CN209865999U - Gas collection heat exchange structure and reaction gas collecting and distributing box - Google Patents

Abstract

The utility model relates to a reaction gas collecting and distributing box and a gas collecting and heat exchanging structure, wherein the reaction gas collecting and distributing box is provided with an air inlet cavity and a collecting and distributing cavity which are mutually independent; the heat exchange unit comprises a plurality of heat exchange sleeves; the heat exchange sleeve comprises an outer sleeve and an inner sleeve positioned on the inner side of the outer sleeve; the outer sleeve is positioned on the reaction gas distribution box and communicated with the distribution cavity; the inner sleeve is positioned on the reaction gas collecting and distributing box, and two ends of the inner sleeve are respectively communicated with the outer sleeve and the gas inlet cavity. Therefore, the reaction gas of each section can be fully utilized and collected, the reaction of each section can be realized in one reactor, and the occupied space and the weight are reduced.

Description

Gas collection heat exchange structure and reaction gas collecting and distributing box

Technical Field

The utility model relates to a chemical industry technical field especially relates to a gas collection heat transfer structure and reaction gas collection and distribution box.

Background

Hydrogen and carbon monoxide are important useful gases. Taking hydrogen as an example, the hydrogen is an important industrial gas and a special gas, and has wide application in the aspects of petrochemical industry, electronic industry, metallurgical industry, food processing, fine organic synthesis, aerospace and the like. The hydrogen and carbon monoxide can be generated from coal gas produced by coal gasification, or can be generated by reaction and conversion of natural gas, methane and steam, and the latter is a modern gas-making method adopted by most industrial enterprises. Specifically, methane, water vapor and oxygen in natural gas are converted into hydrogen, carbon monoxide and carbon dioxide through reaction, exothermic reaction and endothermic reaction exist in the reaction, and finally the reaction reaches heat balance.

The main chemical formula is:

oxidation reaction (exothermic)

CH₄+1/2O₂＝CO₂ △H＝-283.2KJ (1)

CH₄+1/2O₂＝CO+2H₂ △H＝-35.6KJ (2)

H₂+1/2O₂＝H₂O △H＝-241KJ (3)

Conversion reaction (endotherm)

CH₄+H₂O＝CO+3H₂ △H298＝206.3KJ (4)

CH4+2H₂O＝CO₂+4H₂ △H298＝165.3KJ (5)

CO+2H₂O＝CO₂+H₂ △H298＝-41.3KJ (6)

The conventional reaction for producing hydrogen and carbon monoxide is divided into two stages of an exothermic reaction and an endothermic reaction, which are provided with two separate reactors and are loaded with different catalysts.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is necessary to provide a gas collecting and heat exchanging structure and a reaction gas collecting and distributing box capable of connecting an exothermic reaction and an endothermic reaction in one reactor, in order to solve the problem that the conventional apparatus for producing hydrogen and carbon monoxide requires two reactors.

The gas collection and heat exchange structure comprises a heat exchange unit and a reaction gas collecting and distributing box;

the reaction gas collecting and distributing box is provided with an air inlet cavity and a collecting and distributing cavity which are mutually independent;

the heat exchange unit comprises a plurality of heat exchange sleeves; the heat exchange sleeve comprises an outer sleeve and an inner sleeve positioned on the inner side of the outer sleeve; the outer sleeve is positioned on the reaction gas distribution box and communicated with the distribution cavity; the inner sleeve is positioned on the reaction gas collecting and distributing box, and two ends of the inner sleeve are respectively communicated with the outer sleeve and the gas inlet cavity.

In one embodiment, the reaction gas distribution box includes an upper plate, a lower plate, and an intermediate plate between the upper plate and the lower plate, which are disposed to face each other;

the lower end of the outer sleeve is fixed on the upper plate; the lower end of the inner sleeve is fixed on the middle plate, and the top end of the inner sleeve extends into the outer sleeve and is freely arranged.

In one embodiment, the reaction gas distribution box further includes a side plate connected between the upper plate and the lower plate to enclose a cavity;

the middle plate is connected to the side plates and located between the upper plate and the lower plate, and is used for dividing the cavity into the collecting and distributing cavity and the air inlet cavity.

In one embodiment, the side plate is further provided with a reaction gas inlet communicated with the gas inlet cavity.

