RU106140U1 - SHELL-TUBE REACTOR - Google Patents

Abstract

The proposed technical solution relates to reactors for conducting nonisothermal catalytic and non-catalytic reactions and can be used in chemical, petrochemical, fuel, energy, nuclear and other industries related to the generation, absorption and removal of heat or its supply to the reactor.

The technical result is to simplify the design by using cylindrical pipes in the tube bundle and creating in each cylindrical pipe a cross-sectional area that increases along the flow of the reaction mixture.

The technical result is achieved by the fact that in a shell-and-tube reactor for conducting nonisothermal reactions, consisting of a body with a tube bundle fixed in tube sheets and nozzles for entering and exiting the reaction mass and coolant, each tube bundle is cylindrical and provided with a symmetrical mounting the inner surface of the plates with a triangular shape with a base y4 lower end.

Description

The proposed technical solution relates to reactors for conducting nonisothermal catalytic and non-catalytic reactions and can be used in chemical, petrochemical, fuel, energy, nuclear and other industries related to the generation, absorption and removal of heat or its supply to the reactor.

Known shell-and-tube reactor for conducting exothermic and endothermic reactions, comprising a housing, tube sheets, tube bundles, inside of which there is a catalyst and distribution devices made in the form of a tube with slotted slots in the upper part and installed inside each pipe at its lower end, while the tube equipped with covers located above the slotted slots (Ed. St. USSR No. 1134230, Kozhukhotrubny reactor, B01J 8/00, 1985).

The reasons that impede the achievement of a given technical result include the complexity of manufacturing and installing switchgears in each tube of the tube bundle, made in the form of a tube with slotted slots in the upper part and their supply with covers located above the slotted slots.

Known reactor with a tube bundle for carrying out catalytic nonisothermal reactions in the gas phase, which consists of a housing and a tube bundle fixed in tube sheets. Each tube bundle tube is made cylindrical, that is, of equal diameter over the entire height. For uniform distribution of the coolant over the entire cross-section of the annulus, distribution plates are installed in it with a bore that varies in the radial direction. (German Patent No. 2903582, B01J 8/06, 1980).

Reasons that impede the achievement of a given technical result include difficulties in regulating the heat transfer of the reaction mass in cylindrical tubes of the tube bundle to the pipe walls, which requires special external devices that change the flow rate and temperature of the reaction mass at the inlet depending on its temperature inside the tube bundle, and increases the complexity conducting non-isothermal processes.

The closest technical solution for the totality of common features to the claimed object and adopted as a prototype is a shell-and-tube reactor for conducting nonisothermal reactions, consisting of a body with a tube bundle fixed in tube sheets, and nozzles for the inlet and outlet of the reaction mass and coolant, each pipe the tube bundle is made of three or more tubes of equal length, the diameter of which increases along the flow of the reaction mass or conically expanding along the flow of the reaction mass, and e is provided arranged on its outer surface ribs with a height that decreases along the flow of the reaction mass and an outer diameter equal to the diameter of the tube outlet (Ed. St. USSR №1088781, shell and tube reactor V01J 19/00, 1984 YG).

The reasons that impede the achievement of a given technical result include the complexity of manufacturing such sectional tubes with different diameters in each section or conically expanding tubes.

The technical result of the proposed shell-and-tube reactor is to simplify the design by using cylindrical pipes in the tube bundle and creating in each cylindrical pipe a cross-sectional area that increases along the flow of the reaction mass.

The technical result is achieved by the fact that in a shell-and-tube reactor for conducting nonisothermal reactions, consisting of a body with a tube bundle fixed in the tube sheets and nozzles for the inlet and outlet of the reaction mass and coolant, each tube tube is cylindrical and equipped with symmetrically mounted on the inner surface with triangular-shaped plates with a base at the bottom end.

The execution of the tube bundle cylindrical pipes greatly simplifies the design of the shell-and-tube reactor, since such pipes are widely used in shell-and-tube apparatuses. In addition, for the installation of cylindrical pipes, the same upper and lower tube sheets can be used, which also simplifies the design of the shell and tube reactor.

