JPS61259748A - Gas-liquid dispersing device of three-phase fluidized reaction apparatus - Google Patents

Abstract

PURPOSE:To prevent catalyst particles from invading a dispersing cylinder, by providing communication holes to the periphery of the almost central part of the upper part of a cap and providing a valve movable up and down between the upper end surface of the dispersing cylinder and the lower surface of the cap through a slide pin. CONSTITUTION:When a fluid 15 flows in a dispersing cylinder 4 from a gas- liquid mixing bed 5, a valve body 8 is pushed up by the pressure of a fluid and the fluid 15 flows in a cap 9 from the gap between the valve seat 2 and valve body 8 of the dispersing cylinder and further flowed to a fluidized catalyst bed 2 from the lower part of the cap 9. Because the valve body 8 and the cap 9 form a contact seal at the inflow time of the fluid 15, the falling and mixing of catalyst particles from the upper part of the cap is prevented. When the flow of the fluid 15 is stopped, the value body 8 is pushed down by the static pressure of the catalyst bed 2 through the passing holes 10 of the cap 9 to be contact with the valve seat 12 under pressure and, therefore, the catalyst bed is blocked from the gas-liquid mixing bed 5 to prevent the catalyst particles from flowing in the dispersing cylinder 4.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a gas-liquid disperser for a three-phase flow reactor for bringing solids, gases, and liquids into simultaneous contact. More specifically, the present invention relates to improvements in a gas-liquid disperser for dispersing gas and liquid in a three-phase flow reactor in which a solid layer is expanded in a uniform manner by flowing the gas and liquid upward. be.

(Prior art) It is known that a three-phase fluidized reactor using solid, gas, and liquid has good three-phase contact efficiency and is effective in cases where the reaction that occurs is a significantly exothermic reaction because it is in a fluidized state. There is.

An example thereof is a catalytic reactor such as a hydrodesulfurization reactor or a hydrocracking reactor, in which heavy and medium oil fractions fractionated from crude oil are reacted by supplying hydrogen in the presence of a catalyst.

The general flow state of a three-phase flow reactor is described in detail in Sakae Tanaka: Chemical Engineering Vol. 34, No. 12 (1970), etc. Solid particles such as a catalyst occupy a volume that is at least 10 cm larger than that in a static state. A stable fluidized bed of solid particles is formed by flowing the liquid and gas from the lower part of the reaction vessel at a rate sufficient for so-called fluidization and at a rate that does not cause the solid particles to rise along with them.

In order to obtain this fluid state, it is essential to extract the liquid from the upper part of the expanded catalyst bed and supply it to the lower part of the reaction vessel using a pump, as well as to circulate the extracted gas. .

This is done in order to maintain the necessary liquid and gas flow rates for catalyst flow through circulation.

A specific example using this three-phase fluidized reactor is 50 to 150 kliJ/cN''G when hydrodesulfurizing petroleum-based and medium oil fractions.

Under conditions of 350 to 420°C, 0.5 to 5 mφ cylindrical or spherical nickel μm molybdenum-based, cobalt-based
The hydrogenation reaction is accomplished by contacting the feed oil and gaseous hydrogen with a molybdenum-based or tungsten-molybdenum-based catalyst.

Figure 2 shows a conventional disperser, with the reactor main body 1
The upper part of the dispersion tube mounting plate 5 provided at the inner lower part is the catalyst layer 2, and the catalyst layer 2 expands due to the upward flow of liquid and gas.

Most of the liquid and gas discharged from the reactor 1 are transferred to the circulation gas input 6.
And it is circulated to the reactor 1 again as a circulating liquid 7. The gas and liquid that have flowed in are supplied to the catalyst layer 2 through the mixing layer 5 and the dispersion tube 4'f, which is provided with multiple membranes in the dispersion mechanism. Dispersion tube 4
A cap 9 is attached to the cap 9 to prevent the catalyst from falling or entering the catalyst layer 2 into the mixed layer 5 and thereby preventing the catalyst from accumulating.

