JPH07280711A - Gas sampling device - Google Patents

Abstract

PURPOSE:To prevent a filter from being plugged by filtering gas by the filter after centrifugally separating dust in a cyclone way, and dispense with the power source therefor by returning the dust to a flue utilizing the differential pressure of the flue. CONSTITUTION:The lower reaches 42 and upper reaches 43 of the IDF (induction fan) 41 of an exhaust gas flue 40 are communicated by ducts (gas passages) 44, 45. An outer cylinder 46 is provided on the way of the ducts 44, 45. The duct 44 is connected in the connecting direction to the outer cylinder 46 so that gas from the duct 44 is led in the connecting direction to the inner surface of the outer cylinder 46. A cylindrical filter 50 formed of porous material is coaxially installed in an inner cylinder 49.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sampling device for collecting exhaust gas of a combustion apparatus from an exhaust gas flue and sending it to an analyzer, and particularly when applied to sampling gas from the exhaust gas of a cement burning furnace. It relates to a suitable gas sampling device.

[0002]

2. Description of the Related Art Outline of cement burning equipment No. 2
It will be described with reference to the drawings.

A raw material crushed by a raw material mill is heated by a suspension preheater 1 and then fired by a rotary kiln 2 to produce a clinker. The clinker is cooled by the cooler 3 and then supplied to the finishing mill and crushed together with gypsum and the like to become cement.

A housing 4 is provided so as to surround the end of the rotary kiln 2 and the cooler 3.
Is equipped with a burner 5. A combustion flame (burner flame) of heavy oil is formed toward the inside of the rotary kiln 2.

Combustion gas from the burner 5 flows through the rotary kiln 2, the suspension preheater 1 and the induction fan (IDF) 7 in this order, is collected by the electric dust collector 8, and is then discharged from the chimney 9.

Gas analysis of exhaust gas in this cement burning facility is extremely important for combustion management. To perform this exhaust gas analysis, as shown in FIG. 3, a bulging part 6a is provided in the middle of the exhaust gas flue 6, a porous cylindrical filter 6b is installed in the bulging part 6a, and a gas sampling pipe 6c is provided. There is a device in which the above is communicated with the inside of the cylindrical filter 6b and suctioned by a pump.

In order to eliminate clogging of the filter 6b, compressed air is blown into the filter 6b from the air blow pipe 6d at regular intervals.

[0008]

The conventional gas sampling device described above has a problem in that the filter 6b is heavily clogged, and the clogging cannot be sufficiently eliminated even by blowing air.

[0009]

A gas sampling device of the present invention comprises a sampling gas flow passage communicating between an upstream side and a downstream side of an exhaust gas flue provided with an exhaust fan, and the gas flow. Provided in the middle of the passage, the gas from the upstream side is introduced tangentially, and after turning inside,
An outer cylinder that flows out to the downstream side, an inner cylinder that is provided coaxially inside the outer cylinder, a cylindrical filter that is arranged inside the inner cylinder, and suction the inside of the filter. It is provided with a pump for taking out gas, and a ventilation part for introducing sampling gas into the inner cylinder and communicating with a space between the inner cylinder and the outer cylinder.

[0010]

[Operation] By the differential pressure between the suction pressure of the exhaust fan and the exhaust pressure,
In the sampling gas passage, a gas flow is always formed from the downstream side of the exhaust fan to the upstream side.

This gas flow is introduced tangentially inside the outer cylinder. The gas swirls along the inner peripheral surface of the outer cylinder, and centrifugal force causes dust to hit the inner surface of the outer cylinder and settle toward the bottom of the outer cylinder. Then, a part of the gas component flows into the inside of the inner cylinder, passes through the filter, and is taken out to the outside.

The dust settled inside the outer cylinder and the surplus gas flow through the gas passage and are introduced upstream of the exhaust fan in the exhaust gas flue.

[0013]

EXAMPLES Examples will be described below with reference to FIG.

In this embodiment, the I of the exhaust gas flue 40 is
The downstream side 42 and the upstream side 43 of the DF 41 are connected by ducts (gas flow paths) 44 and 45.

