DE102015205552A1 - Shaped body for tempering a fluid and constructed with such moldings heat exchanger - Google Patents

Abstract

A shaped body for tempering a fluid, which can be used, for example, to form a heat bed (24) of a regenerator (14), comprises a block (27) of a thermally conductive material passing through a base (XY) and perpendicular to the base extending height is defined, wherein the block (27) in cross section parallel to its base (XY) has a plurality of cells (28). In the block (27), a plurality of channels (30, 32) are formed, which are substantially parallel to each other and to the height direction (Z) of the block, each of these channels (30, 32) provided in a cell (28) in that there is an inner wall (34) between the channels (30, 32) in adjacent cells (28). Further, a cross-sectional shape of the channels (30, 32) or the inner walls (34) parallel to the base (XY) of the block (27) has a structure length (s) of a portion of constant curvature sign of at most 3.5 mm or at most 20% of Total volume of the cross-sectional shape of the channels.

Description

TECHNICAL FIELD OF THE INVENTION

The present invention relates to a shaped body for tempering a fluid and a heat exchanger having at least one heat bed, which has at least one such shaped body. The present invention further relates to a thermoreactor, in particular for the regenerative thermal oxidation of combustible substances in an exhaust air or exhaust gas stream having at least one such heat exchanger as a regenerator.

TECHNICAL BACKGROUND

Thermoreactors, in particular those in plants for regenerative thermal oxidation (RTO) of combustible substances in a waste air or exhaust gas flow, typically have a combustion chamber acted upon by a gas stream to be thermally reacted and at least two regenerators, for example below the combustion chamber. Preferably, one of the regenerators in a certain operating state of the thermoreactor with a (first) gas flow is applied, which is supplied to the combustion chamber, while the other regenerator is acted upon with a (second) gas stream, which exits from the combustion chamber. Usually, the first gas stream receives from the flow-through regenerator a certain amount of heat energy, while the second gas stream in turn emits heat energy to the associated regenerator. For temporary storage of thermal energy, in addition to heat-storing fillings (eg balls, caliper bodies, etc.), heat generators with ceramic bodies, for example or alternatively, are used in regenerators. These are characterized by a predictable and homogeneous pressure difference at a certain flow through the respective heat bed, since in the channels of the blocks usually a laminar flow of the passed through the regenerator fluid (gas or liquid) is formed.

The thermal efficiency and service life of the regenerators are important parameters for the efficient use of such regenerators. However, the thermal efficiency and the service life are influenced by the formation of deposits within the regenerators with subsequent blockage of individual flow channels or entire blocks in the heated beds (so-called "blocking"). This "blocking" arises in particular by precipitation of solids from the fluid passed through, with certain solids settle on the channel walls and accumulate there. For example, in the purification of siloxane-containing flashings, the failure of Si oxides on the channel walls occurs.

The blocking of the regenerators has the consequence that the heat beds of affected RTO plants have to be freed from the deposits at regular intervals or the affected moldings of the heat beds must be replaced. For this maintenance work, the RTO system must be shut down and cooled down before the heatsinks can be cleaned or replaced. It usually takes 2 to 3 working days for the RTO system to become operational again. During this time, the production area connected to the RTO plant will generally not be able to fully operate, so that the service life, ie. H. The time it takes to lock the heated beds, a regenerator of an RTO system, can be a decisive factor for the efficiency and economy of the system.

SUMMARY OF THE INVENTION

It is an object of the invention to provide an improved heat exchanger which avoids or at least reduces the above described disadvantages of the prior art.

In particular, a heat exchanger with improved resistance to blocking of its flow channels is to be created.

Another object of the invention is to provide a shaped body for tempering a fluid flow, which achieves a favorable ratio between the lowest possible mass of the shaped body on the one hand and the greatest possible dynamic heat capacity on the other.

This object is achieved by the teaching of the independent claims. Particularly preferred embodiments and further developments of the invention are specified in the dependent claims.

According to a first aspect of the invention, a shaped body for tempering a fluid comprises a block of thermally conductive material defined by a base and a height perpendicular to the base, the block having a plurality of cells in cross-section parallel to its base. Also formed in the block are a plurality of channels that are substantially parallel to each other and to the height direction of the block, each of these channels being provided in a cell such that there is an interior wall between the channels in adjacent cells. In addition, a cross-sectional shape of the channels or inner walls parallel to the base of the block has a structure length of a portion of constant curvature sign of at most 3.5 mm, preferably at most 2.85 mm, and / or at most 20%, preferably at most 15%, the total extent of the cross-sectional shape of the channels.

The curvature sign in this context includes the values convex, concave and rectilinear. The structure length of the cross-sectional shape of a channel is understood to be an edge length of the relevant n-edge in the case of an n-cornered channel. It has been found that a tendency to form deposits of solids precipitated from gaseous fluid flow at temperatures between 400 ° C and 1100 ° C, greatly increases from a "critical structure length". Concretely, for a channel of hexagonal cross-sectional shape, the critical structure length with respect to deposition of silicon oxides is about 2.82 mm when the channel is traversed with a siloxane-containing exhaust gas at a speed between 1 m / s and 6.5 m / s. The viscosity of the exhaust gas can be between 15 μPa s and 40 μPa s. By limiting the structure length of the channel cross section, it is generally possible to reduce deposition of solids (precipitated from the fluid flow at relatively high temperatures or entrained in the fluid flow for other reasons) on a channel wall. For gaseous fluids having a nitrogen content of more than 60% by volume, therefore, a limitation of the structure length of the cross-sectional shape of an n-cornered channel to 3.5 mm may be proposed.

