RU235478U1 - Catalytic reactor - Google Patents

Abstract

The utility model relates to catalytic reactors, in particular to catalytic reforming reactors, steam reforming reactors, reactors for producing synthesis gas. The device comprises catalyst tubes 2 filled with granulated catalyst and installed in the reactor in a support base 3. The catalyst tubes 2 contain a rod 8 rigidly connected to them, on which a movable element 9 is installed. The device comprises a limiter 12 connected to the support base 3 and in contact with the movable element 9. The technical result: increased reliability of the device.

Description

Field of technology to which the utility model relates

The utility model relates to catalytic reactors, in particular to catalytic reforming reactors, steam reforming reactors, reactors for producing synthesis gas, ammonia, methanol and other synthesis gas derivatives.

State of the art

A catalytic reactor is known from the prior art, comprising a housing, inside which a support base is installed, in which catalyst tubes are installed with the possibility of movement as a result of thermal elongation (US Patent No. 5958364, published on 09/28/99). The disadvantage of this known means is the lack of means for determining the most heat-loaded catalyst tube.

The essence of the utility model

The objective of the utility model is to create a catalytic reactor equipped with indicators of thermal expansion of catalyst tubes.

The achieved technical result consists in increasing the reliability of the reactor operation in the oil and gas refining process due to the identification of catalyst tubes with increased thermal elongations.

The specified technical result is achieved in that the catalytic reactor comprises a housing, inside which a support base is installed, in which catalyst tubes are installed with the ability to move as a result of thermal expansion, said catalyst tubes contain a rod rigidly connected to them, said rod is made of steel with the ability to synchronously move together with the corresponding catalyst tube during its thermal expansion, a metal movable element is installed on said rod with the ability to slide along it, and inside the reactor a limiter for the movement of said movable element is installed connected to the support base in such a way that during thermal expansion of the corresponding catalyst tube, said movable element interacts with said limiter, wherein when the temperature in the reactor decreases, said movable element is designed with the ability to maintain its position on said rod, which it occupied during the greatest elongation of the corresponding catalyst tube.

A distinctive feature of the utility model is that the catalyst tubes are equipped with means for determining their maximum thermal deformation.

The utility model is presented by drawings.

Fig. 1 shows the general diagram of the reactor.

Fig. 2-4 shows a catalytic tube with different positions of the movable element.

Fig. 5 shows the lower part of the reactor with thermal deformation indicators.

Implementation of a utility model

At present, in the field of hydrocarbon processing, much attention is paid to improving the thermodynamic quality of oil and gas processing equipment. One of the main indicators of the thermodynamic quality of such equipment is the exclusion of overheating of catalyst tubes during operation.

The operating conditions of catalyst tubes during the processing of hydrocarbon raw materials are not the same. Different amounts and conditions of the catalyst and uneven distribution of the feedstock flow across the catalyst tubes, uneven cooling inside the reactor lead to the risk that some of the catalyst tubes will be exposed to the greatest thermal factors, which, in turn, can lead to emergency situations.

The condition of the catalyst tubes is difficult to control using conventional measuring instruments due to the high temperature and pressure inside the reactor in aggressive environments.

Tubular reactors are often used for processing hydrocarbons, in which there is no possibility to control the temperature of the catalyst tubes by means of pyrometry directly during operation. This situation occurs, for example, if the catalyst tubes are in a layer of either a catalyst, or inside a sheath pipe through which an external flow moves, or block each other when arranged in several rows and other similar cases.

The utility model is based on the physical connection between the degree of heating of the catalyst tube and the magnitude of its thermal deformation. By determining the maximum value of thermal elongation of the catalyst tube, one can judge its thermal load.

A typical tubular catalytic reactor shown in Fig. 1 contains a reaction furnace in the form of a cylindrical body 1, inside which are catalytic tubes 2 filled with granulated catalyst. The catalytic tubes 2 are installed in tube grids 3, the lower of which functions as a support base for the catalytic tubes 2. Depending on the size, the reactor may contain, in addition to the upper and lower tube grids, also a middle one.

