DE102020212606A1 - Structure, heat exchanger comprising a structure, heat exchanger system comprising a heat exchanger, method for temperature control of a particle flow, use of a structure for temperature control of a particle flow, method for coating a substrate and method for separating a liquid sample - Google Patents

Abstract

One aspect of the present invention relates to a structure (20), particularly for use in heat exchangers (40), comprising: a grid element (22) made of a thermally conductive substance, the grid element (22) having a plurality of capillaries (24), and wherein a particle flow (P) can flow through the grid element (22) via the plurality of capillaries (24) essentially in a flow direction (D) between two opposite sides (26, 28) of the grid element (22). Further aspects of the present invention relate to a heat exchanger comprising a structure, a heat exchanger system comprising a heat exchanger, a method for temperature control of a particle flow, use of a structure for temperature control of a particle flow, a method for coating a substrate and a method for separating a liquid sample.

Description

The present invention relates to a structure, a heat exchanger comprising a structure, a heat exchanger system comprising a heat exchanger, a method for temperature control of a particle flow, use of a structure for temperature control of a particle flow, a method for coating a substrate and a method for separating a liquid sample.

The exchange of heat or amounts of substance between a fluid and a solid, in particular for the evaporation of liquids and condensation of gases, in components of gas chromatographs or coating systems, has technical and economic importance, since the heat exchange or exchange of amounts of substances, or its speed, which Process speed, accuracy and reproducibility is or can be a determining step, for example in gas chromatography or in certain coating techniques.

In gas chromatography, on the one hand, it is desirable to fill a liquid (sample) into a container, the so-called liner (usually by injecting it), and to evaporate the liquid as quickly and completely as possible. Typically, the liner is flushed with a carrier gas that is introduced at one end and fed into the so-called column at the other end. The carrier gas flushes the resulting sample vapors into the column. This process is called injection and takes place in the so-called injector, which consists of several parts, including the liner itself. After passing through the column, the individual chemical components of the sample exit the column at different times and can thus be specifically analyzed. The separation based on the throughput time cannot be any sharper than the duration of the injection. For this reason, the liquid must be evaporated as quickly as possible when it enters the liner. Furthermore, the sample must evaporate as completely as possible in order to enable the detection or analysis of those sample components that are only contained in small amounts in the sample. There are so-called refocusing methods in which a long evaporation is partially compensated by a recondensation in the column. However, the process management is more complex here and the omission of this step represents a technical benefit.

In coating technology, on the other hand, methods such as atomic layer deposition (ALD) are used, in which at least two different gases or vapors from so-called precursors are introduced into a coating chamber in alternation. Each of the gases then reacts with the surface of the substrate to be coated (so-called half cycle). In the ALD, only one atomic monolayer of an intermediate product is deposited in each half-cycle, which is only converted into the final film material in the second half-cycle by the second precursor or gas or vapor. Therefore, many cycles are often necessary to achieve the desired film thickness. Depending on the application, 10 cycles can be sufficient, but it can also be up to 10,000 cycles and more. It is very important that the vapors do not co-exist in the same area of the plant, so typically the coating chamber is evacuated after each half-cycle to remove unreacted residue of the gases, and the storage tanks for the precursors are valved off from the rest of the plant for the duration of a half cycle are separable. Depending on the machine, the time per cycle is around 1 to 100 seconds, with the main time being used for pumping out. Current valves can only be used up to a maximum of 200 °C, which results in the following disadvantage: There are some chemicals which, from a chemical point of view, would be desirable for use as precursors, but only evaporate to a sufficient extent at temperatures above 200 °C. in order to be able to transport them from a storage container into the coating system, e.g. B. by using a carrier gas as a purge gas. Their use is therefore out of the question, because vapors generated at such high temperatures would recondense at a corresponding temperature when introduced into the coating chamber in the valves that can be heated to a maximum of 200° C. or their supply lines. As a result, clean separation of the two precursor gases from one another and supply of the chemicals in sufficient quantities and in a reproducible manner can no longer be guaranteed, and the wear on the valve is unacceptably high. Furthermore, the process can no longer be carried out with separate gases.

It is the object of the present invention to eliminate the disadvantages of the prior art described above and to ensure efficient temperature control, in particular rapid and uniform heat transfer.

This object is solved by the independent patent claims. Preferred embodiments emerge from the corresponding dependent patent claims.

One aspect of the invention relates to a structure, particularly for use in heat exchangers, comprising: a grid element made of a thermally conductive substance, the grid element having a plurality of capillaries, and wherein a particle stream can flow through the grid element via the plurality of capillaries essentially in a flow direction between two opposite sides of the grid element.

Advantageously, this structure can be made compact and at reasonable cost. Furthermore, this structure has the advantage that it has a particularly large surface or contact area, for example, to exchange heat with a fluid, and in contrast to porous membranes used in the prior art, such as wool or beds of nanoparticles, where it is too stationary heat or cold areas in the membranes, can ensure an even heat exchange. The structure, on the other hand, has uniform flow properties so that the formation of stationary hot or cold areas can be avoided. Further advantageously, the structure has a very low thermal mass and a high thermal conductivity, as a result of which the structure responds and can react very quickly to temperature changes. Due to the particularly large contact surface of the structure, a particularly large number of particles can also be deposited on the structure.

In the context of this description, “flow direction” means the direction in which the particle stream hits one of the sides of the structure, penetrates the structure, in particular the grid element, and leaves the structure on the opposite side. In other words, the flow direction can be parallel to a surface normal that is perpendicular to one of the two opposite sides. Accordingly, the flow direction, based on the structure, can run from left to right or vice versa, from top to bottom or vice versa, or from back to front or vice versa. Furthermore, the direction of flow can coincide with one of the three spatial directions x, y or z of a coordinate system whose origin is located, for example, with the center of mass of the structure. The flow direction can be described with a vector in a three-dimensional Cartesian coordinate system. For the sake of simplicity, it is assumed below that the direction of flow runs in the positive x-direction of a three-dimensional, Cartesian coordinate system.

In the context of this description, the term "essentially in the direction of flow" means that the particle flow penetrating the structure, in particular the grid element, leaves the structure on the opposite side at the same angle, but inside the structure the particle flow can depending on the geometry of the capillaries, flow in a direction different from the direction of flow.

