnace 1 on the wire outlet 3 side, for example, and a signal from the sensor 18 is sent to a controller 19. Each pipe 1
The control valves 12 provided at θ and 1 are operated by an electric mechanism having an electric motor or a lunoid, and the electric mechanism is fully driven by a signal from the controller 19 to control the opening and closing of each control valve 12. shall be taken as a thing.

Next, a method of igniting the main burner of this gas heating device will be explained. First, the control valve 12 of the air pipe 10 of the main burner system is opened at a predetermined angle according to a command from the controller 190, and the air pipe 10, air pipe 8,
7 and the main mixer 5 to be discharged from the main/gas 4 into the inside of the gas furnace 1. The air is heated (preheated) by the preheating heater 6 when it passes through the air filter 7. In this way, the air inside the gas furnace 1 is preheated while flowing at a constant flow rate through the main burner 4, and the air inside the gas furnace 1 is heated to a predetermined set temperature. The sensor 18 detects that the temperature has reached the set temperature, and at this point the fill controller 190 command causes the fill controller to
A mixed gas of air and gas is sent by the atom mixer 15 to the city high lot node J4, and 9'lJ is sent by a heater etc.! Ilot no Guichi! All of the 14 mixed gases are ignited 1. Here, the flame of 14 is detected. Confirm that Ilotpana 14 is ignited. As a result, controller 1
90 command, the control valve 12 of the gas pipe 1 of the main gunner system is gradually opened, and the gas is sent to the gas pipe 11 and the main mixer 5, where it is mixed with the preheated air. Gas flows from main burner 4 to gas furnace 1
Supplied internally. When the proportion of gas in the mixed gas increases and this proportion falls within the combustible range, the mixed gas is ignited from the outside of the gas furnace 1 through the wire outlet 3 by the flame of the pilot burner 14. Next, the sensor 18 detects the main burner 4
At this stage, the controller 190 commands the control valves 12 and 12 of the air piping 10 and the gas piping 11 to maintain their opening degrees, and the gas furnace control valves 7,
? , 12 are gradually increased to gradually increase the amount of air and gas of the mixed gas flowing out from the main burner 4 into the gas furnace 1.

Then, by continuing to burn the mixed gas in the main burner 4, the temperature inside the gas furnace J is increased. Exhaust gas resulting from combustion of the mixed gas passes through the exhaust pipe 9 and is exhausted to the outside. In this case, the heat of the exhaust gas passing through the exhaust pipe 9 preheats the air passing through the air pipe 8. Then, the wire is introduced into the gas furnace 1 from the wire rod 2 and passed through the entire furnace 17 through the wire outlet 3 to perform edge heating.

However, in the method of controlling the ignition and temperature rise of the gas furnace 10 as described above, air that has been heated to a set temperature by preheating is mixed with combustion gas, and this mixed gas is used as the main gas. Since the flame of the pilot gas 14 is fed into the furnace from outside the furnace, the main burner 4 can be reliably ignited by feeding the entire flame of the pilot gas 14 into the furnace from outside the furnace. In addition, since a constant flow rate of preheated air is sent during ignition, and then only the amount of gas is gradually increased while being fed into the mixed gas metal furnace, the interior of the gas furnace 1 is not filled with excess gas. Therefore, quiet ignition without the conventional explosion phenomenon is possible, and safe ignition work and damage to the gas furnace 1 caused by ignition of the main gunner 4 can be prevented. Furthermore, with these things, it is also possible to automatically ignite the main burner 4, and furthermore, after confirming the ignition of the main burner 14, the gas control valve 12 of the main burner system can be automatically ignited.
In order to perform zero opening control, there is a wider degree of freedom than conventional methods in controlling the air-to-gas mixture ratio of the mixed gas at the time of ignition, regardless of air pressure fluctuations and flow rate fluctuations that occur during daily gas furnace operation. Furthermore, there is no need to install expensive equipment in the piping system for automatic ignition.

Figure 2 (1) is a diagram showing the relationship between the opening degree of the control valve of the main burner system and the amount of air and gas in the conventional ignition method. It is a diagram showing the relationship between the opening degree, the amount of air, and the amount of gas.However, A shows air, B shows gas, and C shows the ignition point.

The present invention is applicable not only to linear heating furnaces but also to ignition of gas furnaces in general. -1' Furthermore, the present invention is not limited to automatic ignition, but also allows manual ignition.

〔Effect of the invention〕

Ignition method of the gas heating device of the present invention As explained above, the amount of gas in the main burner is gradually increased while continuously supplying preheated air at a constant flow rate into the main burner gas furnace. Since the main burner is ignited by the pilot burner, the main burner can be ignited easily and reliably.In addition, it can be ignited quietly, making work safe and preventing damage to the furnace.In addition, practical automatic ignition is also possible. .

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing an example of a gas furnace implementing the ignition method of the present invention, and Fig. 2 is a diagram showing the relationship between the valve opening of the main burner system and the amount of air and gas in the conventional method. , FIG. 3 shows the relationship between the valve opening of the main burner system, the air amount, and the gas loss in the method of the present invention: I! It is a diagram showing the l section. 1... Gas furnace, 4... Main burner, 6... Preheater, 7, 8... Air pipe, IO... Air pipe, 1
No...Saz piping, 12...Control pulp, 14...
・Pilot burner, 16... Air piping, 17...
Gas piping, 18...sensor, 19...controller.

Claims (1)

[Claims] (1) In a gas furnace equipped with a main burner that supplies a mixed gas of air and combustion gas, an ignition source is operated while supplying preheated air from the main burner to the entire furnace,
The pilot couch is characterized in that the mixed gas from the main gas is ignited by gradually mixing the combustion gas into the air supplied from the main gas. A method for igniting a gas heating device according to claim 1. (3) The method for igniting a gas heating device according to claim 1, wherein the gas furnace is a wire rod heating furnace having a passage port through which the wire or rod passes.