JPH0940967A - Production of petroleum coke - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish a technique of exactly grasping the time when the cutting- off at each part for cutting off coke from a coke drum is completed. SOLUTION: A process for producing petroleum coke comprising feeding a starting oil into a coker drum C to form coke and cutting off the coke from the drum C by using high-pressure water, which process comprises detecting the sound of cutting produced by high-pressure water from a tool 3 inserted into a pilot hole 2 with an acoustic sensor 4, judging the sound from its frequency distribution whether it is produced from cutting or it is produced from wall strike and thereby administering the cutting-off of coke is provided. Seeing that, as compared with the intensity peak of the sound of cutting, that of the sound of wall strike shifts to the high-frequency side, this shift is detected with an acoustic sensor, the detected sound produced at each part is judged whether it is a sound of cutting or it is a sound of wall strike, and the time when the cutting-off is completed is automatically grasped.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing petroleum coke, and in particular, when cutting out coke from a coke drum using high-pressure water, a sound at the time of cutting is sensed by an acoustic sensor, The present invention relates to a method for producing petroleum coke, which is characterized by determining whether the coke is cutting or the wall of a coke drum is hit from a frequency distribution.

[0002]

2. Description of the Related Art Coke produced as a by-product during the thermal cracking of heavy oil is used in applications such as electrodes for electric furnaces and fuels, depending on its quality. FIG. 5 is a flowchart showing a flow of a part of the heavy oil thermal cracking facility. Crude oil from feed tanks T1, T2, T3 storing various crude oils is fractionated in main distillation column D and cracked gas (LPG) from the top
And cracked naphtha produced therefrom, cracked kerosene, cracked light heavy oil and cracked heavy heavy oil extracted in some intermediate predetermined trays, and the bottom residue of the main distillation column is periodically removed. The oil is taken out. The residual oil taken out is
After being heated via a heating furnace H, it is sent to coke drums C1, C2, which are generally installed in pairs, where coke is produced and recovered. The generation and recovery of coke are performed alternately in the coke drums C1 and C2.

In a coke drum, as shown in FIG.
The raw material oil supplied from the bottom portion is sequentially separated from the upper portion as a liquid phase, a liquid crystal generation phase, a liquid crystal phase, and a coke phase, and the coke phase gradually accumulates and occupies almost the entire inside of the coke drum. Cracked gas and cracked oil discharged from the top of the coke drum are returned to the main distillation column D for reprocessing.

The coke thus deposited in the coke drum has different grades in its upper part, central part and bottom part. The central part is of high quality and is used for metallurgical furnace electrodes such as steel making electrodes. And the bottom is cut and recovered from the coke drum for fuel use.

For cutting coke from a coke drum, for example, a tool capable of vertically moving and rotating with a sharp tip and capable of injecting high-pressure water (water jet) is fed in the axial direction of the drum to form a pilot hole. Then, a nozzle capable of injecting high-pressure water (water jet) horizontally in the direction of the drum wall is inserted into the pilot hole formed thereafter, and is gradually lowered from above,
High-pressure water is sprayed in the radial direction toward the drum wall, and coke is cut out little by little (called cutting). The cut and cut coke is recovered from the bottom of the coke drum through a pilot hole.
The nozzle is lowered again and high-pressure water is again sprayed radially towards the drum wall. This work step is repeated to the bottom of the coke drum.

[0006]

As described above, high-pressure water is used to cut out coke from the coke drum after the pilot hole has been drilled, but the cutting out of the cut-out portion at each cutting position of the pilot hole is completed. Whether or not it was done, that is, whether it was during cutting or wall hitting was judged by the worker. However, in the work relying on such intuition, if the wall hitting time is too long, not only does the working time become longer, but also the parts that should not be cut out are cut out, and the product yield according to the difference in the quality of the cut out parts Decrease. On the other hand, if cutting is stopped early, there is a problem in that coke remains on the drum wall. It is necessary to cut the coke part of constant quality without mixing with other parts and collect it efficiently.
For that purpose, it is necessary to accurately grasp the time when the cutting at each cutout portion is completed. It is an object of the present invention to establish a technique for accurately grasping a point in time when cutting of coke from a coke drum at each cutting portion is completed.