The block of the shaped body is formed of a thermally conductive material. The thermally conductive material preferably has a thermal conductivity of at least about 1.5 W / mK, preferably at least about 2.0 W / mK or more. In addition, the heat-conductive material preferably has a low coefficient of thermal expansion of at most about 1 × 10 ^-4 K ^-1 , preferably at most about 1 × 10 ^-5 K ^-1 , 8 × 10 ^-6 K ^-1 or less (each at 800 ° C) C). Further, the heat conductive material preferably has a high specific heat capacity of at least about 500 J / kgK, preferably at least about 800 J / kgK or more. Moreover, a preferred thermally conductive material has a softening temperature of at least about 1,000 ° C, more preferably at least about 1,200 ° C, even more preferably at least about 1,400 ° C. The thermally conductive material for the molded article is preferably selected from ceramics, brick, clay, metals, precious metals, silica, carbides, graphite or the like high-temperature-stable materials. Particularly preferred are ceramics with a proportion of more than 50% of silica and / or alumina.

The block comprises a plurality of cells according to the invention. The cells are preferably unit cells, i. H. essentially identically designed and dimensioned cells. In addition, the block - in particular depending on the base surface shape of the block and cross-sectional shape of these cells - but also have other cells with different cross-sectional shapes. Such cells with other cross-sectional shapes may preferably be present in the edge region of the block.

The channels are preferably positioned substantially centrally in the individual cells.

The block of the shaped body is preferably formed in one piece. Accordingly, the cells of the block are not formed by separate components, but are defined geometrically within the block.

In a preferred embodiment of the invention, the cross-sectional shape of the channels or of the inner walls has at least one convex section and at least one concave section. Particularly preferably, the cross-sectional shape of the channels or of the inner walls has a plurality of convex portions and a plurality of concave portions, which are provided alternately along the cross-sectional shape. The cross-sectional shape of the channels is preferably formed star-like or flower-like. The cross-sectional shape of a channel is preferably formed substantially point-symmetrical to the longitudinal axis of the channel.

In conventional heat storage moldings are already known with different channel geometries. Thus, the flow channels of the moldings of conventional heat exchangers have, for example, square, rectangular or circular cross-sectional shapes. These cross-sectional shapes have in common that they have a purely convex geometry in the direction changes between adjacent sections the cross-sectional shape are always directed to the center of the cross-sectional shape. It has been found that deposits of solid particles (precipitated or otherwise entrained in the fluid from the fluid passing through the shaped body) on the channel walls of the molded bodies are formed by providing concave portions in the cross-sectional shape of the channels and convex portions in the cross-sectional shape, respectively the inner walls can be effectively delayed or even suppressed.

The concave and convex portions are preferably provided distributed over the entire circumference of the channels. In the context of the invention, however, the concave and convex portions may also be provided only in partial areas of the cross-sectional shapes.

In a preferred embodiment of the invention, the cross-sectional shape of the channels, starting from a basic shape alternately on several sections within the basic shape and a plurality of sections outside the basic form. The basic shape is preferably circular, but in the context of the invention may also be square, rectangular, hexagonal and the like.

Preferably, the cross-sectional shape of the channels is formed starting from the basic shape by periodic oscillations around the basic shape. The periodic oscillations are preferably sinusoidal and / or cosinusoidal oscillations, but other arcuate oscillations or rectilinear oscillations (eg sawtooth patterns) are also possible within the scope of the invention.

Preferably, an amplitude of the deviations, in particular of the oscillations of the basic shape, is at least about 5% and / or at most about 20%, preferably about 7.5% or about 10%, with respect to the basic size of the basic shape (eg circle radius, Edge length or half diagonal).

Preferably, a number of the vibrations around the basic shape are selected from 4, 6, 8 or 12.

Preferably, a distance between the basic shapes of adjacent channels is at least about 0.25 mm, preferably at least about 0.35 mm, and / or at most about 1.00 mm, preferably at most about 0.70 mm.

In another preferred embodiment of the invention, the channels each have a cross-sectional shape parallel to the base of the block in the form of a regular polygon. The cross-sectional shape of these channels is preferably in the shape of a triangle, square, pentagon, hexagon or octagon, with the hexagonal cross-sectional shape being particularly preferred.

In a further preferred embodiment of the invention, the cells each have a cross-sectional shape parallel to the base of the block in the form of a regular polygon. The cross-sectional shape of the cells in the form of regular polygons has the advantage that the cells can be arranged side by side with a small distance from each other, for example to build a thermal bed of a regenerator. In addition, the channels in the cells can be safely separated from one another in this cross-sectional shape of the cells.

In a further preferred embodiment of the invention, a hydraulic diameter of a channel is at least about 2.3 mm and / or at most about 5.0 mm. In the case of channels having a circular cross-sectional shape, the hydraulic diameter is defined essentially by the circular diameter of the cross-sectional shape, in other channel geometries the hydraulic diameter is essentially defined by the diameter of a circle (in-circle diameter) inside the cross-sectional shape.