The particle flow can, for example, comprise particles of a gas, a liquid or solid particles or a mixture of these particles. However, the particle flow can also be a flow of gas, liquid, solid particles or a mixture of these particles.

The two opposite sides of the lattice element can each be one of the outer surfaces of the lattice element. The two opposite sides can be part of the outer surface of the grid element. Each of the two opposite sides can be the interface between the interior or inner space of the lattice element and the outer space of the lattice element surrounding the lattice element. The outer space can be evacuated or filled with a medium such as air, so that the grid element can be surrounded by this medium. Furthermore, the two opposite sides can be surfaces that are plane-parallel to one another.

Preferably, the structure comprises only the lattice element. The lattice element can be the structure.

The plurality of capillaries preferably comprises a first subset of capillaries which extend in a straight line in the direction of flow between the two opposite sides of the grid element. The capillaries of the first subset can extend, in the length direction of the capillaries, from one of the two opposite sides to the other along the direction of flow. The capillaries of the first subset can hydrodynamically connect the two opposite sides of the grid element. The capillaries of the first subset can be parallel to one another. The plurality of capillaries can include two, three, four, five or more capillaries. Preferably, the plurality of capillaries includes 250,000 to 625 million capillaries.

Preferably, the structure has a capillary density greater than or equal to 1 capillary per 400 μm ² and less than 1 capillary per 100 μm ² , a density of capillaries greater than or equal to 1 capillary per 100 μm ² and less than 1 capillary per 50 μm ² , a density of capillaries equal to or greater than 1 capillary per 50 µm ² and less than 1 capillary per 10 µm ² , a density of capillaries equal to or greater than 1 capillary per 10 µm ² and less than 1 capillary per 1 µm ² , or a density of capillaries equal to or greater than 1 capillary per 1 µm ² and less than 1 capillary per 0.16 µm ² . More preferably, the structure has a capillary density of exactly 1 capillary per 400 μm ² or a capillary density of exactly 1 capillary per 0.16 μm ² . Preferably, the structure has a cross-sectional area greater than or equal to 0.1 cm ² and less than 0.5 cm ² , a cross-sectional area greater than or equal to 0.5 cm ² and less than 1 cm ² , or a cross-sectional area greater than or equal to 1 cm ² and less than 5 ^cm2 . More preferably, the structure has a cross-sectional area of exactly 1 cm ² .

Furthermore, the multiplicity of capillaries can comprise a second subset of capillaries which extend or run transversely to the flow direction and/or to the capillaries of the first subset running in the flow direction. The multiplicity of capillaries can accordingly comprise a network of capillaries running perpendicular to one another.

Advantageously, this embodiment allows the contact surface between the structure and the particle flow to be enlarged with a small thermal mass or heat capacity of the structure and a small spatial extent or size of the structure, as a result of which heat and/or the amount of substance can be exchanged more efficiently between the structure and the particle flow .

The grid element preferably has a regular, in particular periodic, geometric grid structure. More preferably, the grating element is monolithic and monocrystalline. In contrast to physical solids such as metals or diamonds, "geometric lattice structure" does not mean the atomic or molecular crystal lattice structure, but the macroscopic design of the lattice element. Of course, the thermally conductive substance of which the lattice element is made may have a specific crystal lattice structure at the microscopic level, such as one of the well-known Bravais lattice structures.

This embodiment advantageously avoids the structures used in the prior art, such as wool and beds of nanoparticles, in which cavities are present on the inside or cavities can form, as a result of which a uniform exchange of heat and/or amount of substance between these structures and a particle stream, in contrast to the structure according to the invention.

Preferably, the grating element is a photonic crystal. In the context of this description, the term “photonic crystal” means an object that can be described by a three-dimensional basic element and its space-filling, periodic repetition, with the periodicity typically being in the range from 100 nm to 100 μm. However, this should not represent the exclusion of objects with larger or smaller periodicities. Photonic crystals are also, in particular, crystals that have a refractive index that varies periodically, as a result of which the propagation of photons can be influenced. Photonic crystals can in particular be made from structured semiconductors, glasses or polymers and can usually be produced using the methods known from microelectronics. With their specific lattice structure, they force the light to propagate in the medium in the way necessary for the component function. This not only makes it possible to direct light to dimensions that are in the order of magnitude of the wavelength, but also to filter and reflect it wavelength-selectively. For example, photonic crystals can be formed according to the methods described in the publications Vlad et al., "Direct transcription of two-dimensional colloidal crystal arrays into three-dimensional photonic crystals", 2013, DOI: 10.1002/adfm.201201138 and Chang et al., 2018, J .Micromech. Microeng. 28 105012, "DREM2: a facile fabrication strategy for freestanding three dimensional silicon micro- and nanostructures by a modified Bosch etch process". The content of these publications is hereby incorporated into this description.

In this embodiment of the structure, however, the capillaries must not be filled with glass or silicon or another material that is common for photonic crystals, since, according to the invention, material must be able to flow through the capillaries. Therefore the capillaries must be open.

In this embodiment of the structure, the lattice element advantageously has no unwanted hollow spaces or cavities or dead spaces or pockets inside the lattice element, so that a homogeneous heat and/or mass exchange is possible. In other words, a particle flow can flow through the grid element via the capillaries without local congestion of the particle flow being able to form within the grid element. In particular, particle accumulation in cavities is advantageously avoided.

The substance preferably has a high melting point. For example, the substance may be silicon, nickel, tungsten, graphite, steel, gold, iridium, ruthenium, palladium, platinum, silver, aluminum, zirconium, titanium, iron, vanadium, manganese, molybdenum, zinc, cobalt, and/or copper as well Alloys of the elements mentioned and/or their oxides. In some embodiments it may be sufficient that only the surface of the structure consists of these materials.

Advantageously, the structure is so resistant to high temperatures and rapid temperature changes. However, the structure quickly responds to temperature changes or heat input with a temperature change.

The substance is preferably electrically conductive. The substance can, for example, comprise or consist of silicon and/or copper. However, the grid element can also be formed from another suitable metal and/or semiconductor.

Advantageously, this embodiment allows the structure to be used for active temperature control, in that an electrical current flows through the grid element when an electrical voltage is applied, the electrical energy of which is partially converted into heat.

