KR20140041392A - In-situ vaporizer and recuperator for alternating flow device - Google Patents

Abstract

The present invention provides an apparatus comprising: (a) channel means having a first end and a second end and having a plurality of channels connecting the first end and the second end; (b) inlet means for directing a liquid feed stream to a first end of the plurality of channels; And (c) outlet means for deriving a vapor phase vapor stream from the plurality of channels, wherein the channel means is substantially solid. Having a cold area and a void area, the channel being characterized by (1) void area A '(x) and (2) channel total cross-sectional area A (x) at any distance d between the inlet and the outlet. The void area A '(x) as a fraction of the total area A (x), with a geometry perpendicular to the water flow direction, is φ _x = pore fraction at distance d = A' (x) / A (x ), And the average pore fraction along the length (L) of the device is φ _a = average pore fraction of the formula I, wherein the average pore fraction is from about 0.3 to about 0.95:
≪ RTI ID = 0.0 >

Description

IN-SITU VAPORIZER AND RECUPERATOR FOR ALTERNATING FLOW DEVICE}

The present invention relates to an in-situ vaporizer and a heat recovery device for an alternating flow system that can be located on-board in a transport vehicle.

Many industrial processes, including steam reforming, often require the conversion of a liquid feed stream (eg, gasoline or other liquid hydrocarbons, or water) to a vapor stream prior to chemical conversion. Traditional vaporizers and boilers require significant heat and usually perform poorly in transient operations due to fluctuating pressure and temperature changes. In mobile products, the transient requirement to operate over a wide dynamic operating range (known as turndown) makes handling the steam stream difficult and makes it difficult to control the equivalent ratio between fuel and oxidizer. In many applications, this vaporization and mixing process is performed under precise mass flow control, operates over a large dynamic range, and is in situ within the reactor volume to minimize heat transfer losses, resulting in low pressure drop losses, In addition, they require resistance to corrosion by process fluid streams. Thus, the art provides accurate material flow control, operates over a large dynamic range of temperature and pressure, minimizes heat transfer losses, results in low pressure drop losses, and is resistant to corrosion by process fluid streams. There is a demand for technology.

The present invention describes a novel in-situ vaporizer and heat recovery apparatus which are particularly suitable for an alternating flow reactor system in which flow through the device alternates between liquid vaporization mode and reheating mode. In a preferred embodiment, this is part of a pressure-varying reformer ("PSR") system described, for example, in US Pat. No. 7,491,250. This allows the design of a small syngas generating system, which can be arranged, for example, in a transport vehicle.

We have found certain design criteria for in-situ vaporizers and heat recovery devices that are required to achieve the advantages described above. These features include specifications for geometry, heat capacity and heat transfer, flow channel dimensions, and pore fraction and pore fraction gradient to minimize the size and weight of the device. The unique combination of these design criteria produces a high efficiency vaporizer / waste heat recoverer, as evidenced by the application of pressure fluctuation reformers taught in the above referenced patents.

The present invention relates to (a) channel means having a first end and a second end, the channel means having a plurality of channels connecting the first end and the second end, and (b) a liquid feed stream having a first end of the plurality of channels. An apparatus for converting a liquid feed stream into a vapor phase vapor stream comprising inlet means for directing the vapor stream and (c) outlet means for directing vapor phase vapor stream from the plurality of channels, wherein the apparatus The channel means have a substantially solid and void area, the channel having (1) void areas A '(x) and (2) at any distance x between the inlet and the outlet. Has a geometry perpendicular to the feed flow direction, characterized by the total cross-sectional area A (x),

이고, The void area A '(x) as a fraction of the total area A (x) is

ego,

이며, The average pore fraction along the length (L) of the device is

Lt;

The average pore fraction is about 0.3 to about 0.95.

In one embodiment, the pore fraction varies along the length of the device.

In other embodiments, the average change in the planned pore fraction over the total length of the device is from about 0.01 to about 0.5.