In an embodiment, the upper plate is further provided with a gas collecting part communicated with the collecting and distributing cavity.

In an embodiment, the gas collection and heat exchange structure further includes a mesh plate disposed on one side of the upper plate away from the middle plate.

In one embodiment, the side plate is further provided with a mixed gas outlet communicated with the collecting and distributing cavity;

the reaction gas inlet and the mixed gas outlet are arranged oppositely.

A reaction gas collecting and distributing box is used for being connected with a heat exchange unit, and the heat exchange unit comprises a plurality of heat exchange sleeves; the reaction gas distribution box comprises an upper plate, a lower plate and a middle plate, wherein the upper plate and the lower plate are arranged in a facing manner, and the middle plate is positioned between the upper plate and the lower plate;

the middle plate divides the reaction gas distribution box into an air inlet cavity and a distribution cavity which are independent of each other;

the upper plate is provided with a first mounting hole for mounting the outer sleeve, and the middle plate is provided with a second mounting hole for mounting the inner sleeve.

In one embodiment, the reaction gas distribution box further comprises a side plate connected between the upper plate and the lower plate to enclose a cavity;

the middle plate is connected to the side plates, is positioned between the upper plate and the lower plate and is used for dividing the cavity into the collecting and distributing cavity and the air inlet cavity;

and the side plate is provided with a reaction gas inlet communicated with the gas inlet cavity and a mixed gas outlet communicated with the collecting and distributing cavity.

In one embodiment, the upper plate is further provided with a gas collecting part communicated with the collecting and distributing cavity.

The gas collection and heat exchange structure and the reaction gas distribution box can fully utilize and collect the reaction gas of each section, ensure that each section of reaction can be realized in one reactor, and reduce the occupied space and the weight.

Drawings

Fig. 1 is a schematic structural view of an axial-radial reactor according to an embodiment of the present invention;

FIG. 2 is a schematic view of a partial structure of the axial-radial reactor shown in FIG. 1.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Where the terms "comprising," "having," and "including" are used herein, another element may be added unless an explicit limitation is used, such as "only," "consisting of … …," etc. Unless mentioned to the contrary, terms in the singular may include the plural and are not to be construed as being one in number.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present invention.

It will also be understood that when interpreting elements, although not explicitly described, the elements are to be interpreted as including a range of errors which are within the acceptable range of deviation of the particular values as determined by those skilled in the art. For example, "about," "approximately," or "substantially" may mean within one or more standard deviations, without limitation.

Fig. 1 shows a schematic structural view of an axial-radial reactor in an embodiment of the present invention; FIG. 2 shows a schematic partial view of the axial-radial reactor of FIG. 1; for ease of illustration, only those portions relevant to embodiments of the present invention are shown.

Referring to the drawings, the gas collection and heat exchange structure in an embodiment of the present invention is disposed in the axial and radial reactor 100, and is configured to collect the reaction gas in the reaction area with a higher reaction temperature and introduce the reaction gas into the heat exchange unit, to exchange heat with the reaction gas in the reaction area with a lower temperature, and to finally collect the reaction gas in the two reaction areas, so as to facilitate final cooling and recycling.

The gas collection and heat exchange structure comprises a reaction gas collecting and distributing box 60 and a heat exchange unit. The reaction gas distribution box 60 has an independent gas inlet chamber 66 and a distribution chamber 68, and the heat exchange unit includes a plurality of heat exchange sleeves. The heat exchange sleeve comprises an outer sleeve 82 and an inner sleeve 84 positioned inside the outer sleeve 82; the outer sleeve 82 is positioned in the reaction gas distribution box 60 and communicates with the distribution chamber 68; the inner sleeve 84 is positioned in the reaction gas distribution box 60, and both ends of the inner sleeve are respectively communicated with the outer sleeve 82 and the air inlet cavity 66.

The air inlet chamber 66 is used for communicating with the reaction zone with higher reaction temperature to introduce high-temperature reaction gas and accessing the heat exchange unit, and the collecting and distributing chamber 68 is used for communicating with the reaction zone with lower reaction temperature to introduce low-temperature reaction gas and introduce and mix the high-temperature reaction gas after heat exchange, so that the final cooling recovery is facilitated.