[0007]

Means for Solving the Problems The present inventor has made a sound when cutting coke with high-pressure water (during cutting) and when the cutting of coke is completed and the high-pressure water hits the wall of the coke drum ( Focusing on the fact that the sound when hitting a wall is different, as a result of research, the peak of the strength of the sound when hitting the wall deviates to the high frequency side compared to the sound when cutting, and the difference is the difference between coke from the coke drum. It was confirmed that it can be used to grasp the time when the cutout at the cutout part was completed. Based on this finding, the present invention provides a method for producing petroleum coke in which a feedstock oil is supplied to a coke drum to generate coke and the coke is cut out from the coke drum using high-pressure water, at the time of cutting out the coke from the coke drum. The present invention provides a method for producing petroleum coke, which is characterized in that cutout of coke is controlled by detecting the sound of the above with an acoustic sensor and judging whether it is cutting or wall hitting from the frequency distribution.

Although there is no involvement in determining whether cutting or wall cutting is performed based on the sound generated when the coke is cut out from the coke drum, a technique utilizing the sound when cutting out the coke from the coke drum is disclosed in US Pat. 892
No. 633 is available.
g. 1 will be described with reference to FIG. The cutting nozzle 13 suspended from the elevation mechanism 22 into the coker chamber 12 cuts the coke 11 from the inside of the coker chamber 12 by spraying water (the details are not described). Coke grains 14 fall onto transfer chute 15 and are transferred into vessel 16. A geophone 19 is attached to the rear side of the transfer chute 15. Geophone 1
9 is connected to an amplifier 21 and leads to a speaker 20 in the area where the operator controls the work. The operator can move the nozzle up and down to an appropriate position where the coke falls due to the presence or absence of the coke dropping sound or vibration from the speaker 20 so that the dropping sound can be heard. Whether falling or small grains are falling can be confirmed (small coke grains are not desired), and the cutting operation can be performed efficiently without visual observation as in the conventional case. Although it uses sound, it listens to the sound of falling into the shoot,
It is not involved in determining whether to cut or hit the wall from the sound of cutting coke.

[0009]

[Function] The sound of a wall hitting has a peak of its intensity shifted to the high frequency side compared to the sound of a cutting, so the deviation is detected by an acoustic sensor, and the cutting of the coke from the coke drum at each cutting part is performed. Judge whether it is wall-mounted or not, and grasp the time when cutting is completed.

[0010]

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 is an explanatory view of an operation for producing coke by sequentially cutting coke from a coke drum in which coke is deposited over substantially the entire length according to the present invention. FIG. 1A shows a state in which a pilot hole is drilled, and FIG. 1B shows a state in which cutting is performed.

The pilot hole can be formed by, for example, sending a tool 1 which can be vertically moved with a sharp tip, rotatable, and capable of jetting high-pressure water in the axial direction of the drum so that the pilot hole 2 is drilled and penetrated vertically. It is carried out by.
The tool 1 jets high-pressure water downward while rotating.
The cutting is then carried out using a tool 3 which is also vertically movable and rotatable and which is capable of horizontally injecting high-pressure water. As already mentioned, the coke deposited in the coke drum is graded differently in the upper, middle and bottom portions, the middle portion is of high quality and is used for metallurgical furnace electrodes such as steel making electrodes and The bottom and bottom are used for fuel. First, after cutting out the upper layer,
The central portion is virtually divided into a plurality of layers as shown by a horizontal line, and cut so as to have the same quality. Finally, the bottom is cut out of the drum and collected. The tools 1 and 3 can be any of those conventionally used. For example, Japanese Patent Application Laid-Open No. 62-270684 discloses a tool which can be used for both punching and cutting a pilot hole.

The cutting of the cut-out portion at each cut-out position of the pilot hole cuts the coke, but when it approaches the wall of the coke drum, the coke disappears and hits the wall. The pressure of the high-pressure jet water is about 200 kg / cm ² , though it varies depending on the type of device. According to the present invention, it is automatically determined by the acoustic sensor 4 that the worker has hitherto determined the time of hitting the wall by relying on the intuition.
That is, since the sound of 500 Hz or less is strong during cutting and the sound of 500 to 2000 Hz is strong during wall striking, it is judged from cutting or wall striking based on the change in frequency distribution.