The reaction furnace has an input pipe for the introduction of raw materials 4, reaction product output lines 5, coolant input 6 and coolant output 7. The raw material mixture is fed into the catalyst tubes 2, where chemical reactions with a certain heat balance (endothermic or exothermic) occur on the catalyst granules. A coolant is fed into the intertube space of the reaction furnace 1, providing the necessary temperature regime for processing hydrocarbons due to heat removal from the reaction zone. The number of catalyst tubes depends on the required reactor productivity.

The catalyst tubes 2 contain a rod 8 rigidly connected to them, made of metal with the possibility of synchronous movement together with the corresponding catalyst tube during its thermal expansion. It is preferable that each catalyst tube 2 is equipped with its own rod 8. It is advisable to make the rod 8 from the same steel from which the catalyst section 2 is made, since the same materials have the same coefficient of linear expansion.

A metal movable element 9 is mounted on the rod 8 with the possibility of sliding along it, interacting with the supporting base either directly or by means of additional structural elements. The essence of the technical solution is that the position of the movable element 9 is an indicator of the amount of thermal elongation of the corresponding catalyst tube 2. It is advisable to make the movable element 9 also from steel.

During thermal expansion of the corresponding catalyst tube 2, synchronous movement of rod 8 occurs. Since movable element 9 mounted on rod 8 rests against the support base, its position on rod 8 changes proportionally to the value of thermal expansion of the corresponding catalyst tube 2. When the temperature in the reactor decreases, cooling of catalyst tubes 2 and decrease in the value of thermal deformation occurs, i.e. the length of the tubes decreases. When cooling the reactor and catalyst tubes to the initial temperature, the value of thermal expansion of the catalyst tubes is compensated by the value of their thermal contraction. Since movable element 9 is designed with the possibility of maintaining its position on rod 8, which it occupied during the greatest expansion of the corresponding catalyst tube 2, after cooling the reactor, based on the position of movable elements 9, it is possible to judge which of the catalyst tubes had the maximum thermal expansion, and therefore the maximum thermal load. In this way, it is possible to identify the most loaded reactor elements and take measures to reduce the load or, during a cold shutdown, to reject tubes that had an elevated average temperature during operation. As a criterion for determining catalyst tubes that require replacement, it is advisable to adopt a threshold of 15% excess of the thermal elongation of the tube from the average elongation to the reactor.

Fig. 2-4 shows a variant of the design of the thermal load indicator unit of the catalyst tube according to the type of design of the oil scraper rings of the internal combustion engine cylinders.

As shown in Fig. 2-4, the catalyst tube 2 is provided with a rod 8 rigidly attached to it, on which a movable element 9 is placed with the possibility of sliding.

The movable element 9 can be made in the form of a bar 10 with an opening, on one side of which a load 11 is secured, ensuring the engagement of the movable element 9 on the rod 8.

The degree of thermal deformation is visualized due to the center of gravity of the bar 10, which interacts with the limiter 12, being shifted from the axis of the rod. The shape of the movable element 9, shown in Fig. 2-4, ensures the occurrence of a moment from the force of gravity, which rotates the bar 10 relative to the rod 8 at any small upward movement of the rod 8. The operation of such a system is more reliable than the embodiment of the movable element 9 in the form of an elastic washer installed with tension on the rod 8, since the properties of elastic elements depend on the temperature and the degree of wear of the mating surfaces. The embodiment of the movable element 9 in the form of a part enclosing the rod 8 (an elastic washer, a bellows, etc.) can also be used.