In another embodiment of the invention, the device has areas of continuous constant void volume, which areas vary along the length of the device.

1 is a schematic representation of an embodiment of the invention.

The present invention relates to an apparatus for converting a liquid stream (s) supplied into a vapor vapor stream. More specifically, the present invention relates to a device for operating a cyclic process to convert a liquid hydrocarbon and optionally a water mixture into a mixture of hydrocarbon vapor and optionally steam. One specific use is to vaporize liquid hydrocarbons and water streams for use in pressure swing steam reforming processes.

The device is designed for continuous operation through a cyclic two-step process. The first stage is the vaporization mode and the second stage is the reheat mode. The inventors have found certain design criteria or features that result in in-situ vaporizers and heat recovery devices that are sufficiently small and light enough to have large dynamic range of operation, minimal pressure drop, corrosion resistance and portable. These features include specifications for geometry, heat capacity and heat transfer capacity, flow channel dimensions, and gradients of void fractions and void fractions within the vaporizer.

The device of the present invention consists of a partially porous medium having an empty passageway comprising a set of characteristic sizes and shapes. The void region in the device forms a set of connected passageways through which the fluid (liquid or gaseous state) can pass through the device. The simplified conceptual device geometry is illustratively shown in FIG. 1. The porosity fraction or partial porosity is the open fraction of the volume of the device at a given point in space. The fluid may enter either end of the device and exit to the opposite end. The first purpose of the device is to vaporize the liquid stream to be fed into steam. As shown in FIG. 1, the surface into which the liquid stream to be vaporized enters the device 11 is defined as an inlet surface, indicated here by 10. The surface through which the vaporized stream exits is defined as the outlet surface 12. In the reheating stage of the apparatus, a hot reheat stream can enter through the inlet or outlet surface and exit to the corresponding opposite end. In the schematic diagram shown in FIG. 1, the reheat stream is shown as countercurrent to the vaporization flow 16. Reheat stream 14 is shown in FIG. 1 as entering exit surface stream 12 and exiting inlet surface 10 as stream 15. In figure 1 the device is shown as a cylindrical device having a constant cross-sectional area. In practice, the device cross-sectional shape is not limited to cylindrical, but may be rectangular, square, triangular, or the like. The cross-sectional area can also vary as a function of axial position.

In general, there are two periods or stages of operation of the device, which limit the design features of the present invention. In a first period of time operating for a certain time t _vap , the liquid or mixture of liquids or liquid-containing stream 16 enters the apparatus at the inlet 10 at a predetermined volume-based liquid flow rate Q _liq . This liquid flow is vaporized into a gaseous stream, which can be characterized in terms of normal gas volume reference flow rate (Q _vap ) along with information about the density and molecular weight of its components. The liquid phase may alternatively be supplied via a pre-atomic liquid stream forming a liquid droplet spray. The liquid or liquid spray enters and impinges on the preheated surface in (11) and changes from liquid to gas phase, which exits the apparatus as vaporized stream 17. In other embodiments, the vapor of the liquid stream 16, or a gaseous stream as a diluent, may enter the apparatus along with the liquid stream 16 and exit with the vaporized stream 17. Any substance that is already gaseous before entering the device during the vaporization period is not considered as part of Q _liq or Q _vap , but this should be taken into account in the dew point calculation. In the second period of device operation, which may begin after the grace period t _d , the heated stream 14 passes through the device for a specific period t _{regen at a} volume reference flow rate Q _regen [one end of the device To the opposite end as the cooled stream 15]. This is a reheating or regenerating step. In the example of FIG. 1, this stream enters the device 11 at the outlet end 12 and exits at the inlet end 10. In other embodiments (not shown), this stream may enter the device 11 at the inlet end 10 and exit at the outlet end 12.