In a further preferred embodiment of the invention, a quotient of a hydraulic diameter of a channel to a minimum wall thickness of the inner wall between adjacent channels is at most about 6.0, preferably at most about 5.5. Specifically, said quotient ranges between 4.1 and 5.9 using a material having a thermal conductivity between about 1.5 W / mK and 8.0 W / mK and an (average) flow velocity of a gaseous fluid flow passing the channels 1 m / s and 6.5 m / s. The viscosity of the gaseous fluid flow can be between 20 μPa s and 40 μPa s. It has been found that in such a (preferably uniform) determination of the ratio between the hydraulic diameter of the channels and wall thickness of the channels in a molded body according to the invention an optimum can be achieved between the lowest possible mass of the block on the one hand and the greatest possible heat capacity.

In yet another preferred embodiment of the invention, a hydraulic flow area of a channel is at least about 50% and / or at most about 65% with respect to a cross-sectional area of the cell. Such an interpretation also contributes to an optimization of the ratio between the smallest possible mass of the block and the largest possible heat absorption capacity. Specifically, said value is between 51% and 63% using a material having a thermal conductivity between about 1.5 W / mK and 8.0 W / mK and a (mean) flow velocity of a gaseous fluid flow passing the channels between 1 m / s and 6.5 m / s. The viscosity of the gaseous fluid flow can be between 15 μPa s and 40 μPa s.

In yet another preferred embodiment of the invention, an open cross-sectional area of a channel is at least about 50% and / or at most about 75% with respect to a cross-sectional area of the cell.

In a further preferred embodiment of the invention, a minimum wall thickness of an inner wall between adjacent channels is at least about 0.20 mm and / or at most about 1.00 mm. Preferably, the wall thickness is configured in a value range between 0.25 mm and 0.89 mm. Particularly preferred individual values for a substantially uniform wall thickness of all channels are 0.23 mm, 0.25 mm, 0.48 mm, 0.56 mm and 0.81 mm. It has been found that in such a (preferably uniform) definition of the wall thickness of all channels in a molded body according to the invention an optimum can be achieved between the lowest possible mass of the block on the one hand and the greatest possible heat capacity on the other. This is especially true when using a material having a thermal conductivity of between about 1.5 W / mK and 8.0 W / mK and a (mean) flow velocity of a gaseous fluid flow passing through the channels between 1 m / s and 6.5 m / s ,

In yet another preferred embodiment of the invention, a Nusselt number of a laminar flow channel is at least about 3.5, preferably at least about 4.0, and / or at most about 4.5. The Nusselt number is defined as a dimensionless quantity as a product of the hydraulic diameter with the quotient of the heat transfer coefficient to the coefficient of thermal conductivity. Such a design choice is particularly preferred with simultaneous execution of the block of a ceramic material with a proportion of more than 50% aluminum and / or silicon oxides. Such a design choice is particularly preferred in the simultaneous execution of the block of a material for producing a block according to the invention, which has a thermal conductivity between about 1.5 W / mK and 8 W / mK. Optionally, it can be provided that a correspondingly shaped molding is passed by a gaseous fluid flow with a (mean) flow velocity between 1 m / s and 6.5 m / s. The viscosity of the gaseous fluid flow can be between 15 μPa s and 40 μPa s.

In a further preferred embodiment of the invention, the walls delimiting the channels are provided with a protective layer, for example in the form of a protective layer of nanoparticles. For the realization of a protective layer according to the invention, particles of silicon oxide, titanium dioxide, aluminum oxide, iron oxide, zinc oxide, silicon carbide, iron carbide, tungsten carbide, titanium nitride, boron nitride and boron carbide are proposed, the largest extent of which is in each case smaller than 100 nm. Such a "nano-protective layer" is produced According to the invention, a nano-scale rough surface on the inner walls of the channels, so that form microscopic vortexes on the channel surface. A deposition of (from the fluid flowing through the shaped body through or for other reasons carried in the fluid) solid particles is prevented or slowed down. In this way, a "blocking" of the channels can be effectively prevented. In preferred embodiments, the protective layer has a surface roughness Ra of less than 25 μm, in particular less than 10 μm, particularly preferably less than 2.5 μm. Preferably, the protective layer may be formed as a hydrophobic layer. In other applications, however, it may also be advantageous to make the protective layer hydrophilic.

According to a further aspect of the invention, a heat exchanger has at least one heat-bed, which has at least one shaped body of the invention described above.

In a preferred embodiment of the invention, the heat bed has a plurality of shaped bodies, which are arranged parallel to the base surface of the molded bodies next to one another and preferably without spacing from one another. In this way, it is possible to divide a fluid flow to be passed through to an arbitrarily expandable number of shaped bodies and thus to set the volume flow per shaped body and the corresponding flow rate. The preferred flow velocity is between 1 m / s and 6.5 m / s.

In a further preferred embodiment of the invention, the heat exchanger has at least two heat beds, which are arranged one above the other in the height direction of the molded bodies. The channels of the superimposed moldings are preferably substantially coaxially or parallel to each other, preferably have the same cross-sectional shapes and / or preferably have the same dimensions. By superimposing heat beds, the heat absorption capacity of the heat exchanger can be adjusted. It has been found that in the case of a number of 5 to 9 layers of similar heat beds, an overall height of the heat exchanger of 1.2 m to 3.5 m and a corresponding total length of through-flow channels can be achieved. Such a design choice is particularly preferred with simultaneous execution of a plurality of heat exchanger blocks of a ceramic material with a proportion of more than 50% aluminum and / or silicon oxides. Such a design choice is particularly preferred with simultaneous execution of the heat exchanger blocks of a material for producing a block according to the invention, which has a thermal conductivity between about 1.5 W / mK and 8 W / mK. Optionally, it can be provided that a correspondingly shaped heat exchanger is passed by a gaseous fluid flow with a (mean) flow velocity between 1 m / s and 6.5 m / s. The viscosity of the gaseous fluid flow can be between 15 μPa s and 40 μPa s.

