DE102005052669A1 - Carrying out high temperature and pressure reactions, e.g. for gas generation or conversion, in vapor drum external pressure vessel with concentric pressure walls, lance-like reactor insert and spiral tube - Google Patents

Abstract

In carrying out high temperature reactions of gaseous and liquid reactants under pressure in a vapor drum external pressure vessel (2) with two concentric pressure walls and a lance-like reactor insert (1), an annular gap (6) is left around the insert, the insert (not subject to presure differences) is formed as a thin-walled vessel (3) and the inner wall of the pressure vessel opens into a spiral tube (10) carrying hot reaction gases. Carrying out high temperature reactions of gaseous and liquid reactants under pressure are based on an external pressure vessel (2), formed as a vapor drum, with two concentric pressure walls and a downwardly opening, lance-like reactor insert (1), forming an internal vessel in which exothermic reactions are carried out under high temperature and pressure. The novelty is that the insert is introduced into the inner tube of the outer pressure vessel and enclosed by the inner pressure wall to leave an annular gap (6) in which the insert is received in contact-free manner. One or more connecting openings (5) provide connection between the inside and outside of the insert, so that no pressure difference occurs between the inside and ouside and the insert can be formed as a thin-walled, non-pressurized vessel (3). The inner wall of the outer pressure vessel opens at the lower end into a spiral tube (10), which runs upwards in the water space of the vapor drum between the inner and outer pressure walls. The hot reaction gases pass through the spiral tube and are cooled in the water bath. Natural circulation flow (13) is generated within the vapor drum, such that the inner wall of the outer pressure vessel is protected against overheating by natural upward convective flow.

Description

method to carry out of high temperature reactions under pressure such as e.g. industrial gas generation and gas conversion reactions are characterized in that the chemical reactions in pressure vessels with thick-walled ceramic Inner insulation at high temperatures expire while the feed materials supplied preheated under heat supply and / or by partial combustion of the reactants with air or oxygen at its highest Temperatures are heated or the resulting hot product gases, before they undergo further process steps, are cooled with heat dissipation have to.

The Prior art systems consist of pressure reactors with interior lining, in which the pressure - bearing walls of the reactor vessel by massive masonry overheating protected Need to become and are isolated from the hot Reaction zone in which the chemical conversion reaction takes place. Furthermore, special high-temperature heat exchangers are necessary to the 1000-1700 ° C hot product gases to cool what in the previously known methods a considerable apparatus Effort caused.

easier Systems that are heretofore known by the sands of the art exist also from pressure reactors with hot, bricked-up reaction zone, in which the chemical conversion reaction takes place at high temperatures, but the hot ones Product gases are cooled by a downstream direct quench of water, what the apparatus execution considerably simplified, but with the disadvantage that that water vapor evaporates into the product gas and at low temperatures must be condensed out of the product gas, creating an efficient heat utilization in the process, e.g. the production of high-pressure steam, not more possible is.

Both solutions have the disadvantage that the reactor as thick-walled, pressure-loaded pressure vessel accomplished must be and the pressure-loaded reactor wall by a massive Interior lining against over-temperature protected must be what increases the mass and thermal inertia of these systems and unsuitable makes for fast and frequent on and off. Another disadvantage of the above-described methods is that maintenance on the reaction system are complex with only a considerable amount of time can be.

Of the Invention has for its object to develop a method with a reaction system which avoids the disadvantages described above. task The invention further, the thermal engineering and apparatus Effort for the implementation of gas generation and gas conversion reactions at high pressures and To reduce temperatures, and to develop a system without massive lining can be safely operated, which is suitable to frequent on and off and can be easily and quickly maintained.

According to the invention this object is achieved by the in 1 described procedural device in which the reaction space as a lance-like, easily extendable reactor insert ( 1 ) is formed in the inner tube of a pressure vessel formed as a steam drum ( 2 ) is used. A thin-walled reaction vessel ( 3 ) of ceramic material and / or refractory metal alloys in the lower part of the reactor insert encloses the hot reaction zone ( 4 ) for carrying out the high temperature reaction into which the reactants ( 3a ) from above. The high-temperature reactions inside the reaction vessel ( 3 ) can be carried out either as thermal non-catalytic gas reactions or else catalytically on a catalyst layer introduced into the reaction space. The reactor insert ( 1 ) is designed so that the inner reaction space ( 4 ) via one or more pressure relief openings ( 5 ) with the ringpaltfoermigen gas space surrounding it ( 6 ) communicates and does not have to absorb pressure. Its outer wall ( 7 ) can be designed as a pressureless thin-walled metallic container with high wall temperature, which makes a massive Innenausmauerung superfluous. A light thermal insulation of insulating materials with low density and heat capacity between the hot reaction vessel ( 3 ) and the metallic outer wall of the reactor insert ( 7 ) only serves to reduce the heat losses in the reaction space. The formed as a thin annular gap free gas space between the hot reactor wall ( 7 ) and the inner tube ( 8th ) designed as a steam drum pressure vessel acts as a controllable insulating layer with controlled heat transfer. It prevents the overheating of the pressure-bearing inner tube ( 8th ) of the pressure vessel formed as a steam drum ( 2 ) and is designed so that the reactor wall ( 7 ) of the reactor insert ( 1 ) is cooled only to the extent necessary to ensure the minimum strength values. The fact that reactor use ( 1 ) and inner tube ( 8th ) of the pressure vessel ( 2 ) do not be Stirring, allows a fast and easy extraction of the entire reactor insert with reaction zone, and thus a fast maintenance by replacing the reactor system.

