JPS607532B2 - Quench distributor and cooling method inside the reaction tower - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a quench distributor and a cooling method within a reaction column.

In the hydrodesulfurization and hydrorefining of petroleum products, quench pipes are installed at several locations within the reaction tower in order to maintain the temperature difference in the catalyst layer within a certain range and improve the catalyst life and hydrogenation effect. Cooling gas is blown from the pipe through a distributor.

Various quench distributor structures have been studied in the past, but although existing ones are large in size, they do not have sufficient cooling effects, and they also lack contact between the liquid in the tower and the cooling gas. The dispersion was also poor, and neither was satisfactory. An object of the present invention is to provide a quench distributor that eliminates the above-mentioned drawbacks and a method for cooling a reaction tower using the quench distributor.

The present invention will be explained with reference to the drawings.

FIG. 1 is a partially omitted cross-sectional view of a reaction tower equipped with the quench distributor of the present invention, and FIG.
-A cross-sectional view. The quench distributor consists of a quench header 2 provided at the center of the reaction column main body 1 and a plurality of branch pipes 3 arranged approximately horizontally and radially from the header. The quench header 2 is connected to a main quench pipe 4, and cooling gas is supplied to the quench header 2 through the main pipe 4. The cooling gas supplied to the header is injected from small gas injection holes provided in branch pipes 3 radially arranged from the header. The small holes for gas injection can be bored in any suitable position, but for example, they can be bored below the horizontal section including the central axis of the branch pipe 3, or they can be arranged alternately above and below the horizontal section. . Furthermore, the small holes can be provided on the same level, ie, in parallel, or in a staggered manner. In addition, when drilling small holes, the holes should be arranged so that they become denser outward from the quench header attachment part of the branch pipe, or in other words, they become denser from the center of the reaction tower toward the inner wall of the reaction tower. It is preferable to do so. The diameter and number of the small holes can be selected as appropriate.As mentioned above, the branch pipes 3 are arranged approximately horizontally and radially in the quench header 2, but when the reaction tower is opened, the branch pipes 3 can be removed from the header. It is preferable to use a structure that allows for easy installation (for example, screwing).

Further, the number of branch pipes to be provided, the pipe diameter, etc. are appropriately determined in consideration of the diameter of the reaction tower, the characteristics of the process, etc. Usually, about 4 to 32 branch pipes are arranged at equal intervals. Cooling of the reaction tower using the quench distributor as described above is carried out by submerging the distributor in the reaction liquid in a space within the reaction tower. As a specific means for this purpose, for example, the liquid retention weir 5 illustrated in FIGS. The quench distributor is configured to be immersed in the reaction liquid stored in the weir. When the quench pipe and the reaction tower body are made of different materials, the quench pipe appears to move up and down because their coefficients of thermal expansion are different. Therefore, it is necessary to set the height of the weir so that the branch pipe is always submerged in the liquid in the liquid retention weir, regardless of the vertical movement of the pipe. The ratio of the internal diameter of the reaction tower, the diameter of the liquid retention weir, and the diameter of the quench distributor is appropriately determined depending on the properties of the reaction liquid, etc.

Usually, diameter of liquid retention weir/inner diameter of reaction tower = 0.40 to 0.6
0, preferably 0.45 to 0.55, diameter of quench distributor/inner diameter of reaction column = 0.35 to 0.55
Preferably 〈 is 0.40 to 0.50. Further, in order to collect the reaction liquid in the weir, it is preferable to fix a liquid collecting plate 7 such as an annular plate to the inner wall of the reaction tower at a position above the weir in the reaction tower. Further, in order to evenly disperse the reaction liquid that has stayed in the weir for a predetermined time into the catalyst layer 6b below, it is desirable to provide a dispersion plate 8 below the weir. In addition,
9 in the figure is a catalyst support plate. According to the quench distributor of the present invention, the cooling gas is injected from the small holes of the branch pipes extending radially outward from the quench header and comes into contact with the reaction liquid at the liquid retention weir. Although the ratio of the internal diameters of the direct-flowing reaction tower is very small, the dispersion of the cooling gas and the contact with the reaction liquid are carried out very efficiently.