In a further preferred embodiment of the invention, a height of the heat bed in the height direction of the shaped body is at least about 20 cm, preferably at least about 25 cm, and / or at most about 50 cm, preferably at most about 40 cm.

In a still further preferred embodiment of the invention, a height of the heat exchanger in the height direction of the shaped body is at least about 100 cm, preferably at least about 150 cm, and / or at most about 300 cm, preferably at most about 200 cm.

According to another aspect of the invention, a thermoreactor comprises a combustion chamber and a regenerator, the regenerator being configured as a heat exchanger of the invention described above. The thermoreactor according to the invention can be used in particular in plants for the regenerative thermal oxidation of combustible substances in a waste air or exhaust gas flow in an advantageous manner. The channels of the moldings are preferably open towards the combustion chamber, so that the fluid can flow through the regenerators into the combustion chamber or out of the combustion chamber.

In a preferred embodiment of the invention, a thermoreactor, in particular for the regenerative thermal oxidation of combustible substances in a waste air or exhaust gas flow, a combustion chamber and a regenerator, wherein the regenerator has at least one heat bed with at least one shaped body for tempering a fluid, the molded body a block of thermally conductive material defined by a base and a height perpendicular to the base, the block having in cross-section parallel to its base a plurality of cells, in which block a plurality of channels are formed which are substantially parallel extend to each other and to the height direction of the block, each of the channels is provided in a cell such that between the channels in adjacent cells, an inner wall is present, and a cross-sectional shape of the channels or the inner walls parallel to the base surface of the block a Strukturlä has a portion of a constant curvature sign of at most 3.5 mm, preferably of at most 2.85 mm, or of at most 20%, preferably of at most 15%, of the total circumference of the cross-sectional shape of the channels.

• – mittlere Strömungsgeschwindigkeit zwischen 1 m/s und 6,5 m/s,
• – Viskosität zwischen 15 μPa·s und 40 μPa·s
• – Temperatur zwischen 400°C und 1100°C
• – Stickstoffanteil größer als 60 Vol.-%.

According to a further aspect of the invention, a thermoreactor has a combustion chamber and a regenerator, wherein the regenerator contains one or more shaped bodies according to the invention, which are in particular composed to a heat bed and flowed through by a particular substantially gaseous fluid flow, wherein the fluid flow of one or more having the following features:

• Mean flow velocity between 1 m / s and 6.5 m / s,
• Viscosity between 15 μPa s and 40 μPa s
• - Temperature between 400 ° C and 1100 ° C
• - Nitrogen content greater than 60 vol .-%.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other relevant features of the solutions according to the invention will become apparent from the following description of various concrete embodiments, for which the above Versions vice versa also apply, with reference to the accompanying drawings. In it show, mostly schematically:

1 a representation of a thermal reactor according to a first embodiment;

2 a representation of a thermal reactor according to a second embodiment;

2A a representation of a thermal reactor according to a variant of the second embodiment;

2 B a representation of a thermal reactor according to another variant of the second embodiment;

3 a top view of a heat bed for a thermal reactor of 1 or 2 ;

4 an enlarged partial plan view of a shaped body of a heat bed of 3 according to a first embodiment;

5 an enlarged partial plan view of a shaped body of a heat bed of 3 according to a second embodiment;

6 a plan view of several channels of a shaped body of 5 according to an embodiment;

7 an enlarged plan view of a cell and a channel of 6 ;

8th a plan view of several channels of a shaped body of 5 according to a further embodiment;

9 an enlarged plan view of a cell and a channel of 8th ;

10 a plan view of several channels of a shaped body of 5 according to a further embodiment;

11 an enlarged plan view of a cell and a channel of 10 ;

12 a plan view of several channels of a shaped body of 5 according to yet another embodiment;

13 an enlarged plan view of a cell and a channel of 12 ;

14 a plan view of several channels of a shaped body of 5 according to yet another embodiment;

15 an enlarged plan view of a cell and a channel of 14 ;

16 various other embodiments of possible cross-sectional shapes of channels of a shaped body of 5 ;

17 an enlarged partial plan view of a shaped body of a heat bed of 3 according to a third embodiment; and

18 a sectional view of a regenerator with multiple layers of thermal beds for a thermal reactor of 1 or 2 ,

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

1 shows a thermoreactor 10 , which can be used, for example, in a plant for regenerative thermal oxidation (RTO) of a combustible substances, in particular volatile organic constituents (VOC) containing exhaust air or exhaust gas stream, according to a first embodiment.