An element of the invention is that both the vaporization period and the reheating period of operation of the device share the same flow path. The regeneration flow heats the device from the initial temperature (in one embodiment, to approximately the dew point of the liquid feed) to the final higher temperature above the dew point of the liquid stream at the defined operating pressure. The dew point, denoted T _DEW herein, is known in the art as the temperature at which the vapor begins to condense and depends on the stream composition and pressure. The flow changes in a periodic manner in an alternating manner between the endothermic vaporization state (energy transfer from the solid material to the fluid phase) and the exothermic regenerative heat transfer state (energy transfer from the fluid flow to the solid material). The initial and final temperatures of the device are determined by combining flow considerations (eg flow rates and velocities), geometric considerations such as device size and design, and thermal properties of both the fluid and the device.

The present invention provides a specification for a geometric channel that performs flow through a vaporizer. Such a channel is defined as an open or "empty" space separated by a full wall. In some embodiments of the invention, the walls themselves may comprise some porosity, typically with a pore diameter of less than 0.1 mm. This porosity is not arithmetic as the “pore” as used herein and is only calculated as a decrease in sidewall density of the full wall.

The geometrical features of the device of the present invention relate to the size of the void fraction, the spatial variation of the void fraction, and the size and shape of the small channel features that make up the void fraction. Along the one virtual spatial plane 19 shown in FIG. 1, the local void fraction is defined as follows:

Where φ _x is the void fraction at a given spatial location, denoted by the subscript x, and the total cross-sectional area of the device in this plane is A (x), containing no solid material in this plane "Open" or "pore area" is given as A '(x). In the present invention, we adopt the convention that there is a flow axis from the inlet surface 10 to the outlet surface 12 and that "x" is the distance along this axis. Thus, x is following the evaporation flow (16) direction, and has a value of L _total in value and a device outlet (12) of zero at the input (10), where L _total is the exit to from the inlet along the axis of fluid flow The length of the device. We also adopt the convention that plane 19 is perpendicular to this axis of flow. Such planes are also known in the art as "axial planes". The average porosity or average porosity fraction according to the specific length L of the device is defined by the formula:

If the average length L is to be the total length L _total of the apparatus, φ _a represents the average void fraction of the entire apparatus, expressed as φ _avg . If the entire device occupies a _total volume (V _total ) (full volume + void volume), the total open volume or void volume in the device is V _void = φ _avg V _total , and the total volume of solid material in the device Is V _xolid = (1-φ _avg ) V _total = V _total -V _void .

We have found that the average pore fraction φ _a of the device is a parameter that leads to the successful operation of the device. We have found that the acceptable average pore fraction of the device of the invention is between 0.3 and 0.95. Preferably, the average pore fraction of the device is between 0.4 and 0.7.

In a preferred embodiment, the void fraction varies axially along the length of the device. The length of the device means the dimension in which vapor flow predominates. In FIG. 1, this dimension or direction is axial and is represented herein by the dimension or direction “x”. The surface pore fraction at the inlet surface 10 of the device has been found to be preferably between 0.5 and 0.995. The most preferred range at this position is 0.65 to 0.995. The pore fraction at the outlet surface 12 of the device is preferably 0.2 to 0.7. The most preferred range of outlet porosity fraction is 0.35 to 0.6.

In the preferred embodiment where the pore fraction varies axially from the inlet surface to the outlet surface, this change can occur through a continuous change in the pore fraction or through a continuous series of constant pore fraction regions. However, the void fraction changes, and the change in the void fraction can be characterized as the average change over the length of the device. For example, a set of φ _x values from inlet 10 to outlet 12 may be analyzed by the least squares method known in the art to yield a least square linear slope of φ _x versus x. This mean change can be expressed as a slope or gradient (i.e. change in pore fraction over length), or as a change in mean total pore fraction, where the mean total pore fraction change is the least square multiplied by the total device length (L _total ). It is calculated as the slope. In many embodiments of the invention, the average total pore fraction change is 0.01 to 0.5. Preferred average total pore fraction changes are 0.15 to 0.35. We have found that the acceptable range of pore fraction gradients averaged for the device in the axial direction is a pore fraction reduction of 0.01 to 0.5 per inch of straight line length. A preferred change in average pore fraction gradient is a decrease in pore fraction of 0.15 to 0.35 per inch of straight length. The inventors have also found that in embodiments in which series of continuous constant porosity regions are used, the preferred number of regions is greater than one and less than twenty. More preferably, the number of regions is 2 to 10, and the most preferable number is 2 to 5.