However, in the case of such a structure, the supplied liquid gas,
Mainly, the gas is not sufficiently dispersed, resulting in poor gas-liquid contact efficiency, so it is necessary to ensure the gas-liquid contact efficiency even if an extremely excessive amount of gas is supplied.

Further, although the cap 9 is provided to prevent the catalyst from falling, it is extremely insufficient to prevent the catalyst from falling and accumulating on the mixed layer 5, which may cause clogging of the circulating fluid 7 line.

FIG. 5 shows another conventional type disperser. The feed liquid and the feed gas form a mixed fluid 15 that flows into the dispersion tube 4 and is circulated through the outlet 13, through the bottom of the cap 9, and into the interstitial layer. This dispersion method has a shape similar to the bubble cap method often used in distillation columns, for example, and the main purpose of this shape is to minimize unevenness in liquid and gas distribution in the horizontal section of the reactor. Monodashi, gas particle size (bubble size)
is not sufficient for miniaturization.

Therefore, in the case of this method, the gas supply amount is 9jcff!
Since the contact interfacial area is small, it is necessary to supply more gas than necessary in order to dissolve the gas necessary for the reaction into the liquid.

In addition, a three-phase flow reactor is a gas-liquid-solid = phase reaction, and the inflow of solid particles into the supply system may pose a serious danger. In other words, the influx of solid particles primarily obstructs the supply of liquid, making it impossible to secure the flow rate (flow rate) necessary to maintain a fluidized bed, resulting in a fixed bed state, which causes abnormal reactions and I am concerned that this may cause a fatal flaw to the vessel.

(Function) FIG. 1 shows an embodiment of the gas-liquid disperser of the three-phase fluidized reactor according to the present invention. The dispersion cylinder holding plate 3 partitions the catalyst fluidized bed 2 and the gas-liquid mixed layer 5, and holds a large number of dispersion cylinders 4 each having a cap 9 on the top. Dispersion tube 4 and cap 9
A valve body 8 that is vertically slidable is provided between the valve body and the valve body. The valve body 8 is provided with sliding pins 14 at the center of the upper and lower surfaces, and the sliding pins are inserted into the center hole at the center of the upper part of the cap 9 and the center hole of the support body 16 provided in the dispersion cylinder. The body 8 slides up and down between the cap 9 and the upper end of the dispersion tube 4 by fluid pressure. The cap 9 has a communication hole 1o around the central hole in the upper part so that the fluid pressure of the catalyst layer 2 can be quickly transmitted to the valve body 8, and also to adjust and maintain a predetermined distance from the valve body 8. , is fixed to the dispersion cylinder 4 via the shim 17 by the cylinder (I/)K. Valve seats 12 and 11 are provided on the dispersion tube 4 and the valve body 8 so that the upper end surface of the dispersion tube 4 and the bottom surface of the cap 9 form a beam when they come into contact with the valve body 8. The valve seat may be provided on the front and back surfaces of the valve body, or may be provided on the back surface of the cap.

Alternatively, a sliding pin may be provided on the cap and the support, and a hole may be provided on the valve body to receive the sliding pin. The communication hole 10 of the cap is located around the inner center of the valve seat, and when the valve body and the cap come into contact to form a seal, the communication hole 10
0 is closed to prevent fluid communication.

When the fluid 15 flows into the dispersion tube 4 from the gas-liquid mixing layer 5, the valve body 8 is pushed up by the fluid pressure, flows out into the cap 9 through the gap between the valve seat 12 of the dispersion tube and the valve body 8, and then flows into the cap 9. From the bottom, it flows out into the fluidized bed 2. In particular, while passing through the gap, the gas in the fluid is further divided into fine bubbles. Further, when the fluid 15 flows in, the valve body 8 and the cap 9 are in contact with each other to form a V-μ, and catalyst particles are not mixed in by falling from the upper part of the cap. On the other hand, when the flow of the fluid 15 stops, the static water pressure of the catalyst layer 2 pushes down the valve body 8 through the communication hole 10 of the cap and presses it against the valve seat 12, so that the catalyst layer 2 and the gas-liquid mixed layer 5 are cut off. Therefore, there is no backflow of fluid and no catalyst particles flowing into the dispersion cylinder 4.

