JPS6046649B2 - Process gas sampling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sampling device for analyzing in-process gases such as naphtha pyrolysis furnace gas.

In the naphtha pyrolysis process in the petrochemical industry, it is necessary to continuously measure the gas components discharged from the pyrolysis furnace in order to improve the yield of ethylene, propylene, etc.

Since the cal pyrolysis furnace gas contains a large amount of dust and tar, it is necessary to remove these for analysis and measurement. Conventionally, cleaning with water has been used to remove such dust and tar, but although this method is good in terms of removing dust and tar from the cracking furnace gas, it removes benzene, It has the disadvantage that components with boiling points of 60° C. to 160° C., such as toluene and xylene, are also liquefied and removed, significantly changing the composition of the gas. Also, the molar ratio of ethylene and propylene was different from the original one due to the difference in solubility in washing water and oil. There is also a method of removing dust and tar using a filter, but when using this method, the filter becomes clogged in a short period of time due to the dust and tar contained in the gas, making it necessary to replace it in a short period of time. It turned out that it had some flaws. SUMMARY OF THE INVENTION An object of the present invention is to provide a process gas sampling device that eliminates the drawbacks of the prior art as described above, eliminates the need to replace parts such as filters for a long period of time, and can reduce analysis errors. The process gas sampling device according to the present invention for the above purpose is characterized by a quencher that cools the high-temperature process gas, and a quencher that is kept at almost the same temperature as the quencher and is cooled to remove dust in the gas. It is equipped with a regenerable filter that removes most of the tar generated, and a fine filter.

In the above, the quencher pumps the hot process gas at 60°C.
The quencher and the regenerable filter are cooled to a temperature of 10°C to 160°C, and the filter is kept at a temperature 10°C to 20°C higher than the regenerable filter. It is preferable that the cleaning device be equipped with a steam introduction section and a cleaning waste liquid discharge section for cleaning.

The benefits of using the process gas sampling device of the present invention are obtained in the following manner.

That is, in the quencher, the sample gas has a temperature of 6
When cooled to a constant temperature in the range of 0°C to 160°C, most of the components that become tar are condensed, and a part of it adheres to the inner wall of the quencher along with dust. removed.

The gas leaving the quencher is a regenerable filter.
A wire mesh filter type dust/tar remover kept at approximately the same temperature as the quencher or a nozzle restricts the gas flow and causes it to collide with a collision plate to cause tar to adhere to the collision surface. Dust and tar are removed from the gas using an impingement-type dust/tar remover. Since the temperature of the dust/tar remover is approximately the same as that of the quencher, it is possible to prevent tar from evaporating and liquefying the measured components. In addition, such dust/tar remover and quencher are provided with a steam introduction pipe and a waste liquid discharge pipe to intermittently introduce steam into the remover and quencher, and also to control the flow of sample gas in the conduit. By flowing in the opposite direction, the dust and tar adhering to the dust and tar remover and quencher and their conduits can be washed away, and the waste liquid can be regenerated by removing it from the discharge pipe.
The gas leaving the dust and tar remover, which is a regenerable filter, is passed through a fine filter to remove any remaining fine dust and tar from the gas.

This fine filter maintains its temperature 10 to 20 degrees Celsius higher than the temperature of the dust/tar remover in the preceding stage to prevent condensation of components in the gas and vaporize the fine mist. In this way, by using the process gas sampling device of the present invention, the composition of the gas for analysis is not changed, and the cost required for parts consumption and replacement can be reduced.

Hereinafter, the present invention will be specifically explained in more detail with reference to the schematic diagram of FIG. 1 in accordance with an embodiment.

In FIG. 1, the process gas sampling device includes a quencher 3, a dust/tar remover 11 which is a reproducible filter, and a fine filter 18. The analysis gas from the plant piping 1 is introduced into the quencher 3 of the sampling device through the gas introduction pipe 2, and then processed by the dust/tar remover 11 and the fine filter 18 before being sent to the analyzer 20. be. Reference numerals 10, 14, and 19 in FIG. 1 indicate gas pipes; 4, 7, and 9;
, 12, 15, 17 are valves, 5, 13 are waste liquid discharge pipes, 8
, 16 are cleaning steam introduction pipes. The sampling operation with the above device is performed as follows.

Temperature 400°C, pressure 0.5k in plant piping 1
A sample gas of 9/CTi consisting of hydrogen, hydrocarbons, water vapor, tar, and carbon is introduced into the quencher 3 through the gas introduction pipe 2.

The quencher 3 cools the introduced gas to 100°C.
Some of the tar and carbon generated in this state adhere to the inner wall surface of the quencher 3 and are removed. The cooled gas is
The gas is led through a gas conduit 10 to a dust/tar remover 11 which is a reproducible filter kept at 100°C.
The dust and tar remover 11 collects and removes dust and tar of 5μ or more. The gas exiting the dust/tar remover 11 passes through the gas conduit 14 and is introduced into the fine filter 18 kept at 110°C, where dust/tar of 0.5μ or more in the gas is removed. The gas from which dust and tar have been removed so that there is no significant change in composition is led to an analyzer 20 through a conduit 19 and is provided for analysis. During the above operation, valves 9, 17 are open and valves 4, 7, 12, 15 are closed.

The dust and tar that has been collected and accumulated in the dust and tar remover 11
After closing valves 17 and 9 and opening valve 12, the tar
5 and introduced from the steam introduction pipe 16, 10 kg/
The deposits are washed away with the steam in step d, and the waste liquid discharge pipe 1
3, it is mixed into the waste liquid and discharged.

Valve 12 is then closed and valve 9 is opened to backwash the gas conduit 10. After closing the valves 9 and 15, open the valve 4, then open the valve 7, and introduce 10 kg/CTl of steam into the quencher 3 from the steam introduction pipe 8 to wash off the dust and tar attached to the inner wall of the quencher, and drain the waste liquid. The waste liquid is discharged from the waste liquid discharge pipe 5. Next, the valve 4 is closed and the gas introduction pipe 2 is backwashed. In this way, cleaning the present sampling device is extremely easy and economical. As described above, according to the sampling device of the present invention, the loss of benzene, toluene, xylene, etc. in the sample gas can be suppressed to 1% or less, and the maintenance of the device can be achieved by replacing the fine filter element once every six months. It is sufficient to replace it only a few times, and the advantages in terms of both performance and economy are extremely large.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the apparatus of the present invention. 1... Plant piping, 2... Gas introduction pipe, 3... Quencher, 4, 7, 9, 12, 1
5, 17... Valve, 5, 13... Waste liquid discharge pipe, 8, 16... Steam introduction pipe, 10, 14, 19
... Gas pipe, 11 ... Dust and tar remover, 18 ... Fine filter, 20 ...
...Analyzer.

Claims (1)

[Claims] 1. A quencher that cools a high-temperature process gas, and a regenerable filter that maintains the temperature at approximately the same temperature as the quencher and removes dust in the gas and most of the tar generated by cooling. A process gas sampling device comprising: and a fine filter. 2 The quencher heats the high temperature process gas from 60°C to 16°C.
The process gas sampling device according to claim 1, wherein the process gas sampling device is cooled to a temperature of 0°C. 3 The fine filter is 10°C lower than the regenerable filter.
The process gas sampling device according to claim 1 or 2, wherein the process gas sampling device is kept at a temperature that is ~20°C higher. 4. The quencher is equipped with a steam introduction part for cleaning the quencher and a discharge part for cleaning waste liquid, and the regenerable filter is equipped with a steam introduction part for cleaning the filter and a discharge part for cleaning waste liquid. A process gas sampling device according to any one of claims 1 to 3.