The thermoreactor 10 has a combustion chamber 12 and two below the combustion chamber 12 arranged regenerators 14 on. In the embodiment shown, the thermoreactor 10 two regenerators 14 on each of which an atrium 16 assigned. In other embodiments, however, can also be three, four or more regenerators 14 be provided. In the combustion chamber 12 a burner (not shown) projects beyond the liquid or gaseous fuel and optionally also combustion air into the combustion chamber 12 be initiated. The burner is used to generate a flame in the combustion chamber, which in turn allows ignition and combustion of the pollutants contained in the raw gas to be purified. The temperature in the combustion chamber 12 may be up to about 1,250 ° C during operation - depending on the energy content of the flammable substances contained in the raw gas.

The antechambers 16 the regenerators 14 are each with a raw gas supply 18 and with a clean gas discharge 20 connected. The about the raw gas feed 18 in an antechamber 16 Raw gas introduced is in the respective regenerator 14 warmed up before it enters the combustion chamber 12 is directed. After a thermal conversion of the raw gas in the combustion chamber 12 hot clean gas is created, which in the other regenerator 14 is cooled before passing over the other antechamber 16 and the clean gas discharge 20 is derived in an exhaust air system. In a modified embodiment, the cooled clean gas stream may be fed to further heat exchange and / or purification stages before the clean gas is discharged into the environment or for further use.

In the embodiment of 1 become the thermoreactor 10 and its regenerators 14 by switching the control valves 22a . 22b in the raw gas feed 18 and the clean gas discharge 29 alternately flows through in opposite predetermined flow directions in certain predetermined time intervals. For more detailed operation of such a thermoreactor is exemplified at the point EP 1 312 861 B1 directed.

2 shows a thermoreactor 10 according to a second embodiment, which can also be used, for example, in a plant for regenerative thermal oxidation (RTO) of a combustible substances-containing waste air or exhaust gas flow.

The thermoreactor 10 from 2 is different from the thermoreactor 10 from 1 through a different kind of flow control. As in 2 shown, are the raw gas supply 18 and the clean gas discharge 20 each with a common rotary valve 23 connected, which in turn with the antechambers 16 both regenerators 14 connected is. By a rotation of the rotary valve 23 become the thermoreactor 10 and its regenerators 14 also flows through in opposite directions alternately in certain predeterminable time intervals.

2A shows a variant of the embodiment of the invention 2 , In this embodiment, the thermoreactor 10 a common regenerator construction 14 , which is fluidically separated into two areas, so that the same operation as in the embodiment of 2 results.

2 B shows a further variant of the embodiment of the invention 2 , In this embodiment, the thermoreactor 10 ' with his regenerators 14 rotatably designed and via a common distribution valve 23 ' with the raw gas supply 18 and the clean gas discharge 20 connected. Such a configuration is especially for small thermoreactors 10 ' be provided.

In further variants of the invention, the embodiments of 2A and 2 B also with the embodiment of 1 be combined.

For embodiments with a rotating thermoreactor 10 ' For the clean gas flow, preferably an average flow velocity between 0.6 m / s and 2.5 m / s and a burner-side temperature between 700 ° C and 900 ° C and an outlet-side temperature between 40 ° and 150 ° C are set. The viscosity of the clean gas flow can be between 15 μPa s and 35 μPa s.

For embodiments with a fixed or stationary thermoreactor 10 For the clean gas flow, preferably an average flow velocity between 1 m / s and 6.5 m / s and a burner-side temperature between 800 ° C and 1100 ° C and an outlet-side temperature between 60 ° and 250 ° C are set. The viscosity of the clean gas flow can be between 20 μPa · s and 40 μPa · s. The values mentioned can acquire particular significance in connection with the geometry of certain shaped bodies described below.

As in 1 and 2 indicated, point the regenerators 14 of the thermoreactor 10 in each case several superimposed heat beds 24 on. These warmth beds 24 are each made of a variety of moldings 26 composed, which are arranged perpendicular to the stacking direction of the heat beds (= height direction Z of the heat beds and the molded body) substantially without a distance from each other next to each other, as in 3 shown. Preferably, the shaped bodies 26 a warm bed 24 designed and dimensioned essentially identical to one another.

Reference will now be made to 4 to 17 various preferred embodiments of a shaped body 26 described in more detail, for example, for the heated beds 24 the thermoreactors 10 from 1 and 2 can be used.

The molded body 26 according to the in 4 illustrated first embodiment has a block 27 made of a ceramic material. Preferably, a hard ceramic with a proportion of more than 50% aluminum and / or silicon oxides can be used. Also preferred are ceramic materials having a thermal conductivity of between about 1.5 W / mK and 8 W / mK (preferably, for example, about 2.1 W / mK), a low thermal expansion coefficient of at most about ^{1.10 -5} K ^-1 (preferably, for example, about 6.5 · 10 ^-6 K ^-1 ) at 800 ° C, a high specific heat capacity of at least about 800 J / kgK (preferably, for example, about 910 J / kgK), and a high softening temperature of at least about 1,000 ° C for the block 27 used. Optionally, other high temperature stable materials can be used for the block 27 be used.

The block 27 has, for example, a substantially rectangular or square base parallel to the XY plane (= drawing plane). As in 4 illustrates is the block 27 parallel to this base XY into a plurality of unit cells 28 divided, which have a hexagonal cross-sectional shape in this embodiment. The unit cells 28 border directly on each other. The cross-sectional shapes of the cells 28 in the form of regular polygons is particularly advantageous for the compact and substantially gapless arrangement of the cells 28 ,

In each of the unit cells 28 is a channel 30 educated. The channels 30 extend substantially parallel to each other and substantially parallel to a height direction Z (perpendicular to the plane of 4 ) of the block 27 , The channels in this embodiment have a hexagonal cross-sectional shape and are each substantially centered in the cells 28 arranged. As in 4 recognizable, is between the channels 30 adjacent cells 28 each an inner wall 34 available. Besides, the block is 27 from an exterior wall 36 enclosed. In the edge region of the molding 26 Optionally, cells can also be used 28 ' and channels 30 ' be present with other cross-sectional shapes.

