JPH01119337A - Three-phase fluid reaction device - Google Patents

Abstract

PURPOSE:To extend the operating area of a pump and enable stable operation by separating gas and liquid efficiently at the inlet part of a liquid suction pipe in a device and suppressing the amount of gas contained in a suction liquid. CONSTITUTION:Gas and liquid are supplied to a solid particle layer 4 from a layer bottom part through a disperser 4 to form a three-phase liquid layer, and the liquid is extracted from a suction layer 11 provided penetrating vertically through the center of the liquid layer after passing through said liquid layer. After this, the liquid is caused to circulate again into a device. The inlet part of the suction pipe 11 is provided with a connection part 19 of inverted conical shape and a cylindrical suction part 18 installed at the top of the connection part 19. Then a plurality of gas and liquid rising pipe parts 16, 17 having a differing length from each other with the internal circumference coming into contact with the periphery of the suction part 18 externally and the periphery coming into contact with the internal circumference of the main unit 1 of a reactor internally, are alternately formed vertically. The operating area of a pump 13 is extended by efficiently separating gas and liquid at the inlet part of the liquid suction pipe and thereby suppressing the amount of gas contained in a suction liquid. Thus stable operation can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a three-phase flow reactor for gas, liquid, and solid that efficiently separates gas and liquid.

[Conventional technology]

A three-phase flow reactor for gas, liquid, and solid has good three-phase contact efficiency and good mixing inside the reactor. It is known to be effective for reaction systems. Examples include a hydrodesulfurization reactor or a hydrocracking reactor in which a nine-fold or medium fraction fractionated from crude oil is treated in the presence of a catalyst while supplying hydrogen gas. Another example is a synthetic reaction apparatus in which methyl alcohol is synthesized by supplying a mixed gas containing carbon oxide and hydrogen as main components into a mixture of a solvent and a catalyst.

The general flow state of a three-phase flow reactor is as described in detail in Sakae Tanaka-1 Chemical Engineering Vol. 34, No. 12, p. 1265 (1970). (a) Flow the liquid and gas upward from the bottom of the melter at a speed that is sufficient to flow solid particles such as catalysts that are filled to about 1/2 to 2/3, and that does not entrain or raise the solid particles. This allows the formation of a more stable fluidized bed of solid particles. In order to achieve this fluid state, it is essential to extract the liquid from the upper part of the expanded catalyst layer and to circulate the liquid by using a pump to supply it to the lower part of the cylindrical container. This is done in order to maintain the liquid flow rate necessary for catalyst fluidization through circulation. ,)Also,
To give a specific example using this three-phase fluidized reactor, when carrying out hydrodesulfurization of petroleum heavy and medium distillates,
~150ρG, 0.5~ under the conditions of 350~400℃
By bringing a 2 mφ cylindrical or spherical nickel-molybdenum catalyst into contact with supplied oil and gaseous hydrogen]
A hydrogenation reaction is achieved.

The structure of a typical conventional three-phase fluidized reactor will be explained using FIG.

A catalyst is filled inside the reactor body 1, and the upper surface 2 of this catalyst layer is fluidized by the upward flow of liquid and gas, and expands on the expanded catalyst layer upper surface 3t. A dispersion plate 4 such as a perforated plate is provided at the bottom of the catalyst layer to improve the dispersion of the gas and liquid supplied from the bottom to prevent the catalyst from falling and accumulating at the bottom of the container. ing. Supply gas 5 and supply liquid 6
is supplied together with the circulating liquid 7 or separately from the lower part of the reactor main body 1, passes through the dispersion plate 4, and reacts while rising through the catalyst layer. After passing through the catalyst layer, the gas and liquid pass through a clarification layer 8 for separating the catalyst, the reaction gas 9 is extracted from the upper part of the reactor body 1, and the reaction liquid is passed through the suction pipe inlet 10 and the suction tube. It is extracted to the outside of the reactor main body 1 through a pipe 11. A part of the reaction liquid is discharged outside the system as a reaction product liquid 12, but most of the reaction liquid is circulated to the reactor main body 1 as a circulating liquid 7 via a pump 13 placed inside or outside the reactor main body. .

[Problem that the invention seeks to solve]

The above is a typical three-phase fluidized reactor according to the conventional method. With such a structure, unreacted gas among the supplied gas flows out from the upper surface 3 of the expanded catalyst layer together with the liquid, resulting in clarification. It rose through layer 8 and flowed into the suction tube inlet 1011C without being sufficiently separated into gas and liquid. For this reason, pump 1
The discharge performance of No. 3 was extremely degraded.