The pore volume consists of a plurality of structured small scale pore regions, hereinafter referred to as channels or channel regions. These channels come in tight shapes and a wide range of sizes. Preferred shapes of the cross section of the channel size void area are highly structured regular shapes, for example round, semicircular, annular, periodic wavy wall valleys, or rectangular channels and slots.

One embodiment of the device has a nearly identical channel geometry in size and shape throughout the device volume. Preferred embodiments of the device have almost the same channel shape within the device, which shape varies in size at different axial positions (ie a set of circular channels with different diameters). Even more preferred embodiments of the device have an axial change in both channel shape and size. In other words, changes in shape and / or size can increase the surface area available for heat transfer and thereby vaporization.

Other embodiments use disordered channels of wormhole reticulated tissue (eg, material features of ceramic or metal foams) consisting of a number of irregular channel shapes. Additional embodiments utilize structural passages formed by interwoven network of wire materials, for example made of lamination or knitting of metal wires.

The channel shape that makes up the void region of the device can be characterized by a set of spatial dimensions. One dimension is referred to as the hydraulic diameter. For flow channels consisting of simple closed connected surfaces (ie, circular cylinders, squares, rectangles, triangles, or bent channels), the hydraulic diameter is defined as d _h = 4 A / P, where A is the void carrying the flow of the channel. Is a cross-section, and P is the boundary around the closed surface. In the case of complex channel shapes that do not consist of simply connected shapes, the channel hydraulic diameter can be defined in terms of the axial plane 19 described in connection with FIG. 1. Within any axial plane, d _h '(x) = 4A' (x) / P '(x), where A' (x) represents the total pore area of the device at a given axial position and P ' (x) is the total length of the boundary surface between the full and void areas.

에 의해 어림된다. The characteristic horizontal size (h _char ) of the device is obtained by taking the square root of the device volume over the total axis length, or

Approximated by

We also found that certain channel characteristics are preferred within the inlet area of the device. The limit of this inlet area is preferably from about 5% to about 40% of the device length. In other words, the inlet region may extend from x = 0 (inlet surface 10) as little as x = 0.05L _total or as much as x = 0.4L _total . Preferably, the inlet area is 10% to 30% of the device length. The orientation of the channels in the inlet region is preferably arranged such that the movement of the incoming inlet flow stream is perpendicular to its average flow direction. This allows mixing while dispersing the components and distributing the components to flow. The preferred design has a flow path perpendicular to the flow axis proportional to the characteristic horizontal size h _char , which is co-current with the flow in the axial direction. The preferred design has a continuous flow path perpendicular to the flow axis, which is at least 10-50% of the characteristic horizontal size h _char of the device within the inlet region. Another preferred design has a continuous flow path of at least L _total at length in all axial planes within the inlet region of the device.

We have found that the characteristic channel hydraulic diameter size d _h (x) that is acceptable in the inlet region of the device is 0.1 to 10 mm, preferably 0.3 to 5 mm, even more preferably 0.7 to 2 mm. The characteristic channel size at the outlet of the device is 0.2 to 5 mm, preferably 0.4 to 2 mm, even more preferably 0.5 to 1.5 mm.

In a preferred embodiment, the ratio of channel hydraulic diameter to channel length is from 0.5 to 10,000, preferably from 10 to 5000, even more preferably from 40 to 200.