The substance preferably has a high thermal conductivity. As a result, heat, which can easily be introduced into the structure at its boundary surfaces, can be effectively distributed in its interior.

The capillaries of the plurality of capillaries preferably have cross sections in the square millimeter range and/or square nanometer range. The capillaries of the plurality of capillaries preferably each have cross sections of 1 μm×1 μm to 10 μm×10 μm, particularly preferably 10 μm×10 μm. In the case of capillaries which are straight or run straight in the direction of flow, the length of the capillaries of the plurality of capillaries is preferably identical to the extent of the grid element in the direction in which the capillaries run. The grid element can have a thickness of 2 μm to 0.5 mm. The grid element preferably has a thickness of 2 μm to 10 μm, a thickness of 10 μm to 50 μm, a thickness of 50 μm to 0.1 mm, or a thickness of 0.1 mm to 0.5 mm.

The lattice element can have a similar or identical extent in the aforementioned areas in the width direction and/or in the thickness direction and/or length direction. In particular, the lattice element can have the same or different dimensions in the three spatial directions (i.e. in the thickness direction (or also referred to as the height direction), in the width direction (or also referred to as the depth direction) and/or in the length direction), with each dimension in the areas listed above for thickness located. In addition, the grid element can have a flow-through surface, namely the surface perpendicular to the flow-through direction of the grid element, with the flow-through surface being in the range of 100 square nanometers to a few square centimeters. The area through which flow can take place can in particular be equal to the sum of the opening areas of the capillaries which are arranged in the grid element or which form the grid element. In other words, the area through which flow can take place can in particular be equal to the sum of the cross sections of the capillaries, in particular the internal cross sections, which are arranged in the grid element or form the grid element. The grid element preferably has a flow-through surface in the square millimeter range to square centimeter range. The grid element can have a length and/or width of 2 μm to several cm. The grid element preferably has a length and/or width of 2 μm to 3 cm, a length and/or width of 10 μm to 2 cm, a length and/or width of 50 μm to 1 cm, or a length and/or width from 0.1 mm to 5 mm.

Preferably the structure is a membrane.

A further aspect according to the invention relates to a heat exchanger, in particular for use in heat exchanger systems for controlling the temperature of a particle flow, comprising: a structure according to the corresponding aforementioned aspect, the structure being temperature-controllable.

Advantageously, an improved heat exchanger can be realized by this aspect, in particular by the use of the structure, which has a more efficient, i. H. faster, more uniform and complete tempering of a particle flow as described above, such as a liquid, allows. In addition, the heat exchanger can be used as a substance quantity exchanger, in which, due to the more efficient temperature control, a larger quantity of particles in the particle flow can be deposited or accumulated more evenly.

In the context of this description, the term “temperature control” includes the terms “heat” and/or “cool” or “keep the temperature constant”.

The structure preferably has electrical connections. An electrical voltage can be applied to the structure, in particular to the grid element, via these electrical connections, as a result of which an electric current can flow through the structure, in particular the grid element. Some of the electrical energy in the current is converted into heat, which can heat the structure.

Advantageously, this embodiment allows the temperature of the structure to be set and/or adjusted quickly and precisely. In addition, the heat exchanger can be made more compact.

The heat exchanger preferably has a temperature control device. The structure can be temperature-controlled from the outside via the temperature-control device. The temperature control device can, for example, A heat reservoir, such as a preheated metal block, or a heat sink, such as a precooled metal block.

For example, the temperature control device can include at least one heating element and/or at least one cooling element. The at least one heating element can be, for example, an electrical resistor, a heating coil, a preheated container wall with which the structure is in contact, or another suitable means for heating the structure. The at least one cooling element can be, for example, a Peltier element, a hose that is charged with a coolant, a pre-cooled container wall with which the structure is in contact, or another suitable means for cooling the structure.

The temperature control device can also have a temperature sensor.

Advantageously, the temperature of the structure can be set quickly and precisely by the temperature control device described and/or adjusted or changed according to the temperature of the environment, in particular of the particle stream.

The heat exchanger preferably also has a structural support. This structural support is designed to accommodate the structure. The structural support can be conical. However, the structural support can also have other suitable geometric shapes. The structural support can also be cylindrical or cuboid, for example. The structure support can have an axial through bore in which the structure is arranged. The structural support can also be made of a thermally conductive material. Furthermore, the structural support can have fastening means in order to fasten the heat exchanger, for example, in a container such as a liner of a gas chromatograph. For example, screws and/or screw threads or one or more adhesive layers on the structural support can be used as fastening means.

Advantageously, in this embodiment, the heat exchanger is easy to install and position in existing equipment or devices.

A further aspect of the invention relates to a heat exchanger system, comprising: a heat exchanger according to the corresponding aspect mentioned above, and a first container into which the particle flow to be temperature-controlled can be introduced via a first opening of the first container, the heat exchanger being arranged inside the first container.

The advantages mentioned in relation to the heat exchanger described above result analogously for the aspect of the heat exchanger system according to the invention described below.

The particle flow to be temperature-controlled can be introduced into the first container under pressure via the first opening of the first container, which can be formed in the wall of the first container. The particle stream to be tempered can also be part of a carrier gas. The first opening of the first container can be arranged in the first container in such a way that the particle stream to be temperature-controlled can penetrate the first container in the direction of flow through the structure of the heat exchanger and can impinge on the structure of the heat exchanger in the direction of flow. Alternatively, the heat exchanger can also be arranged at the first opening of the first container. For example, the heat exchanger can be arranged inside the first container or outside the first container at the first opening.

Preferably, the first container has a second opening. The second opening can be formed in the wall of the first container. The second opening can be arranged in the direction of flow behind the heat exchanger comprising the structure, so that the particle flow leaving the heat exchanger and being temperature-controlled can leave the first container. Alternatively, the temperature-controlled particle flow can also leave the first container via the first opening of the first container. However, a stream of particles can also enter the first container via the second opening. The heat exchanger can also be arranged at the second opening of the first container. Correspondingly, what was described above for the first opening applies to the second opening.