The configuration of the acoustic sensor is, for example, as shown in FIG.
The configurations shown in (a), (b) and (c) can be adopted. (A) uses a band pass filter on the high frequency side to convert the wall sound into a voltage. The sound from the microphone is amplified by an amplifier, for example, 500 to 2000.
After passing through a band pass filter on the high frequency side in the Hz range, an LED array is displayed through a voltmeter. In (b), the signal intensities of the low frequency component and the high frequency component are compared, the sound from the microphone is amplified by an amplifier, and then, for example, 500 H
After passing through a low-pass filter of z or less and a high-pass filter of 500 Hz or more, a comparator is used to compare the voltages. When a predetermined threshold value is reached, for example, an alarm is output. (C) is for comprehensively judging the end from the sound and the sequence, etc., and is separated into each frequency component by the FFT analyzer (Fourier function transform analysis device), and the signal processing PC is selected by the pre-programmed judgment algorithm. Uses computer processing to make the determination. From the viewpoint of accuracy and simplicity, (b)
It is considered that the method of comparing the signal intensities of the low frequency component and the high frequency component of is preferable. The microphone should be installed near the top wall of the coke drum so that the falling noise of coke does not enter.

Automation can be realized by linking the output of the acoustic sensor and the operation of the tool. According to the pre-set cutting schedule including the tool descent distance,
When it is confirmed from the output from the acoustic sensor that the wall has been hit, the elevating device is activated and the tool is automatically lowered by a predetermined distance, and then the next cutting is performed.

[0015]

EXAMPLE Cutting was performed with the pressure of the jet water set at 180 kg / cm ² . FIG. 3 shows the frequency distribution during cutting and FIG. 4 shows the frequency distribution during wall striking.
The horizontal axis is the frequency in the 20 KHz range and the vertical axis is 0.100.
The voltage is standardized to zero. The peak frequency in the case of FIG. 3 was 100 Hz, and the peak frequency in the case of FIG. 4 was 950 Hz (all four averaging times). It can be seen that when the wall is hit, the intensity peak shifts to the high frequency side.

[0016]

As compared with the conventional method that relies on worker's intuition, it is possible to judge mechanically, so that products of constant quality can be separated without leaving coke on the coke drum wall, and automation is possible. Becomes

[Brief description of drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view of an operation for producing coke by cutting coke from a coke drum on which coke is deposited according to the present invention, wherein (a) shows a state in which a pilot hole has been drilled and (b) cuts out Indicates the situation that you are doing.

2A and 2B show a configuration example of an acoustic sensor, in which FIG. 2A shows a method of converting wall sound into a voltage after passing through a high-frequency bandpass filter, and FIG. And (c) shows a method of comprehensively judging the end from the sound and the sequence.

FIG. 3 is a graph showing a frequency distribution during cutting.

FIG. 4 is a graph showing a frequency distribution at the time of wall striking.

FIG. 5 is a flowchart showing a flow of a part of a heavy oil thermal cracking facility incorporating a coke drum.

FIG. 6 is a schematic diagram of coke generation in a coke drum.

FIG. 7 is a U.S. Pat.
892,633, FIG. 1 is quoted.

[Explanation of symbols]

 1 Pilot hole drilling tool 2 Pilot hole 3 Cutting tool 4 Acoustic sensor T Raw material tank H Heating furnace C Coke drum D Main distillation column

Claims (4)

[Claims] 1. A method for producing petroleum coke in which a raw material oil is supplied to a coke drum to generate coke and the coke is cut out from the coke drum by using high-pressure water, in which a sound generated when the coke is cut out from the coke drum is acoustic sensor. A method for producing petroleum coke, which is characterized in that cutting out of coke is controlled by determining whether to cut or hit the wall based on the frequency distribution detected by. 2. The method according to claim 1, wherein the decision of cutting or wall striking from the frequency distribution is performed using a bandpass filter on the high frequency side. 3. The method according to claim 1, wherein the decision of cutting or wall striking from the frequency distribution is performed by comparing using a low pass filter and a high pass filter. 4. The method according to claim 1, wherein the judgment of cutting or wall striking from the frequency distribution is performed by using an FFT analyzer.