It will be appreciated that in the steam reforming reaction of natural gas methane (1), (2), (3) and (6) in the background art are exothermic reactions, providing the heat required for the endothermic reactions (4) and (5). Thus, the reaction is mainly divided into two stages, one stage being mainly endothermic reactions (4), (5), (6), the second stage being mainly exothermic reactions (1), (2) and partial endothermic reactions (4), (5). In the prior art, two independent reactors are arranged in two reaction sections and are loaded with different catalysts, but the prior art has large occupied space and heavy weight.

The utility model provides a gas collection heat transfer structure can guarantee that each section reaction can realize in a reactor with the reaction gas make full use of each section and collect, has reduced occupation of land space and weight.

For better understanding of the specific structure and technical effects of the gas collection and heat exchange structure of the present invention, the structure of the axial-radial reactor 100 is further combined for explanation.

The axial-radial reactor 100 comprises an outer cylinder 10, an inner cylinder 30, a porous sleeve 40 and the gas collection and heat exchange structure.

The outer cylinder 10 is a pressure cylinder. Specifically, the outer cylinder 10 is a hollow cylinder, and may include a cylinder 12, a top portion and a bottom portion. In specific embodiments, the cylinder 12 may be cylindrical, and the top and bottom of the cylinder are hemispherical or elliptical heads, and the top head 14 and the bottom head 16 are fixed at the upper and lower ends of the cylinder 12 to form the outer contour of the axial-radial reactor 100. The top of the outer cylinder 10 is further provided with a manhole 18 and a feed inlet 19 to facilitate the addition of catalyst, maintenance or repair into the axial-radial reactor 100, and correspondingly, the bottom of the outer cylinder 10 is provided with a discharge port for discharging catalyst.

The inner cylinder 30 is disposed inside the outer cylinder 10, and forms the first reaction zone 20 with the outer cylinder 10. Specifically, the upper and lower ends of the inner cylinder 30 are welded to the top head 14 and the bottom head 16 of the outer cylinder 10, the inner cylinder 30 may also be cylindrical, and the first reaction zone 20 is an annular reaction zone surrounding the inner cylinder 30, that is, the outer cylinder 10 and the inner cylinder 30 are two concentric cylinders. Also disposed within the first reaction zone 20 is a catalyst bed for loading catalyst suitable for the reaction in that zone.

It should be noted that the pressure cylinder refers to a cylinder which can bear higher pressure. For example, in some embodiments, the pressure of the feed gas in the first reaction zone 20 is 3 to 4 Mpa.

Further, the top of the outer cylinder 10 is further provided with a first gas inlet 13 communicated with the first reaction zone 20, so as to convey the raw gas to the first reaction zone 20, so that the raw gas flows from top to bottom along the axial direction and is heated by the heat exchange unit 80, thereby ensuring the normal operation of the conversion reaction.

Specifically, in the embodiment, the raw material gas input by the first gas inlet 13 is a small stream of refined desulfurized and preheated natural gas + steam. That is, the first reaction zone 20 corresponds to a stage of reaction in the prior art design.

The porous sleeve 40 is disposed in the inner cylinder 30, and forms an air inlet gap 32 (see fig. 2) with the inner cylinder 30 at an interval, the porous sleeve 40 is axially provided with a second reaction zone (not shown) and a third reaction zone 48 which are independent from and communicated with each other, and the second reaction zone and the third reaction zone 48 are communicated with the air inlet gap 32. Specifically, the porous sleeve 40 is also cylindrical, and the wall of the porous sleeve is provided with a plurality of air inlets along the circumferential direction, so that the raw material gas in the air inlet gap 32 can flow to the center of the porous sleeve 40 along the radial direction. It will be readily appreciated that since the second reaction zone is in communication with the third reaction zone 48, the reactant gas after reaction in the second reaction zone can flow axially toward the third reaction zone 48 and further react with the feed gas flowing in from the porous sleeve 40. Further, a second gas inlet (not shown) is provided at the top of the outer cylinder 10 and communicates with the gas inlet gap 32, so that the raw gas can be input into the gas inlet gap 32 through the second gas inlet. Specifically, the feed gas flowing into the inlet gap 32 from the second inlet is a large stream of finely desulfurized and preheated natural gas. That is, the second and third reaction zones 48 correspond to the two-stage reaction of the prior art design.

