JP4575848B2 - Gas sampling device and gas sampling method - Google Patents

Description

  The present invention relates to a gas sampling device and a gas sampling method for collecting gas for analysis when, for example, gas components in combustion exhaust gas are continuously measured.

  In such a gas sampling device, a filter is usually provided to remove dust and tar content in the gas to be collected, and since these adhere to the filter, it is necessary to periodically clean the deposit. is there. Conventionally, as a filter cleaning method, a method of cleaning by a backwash operation using a compressed gas as a backflow gas is known (see, for example, Patent Document 1).

However, especially when the collected gas contains a large amount of dust and tar, it is not possible to obtain a sufficient cleaning effect by simply performing a backwash operation with the backflow gas, and the filter is clogged and replaced in a short period of time. In order to prevent clogging, it was necessary to frequently perform backwashing operations. Thus, the conventional cleaning method has problems in both running cost and maintainability.
JP 2002-131198 A

  The problem to be solved by the present invention is to improve the maintainability and reduce the running cost by efficiently cleaning the filter for removing dust and tar content in the collected gas in the gas sampling device. There is.

  In order to solve the above-mentioned problem, the gist of the present invention is to spray a backflow gas on the inside and outside of a cylindrical filter disposed inside a gas sampling pipe to blow away the adhering matter on the filter and wash the filter. It is to have done.

That is, the gas sampling device according to the present invention is a gas sampling device having a gas sampling tube for collecting gas and a cylindrical filter disposed inside the gas sampling tube, and the backflow gas for cleaning the filter is removed from the filter. There are provided first and second blaster means for blowing inside and outside to blow away the deposits on the filter, and the backflow gas is blown from the outside of the gas sampling tube to the vicinity of the gas sampling port of the gas sampling tube to deposit the vicinity of the gas sampling port. A third blaster means is provided for blowing off.

Further, the gas sampling method according to the present invention is a gas sampling method using a gas sampling device having a gas sampling tube for collecting gas and a cylindrical filter disposed inside the gas sampling tube. After the backflow gas is blown to the inside of the filter, it is blown to the outside of the filter to blow off deposits on the filter, and further, the backflow gas is blown from the outside of the gas sampling tube to the vicinity of the gas sampling port of the gas sampling tube. It is characterized by repeatedly blowing off the deposits .

In the present invention, the backflow gas is blown to the outside of the filter after being blown to the inside of the filter . About the backflow gas sprayed inside a filter, it is preferable to spray so that it may blow in a pulse shape by operation | movement of a high-speed on-off valve, and may give an impact to a filter instantaneously. Moreover , it is preferable to spray the backflow gas supplied to the outside of the filter so as to form a swirling flow along the outer surface of the filter. Thereby, deposits such as dust and tar blown off from the filter can be efficiently purged outside the gas sampling device.

In the present invention, in addition to the inside and outside of the filter, the vicinity of the gas sampling port is cleaned by blowing a backflow gas to the vicinity of the gas sampling port of the gas sampling tube . About the backflow gas sprayed in the vicinity of the gas sampling port of the gas sampling tube, it is preferable to spray it instantaneously in the form of pulses by the operation of the high-speed on-off valve, and to blow off deposits such as dust and tar by the impact.

  Furthermore, in the present invention, it is preferable that a gas tank for supplying the backflow gas to each blaster means is provided integrally with the gas collecting device, whereby the backflow gas piping of the blaster means can be shortened, and the equipment cost can be reduced. Can be reduced.

  According to the present invention, the cleaning ability is improved by supplying the backflow gas to the inside and the outside of the filter, respectively, and the frequency of maintenance and replacement of the filter can be reduced.

  Embodiments of the present invention will be described below based on examples shown in the drawings.

  FIG. 1 is a configuration diagram showing an embodiment of a gas sampling apparatus according to the present invention. The gas sampling device shown in the figure is provided so as to collect exhaust gas from a waste gasification and melting furnace and supply it to a gas analyzer. The exhaust gas is shown in FIG. Is collected via the gas sampling port 1a of the gas sampling tube 1 and passed through the cylindrical filter 2 (made of metal) disposed inside the gas sampling tube 1 from the outside to the inside and supplied to the gas analyzer. The

  This gas sampling device is integrally provided with a gas tank 3 for storing a backflow gas (0.5 MPa air or nitrogen gas) for cleaning the filter 2, and the backflow gas is supplied from the gas tank 3 to the first to third blasters. It is supplied via means 4-6 (backflow gas piping).

  The first blaster means 4 is provided so as to blow back flow gas inside the filter 2, and the second blaster means 5 is provided so as to blow back flow gas outside the filter 2. Among these, the second blaster means 5 is arranged so that the backflow gas forms a swirling flow along the outer surface of the filter 2. The third blaster means 6 is provided so as to blow back flow gas in the vicinity of the gas sampling port 1 a of the gas sampling pipe 1. The first to third blaster means 4 to 6 are provided with solenoid valves 4a to 6a as on-off valves, respectively. Among these, as the solenoid valve 4a of the first blaster means 4 and the solenoid valve 4a of the third blaster means 6, high-speed solenoid valves (pulse jet valves) that can be opened and closed at high speed are used. The electromagnetic valve 5a of the second blaster means 5 may have a normal opening / closing speed. In FIG. 1, the electromagnetic valve 4a is shown overlapping the electromagnetic valve 5a, and the electromagnetic valve 4a is disposed on the back side of the electromagnetic valve 5a.