The limiter 12 can be an end wall of the sleeve 13, fixed on the support base, i.e. on the lower tube sheet 3. The catalyst tube 2 can be installed in the sleeve by means of oil scraper rings either directly or with the help of intermediate tubes 14, as shown in Figs. 2-4. This example of the structural connection of the limiter 12 and the support base is not the only possible one. Depending on the design of the reactor, the structural connections of the rod 8 with the movable element 9, the catalyst tube 2 and the limiter 12 can vary. It is essential that the rod 8 is rigidly connected to the catalyst tube 2, the limiter 12 is rigidly connected to the support base 3, and the movable element 9 slides along the rod 8 only forcibly upon contact with the limiter, i.e. until an external force is applied to the movable element 9, its position on the rod 8 does not change.

Fig. 2 shows the initial (cold) state of the catalytic tube 2. In the initial cold state, the length of the catalytic tube 2 and the corresponding rod 8 are minimal. The movable element 8 occupies the extreme lower position, in particular, it can be located on the limiter 12.

As the temperature in reactor 1 increases, the length of catalyst tube 2 increases and rod 8 fixed to this tube moves downwards by the amount of thermal elongation. Movable element 9 rests against limiter 12 and slides along the surface of rod 8.

Fig. 3 shows the moment of the extreme lower position of rod 8 at the moment of maximum thermal load.

As the temperature inside reactor 1 decreases, the length of catalyst tube 2 decreases, and the rod begins to rise upward, dragging movable element 9 along with it.

However, under the action of gravity on load 11, the bar 10 of the movable element 9 rotates, the edges of the hole in the bar 10 catch on the surface of rod 8 and the movable element 9 also begins to rise upward. After reactor 1 cools down, the movable element 9 of the corresponding catalyst tube 2 is at a height that is clearly related to the degree of thermal elongation of this tube.

Since each catalyst tube 2 is equipped with a movable element 9, in the case of different thermal loads, the movable elements 9 will be at different heights. After this, a simple visual review of the position of the movable elements 9 can identify the most thermally loaded catalyst tubes in the reactor and, for example, carry out their selective replacement. It is advisable to make the movable element 9 visually accessible both when the reactor is cold and when it is hot. The position of the movable element 9 on the rod 8 can be calibrated, i.e. an exact quantitative relationship between the amount of movement of the movable element 9 and the heating temperature of the catalyst tube 2 can be established.

The utility model is applicable to catalyst tubes with any cross-sectional shape.

Example of implementation.

Preheated feedstock, in particular steam-gas mixture (SGM), begins to enter catalyst tubes 2 of the catalytic reforming reactor through inlet pipe 4 at the required temperature, usually from 620°C to 650°C. Alumina-platinum catalysts were used as a cataloger. The reactor operation cycle was 35 days. After stopping and cooling the reactors, the positions of the movable elements 9 on the rods 8 were removed. It turned out that the thermal deformation values of 6% of the catalyst tubes exceeded the average by at least 15%. Tubes with increased thermal deformation were replaced. During the next reactor operation cycle, no catalyst tubes with thermal elongation exceeding the average by at least 15% were detected.

Claims (5)

1. A catalytic reactor comprising a housing, inside which a support base is installed, in which catalytic tubes are installed with the ability to move as a result of thermal expansion, characterized in that said catalytic tubes contain a rod rigidly connected to them, said rod is made of steel with the ability to move synchronously together with the corresponding catalytic tube during its thermal expansion, a metal movable element is installed on said rod with the ability to slide along it, and a limiter for the movement of said movable element is installed inside the reactor, connected to the support base, in such a way that during thermal expansion of the corresponding catalytic tube, said movable element interacts with said limiter, wherein said movable element is designed with the ability to maintain its position on said rod, which it occupied during the greatest elongation of the corresponding catalytic tube. 2. The reactor according to item 1, characterized in that the rod is located inside the catalyst tube. 3. The reactor according to item 1, characterized in that the rod is located outside the catalyst tube. 4. The reactor according to item 1, characterized in that the movable element is made in the form of an elastic washer enclosing the rod. 5. The reactor according to item 1, characterized in that the movable element is made in the form of a bar with an opening, on one side of which a load is secured, ensuring the engagement of the movable element on the rod.