(Example) A performance test was conducted on a specific example of the present invention using a plastic cold model.

The reactor body has an inner diameter of 300m and a height of 300011m, and the dispersion cylinder has an inner diameter of 20m and a cap diameter of 30m.
The gap between the cap and the dispersion cylinder mounting plate is 2 sm. Installing four such dispersion cylinders is a good idea.

The supply liquid used was JI8 standard white kerosene, the gas was nitrogen, and the catalyst had an apparent specific gravity of 1.55, a diameter of 1.5 cm, and a length of about 5 mm.
An extrusion molded product was used. The operating temperature is normal temperature and the operating pressure is normal pressure. The gas has a superficial velocity of 4 cptt/B
B (2).The catalyst was packed so that the height of the packed bed at rest was 1700 m.The liquid had a superficial velocity of 1.
It was supplied in the range of ~10 cm/sec.

When the test was conducted under these conditions and the amount of gas retained (cashold up) was measured, it reached 20 vol %, and there were almost no bubbles larger than a few diameters, indicating a uniform flow. formed the state. Furthermore, there was no trap μ due to backflow or intrusion of catalyst particles.

(Comparative Example) A test was conducted using the disperser shown in FIG. 3 under the same conditions as in the above example.

There are no differences in the conditions except that the upper part of the dispersion tube is closed and 5-diameter outlet ports are provided at four equal locations around the circumference.

When the test was carried out under such conditions and the amount of gas retained (cashold up) was measured, it was found to be 12 to 15 vol %, and many large bubbles exceeding several square meters in diameter were observed.

In addition, catalyst intrusion into the disperser was also observed, especially when the liquid and gas were stopped, causing a large amount of catalyst to enter, causing uneven flow during recirculation.

(Effects of the Invention) By adopting the above configuration, the present invention promotes the miniaturization of gas when it flows out of the disperser, significantly increasing the gas-liquid contact area, and as a result, reducing the amount of gas supplied. I was able to lower it.

(9) It is possible to maintain stable and uniform fluidization of the catalyst fluidized bed, and it is also possible to prevent catalyst particles from entering the dispersion cylinder, ensuring efficient and smooth operation of the three-phase fluidized reactor. made possible.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of a gas-liquid disperser of a blood phase fluid reaction device, which is an embodiment of the present invention, 2vA is a lower sectional view of a conventional blood phase fluid reaction device, and FIG. - An enlarged sectional view of the liquid disperser. Sub-Agents 1) Meifuku Agent Ryo Hagiwara − Sub-Agent Atsuo Anzai

Claims (1)

[Claims] A dispersion cylinder holding plate provided at the lower part of the three-phase fluidized reactor and partitioning into a catalyst fluidized bed and a gas-liquid mixed layer above and below, and a plurality of dispersion cylinder holding plates that penetrate the holding plate and communicate the fluidized bed and the mixed bed. of,
In a gas-liquid disperser for a three-phase flow reactor comprising a dispersion cylinder with a cap, a communication hole is provided around the center of the upper part of the cap, and a sliding pin is provided between the upper end surface of the dispersion cylinder and the lower surface of the cap. The valve element is arranged so that it can move up and down, and when the valve element contacts the upper end surface of the dispersion tube or the lower surface of the cap, a seal can be formed on each contact surface. A gas-liquid disperser for a three-phase flow reactor, characterized in that when the body is lifted up, a communicating hole in the cap is closed by a valve body to form a seal.