The edge length of the hexagon of the cross-sectional shape of the channels 30 , which forms the structure length s in the sense of the invention, is preferably at most about 2.82 mm. At RTO-typical flow velocities of, for example, about 2.5 m / s, this limited structure length s is advantageous for slowing down or suppressing deposits on the channel walls.

Further define the channels 30 each having a hydraulic diameter Dh, which in the hexagonal channels 30 corresponds to the diameter of a circle inscribed in the hexagon, and a hydraulic flow area Ah. For example, the hydraulic diameter Dh is about 2.90 mm or 4.85 mm, and the hydraulic flow sectional area Ah is about 60.8% or about 62.0% of the cross-sectional area of the cell, for example 28 ,

The interior walls 34 between the channels 30 adjacent cells 28 have a wall thickness t. The wall thickness t 'of the outer wall 36 is greater than the wall thickness t of the inner wall. The wall thickness t of the inner walls 34 For example, it is about 0.56 mm or about 0.89 mm.

5 shows a shaped body 26 according to a second embodiment. The molded body 26 of the second embodiment differs from that of the first embodiment by the cross-sectional shapes of the channels 32 ,

In the second embodiment of 5 have the unit cells 28 also a hexagonal cross-sectional shape. The channels 32 however, have a cross-sectional shape based on a circular basic shape. Ie. the cross-sectional shape of the channels 32 is not circular, but based only on this 5 illustrated circular basic shape.

It has been shown that a resistance of the channels 32 can be increased against deposits from the exhaust air passed through it, if the cross-sectional shape of the channels 32 not solely convex, but has convex and concave sections.

Referring to 6 to 16 will be explained below with reference to various embodiments, as the channel geometries based on the circular basic shape of 5 can be formed.

In the embodiment of 6 and 7 indicates the cross-sectional shape of the channels 32 starting from the circular basic shape 38 a total of six convex sections 38a and six concave sections 38b on, which are arranged alternately along the circumference. In another way of looking at the interior walls 34 between the adjacent channels 32 Cross-sectional shapes with alternating concave and convex sections.

RI

= Radius des Grundkreises, 1,45 mm

P

= Schwingungsamplitude in Bezug auf RI, 10%

N

= Anzahl der Schwingungen, 6

Dsep

= Abstand zwischen benachbarten Grundkreisen, 0,55 mm

The cross-sectional shape of the channels 32 is in the embodiment of 6 and 7 starting from the circular basic shape 38 formed according to the following equation (1): r _i (φ) = RI * (1 + P * sin (N * φ -π / 2)) (1) With:

RI

= Radius of the base circle, 1.45 mm

P

= Oscillation amplitude with respect to RI, 10%

N

= Number of vibrations, 6

DSEP

= Distance between adjacent base circles, 0.55 mm

The radius r of the cross-sectional shape oscillates at six times the frequency and with an amplitude P of 10% of the nominal radius RI, which is preferably selected between 1.2 mm and 2.5 mm. Due to the sixfold vibration frequency, the channels 32 are preferably arranged analogously to a densest packing of circles in a hexagonal grid, which in addition the distance Dsep flows into this arrangement, which is the minimum wall thickness t of the inner walls 34 between adjacent channels 32 certainly.

As in 7 recognizable, is the hydraulic diameter Dh of the channels 32 reduced compared to the circular cross-sectional shape. It is about 2.61 mm in this embodiment. This disadvantage can be at least partially compensated in a modification (not shown) of this embodiment, for example, by the fact that the parameter Dsep is reduced by the nominal radius RI is increased so that the radius oscillation as a minimum the base circle 38 from 7 and thus the hydraulic diameter is about 2.90 mm.

The above-described radius oscillation can also be superimposed by one or more further oscillations.

Such is the cross-sectional shape of the channels 32 in the embodiment of the 8th and 9 starting from the circular basic shape 38 formed according to the following equation (2): r _i (φ) = RI * (1 + P × sin (N × φ-π / 2) + P2 × sin (F × N × φ-DPHI × π / 2)) (2) with: RI = 1.45 mm, P = 10%, N = 6, Dsep = 0.55 mm, P2 = 25% (secondary oscillation amplitude), F = 0.5 and DPHI = 3.

The embodiment of the 10 and 11 goes out of the one 8th and 9 by changing the parameters.

Such is the cross-sectional shape of the channels 32 in the embodiment of the 10 and 11 starting from the circular basic shape 38 also according to equation (2) above, but with RI = 1.45 mm, P = 10%, N = 6, Dsep = 0.4 mm, P2 = 25%, F = 2 and DPHI = 3.

In addition to the above embodiments of the 6 to 11 with N = 6, other multiples of the angular frequency (eg, N = 4, N = 8, or N = 12) may also be used to achieve a reduced tendency to deposit on the channel walls.