The heat exchanger is preferably arranged in such a way that the flow of particles introduced into the first container flows through the heat exchanger and heat is exchanged between the flow of particles introduced and the structure. Furthermore, the introduced particle stream can exchange substance quantity or particles with the structure. Particles from the introduced particle flow can be adsorbed by the structure of the heat exchanger and/or adsorbed particles can be desorbed from the structure. For example, the heat exchanger can be connected to the inner wall of the first container. The heat exchanger can be connected to the first container in particular by means of gluing, screwing or soldering.

Preferably, the heat exchanger is arranged inside the first container between the first opening and the second opening. the The first opening, the heat exchanger and the second opening can be arranged approximately in line with the through-flow direction, so that a particle stream passing through the first opening hits the heat exchanger approximately in the through-flow direction, leaves the heat exchanger in the through-flow direction and passes through the second opening in the through-flow direction.

The inner wall of the first container can preferably be temperature-controlled at least in sections. For example, heating wires can run through the wall of the first container, or the wall of the first container can have one or more Peltier elements. Alternatively or additionally, the wall of the first container may also be in thermal contact with a preheated heat reservoir, such as a metal block.

The heat exchanger system preferably also comprises a second container. The first container and the second container can be arranged relative to one another. The second container may have an opening and the second opening of the first container and the opening of the second container may be arranged relative to each other such that the particle stream leaving the structure in the first container can enter the second container.

The first container is preferably arranged on the second container. The first container can be connectably or detachably arranged on the second container. The first container can be arranged with its second opening at the opening of the second container. Alternatively, the first container can be arranged with its first opening at the opening of the second container. Furthermore, the first container can be partially arranged in the second container. For example, the first container with the area in which the heat exchanger is arranged can be pushed so far into the second container via the opening of the second container that the area of the first container including the heat exchanger is located in the second container.

The second container preferably has a temperature control device. This temperature control device can be designed as already described above. The temperature control device can also be arranged on the first container.

The heat exchanger system is preferably a gas chromatograph or a coating system. The wall of the first vessel of the gas chromatograph may be in thermal contact with a preheated heat reservoir, such as a metal block. In this case, the metal block can in particular be a metal block in the injector of the gas chromatograph.

Advantageously, the heat exchanger system in its embodiment as a gas chromatograph allows a sample to be analyzed to be separated faster, more reproducibly and with increased resolution, since the evaporation of the sample is more efficient, in particular faster and more complete, through the use of the heat exchanger comprising the structure can.

In its embodiment as a coating system, the heat exchanger system has the advantage that coating materials can be used that have boiling or sublimation temperatures of over 200°C. At such high temperatures, in the case of the conventional coating systems used in the prior art, there is increased wear, in particular of the valves used. Wear is reduced by using the heat exchanger system as a coating system. In addition, the entire coating process can be accelerated.

Another aspect of the invention relates to a method for tempering a particle stream, the method comprising the following steps: tempering a structure according to the corresponding aspect mentioned above, and flowing the structure with the particle stream to be tempered, the particle stream to be tempered on a first side of the structure penetrates into the structure and a temperature-controlled particle stream leaves the structure on a second side of the structure opposite the first side.

Advantageously, with the method according to this aspect, a particle flow to be temperature-controlled, such as a fluid, can be temperature-controlled more efficiently. In particular, the particle stream can be warmed up faster.

The flow can take place by means of a nozzle, from which the particle flow to be temperature-controlled, for example as a component of a carrier gas, is fed to the structure under pressure in the flow direction of the structure. The carrier gas can be, for example, steam, hydrogen, argon, helium or nitrogen. The particle stream to be temperature-controlled can be fed onto the structure in such a way that the particle stream to be temperature-controlled penetrates completely into the structure or only part of the particle stream penetrates into the structure.

Tempering preferably includes heating and/or cooling. However, tempering can also include maintaining the temperature at a constant temperature.

The above method can be carried out, for example, on or using the heat exchanger according to the invention described above.

A further aspect according to the invention relates to the use of a structure according to the corresponding aspect mentioned above for temperature control of a particle stream.

Advantageously, by using the structure described above for tempering a particle flow, a particle flow to be tempered, such as a fluid, can be tempered more efficiently. In particular, the temperature of the particle stream can be controlled more quickly.

Another aspect of the invention relates to a method for coating a substrate with a coating material, the method comprising the following steps: depositing the coating material on a structure of a heat exchanger system according to the corresponding aspect mentioned above by flowing a particle stream comprising particles of the coating material onto the structure, placing the first container against the second container in which the substrate is located and releasing the coating material deposited on the structure by heating the structure.

Advantageously, this coating method makes it possible to use coating materials that only change into the gas phase at very high temperatures. Furthermore, this method makes it possible to coat a substrate with a coating material more quickly and with reduced wear.

The coating material with which the substrate is to be coated can be in solid form or as a solid at the start of the process. The coating material may comprise one or more materials that vaporize, boil, sublime or vaporize at a temperature above 200°C. The coating material can be referred to as a precursor material.

Depositing the coating material may include evaporating the coating material. The evaporation can be carried out, for example, by means of an oven. Furthermore, depositing the coating material can include transporting the vaporized coating material from the oven into the first container by means of a carrier gas in the direction of the structure or by sucking off the vaporized coating material in the direction of the structure, for example by setting a pressure difference along the flow direction so that the particles of the vaporized coating material move towards the structure. The vaporized coating material can, for example, be sucked off by means of a vacuum pump.

The flow can then additionally take place by means of a nozzle, from which the particle flow from the coating material, for example as a component of the carrier gas, is fed to the structure under pressure in the direction of flow through the structure. The carrier gas can be, for example, nitrogen, argon or helium. The particle flow from the coating material can be directed onto the structure in such a way that the particle flow penetrates completely into the structure and can thus be deposited on the structure.

After the coating material has been deposited on the structure, the first container having the structure is now separated from the oven, for example, and placed on the second container so that the container openings abut one another. However, the first container can also be pushed into the second container in sections, so that the area of the first container that includes the heat exchanger or the structure is located inside the second container. By heating the structure, for example by means of a temperature control device or by applying an electrical voltage to the structure, the deposited coating material is now desorbed or released from the structure in the form of a particle stream.

Releasing may further include transporting the deposited and heated coating material by a carrier gas from the structure into the second container and towards the substrate to be coated. However, releasing may also include transporting the deposited and heated coating material from the structure into the second container via applying negative pressure in the second container.