  In the above configuration, when cleaning the filter 2, the electromagnetic valves 4 a, 5 a of the first and second blaster means 4, 5 are opened, and a backflow gas is sprayed on the inside and outside of the filter 2 to adhere to the filter 2. Blow away dust and tar. At this time, since the backflow gas is supplied to the outside of the filter 2 as a swirling flow, the blown-off dust and tar can be efficiently purged inside the furnace. Further, if the electromagnetic valve 6a of the third blaster means 6 is opened, the backflow gas is blown toward the inside of the furnace also in the vicinity of the gas sampling port 1a, and the inside of the piping of the third blaster means 6 and the gas sampling port 1a. Dust and tar adhering to the vicinity can be blown away and purged inside the furnace. This operation is periodically performed to periodically clean the vicinity of the filter 2 and the gas sampling port 1a.

  FIG. 2 is a time chart showing a specific example of the cleaning (purge) operation by the first to third blaster means 4-6. In the example shown in the figure, first, the electromagnetic valve 4a of the first blaster means 4 is opened, the backflow gas is blown into the inside of the filter 2 and the dust and tar adhering to the filter 2 are blown off, and the gas sampling tube 1 To drop. The electromagnetic valve 4a is opened in pulses for t1 time (here 1 second), and this is repeated several times at t3 time intervals.

  Next, the electromagnetic valve 4a is closed and held for t3 hours to restore the pressure in the gas tank 3, and then the electromagnetic valve 5a of the second blaster means 5 is opened to remove the dust dropped in the gas sampling pipe 1. The tar content is purged by blowing it inside the furnace. Here, the electromagnetic valve 5a may have a normal opening / closing speed.

  Next, after the electromagnetic valve 5a is closed and held for t3 hours to restore the pressure in the gas tank 3, the electromagnetic valve 6a of the third blaster means 6 is opened, and the inside of the piping of the third blaster means 6 and The dust and tar adhering to the vicinity of the gas sampling port 1a are purged by blowing them to the inside of the furnace. Similarly to the electromagnetic valve 4a of the first blaster means 4, the electromagnetic valve 6a is opened in pulses for t1 hours, and this is repeated several times at intervals of t3.

  The above operation is repeated at t4 time intervals, and the filter 2 and the vicinity of the gas sampling port 1a are cleaned and purged.

  FIG. 3 is a block diagram showing another embodiment of the gas sampling device according to the present invention. In the figure, the same reference numerals are given to the same components in the embodiment of FIG. 1, and the description thereof is omitted. In the embodiment of FIG. 3, the gas sampling tube 1 is inclined obliquely downward toward the inside of the furnace, so that it is difficult for dust and tar components to accumulate on the gas sampling tube 1. Also in this embodiment, the backflow gas is blown by the first to third blaster means 4 to 6 to clean and purge the vicinity of the filter 2 and the gas sampling port 1a.

  As described above, according to the present invention, dust and tar adhering to the vicinity of the filter 2 and the gas sampling port 1a can be efficiently blown out and purged inside the furnace. can do. Further, in each of the above embodiments, only the filter portion (wire mesh) of the filter 2 can be removed, so that maintenance can be easily performed, and it is only necessary to replace the filter portion at the time of replacement, thereby reducing the running cost. Can do.

It is a lineblock diagram showing the example of the gas sampling device concerning the present invention. It is a time chart which shows the specific example of washing | cleaning (purge) operation of the filter etc. by this invention. It is a block diagram which shows the other Example of the gas sampling apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas sampling pipe 1a Gas sampling port 2 Filter 3 Gas tank 4 1st blaster means 5 2nd blaster means 6 3rd blaster means 4a, 5a, 6a Solenoid valve 7 Exhaust gas suction pipe

Claims (3)

In a gas sampling device having a gas sampling tube for collecting gas and a cylindrical filter disposed inside the gas sampling tube,
First and second blaster means for blowing back flow gas for cleaning the filter to the inside and outside of the filter to blow away the deposits on the filter are provided , and the back flow gas from the outside of the gas sampling pipe is provided in the vicinity of the gas sampling port of the gas sampling pipe. A gas sampling apparatus comprising a third blaster means for blowing and blowing off deposits near the gas sampling port . The gas sampling apparatus according to claim 1, wherein a gas tank for supplying backflow gas to the first to third blaster means is integrally provided . In a gas sampling method by a gas sampling device having a gas sampling tube for collecting gas and a cylindrical filter disposed inside the gas sampling tube, after the backflow gas is blown inside the filter at the time of cleaning the filter, Blowing away the deposits on the outside of the filter by blowing it outside the filter, and then blowing back flow gas from outside the gas sampling tube to the vicinity of the gas sampling port of the gas sampling tube to repeatedly blow off the deposit near the gas sampling port. A characteristic gas sampling method.

Images