The pressure-bearing inner tube ( 8th ) of the outer pressure vessel is protected by a water bath and opens at the lower end in an ascending pipe spiral ( 10 ), in which the cooling of the hot product gases with steam generation in a water bath ( 11 ) of the pressure vessel, which is designed as a steam drum, and in which also one or more spiral-shaped heat transfer surfaces ( 12 ) for heating the feed gas streams ( 3a ) are integrated.

The gas-carrying coils inside the steam drum are arranged so that one or more natural circulating flows are created in the water space of the steam drum ( 13 ), which cool and protect all pressurized parts of the equipment from overheating. The gas-carrying coils in the water space are concentrically arranged by an insert ( 14 ) so separated that at the inner, hot product gas-carrying coil ( 10 ) upflow occurs by vapor bubble formation, and steam is condensed on the outer, cold feed gases, and steam is cooled, causing downflow. The resulting high circulating flow protects all pressure-bearing parts of the process from overheating. Excess water vapor, which results from the enthalpy difference between cooling of the hot product gases and heating of the cold feedstocks, is conveyed via a connecting piece ( 15 ), while the cooled product gas through a nozzle ( 16 ) is discharged.

The reaction system described has the advantage that no massive wall thicknesses for the reactor and no massive lining is necessary, which considerably reduces the mass of the reaction system and makes the method suitable for fast startup and shutdown. The fact that the "hot" process and device parts ( 1 ) and the "cold" pressure-bearing process and device parts ( 2 ) can be used without contact with each other and only via a single cold flange connection ( 17 ), or can be easily and simply separated from each other, opens up the possibility of a simplified maintenance or a quick replacement of the lance-shaped reaction part.

One another major advantage of the method lies in the fact that the steam and water phases in the steam drum as transfer fluid between reacting reactants and effluent hot products, wherein in the hot product gases contained heat with high heat transfer coefficient transferred to the cold feed streams becomes. The resulting internal heat integration reduces significantly the apparatus required to heat the feed streams and to cool the be called Product gases, as well as the consumption of resources of the process. The production of excess steam is significantly reduced because only the enthalpy difference between outflowing be called Products and inflowing cold reactants as excess water vapor dissipated must become.

Claims (7)

Method and apparatus for carrying out High temperature reactions under pressure with gaseous and liquid reactants consisting of a designed as a steam drum outer pressure vessel with two concentric pressure-bearing walls, and a lance-like downwardly open reactor insert, in the inner container at high Temperatures and pressures ongoing exothermic reactions are carried out marked in that the reactor insert is introduced into the inner tube of the outer pressure vessel and from the inner pressure-bearing wall of the outer pressure vessel so is enclosed, that an annular gap-shaped gas space is formed, the the reactor use contactless receiving, wherein for the pressure relief of the reactor wall insert the inside and outside the reactor insert through one or more connection openings communicate with each other, so no pressure difference between Inside and outside of the reactor used and thus the same as unpressurized thin-walled container can be trained further characterized by in that the inner wall of the outer pressure vessel designed as a steam drum is connected to the bottom ends in a coil, which in the water room of the Steam drum between inner and outer pressure wall of the steam drum guided from bottom to top and by that the hot ones Reaction gases discharged and cooled in a water bath be such that generates a natural circulation flow inside the steam drum is, wherein the inner wall of the outer pressure vessel through a natural convective Upward flow before overheating protected becomes. A method and apparatus according to claim 1, characterized in that the pipe leading the hot product gas is so separated by suitable internals from the outer wall of the outer pressure vessel, so that the water space of the steam drum is divided into an annular zone with rising flow with high vapor bubble content at the inner pressure-bearing wall of the steam drum and in zones with partition gender flow on the outer wall, which are formed by the internals so that the intensity of the circulating flow can be controlled. Method and device according to claims 1 and 2, characterized in that in the annular zone with descending flow one or more coils for preheating the reaction feeds are installed whose maximum outlet temperature at any Inlet temperature is identical to the temperature of the water bath. Method and device according to claims 1 to 3, characterized in that the temperature of the pressure-bearing parts of the outer than Steam drum trained pressure vessel by the pressure level of the water bath between 110 ° C and 360 ° C can be controlled and adjusted. Method and device according to claims 1 to 4, characterized in that the gas pressure in the reaction part between 5 and 250 bar, preferably between 20 and 80 bar, wherein the gas temperatures inside the reaction use and in the be called gas-bearing Coiled pipes between 620 ° C and 1850 ° C, preferably 800 ° C to 1550 ° C lie. Method and device according to claims 1 to 5, characterized in that with the presented method both purely thermal high temperature reactions under pressure as well as catalytic reactions carried out can be wherein the interior of the reactor insert optionally as a free gas space is formed or with a catalyst or a fixed bed can be filled from inert ceramic material. Method and device according to claims 1 to 6, characterized in that the reactor insert in which the reaction at high temperatures and pressures carried out is formed, and designed as a steam drum outer pressure vessel by a only flange connection are connected, the maximum temperature the water bath in the steam drum and can be so formed is that they have a simple separation of the two parts of the device or a fast and low-maintenance replacement of the hot reactor use allowed.