Preferably, the release also includes allowing a carrier gas to flow through the structure, wherein the carrier gas can form a buffer zone on a side of the structure facing the second container, particularly when no more coating material is released from the structure.

Advantageously, the buffer zone prevents free gas particles in the second container, for example the coating chamber of the above-mentioned coating system, from getting back into the structure of the first container and reacting with the coating material remaining there and deposited on the structure to. The buffer zone further prevents free gas particles of a precursor gas (hereinafter referred to as precursor "B") present in the second container, i.e. for example in the coating chamber of the above-mentioned coating system, from entering the first container and with can react with or mix with the precursor material of another precursor (hereinafter referred to as precursor “A”) that is present and deposited on the structure.

Furthermore, by forming the buffer zone, highly reactive coating materials which, for example, easily react with water vapor and generate harmful products such as HCl vapor can be used. Forming the buffer zone also allows the use of strongly interacting precursors A and B, such as indium trimethyl and H ₂ O when depositing In ₂ O ₃ on the substrate or CuCl and H ₂ O when depositing CuO on the substrate will.

Indium trimethyl has a sufficiently high vapor pressure at room temperature that a reservoir that is isolated by a valve can be used. Indium trimethyl and H ₂ O are both in reservoirs that are valved off from the rest of the chamber. If both valves are opened at the same time, the vapors would react explosively, since indium trimethyl burns violently in air.

Although CuCl and H ₂ O react less violently (to form CuO and HCl), contact of the amount of water vapor used in one half cycle with the CuCl reservoir would still convert the CuCl reservoir to CuO too quickly. At 200 °C, CuCl has too low a vapor pressure to be able to run an ALD process with valves. With the coating method according to the invention, sufficient CuCl can be applied to the substrate for a chemisorbed monolayer of CuCl to be present there. In the second half-cycle (when water is introduced), this reacts with the water vapor present in large quantities to form CuO, which remains on the substrate, and HCl, which is vaporized and flushed into the exhaust line or pump line.

Thanks to the buffer zone, the CuCl reservoir, which is not protected by a valve, is not damaged despite the large amount of water vapor introduced into the chamber.

For example, by cooling the structure just below the temperature at which the coating material is released, the release of the coating material can be suppressed. The release of the coating material can also be suppressed by no longer actively heating the structure. Provided that the ambient temperature relative to the structure is at least slightly below the temperature at which the coating material is released, thermal equilibrium will be established between the structure and the environment relative to the structure after a certain period of time, thus suppressing the release of the coating material from the structure .

The carrier gas can also be one of the protective gases mentioned above.

Preferably, the coating method may further include the step of introducing a precursor, such as steam, to react with the coating material. This step is preferably carried out after the releasing step.

In this way, for example, a product, for example a metal oxide, can advantageously be deposited on the substrate from the coating material and the aforementioned precursor, for example water vapor.

Preferably, the method steps of this aspect are repeatable.

The particle flow preferably comprises the carrier gas and the particles of the coating material. The particles further preferably comprise precursor material or are made of precursor material such as CuCl or indium trimethyl. The coating material may comprise or be CuCl or indium trimethyl, for example.

The coating method according to the invention described above can be carried out, for example, by means of the above-mentioned coating system.

A last aspect of the invention relates to a method for separating a liquid sample, the method comprising the following steps: introducing the sample into the first container of a heat exchanger system according to the corresponding aspect mentioned above, evaporating the sample by means of the structure, and discharging the evaporated sample into the second container.

Advantageously, this method enables liquid samples to be separated, broken down into their components and analyzed more quickly and with increased accuracy. The method enables a higher resolution in the analysis of the components of the liquid sample.

The first container can be, for example, a liner of a gas chromatograph. The second container can contain the column of the gas chromatograph. The heat exchanger system can therefore be a gas chromatograph.

The sample can be injected into the first container by means of a nozzle. The liquid sample can flow partially or completely through the structure in the first container. Some or all of the liquid sample may penetrate the structure. The liquid sample that has penetrated can now be vaporized instantaneously by means of the structure. Thereafter, the vaporized sample is discharged into the second container.

The evaporated sample can be discharged into the second container by means of a nozzle, which is arranged behind the structure on the first container in the direction of flow. Furthermore, the vaporized sample can be discharged into the second container by a carrier gas flowing through the first container.

• 1 schematische Darstellung eines Längsschnitts einer Ausführungsform des erfindungsgemäßen Wärmetauschers,
• 2 Rasterelektronenmikroskop-Aufnahme einer Ausführungsform der erfindungsgemäßen Struktur,
• 3a schematische Darstellung einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Beschichtungsanlage und Darstellung des Ablagerungsschritts des erfindungsgemäßen Beschichtungsverfahrens,
• 3b schematische Darstellung einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Beschichtungsanlage und Darstellung des Freisetzungsschritts des erfindungsgemäßen Beschichtungsverfahrens,
• 3c schematische Darstellung einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Beschichtungsanlage und Darstellung des Freisetzungsschritts des erfindungsgemäßen Beschichtungsverfahrens, insbesondere des Schritts des Ausbildens einer Pufferzone,
• 4a perspektivische Skizze einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Gaschromatograph und Darstellung der Verdampfung einer flüssigen Probe,
• 4b Schnittskizze einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Gaschromatograph und Darstellung der Verdampfung einer flüssigen Probe,
• 5 schematische Schnittzeichnung einer Ausführungsform der erfindungsgemäßen Wärmetauscheranlage als Gaschromatograph und Darstellung der Verdampfung einer flüssigen Probe, und
• 6 Rasterelektronenmikroskop-Aufnahmen einer Ausführungsform der erfindungsgemäßen Struktur auf verschiedenen Längenskalen, wie sie zum Beispiel in der Wärmetauscheranlage der 4a und 4b verwendet wird.