An additional characteristic parameter of the device is the internal surface area that can be used for vaporizing the incoming stream and reheating the waste heat recovery volume. We have defined the surface area per unit volume or surface area per unit volume measured locally in a device where S _v = S / V, where S is contained within a defined total volume V (void volume + volume of solid material). Internal surface area. In one embodiment of the present invention a constant value of S _v is used. Other embodiments of the present invention utilize non-uniform values of S _v across different regions of the device. The average S _v of a device is simply the total device surface area divided by the total device volume, or S _{v, avg} = S _total / V _total . We have found that the acceptable average range of unit volume or internal surface area per device is 10 in ² / in ³ to 2000 in ² / in ³ . Preferred values of the average range of internal surface areas per unit volume are 20 in ² / in ³ to 1000 in ² / in ³ . Even more preferred values of the average range of internal surface areas per unit volume are 50 in ² / in ³ to 250 in ² / in ³ .

The available heat transfer area and device volume only describe the surface contact between the fluid and the solid material. The composition and physical properties of the solid materials of the device have been found to aid its successful operation and its ability to function efficiently in terms of reheat capacity, energy storage and energy transfer. Accordingly, the inventors have found that the composition of the materials constituting the device has a value of a heat capacity of at least 100 J / kg-K, preferably of more than 500 J / kg, even more preferably of more than 1000 J / kg. It was found to be.

In terms of thermal management within the device, thermal contact between the various areas of the device should be maximized. The inventors have found that the acceptable value of the thermal conductivity of the material should be at least 10 W / mK (preferred value above 50 W / mK, more preferred value above 200 W / mK). The inventors have also the composition of the materials that make up the device, screwing that that such that (still more preferred values that exceed the desired value, 7000kg / m ³ greater than 5000kg / m ³⁾ density of the packed material 2500kg / m ³ or higher Found.

The specific design of the device will depend on the liquid injection conditions and the time required to achieve the vaporization process. The amount of energy H required to vaporize the flowing liquid stream for a certain period of time is given by:

는 액체의 물질 유속이고, λ _liq 는 액체의 기화 잠열(질량 단위)이며, τ _vap 는 주입 기간이고, Q _vap 는 기화된 액체의 노르말 부피 기준 기체 유속이고, λ _vap 는 액체의 기화 잠열(노르말 기체 부피 단위)이다. 요구되는 에너지의 양은 액체 공급 속도, 유체의 단위 질량(또는 부피)당 기화 에너지 및 공정의 기간에 비례한다. 여기에서, 액체 기준 및 전환되는 기체 기준 표현은 둘 다 이들의 전환 계수를 포함하여 표시된다. 통상적인 기체 조건은 당 업계에 공지되어 있으며, 전형적으로는 0℃ 및 1절대기압으로 취해진다.In these expressions,

Is the mass flow rate of the liquid, λ _liq is the latent heat of vaporization (in mass) of the liquid, τ _vap is the injection period, Q _vap is the gas flow rate based on the normal volume of the vaporized liquid, and λ _vap is the latent heat of vaporization of the liquid (normal Gas volume units). The amount of energy required is proportional to the liquid feed rate, the vaporization energy per unit mass (or volume) of the fluid and the duration of the process. Here, both the liquid reference and the gas reference representation to be converted are displayed including their conversion coefficients. Typical gas conditions are known in the art and are typically taken at 0 ° C. and 1 absolute atmospheric pressure.

The vaporization capacity of a device is directly proportional to its available energy storage. The maximum temperature of the device is the start of the liquid injection step. The average temperature of the device at this time is T _DVI . As the liquid is injected and vaporized, the device temperature drops to the final average temperature T _DVF , at which point the vaporization portion of the operating cycle ends. At this time, we define that ΔT _DEVICE is the average temperature difference (T _DVI -T _DVF ) in the device from the start of the liquid injection process to the end. The absolute values of high and low temperatures depend on the device characteristics and the heat balance and operating conditions of the process. The maximum vaporization capacity H 'of the device is given by:

Where ρ _device is the average density of the solid material of the device, φ is the average porosity of the _device , C _{p , device} is the average specific heat capacity of the device (in mass units), and C " _{p, device} is the average of the device Specific heat capacity in volume, ρ _device C _{p , device} = C " _{p, device} . The vaporization capacity is proportional to the specific heat capacity, the volume of the solid material, and the material density of the device, and also directly proportional to the temperature difference during the process.

