RU2080914C1 - Shell-and-tube reactor - Google Patents

Abstract

FIELD: chemical engineering. SUBSTANCE: shell-and-tube reactor for conducting catalytic conversion of hydrocarbons has shell with inlet and outlet fittings for raw material and heat carrier, covers, and catalyst-packed tube bundle. Tube ends have slot rectangular openings with internal guiding plates. EFFECT: improved structure. 4 dwg

Description

 The invention relates to the design of shell-and-tube reactors for carrying out the processes of catalytic conversion of hydrocarbons and can be used in the chemical, petrochemical and oil refining industries.

 A known shell-and-tube reactor design for carrying out a hydrocarbon conversion process, comprising a housing with inlet and outlet nozzles for raw materials, a housing with inlet and outlet nozzles for raw materials and coolant, covers and a bundle of tubes with open ends filled with catalyst [1] However, under industrial conditions with a diameter a reactor up to 5 m and a number of tubes up to 15,000 pcs, it is not possible to achieve a strictly horizontal tube plate, as a result, liquid does not get into some pipes, the reaction products are unevenly cooled tsya, overheat the reactor tube, which contributes to uneven deposition of tar and coke on the catalyst.

A known design of a multitubular reactor containing a housing with inlet and outlet nozzles for raw materials and coolant, caps and a bundle of tubes with a catalyst, where the upper edges of each reaction tube are equipped with a cap having a gas inlet that defines the liquid inlet into the reaction pipe [2]
A disadvantage of the known design is the use of gas to distribute the liquid, which affects the heat removal from the reaction products.

A known shell-and-tube reactor design, selected as a prototype, in which the distribution of raw materials through the reaction tubes is carried out through rectangular slotted holes at the end of the tubes [3]
This design allows you to evenly distribute the feedstock over the cross section of the reactor, but does not solve the problem of the distribution of feedstock through the catalyst inside the reaction tubes due to its jet flow into the central (axial) part of the tubes through rectangular slotted holes (see figure 2, item 9).

 As a result of such a regime of the feedstock to the catalyst, the inner walls of the reaction tubes, especially their upper part, turn out to be poorly wetted, which makes it difficult to transfer the heat of reaction through the walls of the reactor tubes to the coolant and causes a more rapid development of the catalyst and a decrease in the yield of catalyst.

 This refers to the drawbacks of the known construction, since the practice of operating shell-and-tube reactors shows that the efficiency of the reactor is determined to a large extent by the amount of heat removal from the reaction products that occurs through the walls of the reaction tubes.

 The aim of the invention is to increase the production of target products, the life of the catalyst, reduce the yield of coke and provide a wide range of stable and efficient operation of shell and tube reactors for the catalytic conversion of hydrocarbons due to the distribution of the liquid phase of the feed to the walls of the reaction tubes.

 This goal is achieved by the fact that the inlet rectangular slit openings at the ends of the reaction tubes (pos. 9, Fig. 3) are provided with internal guide plates (pos. 10, Figs. 3, 4), bent from the vertical axis of each inlet rectangular slit openings in opposite directions so that the area of vertical holes (ABCD, item 12, figure 3) between adjacent guide plates is less than the area of horizontal holes formed by adjacent inner guide plates and walls of the reaction tubes (CDFE, item 11, figure 4), and mmar area of these holes AbCD and CDFE is equal to the area of the input rectangular slotted holes (item 9, figure 3).

 In FIG. 1 shows a shell-and-tube reactor for carrying out processes of catalytic conversion of hydrocarbons.

 Figure 2 is a fragment of the mounting of the distributor in the reactor; figure 3 is a projection of a switchgear; figure 4 shows a top view of the switchgear.

 The shell-and-tube reactor consists of a casing 1 with input 2 and output 3 pipes for raw materials, input 2 and output 3 pipes for raw materials, input 4 and output 5 pipes for coolant, caps 6 and a bundle of reaction tubes 7 with a catalyst, which end with distributors 8 s rectangular inlet slots 9 provided with inner guide plates 10 forming holes (ABCD pos. 12, Fig. 3) and CDEf (Fig. 4, pos. 11), through which the feed is distributed to the catalyst.

 The device operates as follows. The raw material enters the upper inlet pipe 2 (Fig. 1) and is distributed evenly through the reaction tubes 7 (Fig. 1) filled with a catalyst using distributors 8 (Fig. 1) with rectangular inlet slots 9 (Fig. 2, 3) . Through holes 9 (Fig. 2, 3), the raw material enters the pipe. The following describes the operation of the device at various feed rates to the reactor.

 With reduced productivity, the raw material is poured through the lower edge of the hole 9 (FIGS. 2, 3) and completely enters the catalyst through the holes (CDFE) formed by adjacent guide plates 10 (FIGS. 3, 4) and pipe walls. Bending guide plates (pos. 10, Figs. 3, 4) give the raw material a directed flow to the walls of the reaction tubes in the CDFE holes (pos. 11, Fig. 4), the areas of which are sufficient for the distribution of raw materials at reduced productivity.

 At high productivity, the raw material through the slot hole 9 (see Fig. 3) enters the inner part of the reaction tube 7 (see Fig. 1) and is proportionally distributed over the cross section of the catalyst.

 Most of the raw material due to gravity will pass through the horizontal holes of the CDFE formed by the guide plates 10 and the pipe walls (see Fig. 4), and the rest will flow through the vertical holes ABCD (see Fig. 3) formed by the guide plates 10.

 Thus, due to the proposed structural design of the shell-and-tube reactor, its more stable operation is ensured in a wide range of raw material supply. The liquid phase of the feed is always present in the wall region of each reaction tube, which ensures that the temperature is maintained without overheating and coking of the catalyst, which ultimately allows to increase the conversion of the feed to the catalyst cycle.

Claims (1)

 A shell-and-tube reactor for carrying out the process of catalytic conversion of hydrocarbon feedstock, comprising a housing with inlet and outlet nozzles for the feedstock and coolant, covers and a bundle of reaction tubes ending with inlet rectangular slotted holes on the side surface, characterized in that the input rectangular slotted holes at the ends of the reaction pipes are provided internal guide plates bent from the vertical axis of each input slotted rectangular slotted hole in the opposite direction GOVERNMENTAL directions so that the area of vertical openings between adjacent guide plates less than the area of the horizontal holes formed adjacent guide plates and inner walls of the reaction tubes, and the total area of these openings is equal to the square of the input rectangular slotted holes.

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