A description of some preferred embodiments of the present invention follows with reference to the figures. Show it:

• 1 schematic representation of a longitudinal section of an embodiment of the heat exchanger according to the invention,
• 2 Scanning electron micrograph of an embodiment of the structure according to the invention,
• 3a schematic representation of an embodiment of the heat exchanger system according to the invention as a coating system and representation of the deposition step of the coating method according to the invention,
• 3b schematic representation of an embodiment of the heat exchanger system according to the invention as a coating system and representation of the release step of the coating method according to the invention,
• 3c schematic representation of an embodiment of the heat exchanger system according to the invention as a coating system and representation of the release step of the coating method according to the invention, in particular the step of forming a buffer zone,
• 4a perspective sketch of an embodiment of the heat exchanger system according to the invention as a gas chromatograph and representation of the evaporation of a liquid sample,
• 4b Sectional sketch of an embodiment of the heat exchanger system according to the invention as a gas chromatograph and representation of the evaporation of a liquid sample,
• 5 schematic sectional drawing of an embodiment of the heat exchanger system according to the invention as a gas chromatograph and representation of the evaporation of a liquid sample, and
• 6 Scanning electron microscope images of an embodiment of the structure according to the invention on different length scales, as for example in the heat exchanger system 4a and 4b is used.

1 shows a schematic longitudinal section of an embodiment of a heat exchanger 40 according to the invention. The heat exchanger 40 can, for example, be of cylindrical design, with the flow direction D forming one of the main axes of inertia of the cylindrical heat exchanger 40 . In the present case, the direction of flow D and the x-axis of an xyz coordinate system coincide. From the inside to the outside, in the radial direction, the heat exchanger 40 has the structure 20 , which can be present in the embodiment shown, for example, and the temperature control device 42 .

In the 1 The embodiment of the structure 20 shown comprises exclusively or consists of a highly ordered silicon lattice 22 which, due to its structuring, has a network of a large number of capillaries 24 . The network of the plurality of capillaries 24 runs through the structure 20 so that, for example, a fluid which can penetrate into the structure 20 at the interface or side 26 of the structure 20 flows through the structure 20 via the plurality of capillaries 24 essentially in the flow direction D and leaving the structure 20 at the interface or side 28 of the structure.

In the embodiment shown, the temperature control device 42 is arranged around the structure 20, on the lateral surface of the structure 20. FIG. As described above, the temperature control device 42 can be a heat reservoir or a heat sink. For example, the temperature control device 42 can be a wall traversed by heating wires or cooling hoses.

In addition to the advantages of the heat exchanger 40 already mentioned above, the heat exchanger 40 has the advantage that the so-called Leidenfrost effect is reduced and practically no heat-insulating layer can form between the grid element 22 and the fluid flowing around the grid element 22 .

2 12 shows a scanning electron microscope image of an embodiment of the structure 20 according to the invention. The image shows the structure 20, which is in the form of a membrane, on the micrometer scale.

the 3a and 3b taken together show schematic representations of an embodiment of a heat exchanger system 60 according to the invention in its embodiment as a coating system 76 and the corresponding coating method according to the invention for coating a substrate 78.

3a essentially shows the loading of the structure 20 (in Figs 3a , 3b and 3c drawn hatched) with coating material or the deposition of the coating material on the structure 20.

Those coating materials or precursors that can only be vaporized sufficiently well from a temperature above the maximum operating temperature of conventionally used valves (approx. 200 °C) are vaporized in a separate apparatus before the start of the process, e.g. B. a steel or glass container with the coating material 80 or precursor material (e.g. a crucible 81) is vaporized in a furnace 82. This apparatus has at least one point at which gas containing the vaporized coating material can be sucked off via a container 62 embodied, for example, as a tube via the opening 64 of the container 62 . The heat exchanger 40 is fastened within the tube 62 transversely to the direction of flow or flow direction D of the gas and over the entire cross section of the container or tube 62 . The gas can be an inert gas and acts as a carrier gas for the coating material.

The heat exchanger 40, in particular the structure 20 (shown hatched), has the further advantage that it is dimensionally stable over a wide temperature range and does not deform.

The heat exchanger 40, in particular the structure 20 (drawn hatched), has the further advantage, based on the total volume comprised by the structure, due to the high density of capillaries and the associated high surface area of the structure, a large amount of coating material in one overall compact volume deposited i.e. can be separated.

As already mentioned above, the heat exchanger 40 can also have a temperature control device 42 (not shown in 3a ) exhibit. The structure 20 (shown hatched) can be cooled and/or heated and kept at a constant temperature by means of this temperature control device. The deposition of the coating material on the structure 20 (hatched) can be supported by cooling the structure 20 (hatched). By heating the structure 20 (drawn hatched), in the step described below of releasing the deposited coating material (see FIG 3b ) releasing are supported. The in the 3b and 3c The temperature control device 42 shown can be part of the second container 70, in particular of the coating system 70. Alternatively or additionally, the temperature control device 42 can be at least partially or completely a component of the heat exchanger 40 .

During the extraction process through the pipe 62 with the inserted, flowable heat exchanger 40, the coating material contained in the vapor or particle stream P extracted from the apparatus settles on the structure 20 (shown hatched) and forms a film or a layer 80a of coating material there (Black border of the hatched structure 20). This effect can be further intensified by targeted cooling of the structure 20 (shown hatched).

In summary shows 3a part of the heat exchanger system or coating system 76 as an example. The loading or deposition step is shown: in a furnace 82, which in this case is heated from the outside, there is solid precursor or coating material 80 (for example in a crucible 81 ). The heating produces precursor vapors or a gaseous particle stream P from the coating material, which is carried by a carrier gas to the heat exchanger 40, which can flow through the structure 20 (shown hatched). The carrier gas can be introduced into the furnace via the gas inlet 82a. The heat exchanger 40 is fixed in a tubular container 62 . Over time, a thin layer of solid precursors or the coating material 80a (black edge of the structure 20 shown hatched) forms on the structure 20 (shown hatched) without closing the channels or capillaries 24 of the structure 20 (shown hatched).

After the coating material 80 has been deposited on the structure 20 (shown hatched), the tube 62 is separated from the furnace 82 and placed on a container 70 containing the substrate 78 to be coated. The step of arranging the coating method described here, inter alia, is neither in 3a still in 3b shown. the 3a and 3b show "snapshots" of the coating process and the corresponding configurations of the heat exchange system 60 or the coating system 76.

3b shows essentially the discharge of the structure 20 (hatched) or the release of the deposited coating material 80a (black edge of the hatched structure 20) and the corresponding part of the coating system 76.

