JPH0129409Y2 - - Google Patents

Description

[Detailed description of the invention] This invention is a pilot burner installed in a flare stack (combustion chimney) to burn waste gas in the atmosphere from chemical plants, iron and steel manufacturing plants, etc., and to diffuse and dilute this combustion gas into the atmosphere. Regarding windshields.

Many of the gases emitted from chemical plants, iron and steel plants, etc. are flammable, toxic, and have abnormal odors, and it is well known that flare stacks are used as equipment to treat these gases from an environmental hygiene standpoint. . In this flare stack, if the flame is extinguished and combustion is interrupted and this is not noticed for a long time, waste gas will fall to the ground and cause a major accident. For this purpose, the flare stack is equipped with a pilot burner to constantly burn a small amount of fuel gas such as LPG in addition to the plant gas, and a so-called pilot flame is provided to ignite the plant gas immediately after it is released. ing. Therefore, the cost of fuel spent on pilot burners is enormous, and reducing the cost has become a major issue.

By the way, the pilot burner not only needs to reliably ignite the main burner, but also needs to maintain a stable flame so that it will not be extinguished by wind, rain, combustion exhaust gas from the main burner, or the like. The former is not technically difficult, but the latter generally produces an unstable flame when the burner consumes less heat.
This is contrary to the above-mentioned request for fuel saving. In other words, flame stability is thought to be maintained by the balance between combustion velocity and unburned gas velocity;
In the case of a flare stack, the flame base is mixed, diluted and cooled by wind and rain, which reduces the combustion rate, disrupts the above balance, and extinguishes the flame. Conventionally, a windshield has been provided around the flame base of the pilot burner to protect it from wind and rain.

1 and 2, 1 is the flare burner (main burner) of the flare stack, 2 is the flare burner chip (orifice plate) provided on the inner peripheral surface of the upper end of the flare burner 1, and 3 is the flare burner tip (orifice plate) provided near the opening of the flare burner 1. A plurality of pilot burners (only one is shown in the figure) are provided at appropriate intervals in the circumferential direction, and each pilot burner 3 is connected to a fuel gas conduit 5 with an aspirator 4 interposed in the middle. There is. The reason why a plurality of pilot burners 3 are provided is that the flow of the waste gas 6 from the flare burner 1, especially when the flow rate is small, is caused to flow to the leeward side by the wind, so that ignition is possible even in this case. 7 is an ignition gas conduit installed to ignite the pilot burner 3; 8 is a thermocouple (thermometer) equipped to detect the presence or absence of a flame in the pilot burner 3; 9;
1 is a pilot burner windshield provided to cover the upper ends of the pilot burner 3, the ignition gas conduit 7, and the thermocouple 8, and as is clear from the figure, a cylindrical shape is used.

With this configuration, the conventional windshield 9 protects the flame base of the pilot burner 3 from wind and rain. However, since it is simply constituted by a cylinder, the flame of the pilot burner 3 is shielded, and the ignitability of the flare burner 1 is hindered. That is, the waste gas 6 only crossed the top of the windshield 9 and was difficult to enter inside. Therefore, even if the waste gas 6 is released from the flare burner 1, there is a delay in ignition, and there is a problem in that small explosions often occur when the raw gas is released into the atmosphere or ignited.

The purpose of the present invention is to solve these problems, and includes a semi-cylindrical inner cylinder with its back facing toward the flare stack, and a space between the outer circumference of the inner cylinder and the back of the inner cylinder. By providing a windshield for a pilot burner of a flare stack, the windshield is installed at a high height, has an upper end cut out diagonally so as to become lower toward the flare stack, and has an outer cylinder having a cutout side surface on the flare stack side. This achieves this purpose by making it possible to protect the base of the pilot burner's flame from wind and rain without shielding the pilot burner's flame, thereby making it possible to immediately ignite the waste gas released from the flare burner. It is possible.

An embodiment of the present invention will be described in detail below with reference to the drawings.

3 to 5, 10 is a flare burner (main burner) of the flare stack, 11 is a flare burner chip, 12 is a plurality of pilot burners provided at appropriate intervals in the circumferential direction near the opening of the flare burner 10, Reference numeral 13 denotes a fuel gas conduit, the structure of which is the same as that shown in the conventional example. Additionally, thermocouples, ignition gas conduits, etc. are omitted from the drawing because they are the same as in the conventional example. 14 is a windshield for a pilot burner according to the present invention, and the pilot burner 12
It is composed of an inner cylinder 15 and an outer cylinder 16, which are provided so as to cover the periphery of the cylinder. The inner cylinder 15 has a semi-cylindrical shape and is provided with its back face facing the flare burner 10 side, and the outer cylinder 16 is spaced apart from the outer periphery of the inner cylinder 15 and is taller than the inner cylinder 15. The upper end portion is cut out diagonally so that it becomes lower toward the flare burner 10 side, and the side surface on the flare burner 10 side is cut out.

With such a configuration, the unignited waste gas 17 released from the flare burner 10 passes between the inner cylinder 15 and the outer cylinder 16 and enters the windshield 14, as is particularly clear in FIG. is ignited by the flame. Also, depending on the relationship between the exit flow velocity of the exhaust gas 17 and the wind speed, the exhaust gas 17 may cross the top of the windshield 14, but in this case, since the top of the outer cylinder 16 is cut diagonally, the outer cylinder 16
The waste gas 17 hits the top of the cylinder, and this force causes it to flow downward. Thereby, the waste gas 17 is reliably ignited by the flame of the pilot burner 12. On the other hand, when the exit flow velocity of the waste gas 17 is high, the waste gas 17 is expanded and enlarged by the flare burner chip 11 at the exit of the flare burner 10 and becomes a large vortex, making it easier to ignite.

As described above, according to the present invention, the flame base of the pilot burner can be protected from wind and rain without shielding the flame of the pilot burner, and the waste gas released from the flare burner of the flare stack can be immediately ignited. Therefore, there is no delay in igniting the waste gas, and small explosions can be prevented.

[Brief explanation of the drawing]

1 and 2 show a conventional example, FIG. 1 is a longitudinal sectional view of a flare burner, FIG. 2 is a longitudinal sectional view of a windshield, and FIGS. 3 to 5 show an embodiment of the present invention.
FIG. 3 is a plan view of the flare burner, FIG. 4 is a longitudinal sectional view of the windshield, and FIG. 5 is a plan view of the windshield. 10... Flare burner, 14... Pilot burner windshield, 15... Inner cylinder, 16... Outer cylinder.

Claims (1)

[Scope of utility model registration request] A semi-cylindrical inner cylinder is provided with its back facing toward the flare stack, and a semi-cylindrical inner cylinder is provided on the outer periphery of this inner cylinder with a gap and taller than the inner cylinder, with the upper end becoming lower towards the flare stack. A windshield for a pilot burner of a flare stack, characterized by having an outer cylinder having an oblique cutout and a side face on the flare stack side cut out.