Such is the cross-sectional shape of the channels 32 in the embodiment of the 12 and 13 starting from the circular basic shape 38 also according to equation (2) above but with RI = 1.45 mm, P = 10%, N = 8, Dsep = 0.4 mm, P2 = 15%, F = 2 and DPHI = 3.

Next is the cross-sectional shape of the channels 32 in the embodiment of the 14 and 15 starting from the circular basic shape 38 according to the above equation (1), but formed with RI = 1.45 mm, P = 7.5%, N = 12 and Dsep = 0.55 mm.

All of the above embodiments may be modified within the scope of the invention by using corresponding or similar cosine terms instead of the sine terms. Corresponding or similar cosine terms are used. For example, a development in a plurality of sine and / or cosine terms according to the following equation (3) is also conceivable:

In all the above embodiments, the structure lengths s of the portions having constant curvature, ie, the convex portions 38a and the concave sections 38b the cross-sectional shapes of the channels 32 each smaller than 2.85 mm.

In addition to the above-described cross-sectional shapes of the channels 32 Of course, numerous other variants are conceivable within the scope of the present invention. So shows 16 by way of example some further embodiments of star-like or flower-like cross-sectional shapes of the channels 32 , In addition to the in 16 indicated hexagonal cross sections of the unit cells 28 others can use the respective channel 32 enveloping cross sections of unit cells 28 For example, polygons [e.g. As triangles, squares, pentagons, octagons, etc.], polygon-like geometries, etc., be advantageous, especially if by a corresponding cross-section of the unit cell 28 a preferably dense tiling a base of the block 27 can be achieved. Under an enveloping cross-section of the unit cell 28 In this case, in particular, an embodiment of the unit cell 28 concerning the respective channel 32 understood, at the one between the respective channels 32 of two adjacent unit cells 27 resulting wall thickness does not fall below a value of 0.2 mm and / or does not exceed 1.0 mm. Under a preferably dense tiling is in particular a tiling of the base of the block 27 understood, in which the sum of the cross-sectional areas of all channels 27 in the base area min. 50%, preferably min. 60%, more preferably min. 65% of the floor area of the block.

In a further modification of the invention shows 17 a shaped body 26 with a block 27 in which cells 28 are defined with a square cross-sectional shape. The cross-sectional shapes of the channels 32 are based on a circular basic shape 38 and correspond to, for example, the above embodiments of 6 to 16 ,

Referring to 18 eventually becomes the construction of a regenerator 14 with several layers of a-g of heated beds 24 described in more detail.

The regenerator 14 is in a reactor housing 40 of the thermoreactor 10 below the combustion chamber 12 arranged. The lower base of the regenerator 14 forms a grate 42 (eg of metal or precious metal), on which optionally an expanded metal or expanded metal mesh 44 lies.

On the grate 42 and the expanded metal 44 are the several layers a-g of warming beds 24 arranged. Every heat bed 24 is made of a variety of moldings 26 composed. The warming beds 24 or shaped body 26 the layers a-f each have a height h of, for example, about 30 cm, while the heat bed 24 or the shaped body 26 The optional top layer will have a height h of, for example, only about 15 inches, allowing for the regenerator 14 Overall, a height H of about 195 cm results in this embodiment. Between the warming beds 24 and the reactor housing 40 is optional also a so-called caliper body 46 provided from heat-storing bulk material.

In this embodiment, the heat beds 24 the layers a-e, for example, from 23 × 29 moldings 26 formed, and are the heat beds 24 the layers f-g, for example, from 21 × 27 moldings 26 educated. It can in the warm beds 24 the different layers a-g optionally identical or different moldings 26 , ie in particular shaped bodies with cells 28 identical or different cross-sectional shapes and / or channels 30 . 32 be used the same or different cross-sectional shapes. Furthermore, the heat beds 24 Partly be formed from moldings that do not correspond to the embodiments of the invention. The advantages of the invention can also already be achieved if at least a portion of the heat beds 24 of the regenerator 24 is configured according to the invention described above.

Other typical variants of regenerators 14 contain by way of example the following numbers of moldings 26 in the X or Y direction and on layers of heat beds 24 : Number of moldings X Y documents 8th 13 5-7 10 13 5-7 14 13 5-7 16 13 5-7 15 16 5-7 17 16 5-7 15 23 5-7 19 23 5-7 22 23 5-7 29 23 5-7 29 26 5-7

LIST OF REFERENCE NUMBERS

10

thermoreactor

10 '

thermoreactor

12

combustion chamber

14

regenerator

16

antechamber

18

Rohgaszuführung

20

Clean gas outlet

22a

control valve

22b

control valve

23

rotary valve

23 '

distribution valve

24

Warmer

26

moldings

27

block

28

Cell, unit cell

28 '

modified cell, border cell

30

Channel (polygonal cross-sectional shape)

32

Channel (circular cross-sectional basic shape)

34

inner wall

36

outer wall

38

Basic shape, preferably circular

38a

convex section

38b

concave section

40

reactor housing

42

grating

44

expanded metal

46

saddles

Ah

hydraulic flow cross-sectional area

Ao

open flow cross-sectional area

ie

hydraulic diameter

DSEP

Distance of the base circles

H

Height of 24 respectively. 26

H

Height of 14

N

Number of vibrations

P

amplitude

RI

Radius of the base circle

s

structure length

t

minimum wall thickness of the inner wall

t '

Wall thickness of the outer wall

X-Y

Floor space

Z

height direction

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1312861 B1 [0064]