The tube 62 off 3a was pushed or plugged into the container 70, in which the substrate 78 to be coated is located, that the heat exchanger 40 is just inside the container 70. The position of the container or tube 62 can be variable so that an optimal coating of the substrate 78 can be achieved. The correct distance of the container 62 from the substrate 78 or the position of the container 62 in relation to the substrate 78 results from the requirement that the container or the tube 62 is just far enough away from the substrate 78 that the substrate 78 is still flow is sufficiently uniform.

During the coating process, whenever the precursor vapors or the vapors of the hard-to-evaporate, deposited precursor or coating material 80 are required, the structure 20 (shown hatched) is heated to the temperature required for sufficiently rapid evaporation. The container 70 shown can have a temperature control device 42 for this purpose. However, the temperature control device 42 can also be arranged on the container 62 or the tube. The temperature at which the precursor material is vaporized can now be higher than the maximum operating temperature of common valves. At the same time, the heat exchanger 40 or the structure 20 (shown hatched) is flushed through by a carrier gas (in the direction of flow D). By means of a carrier gas, the coating material 80 vaporized from the film of coating material 80a (black edge of the structure 20 shown hatched) present on the structure 20 (hatched) can efficiently reach the substrate 78 to be coated.

The temperature control device 42 now heats the structure 20 (shown hatched), so that vapors or streams of particles P of the coating material 80 form and are carried by the carrier gas to the substrate 78 to be coated. The carrier gas can leave the coating system on the right in the direction of an additional vacuum pump or an exhaust pipe 86 of the container 70 . In addition, a precursor that is easy to vaporize (here H ₂ O in the container 84) is shown here, the storage container 84 of which is separated from the coating chamber or the container 70 by a valve.

In 3c it is shown that whenever the particle streams of the difficult-to-evaporate coating material are not required and should not get into the coating system 76 or the container 70 or the coating chamber 70, the structure 20 (shown hatched) is not heated, but rather actively cooled and is flushed with an inert gas (carrier gas or protective gas).

The constant flow of inert gas prevents gases from the process area in the container 70 from reaching the structure 20 (shown hatched) via convective or diffusive processes or at least prevents this from happening in relevant quantities (see buffer zone 90 in 3c ).

In contrast to 3b the temperature control device 42 is cold. The valve of the water reservoir 84 is open, so that water vapor enters the coating chamber or the container 70 via the inlet 88 and can react there with the coating material 80 deposited on the substrate 78 . A different material, ie a different precursor material, can also be arranged and used in the storage container 84 .

The gas continuing to flow through tube 62 into chamber 70 prevents significant water vapor contact with the layer of coating material 80a (black border of shaded structure 20) located on structure 20 (shaded). An almost water-vapour-free zone 90 (buffer zone 90) is formed by the gas serving here as protective gas.

Spatially varying layers can also be applied by controlling the gas flows, the temperature and the position of the tube 62 via a movably attached tube 62 .

benefits of in the 3a , 3b and 3c Heat exchanger system 60 or coating system 76 shown are that coating materials can be used which have a boiling or evaporation or sublimation temperature of over 200 ° C. At such high temperatures, on the other hand, in the conventional coating systems used in the prior art, there is increased wear, in particular of the valves used. The heat exchanger system 60 as a coating system 76 reduces wear and the use of a valve for the provision and temporary separation of a coating material that is difficult to vaporize is not necessary. In addition, the entire coating process can be accelerated.

In summary, the 3b and 3c one half cycle each. In the first half cycle ( 3b ) the structure 20 is so hot that the deposited precursor material, such as CuCl, vaporizes. It is advantageous here that the structure 20 is in direct proximity to the substrate 78 . The structure 20 can be flown through, so that vapors can be transported away well. In the second half-cycle, the structure 20 is so cold that no relevant amounts of precursor material vapor can arise. The structure 20 is flushed with a shielding inert gas or carrier gas, so that vapors of another precursor material located in the coating chamber, such as water vapor, cannot come into contact with the precursor material in the structure 20.

The low thermal mass of the precursor material reservoir or structure 20 makes it possible to quickly switch between the aforementioned half cycles. The functional integration of the reservoir or the structure 20 and the line of the shielding inert gas keep the installation space and the complexity of the coating system acceptably small, with the volume to be pumped being another time-driving factor.

The structure 20 offers significantly more surface area from which the precursor material or coating material can evaporate. In addition, the structure 20 has a lower thermal mass than the tube 62, which enables a shorter cycle time to be achieved.

In the 4a and 4b an embodiment of the heat exchanger system 60 as a gas chromatograph 74 is shown. 4a shows a perspective sketch, whereas 4b shows an enlarged cross section.

4a shows a sketch of a liner (container 62) from the prior art. From this, the filter in the constriction was removed and the heat exchanger 40 with the structure 20 and a conical structural support 92, which has a central through-hole, was applied. Due to its conical shape, the heat exchanger 40 with the structural support 92 sits well in the taper of the liner 62 and can force the flow through the structure 20 or the sample film Pr located on it (see 4b ).

The vaporized sample Pr exits below the structural support 92 and can be transported by a carrier gas in the direction of the container 70 which can contain the gas chromatography column.

The structural support 92 can be made of aluminum or steel, but other materials are also conceivable. For example, the carrier gas must not chemically interact with the sample. Furthermore, the liner 62 must not be made of any material with which the sample can chemically react. For example, the container 62 or liner can be made of glass and/or silicon. The structure carrier 92 can be made of silicon.

benefits of in the 4a and 4b The heat exchanger system 60 or the gas chromatograph 74 shown is that the separation of a sample Pr to be analyzed can be carried out faster, more reproducibly and with increased resolution, since the evaporation through the use of the heat exchanger 40 comprising the structure 20 takes place more efficiently, in particular faster and more completely can. The resolution of gas chromatography can be increased.

5 FIG. 12 schematically shows a liner (container 62) from the prior art. From this, the filter in the constriction was removed and the heat exchanger 40 with the structure 20 and a conical structural support 92, which has a central through-hole, was applied. Because of its conical shape, the heat exchanger 40 with the structural support 92 sits well in the taper of the liner 62 and can force the flow through the structure 20 or the sample film Pr located thereon.