The present invention aims to solve the above problems.

[Means for solving problems]

The present invention involves supplying gas and liquid to the bottom of the solid particle bed through a disperser to form a three-phase fluidized bed. In a three-phase fluidized bed reactor in which the fluid is drawn out from the tube and circulated back into the device, the inlet of the suction tube has an inverted conical connection section and a conical suction section provided at the top of the connection section. A plurality of gas-liquid riser pipes of two different lengths are alternately arranged in the vertical direction, the inner circumference of which is circumscribed by the outer circumference of the same cylindrical suction part, and the outer circumference of which is inscribed in the inner part of the reactor main body. was formed.

[Effect]

In the present invention, when the gas that rises together with the liquid passes through the outer periphery of the cylindrical part at the inlet of the suction pipe, it passes through two different lengths of the gas-liquid rising pipe part provided on the outer periphery of the cylindrical part. At this time, since the longer ascending pipe extends further down from the cylindrical part to the inverted embankment, a portion of the gas and liquid is connected to the conical suction pipe in the opposite direction. Conflicts between departments. There is a space between the long riser pipe and the inverted conical part, so gas tends to stay there.The stagnant gas becomes large bubbles and rises inside the adjacent riser pipe. .

Since this stock solution is sucked into the suction tube, there is also a liquid flow downward from the upper end of the suction tube, but since the gas bubble diameter is large, the buoyancy is large, and it rises without being accompanied by this liquid flow. Therefore, gas-liquid separation is easily performed.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a longitudinal sectional view of the vicinity of the inlet of the liquid suction section according to this embodiment.

FIG. 2 is a sectional view taken along the line AA in FIG. 1.

This embodiment has the same structure as the conventional three-phase flow reactor shown in FIG. 5 except for the points explained below. A connecting portion 19 and a cylindrical suction portion 18 extending upward from the upper end of the connecting portion 19 are provided to form a suction tube inlet portion 10 . Between the outer periphery of the suction part 18 and the inner periphery of the reactor main body l, gas-liquid rising pipes 16 having a long vertical length and gas-liquid rising pipes 17 having a short vertical length are arranged alternately, and Suction part 1
8 and is provided in the vertical direction over the entire circumference of the suction portion 18 .

The same air-liquid riser pipe 16.17 is the ? As shown in the figure, its sides are close to each other, and its outer periphery is circumscribed to the inner periphery of the reaction body 1. By the way, as shown in FIG.
The lower end of the short gas-liquid riser pipe 17 is located at the upper end of the inverted conical connection part 19, and the lower end of the long gas-liquid riser pipe 16 is located at the same height as the upper end of the short gas-liquid riser pipe 17. It is located below the lower end of the rising pipe 17 and slightly below the upper end of the inverted conical connecting portion 19.

In this example, during steady operation of the three-phase fluidized reactor, the catalyst layer 14 expands by several hundred degrees. The liquid flowing out from the catalyst layer rises through the clarification layer 8, is sucked through the suction tube inlet portion 10, and is extracted from the suction tube 11. The gas becomes bubbles 15 and rises.

The gas is entrained in the liquid and passes through gas-liquid riser pipes 16 and 17 of two different lengths, which are inscribed in the reactor main body 1 and alternately provided around the outer periphery of the suction pipe inlet 10.

Since the long gas-liquid ascending pipe 16 extends further downward than the cylindrical suction part 18 of the suction pipe, an inverted conical suction pipe connection part 19 is formed.
The upper part is closed and a virtual space is formed between the outer surface and the outer surface of the upper part.

Some of the gas and liquid remain in the space created between the longer gas-liquid riser pipe 16 and the inverted conical suction pipe connection part 19. The gas entrained in the liquid rises faster than the rising speed of the liquid due to the buoyancy of the bubbles themselves. This nineteenth longer gas-liquid riser pipe 16 and the inverted conical suction pipe connection part 19
The nine bubbles that reach between 0 and 9 form a gas reservoir 20 that tends to stay in this space, or a large bubble. The gas in the gas pool 20 rises in the adjacent short gas-liquid rising tube 17 due to its own buoyancy, becomes a large bubble 21, and rises from the upper end of the suction tube inlet section 10. Since the bubbles 21 have a larger diameter than entrained bubbles in the liquid and therefore have greater buoyancy, they are less likely to be entrained in the liquid sucked into the suction section 18 and directed toward the reactor outlet 22 provided above the reactor main body 1. .