Claims (20)

Shaped body for tempering a fluid, comprising: a block ( 27 ) of a thermally conductive material defined by a base (XY) and a height perpendicular to the base, the block ( 27 ) in cross-section parallel to its base (XY) a plurality of cells ( 28 ), in the block ( 27 ) a plurality of channels ( 30 . 32 ) which are substantially parallel to one another and to the height direction (Z) of the block, each of the channels ( 30 . 32 ) in a cell ( 28 ) is provided such that between the channels ( 30 . 32 ) in adjacent cells ( 28 ) an inner wall ( 34 ), and a cross-sectional shape of the channels ( 30 . 32 ) or the inner walls ( 34 ) parallel to the base (XY) of the block ( 27 ) has a structure length (s) of a portion of a constant curvature sign of at most 3.5 mm, preferably at most 2.85 mm, or at most 20%, preferably at most 15%, of the total circumference of the cross-sectional shape of the channels. Shaped body according to claim 1, in which the cross-sectional shape of the channels ( 32 ) or the inner walls ( 34 ) at least one convex portion ( 38a ) and at least one concave section ( 38b ) having. Shaped body according to claim 1, in which the cross-sectional shape of the channels ( 32 ) or the inner walls ( 34 ) a plurality of convex portions ( 38a ) and several concave sections ( 38b ) which are provided alternately along the cross-sectional shape. Shaped body according to one of the preceding claims, in which the cross-sectional shape of the channels ( 32 ) starting from a basic form ( 38 ), preferably a circular basic shape, alternately having a plurality of sections within the basic shape and a plurality of sections outside the basic shape. Shaped body according to claim 4, in which the cross-sectional shape of the channels ( 32 ) starting from the basic form ( 38 ), preferably a circular basic shape, by periodic oscillations around the basic shape ( 38 ) is formed. Shaped body according to claim 4 or 5, wherein an amplitude (P) of the deviations from the basic shape ( 38 ) is at least about 5% or at most about 20%. Shaped body according to one of claims 4 to 6, in which a number (N) of the vibrations around the basic shape ( 38 ) is selected from 4, 6, 8 or 12. Shaped body according to one of claims 4 to 7, wherein a distance (Dsep) between the basic shapes ( 38 ) of adjacent channels ( 32 ) is at least about 0.25 mm, preferably at least about 0.35 mm, or at most about 1.00 mm, preferably at most about 0.70 mm. Shaped body according to claim 1, wherein the channels ( 30 ) each have a cross-sectional shape parallel to the base surface (XY) of the block ( 27 ) in the form of a regular polygon. Shaped body according to one of the preceding claims, in which the cells ( 28 ) each have a cross-sectional shape parallel to the base surface (XY) of the block ( 27 ) in the form of a regular polygon. Shaped body according to one of the preceding claims, wherein a hydraulic diameter (Dh) of a channel ( 30 . 32 ) is at least about 2.3 mm or at most about 5.0 mm. Shaped body according to one of the preceding claims, wherein a hydraulic flow cross-sectional area (Ah) of a channel ( 30 . 32 ) at least about 50% or at most about 65% with respect to a cross-sectional area of the cell ( 28 ) is. Shaped body according to one of the preceding claims, in which the channels ( 30 . 32 ) bounding walls ( 34 . 36 ) are provided with a protective layer. Heat exchanger ( 14 ), comprising at least one thermal bed ( 24 ), the at least one shaped body ( 26 ) according to one of claims 1 to 13. Heat exchanger according to claim 14, in which the heat bed ( 24 ) several moldings ( 26 ), which are arranged parallel to the base surface (XY) of the shaped bodies next to one another, preferably without spacing from one another. Heat exchanger according to claim 14 or 15, which comprises at least two heat sinks ( 24 ), which in the height direction (Z) of the shaped body ( 26 ) are arranged one above the other. Heat exchanger according to one of claims 14 to 16, wherein a height (h) of the heat bed ( 24 ) in the height direction (Z) of the shaped bodies ( 26 ) is at least about 20 cm, preferably at least about 25 cm, or at most about 50 cm, preferably at most about 40 cm. Heat exchanger according to one of claims 14 to 17, wherein a height (H) of the heat exchanger ( 14 ) in the height direction (Z) of the shaped bodies ( 26 ) is at least about 100 cm, preferably at least about 150 cm, or at most about 300 cm, preferably at most about 200 cm. Thermoreactor ( 10 ), in particular for the regenerative thermal oxidation of combustible substances in an exhaust air or exhaust gas stream, comprising a combustion chamber ( 12 ) and a regenerator ( 14 ), wherein the regenerator ( 14 ) is configured as a heat exchanger according to one of claims 14 to 18. Thermoreactor ( 10 ), in particular for the regenerative thermal oxidation of combustible substances in an exhaust air or exhaust gas stream, comprising a combustion chamber ( 12 ) and a regenerator ( 14 ), wherein the regenerator ( 14 ) one or more moldings ( 26 ) according to one of claims 1 to 13, in particular to a heat bed ( 24 ) are flowed through and flowed through by a particular substantially gaseous fluid flow, the fluid flow having one or more of the following characteristics: average flow velocity between 1 m / s and 6.5 m / s, viscosity between 15 μPa s and 40 μPa · s, - temperature between 400 ° C and 1100 ° C, - nitrogen content greater than 60 vol .-%.

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