The space velocity of the system may be expressed as the gas hourly space velocity or gas flow rate per hour based on the normal volume of the feed divided by the volume of the device, referred to as GHSV. The gas feed rate is calculated as the molar rate of the feed and the normal volume rate calculated as if the component is a gaseous compound. As an example, a liquid water feed having 0.5 liters entering the device and flowing at a rate of 1 g / sec has a gas hourly space velocity of the liquid injection step given as follows:

Where Q _vap is the normal volume reference gas flow rate in NL / hour and V _total is the total device volume. In general, the miniaturization of the device in terms of vaporization rate per unit volume and the resulting efficiency are directly proportional to the space velocity. For integrated systems using hydrocarbon feeds that will undergo subsequent chemical or catalyst reactions, the overall space velocity of the system is proportional to the productivity of the system. It is desirable for the space velocity to have a value as high as possible.

In a preferred embodiment of the invention, the space velocity GHSV is preferably greater than 500, even more preferably greater than 1000.

For devices operated in a cyclic manner, the amount of heat consumed in the vaporization step is balanced by the amount of heat accumulated in the device during the reheating (regeneration) portion of the cycle. When liquid feeds are supplied at high speeds (high GHSV), heat must be used quickly and cycle times should be short. When the liquid feed is supplied at low speed (low GHSV), heat is used slowly and the cycle time is longer. Combining the above expressions for H and H 'and setting them the same, it is expressed as follows:

Q _vap λ _vap τ _vap = V _total (1-φ) C " _{p, device} Δ T _DEVICE

By rewriting both sides of the equation in dimensionless terms and substituting the expression for GHSV from above, the following relationship is established:

Here, all variables are assumed to have their previous definitions.

The heat transfer requirement of the apparatus can be expressed as the product of the volume-based vaporization heat of the liquid feed and the GHSV of the feed stream. Volumetric heat transfer requirements for vaporization are as follows:

에 대한 표현이 표시된다. 이들 표현은 액체 스트림의 기화에 충분한 에너지가 제공되도록 하기 위해 필요한 에너지 균형을 정의한다.This is the required energy transfer per unit volume per unit time for liquid vaporization. Because time depends on time rather than seconds

The expression for is displayed. These representations define the energy balance needed to ensure that enough energy is provided for vaporization of the liquid stream.

After the liquid enters the device for a period of time τ _vap , the hot reheat stream is passed through the device to bring the temperature back to the initial high temperature at the start of the liquid injection cycle. The ability to raise the temperature of the device during this reheating step is closely related to the geometrical features of the device as indicated above. Variables include porosity, hydraulic passage size, and thermal characteristics of which the device is constructed. It is known in the art that a porous medium composed of a solid material having a characteristic channel passage shape can be characterized by a heat transfer coefficient (h) and a characteristic heat transfer surface area (A). Preferred values of surface area characteristics per unit volume are defined above. Correlation of heat transfer coefficients based on gas and solid properties is also known in the art. These heat transfer coefficients are a function of flow rate and gas phase composition. The coefficient typically increases as the characteristic channel size of the porous material decreases. The volumetric heat transfer coefficient is defined as follows and can be given in the following units:

Volume-based heat transfer requirements for vaporization rewritten in consistent time units can be written as follows:

The present invention has a characteristic heat transfer temperature change as the ratio of volume based vaporization demand to volume based heat transfer coefficient for regeneration of the device. This characteristic temperature difference is expressed as:

Δ T _HT = H _v / h _v

This temperature difference describes the balance between heat transfer supply and demand during the cyclical operation of the device. As used herein, this is based on the heat transfer coefficient used in the reheat portion of the cycle, which is typically the lower heat transfer coefficient portion of the cycle and serves as a limiting design condition. This temperature difference is the basic design parameter of the device. Device design and material properties are selected to meet the conditions of the present invention.