Therefore, the cooling effect within the reaction tower is improved, and the temperature difference within the tower can be reduced. As a result, product properties and yields are improved, and the catalyst life is also extended. Furthermore, one of the features of the present invention is that the temperature of the reaction tower can be easily controlled by virtue of the above-described structure. Therefore, the apparatus of the present invention and the method for cooling the inside of a reaction tower using the apparatus can be very advantageously applied in the fields of petroleum refining industry and petrochemical industry. Next, examples of the present invention will be shown.

Example diameter 2.4 filled with nickel-tungsten catalyst
A liquid retention weir with a diameter of 1.1 mm was installed in the hydrorefining tower, and a quench distributor with a diameter of 1.0 mm and having 16 quench pipe branches was installed.

The reaction temperature was set at 40,000 ℃, and vacuum gas oil was passed through the reactor at a rate of 1,700 ℃/day. Liquid oil and gas introduced from the upper entrance of the reaction tower react in the first stage catalyst layer, and enter the lower internal while being accompanied by a temperature rise.

The reacted oil is once collected in the central liquid retention weir by a liquid collection plate, cooled by hydrogen gas injected from the small hole of the quench pipe branch, and mixed at the same time to produce a uniform first-stage reaction. Become a thing. Next, the homogeneous reaction product oil overflowing from the liquid retention weir flows down the lower dispersion plate and enters the second stage catalyst bed. Thereafter, the reaction proceeds in the same manner as above. The same procedure is applied to the third and subsequent catalyst layers.

As a result, the temperature difference in the horizontal direction of the reaction tower is 0 to io
.

It became 0.

Furthermore, compared to the conventional method, the catalyst life was extended by about 1.3 times, the desired product composition was uniform, and the yield was increased by 1.5%. Comparative Example A reaction similar to that of the Example was carried out using the conventional quench distributor shown in FIGS. 3 and 4.

As a result, the horizontal temperature difference in the reaction tower is 10-3
It was 000.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted cross-sectional view of a reaction tower equipped with a quench distributor of the present invention, and FIG. 2 is a cross-sectional view taken along the line A--A in FIG. FIG. 3 is a partially omitted cross-sectional view of a reaction tower equipped with a conventional quench distributor, and FIG. 4 is a cross-sectional view taken along the line A--A in FIG. 1... Reaction tower main body, 2... Quench header, 3... Branch pipe, 4... Main quench pipe, 5... Liquid retention weir, 6, 6a, 6b.
... Catalyst layer, 7 ... Liquid collection plate, 8 ...
. . . Dispersion plate, 9 . . . Catalyst support plate. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Scope of Claims] 1. A quench header provided at the center of the reaction column, and branch pipes disposed approximately horizontally and radially from the header, the branch pipes being densely perforated outward from the quench header attachment portion of the branch pipes. A quench distributor consisting of multiple branch pipes with small holes for gas injection. 2. The quench distributor according to claim 1, wherein the gas injection small holes are arranged below a horizontal cross section including the central axis of the branch pipe. 3. The quench distributor according to claim 1, wherein the gas injection small holes are arranged alternately above and below a horizontal section including the central axis of the branch pipe. 4 Diameter of liquid retention weir/inner diameter of reaction tower = 0.40 to 0.60
The quench distributor according to claim 1, wherein the diameter of the quench distributor/inner diameter of the reaction column is 0.35 to 0.55. 5. A quench header installed in the center of the reaction tower and branch pipes arranged approximately horizontally and radially from the header, which are for gas injection and are perforated outward from the quench header attachment part of the branch pipes so as to be densely arranged. A reaction characterized by injecting cooling gas by immersing a quench distributor consisting of a plurality of branch pipes with small holes into the reaction liquid in a liquid retention weir installed in a space within the reaction tower. Cooling method inside the tower.