An outer cylinder 46 is provided in the middle of the ducts 44 and 45. The duct 44 is connected to the outer cylinder 46 in the connecting direction so that the gas from the duct 44 is introduced into the inner surface of the outer cylinder 46 in the connecting direction. In addition, the duct 45
Is also tangentially connected to the outer cylinder 46, and the gas introduced from the duct 44 into the outer cylinder 46 swirls along the inner peripheral surface of the outer cylinder 46 and flows out to the duct 45 in the tangential direction as it is. Is configured to. The duct 44 is connected to the upper portion of the outer cylinder 46, and the duct 45 is connected to the lower portion of the outer cylinder 46.

The top and bottom of the outer cylinder 46 are sealed by end plates 47 and 48, respectively.

An inner cylinder 49 is hung coaxially with the outer cylinder 46 from the upper end plate 47. The lower end of the inner cylinder 49 is slightly separated from the lower end plate 48.

In the inner cylinder 49, a cylindrical filter 50 made of a porous material is installed coaxially with the inner cylinder 49. A vertical pipe 51 is provided through the end plate 47 so as to communicate with the inside of the filter 50.

The vertical pipe 51 includes an air blow pipe 52.
And a gas sampling pipe 53 are connected to each other, and ball valves 54 and 55 are provided respectively.

The pipe 53 is connected to the air pump 56. The downstream side of the air pump 56 is connected to a gas analyzer 58 via a pipe 57.

In the gas sampling apparatus thus constructed, the duct 4 is arranged from the downstream side 42 of the IDF 41.
The gas flowing toward the downstream side 43 via 4, 45 swirls along the inner peripheral surface of the outer cylinder 46 when introduced into the outer cylinder 46. The dust in the gas hits the inner peripheral surface of the outer cylinder 46 by the centrifugal force at the time of turning and settles along the inner surface of the outer cylinder 46.

A part of the gas component from which dust has been separated is partly ventilated 59 between the lower end of the inner cylinder 49 and the end plate 48.
Into the inner cylinder 49, then passes through the filter 50, is sent to the gas analyzer 58 via the pipe 53, the air pump 56 and the pipe 57, and is subjected to gas analysis.

The dust settled in the outer cylinder 46 is collected in the duct 4
5 is sucked into and returned to the upstream side 43 of the flue 40.

In the gas sampling apparatus of this embodiment, since the dust in the gas is centrifuged and then the gas is filtered by the filter 50, the amount of dust adhering to the filter 50 is extremely small. Dust filter 50
When the particles adhere to the filter, the ball valve 54 is opened, the ball valve 55 is closed, and air is blown by the air blow pipe 52, so that the adhered dust can be easily removed from the filter 50.

The dust settled in the outer cylinder 46 is naturally returned to the upstream side 43 of the flue 40 by the gas flow flowing into the duct 45. Therefore, the outer cylinder 46 is not filled with dust, and the power for discharging the dust is unnecessary.

[0026]

As described above, according to the gas sampling device of the present invention, the dust is centrifugally separated and then the gas is filtered by the filter, so that the filter is less likely to be clogged. Moreover, the dust can be returned to the flue by utilizing the differential pressure of the flue, and a power source for that purpose is unnecessary.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an apparatus according to an embodiment.

FIG. 2 is a perspective view of a cement burning facility.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 40 Exhaust gas flue 44, 45 Duct 46 Outer cylinder 49 Inner cylinder 50 Filter

Claims (1)

[Claims] 1. A sampling gas flow path communicating between an upstream side and a downstream side of the exhaust fan of an exhaust gas flue provided with an exhaust fan, and a sampling gas flow path provided in the middle of the gas flow path from the upstream side. The gas is introduced tangentially, swirls inside, and then flows out to the downstream side, an inner cylinder coaxially provided inside the outer cylinder, and an inner cylinder arranged inside the inner cylinder. And a cylindrical filter, a pump for sucking the inside of the filter to take out gas, and communicating with a space between the inner cylinder and the outer cylinder for introducing sampling gas into the inner cylinder. A gas sampling device comprising a ventilation part.