In the practice of the present invention, the characteristic Δ T _HT is preferably from about 0.1 ℃ to 600 ℃. More preferably, the characteristic Δ T _HT is 0.5 ℃ to 300 ℃.

The characteristic energy utilization ratio of the device is defined as:

This is a desirable parameter for evaluating the efficiency of the device. Values close to 1 mean ideal use of the energy available in the vaporizer, while values less than 1.0 reflect the realization of the temperature gradient needed to move heat quickly. The inventors have found that the required range for energy use efficiency (R) is 0.05 to 0.7. It is found that the preferred range of the ratio R is 0.1 to 0.5. The most preferred range is 0.2 to 0.4.

An additional feature of the device is its low axial resistance to flow to minimize pressure drop during both steam generation and reheat regeneration processes. Axial flow resistance can be defined as orthotropic anisotropic resistance, such as laminar flow through small channels:

Here, Δp is the pressure drop from the friction resistance, L is the length on the average space, dx is localized increasing axial distance a, φ _x is the local void fraction, GHSV is the gas hourly space velocity ^{(hours- 1} ), μ is the fluid velocity, and ρ _c is the bubble number density per unit area (number of channels per unit cross-sectional area of the device). All values are taken as a function of local coordinates so that the overall pressure drop is the integration of the contributions from all axial regions of the device.

The pressure drop is limited by the channel size of the device, the density of the number of bubbles per unit area, the porosity and the GHSV (flow per unit volume). Porosity is related to channel size by the expression:

The physical parameters of the device are selected in a way that meets the design constraints of the system for operation. For those skilled in the art, in the case of devices designed for a wide dynamic range of operating conditions, the design conditions are selected based on the maximum flow conditions in the region of the device with the minimum flow passage.

A feature of the device for successful operation is that the device is operated with a low axial resistance to flow such that the overall average Δp per unit length of the device is less than 5 psi / inch. The range of acceptable parameters for the device allows for a pressure drop of 0.01 to 5 psi / inch (preferably 0.03 to 1 psi / inch).

In one embodiment, the device can be fabricated using an array of thin, corrugated sheets of various metal compositions stacked in tightly spaced or rolled closely spaced layers. The geometry of the valleys creates a series of small annular bubbles. By changing the thickness of the rolled material sheet and the density of the corrugated concentric rings or sheet, and also by changing the adhesion of the packing along its axial direction, the diameter of the bubble can be changed.

In one example of this embodiment, the material consists of a sheet of Fecralloy® metal. The valley and sheet thickness of this design is selected to produce an overall porosity (open volume) of about 40% for the low pore volume exit area cross section. Low design porosity is used to meet design conditions for maximum metal mass (heat capacity and energy storage at the highest flow rate conditions). The high porosity inlet region has a porosity of about 80%. This high porosity allows for significantly higher penetration of the liquid into the internal volume of the device. The interior of the device comprises a monolith having a median of porosity of about 60%, which is used as a transition between the low porosity inlet region and the high porosity outlet region. As indicated above, the sheet consists of continuous pieces of material (different in length) in the axial direction.

The bubble design of the device is to provide a minimum pressure drop from the fluid stream supplied in either direction. Low pressure drop operation is particularly useful for applications involving the reheating of the device by a high velocity hot gas stream resulting in substantial pressure drop losses.

This apparatus is particularly useful for circulating endothermic steam regeneration processes with exothermic regeneration processes to produce syngas. In the reactor phase structure, an electronic fuel injector is used to inject a mixture of liquid hydrocarbon fuel and liquid water onto the top (inlet) surface and into the internal volume of the vaporizer. The vaporized mixed stream is then flowed down through the gas mixer and then into the reaction zone, where the feed is steam reformed using energy from the previously accumulated phase from the reheat portion of the cycle to make the synthesis gas. This syngas can be burned from the device at the bottom and used externally.