The symmetrical installation of triangular-shaped plates on the inner surface of each cylindrical pipe with a base at the lower end allows one to create a variable cross-section inside each cylindrical pipe, gradually increasing along the flow of the reaction mass, which ensures the highest reaction mass velocity at the inlet of the tube bundle and its gradual decrease in as you move out of the pipe. The high reaction mass velocities at the inlet to the tube bundle tubes in turn increase the heat transfer coefficient. Since the concentrations of reacting components in the reaction mass are greatest at the inlet to the tubes of the tube bundle, the heat release in the exothermic reaction or the heat absorption in the endothermic reaction will also be the highest, and a high heat transfer coefficient will contribute to a good transfer of the reaction heat released through the surface of the pipe and plates to the refrigerant in annulus to the refrigerant during an exothermic reaction, or heat transfer through the wall of the pipe and plates from the coolant in the annulus tve to the reaction mass during the endothermic reaction.

A gradual decrease in the width of the triangular plates as the reaction mass moves to the exit from the tube bundle leads to an increase in the cross section in which the reaction mass moves and a decrease in the heat transfer coefficient, but the heat release or heat absorption due to the reaction also gradually decreases as the concentration of reacting components decreases. Therefore, a smaller amount of released or absorbed thermal energy due to the reaction will correspond to a lower heat transfer coefficient.

The symmetrical installation of triangular-shaped plates on the inner surface of each pipe makes it possible to evenly use the surface of pipes and plates for heat transfer.

Figure 1 shows a General view of a shell-and-tube reactor with cylindrical tubes in a tube bundle, Figure 2 is a top view of a cylindrical tube with triangular-shaped plates mounted in it with a base at the lower end, and Fig. 3 is a triangular-shaped plate.

The shell-and-tube reactor consists of a casing 1 with nozzles of the inlet 2 and outlet 3 of the coolant in the annulus, nozzles of the inlet 4 and outlet 5 of the reaction mass, tube sheets 6, in which cylindrical tubes 7 of the tube bundle are fixed. Inside each cylindrical pipe 7 there are symmetrically mounted triangular-shaped plates 8 with a base at the lower end. When carrying out catalytic processes, inside each pipe 7 grains or granules of catalyst 9 are filled.

The shell-and-tube reactor operates as follows.

The initial flow of the reaction mass is supplied through pipe 4 to cylindrical tubes 7 of the tube bundle. At the entrance to the pipe 7, where the concentration of the reacting components in the feed is the highest, heat generation in the exothermic reaction or its absorption in the endothermic reaction is maximized.

However, at the entrance to the pipes 7, the cross-sectional area in which the reaction mass moves is the smallest, since its part is occupied by triangular-shaped plates 8 with a base at the lower end, that is, at the entrance of the reaction mass. The smallest cross-sectional area at the entrance to the tube bundle pipes corresponds to the highest reaction mass rate, and therefore, the highest heat transfer from the reaction mass to the walls of the pipe 7 and plates 8 in the exothermic reaction or from the walls of the pipe 7 and plates 8 in the endothermic reaction.

As the reaction mass moves from entrance to exit, the cross-sectional area increases, and the reaction mass velocity decreases, and the heat transfer coefficient decreases accordingly. However, the heat release in exothermic or heat absorption in the endothermic reaction also decreases due to a decrease in the concentration of reacting substances of the reaction mass. The reaction products exit the housing 1 through the outlet pipe 5. The coolant enters the annulus through the pipe 2, and exits through the pipe 3.

The symmetrical installation on the inner surface of each cylindrical pipe 7 of a tube bundle of plates of triangular shape with a base at the bottom end, that is, at the inlet of the reaction mass stream, makes it possible to align the temperature profile with the height of the reactor tubes, reduce the absolute temperature by 2-5%, increase the degree of conversion by 0.8%, prevent thermal degradation of the starting materials and reaction products and thermal deactivation of the catalyst 9 without installing special temperature control devices along the length of the pipes and regulating feeding the reaction mass, which simplifies the design of the tube bundle pipes and their operation, and also allows the use of ordinary cylindrical pipes of equal diameter in height, but gradually increase in their height the cross-sectional area through which the reaction mass moves.

Claims (1)

A shell-and-tube reactor for conducting nonisothermal reactions, consisting of a body with a tube bundle fixed in tube sheets and nozzles for entering and exiting the reaction mass and coolant, characterized in that each tube bundle tube is cylindrical and provided with triangular-shaped plates symmetrically mounted on the inner surface with a base at the bottom.