Therefore, the effect of separating gas and liquid is large, and the entrainment of gas into the suction liquid is reduced.

An example of examining the above effects using a cold model is shown below.

In order to understand the performance of the three-phase flow reactor according to this example, the amount of gas contained in the circulating fluid 7 was compared using a cold model device made of transparent plastic as shown in Fig. 3. . The inner diameter of the reactor body 1 of the device used is t o o o
lWIA, and the height is 60001 Im. As the disperser 4, a bubble cap was used. The suction tube 11 had an inner diameter of 230 mm, and the suction tube inlet 10 had the same structure as in the above embodiment, and the inner diameter Fi of the upper part was 700 m.

The catalyst particles used were extruded products with a diameter of 1.2 mm and a length of approximately 211,111 mm. Air was used as the gas, and an aqueous solution containing 2031 parts of ethanol was used as the liquid.

In order to confirm the gas-liquid separation performance of the suction pipe inlet 10, the circulating liquid 7 was circulated by the pump 13, and the relationship between the amount of gas in the circulating liquid 7 and the superficial velocity of the supplied gas 5 was determined. At this time, the liquid flow rate is approximately 5
It was set to 1/S.

FIG. 4 shows the results obtained with the suction tube inlet structure according to the prior art shown in FIG. 5 and the structure according to the present embodiment.

As is clear from FIG. 4, in the conventional example, the operating range of the pump is approximately 1.551/! in superficial gas velocity. ! However, in the case of the present invention, it becomes about 5aII/s or more,
It was found that the operating range of the pump was expanded.

A desirable structure of the suction tube inlet portion 10 according to the present invention is to alternately arrange a plurality of long riser pipes 16 and short riser pipes 17 as shown in FIG. 2, so that the flow is as uniform as possible in each part.

In the above embodiment, two types of gas-liquid riser pipes, long and short, are used, but the short gas-liquid riser pipes include the outer wall at the inlet of the suction pipe, the inner wall of the reactor body, and the side part of the long gas-liquid riser pipe. It is not necessary to specially attach two types of pipes, long and short, by using the tubular part formed by the above.

In addition, in the above embodiment, the suction part between the reactor body and the inlet of the suction pipe is cylindrical, and the connection part of the suction pipe inlet is in the shape of an inverted cone. It can also be made into a shape, etc.

〔Effect of the invention〕

As described above, the three-phase flow reactor according to the present invention efficiently separates gas and liquid at the inlet of the liquid suction pipe in the cod, and by suppressing the amount of gas contained in the suction liquid, the pump It is possible to expand the operating range and achieve stable operation.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of the main part of an embodiment of the present invention, Fig. 2 is a sectional view taken along line A-A in Fig. 1, and Fig. 3 is an explanation of a cold model device for understanding the performance of the present invention. Figures 1 and 4 are diagrams showing the relationship between gas superficial velocity, porosity, and pump inoperability region based on experiments using the cold model device shown in Figure 3. Figure 5 is a diagram showing the relationship between the gas superficial velocity, porosity, and the pump no-operability region based on experiments using the cold model device shown in Figure 3. FIG. 2 is an explanatory diagram of the device. 1...Reactor main body, 2...Top surface of catalyst layer when stationary, 3.
...Top surface of expanded catalyst layer, 4...Distribution plate, 5-...Supply gas, 6...Supply liquid, 7...Circulating liquid, 8...Clean layer, 9...Reaction gas, 10 -... Suction pipe inlet section, 11.
...Suction pipe, 12--Reaction product liquid, 13--Pump, 14--Catalyst layer, 15--Bubble, 16--Long riser pipe, 17--Short riser pipe, 18- ... Suction pipe suction part, 19... Suction pipe connection part, 20... Gas reservoir, 2
1...Large bubbles. Agent Patent attorney Akira Sakama 2 other people fi7 prisoner t'

Claims (1)

[Claims] A three-phase fluidized bed is formed by supplying gas and liquid to the solid particle bed from the bottom of the bed through a disperser, and after passing through the fluidized bed, the liquid is extracted from a suction pipe provided vertically through the center of the bed and returned to the apparatus. In a three-phase fluidized bed reactor of a type in which internal circulation is carried out, the suction pipe inlet section includes an inverted conical connection section and a cylindrical suction section provided above the connection section; A plurality of gas-liquid riser pipes having two different lengths are alternately formed in the vertical direction, the inner circumference of which is circumscribed by the outer circumference of the reactor body, and the outer circumference of which is inscribed in the inner circumference of the reactor body. Three-phase flow reactor.