The vaporized sample Pr exits below the structural support 92 and can be transported by a carrier gas in the direction of the container 70 which can contain the gas chromatography column.

The structural support 92 can be made of aluminum or steel, but other materials are also conceivable. For example, the carrier gas must not chemically interact with the sample. Furthermore, the liner 62 must not be made of any material with which the sample can chemically react. For example, the container 62 or liner can be made of glass and/or silicon. The structure carrier 92 can be made of silicon.

advantages of in the 5 The heat exchanger system 60 or the gas chromatograph 74 shown is that the separation of a sample Pr to be analyzed can be carried out faster, more reproducibly and with increased resolution, since the evaporation through the use of the heat exchanger 40 comprising the structure 20 takes place more efficiently, in particular faster and more completely can. The resolution of gas chromatography can be increased.

The structure 20 on the structural support 92 can, for example, as in 6 shown to be constituted. the 6 shows scanning electron microscopy p-scans of different variants of structure 20 on different length scales.

Reference List

20

structure

22

grid element

24

variety of capillaries

26

first page of the structure

26a

flow-through surface of the grid element

28

second side of the structure opposite to the first side

40

heat exchanger

42

temperature control device

60

heat exchanger system

62

first container

64

first opening of the first container

66

second opening of the first container

68

Inner wall of the first container

70

second container

72

Opening of the second container

74

gas chromatograph

76

coating plant

78

substrate

80

coating material

80a

Coating material applied to the structure

81

crucible

82

oven

82a

gas inlet

84

reservoir

86

exhaust pipe

88

inlet

90

buffer zone

92

structural support

D

flow direction

P

particle stream

Pr

sample / vaporized sample

Claims (16)

Structure (20), particularly for use in heat exchangers (40), comprising: a grid element (22) made of a thermally conductive substance, wherein the grid element (22) has a plurality of capillaries (24), and wherein a particle flow (P) can flow through the grid element (22) via the plurality of capillaries (24) essentially in a flow direction (D) between two opposite sides (26, 28) of the grid element (22). Structure (20) after claim 1 , wherein the plurality of capillaries (24) comprises capillaries which extend linearly in the flow direction (D) between the two opposite sides (26, 28) of the grid element (22). Structure (20) according to one of the preceding claims, wherein the grating element (22) has a regular, in particular periodic, geometric grating structure, and/or wherein the grating element (22) is a photonic crystal. Structure (20) according to any one of the preceding claims, wherein the substance is electrically conductive, and/or wherein the substance comprises silicon and/or copper. Structure according to one of the preceding claims, wherein the capillaries of the plurality of capillaries (24) have cross sections in the square millimeter range and/or square nanometer range, preferably each capillary has a cross section of approximately 100 µm ² , and/or wherein the grid element has a surface (26a ) perpendicular to the flow direction (D) in the square nanometer to square centimeter range. Heat exchanger (40), in particular for use in heat exchanger systems (60) for temperature control of a particle flow (P), comprising: a structure (20) according to any one of the preceding claims, wherein the structure (20) can be temperature-controlled, and wherein the structure (20) preferably has electrical connections. Heat exchanger (40) after claim 6 , wherein the heat exchanger (40) has a temperature control device (42) and wherein the temperature control device (42) preferably comprises at least one heating element and/or at least one cooling element, the at least one heating element being in particular an electrical resistor or a preheated container wall with which the structure (20) is in contact, and/or wherein the at least one cooling element is in particular a Peltier element, a tube that is charged with a coolant, or a pre-cooled container wall with which the structure (20) is in contact. Heat exchanger system (60), comprising: a heat exchanger (40) according to any one of Claims 6 or 7 , and a first container (62) into which the particle flow (P) to be temperature-controlled can be introduced via a first opening (64) of the first container (62), the heat exchanger (40) being arranged inside the first container (62). . Heat exchanger system (60) after claim 8 , wherein the first container (62) has a second opening (66), and preferably wherein the heat exchanger (40) is arranged inside the first container (62) between the first opening (64) and the second opening (66), and the inner wall (68) of the first container (62) preferably being able to be heated at least in sections. Heat exchanger system (60) according to one of Claims 8 or 9 , wherein the heat exchanger system (60) further comprises a second container (70), wherein the second container (70) has an opening (72) and wherein the second opening (66) of the first container (62) and the opening (72) of the second container (70) are arranged relative to one another in such a way that the particle stream (P) leaving the structure (20) in the first container (62) can reach the second container (70), and wherein preferably the second container (70 ) has a temperature control device. Heat exchanger system (60) according to one of Claims 8 until 10 , wherein the heat exchanger system (60) is a gas chromatograph (74) or a coating system (76). Method for tempering a particle flow (P), the method comprising the following steps: tempering a structure (20) according to one of Claims 1 until 5 , and flowing the structure (20) with the particle flow (P) to be temperature-controlled, wherein the particle flow (P) to be temperature-controlled penetrates into the structure (20) on a first side (26) of the structure (20) and a temperature-controlled particle flow (P ) leaves the structure (20) on a second side (28) of the structure (20) opposite the first side (26). Use of a structure (20) according to any one of Claims 1 until 5 for tempering a particle flow (P). A method of coating a substrate (78) with a coating material (80), the method comprising the steps of: depositing the coating material (80) on a structure (20) of a heat exchanger system (60) according to any one of Claims 10 or 11 by flowing a particle stream (P) comprising particles of the coating material (80) onto the structure (20), arranging the first container (62) on the second container (70) in which the substrate (78) is located, and releasing of the coating material (80) deposited on the structure (20) by heating the structure (20), the release preferably including: flowing a carrier gas through the structure (20), the carrier gas, in particular when no coating material (80) is removed from the Structure (20) is released more, a buffer zone (90) on a second container (70) facing side of the structure (20) forms, and wherein the method steps are preferably repeatable. procedure after Claim 14 , wherein the particle flow (P) comprises the carrier gas and the particles of the coating material (80). Method for separating a liquid sample (Pr), the method comprising the following steps: Introducing the sample (Pr) into the first container (62) of a heat exchanger system (60) according to one of Claims 10 or 11 , evaporating the sample (Pr) by means of the structure (20), and discharging the evaporated sample (Pr) into the second container (70).

Images