In the reheat portion of the cycle, carbon monoxide, hydrogen and possibly also fuel mixtures are burned. This hot stream is used to reheat the catalyst phase in the reaction zone. After the regeneration phase of the process, the cycle returns to the liquid injection mode. These two cycle processes of this configuration correspond to the injection step and the reheating step of the invention described above.

Claims (21)

(a) channel means having a first end and a second end, the channel means having a plurality of channels connecting the first end and the second end;
(b) inlet means for directing a liquid feed stream to a first end of the plurality of channels; And
(c) outlet means for directing a vapor vapor stream from the plurality of channels;
An apparatus for converting a liquid feed stream into a vapor phase vapor stream comprising:
Wherein the channel means has a substantially solid region and a void region,
The channel has a geometry perpendicular to the feed flow direction, characterized by 1. void area A '(x) and 2. channel total cross-sectional area A (x) at any distance d between the inlet and the outlet; ,
The void area A '(x) as a fraction of the total area A (x) is

ego,
The average pore fraction along the length (L) of the device

Lt;
And the average pore fraction is about 0.3 to about 0.95. The method according to claim 1,
Wherein the pore fraction varies from about 0.5 to about 0.995 in the inlet means along the length of the device from about 0.2 to about 0.7 in the outlet means. 3. The method of claim 2,
Wherein the change in pore fraction along the length of the device is a decrease in pore fraction between about 0.01 and about 0.5 per inch of straight length. The method of claim 3, wherein
Wherein the change is a decrease in pore fraction between about 0.15 and about 0.35 per inch of straight length. The method according to claim 1,
And the pore fraction decreases from the inlet means to the outlet means in the region of more than one and less than twenty consecutive constant pore fractions. 6. The method of claim 5,
Wherein the number of regions of said constant void fraction is three to ten. The method according to claim 1,
Wherein the channel has a channel hydraulic diameter (d _H ) that is from about 0.1 to about 10.0 mm at the inlet to about 0.2 to about 0.5 at the outlet, and a channel length. The method of claim 7, wherein
Wherein the channel hydraulic diameter is from about 0.3 to about 5.0 mm at the inlet to about 0.4 to about 2.0 mm at the outlet. The method of claim 7, wherein
And the channel hydraulic diameter to channel length ratio is about 0.5 to about 10,000. The method of claim 9,
And the ratio is about 10 to about 5000. 11. The method of claim 10,
And the ratio is about 40 to about 200. The method according to claim 1,
Further characterized in that said channel has an average surface area (S _{v , avg} ) per unit volume of from about 10 in ² / in ³ to about 2000 in ² / in ³ . 13. The method of claim 12,
S _{v , wherein the avg} is from about 20 in ² / in ³ to about 1000 in ² / in ³ . 14. The method of claim 13,
S _{v , wherein the avg} is from about 50 in ² / in ³ to about 250 in ² / in ³ . The method according to claim 1,
Wherein the channel is made of a material having a heat capacity of at least 100 J / Kg-K, a thermal conductivity of at least about 10 W / mK, and a density of at least about 2500 Kg / m ³ . 16. The method of claim 15,
Wherein the thermal capacity is at least about 500 J / Kg, the thermal conductivity is at least about 50 W / mK, and the density is at least about 5000 Kg / m ³ . 17. The method of claim 16,
Wherein the thermal capacity is at least about 100 J / Kg, the thermal conductivity is at least about 200 W / mK, and the density is at least about 7000 Kg / m ³ . The method according to claim 1,
Wherein the device is operated at a gas hourly space velocity of greater than about 500. 19. The method of claim 18,
Wherein the device is operated at a gas space velocity of greater than about 1000. The method according to claim 1,
And the channel has a pressure drop Δp of less than about 5 psi / inch. 21. The method of claim 20,
Wherein the Δp is less than about 1 psi / inch.

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