It will be readily appreciated that the reaction in third reaction zone 48 is carried out by reacting the high temperature reactant gas flowing from the second reaction zone with the finely desulfurized and preheated natural gas plus steam feed gas flowing radially from the gas entry gap 32. Thus, in one embodiment, the third reaction zone 48 is a radial reaction zone, which further comprises a radial reaction frame, wherein the radial reaction frame is loaded with a catalyst suitable for the reaction in the third reaction zone 48.

In the embodiment, a manhole 18 and a feed inlet 19 are provided at the top of the outer tub 10, and the second and third reaction zones 48 may be added with the catalyst through the manhole 18, and the first reaction zone 20 may be added with the catalyst through the feed inlet 19. Correspondingly, there are two discharge openings, one discharge opening 15 for discharging catalyst in the first reaction zone 20 and the other discharge opening 17 for discharging catalyst in the second and third reaction zones 48.

In the embodiment of the present invention, the reaction temperature of the second reaction zone and the third reaction zone 48 are higher than the reaction temperature of the first reaction zone 20. That is, the heat generated from the second reaction zone and the third reaction zone 48 is used to heat the reaction gas in the first reaction zone 20 through the heat exchange unit 80, thereby ensuring that the reactions in each stage can be stably performed. Specifically, the second reaction zone includes a combustion zone 42, and the raw material gas entering from the air inlet gap 32 firstly undergoes an oxidation combustion reaction in the combustion zone 42, and the oxidation combustion reaction generates a large amount of reaction heat, so that the temperature of the top of the axial-radial reactor 100 reaches 1200 ℃ to 1300 ℃, thereby providing heat for the subsequent reaction. The high-temperature reaction gas can flow to the third reaction zone 48 for continuous reaction, the temperature after the reaction is reduced to 950-1050 ℃, the temperature is reduced to 600-650 ℃ after the heat exchange is carried out in the first reaction zone 20 through the heat exchange unit 80, and the final temperature reduction and recovery are facilitated.

Further, the axial-radial reactor 100 further comprises a feeding unit 90 disposed at the top of the outer cylinder 10, and the feeding unit 90 comprises a pressure-bearing sleeve 92, an air inlet pipeline 94 and a mixed gas burner 96. The pressure-bearing sleeve 92 is arranged at the top of the outer cylinder 10, the air inlet pipeline 94 axially penetrates through the seal head of the pressure-bearing sleeve 92 and the top of the outer cylinder 10 and extends into the combustion zone 42, and the mixed gas burner 96 is arranged at one end of the air inlet pipeline 94 extending into the combustion zone 42. Wherein, the pressure-bearing sleeve 92 is further provided with a raw material gas inlet 922, and the raw material gas enters the gas inlet gap 32 through the raw material gas inlet 922, the pressure-bearing sleeve 92 and the second gas inlet on the outer cylinder 10, and finally flows to the second reaction zone and the third reaction zone 48.

Specifically, in the combustion zone 42, a refractory lining is provided, which is made of refractory alumina material, and the combustion nozzle of the mixed gas burner 96 is made of high temperature resistant metal material Incoloy800 and coated with zirconia. The combustion zone 42 primarily conducts a hydrogen and methane combustion reaction.

It is noted that Incoloy800 is an alloy containing Cr in an amount of usually 15 to 25%, nickel in an amount of 30 to 45%, and small amounts of aluminum and titanium.

It is understood that the end socket of the pressure-bearing sleeve 92 may be fixedly connected to the top of the pressure-bearing sleeve 92, or may be detachably connected to the top of the pressure-bearing sleeve 92, which is not limited herein.

It is understood that the gas mixture burner 96 is well known to those skilled in the art, and therefore, the detailed structure and principle thereof will not be described herein.

It will be understood from the foregoing description that the two stages are mainly the exothermic reactions of (1) and (2) and the partial endothermic reactions of (4) and (5) described above, and therefore the raw material gas introduced into the mixed gas burner 96 from the gas inlet line 94 is a mixed gas of oxygen and steam.

Further, the feeding unit 90 further comprises a water cooling jacket 98 sleeved on the pressure-bearing sleeve 92 to cool the feeding unit 90.

In particular, the inlet gap 32 provides finely desulfurized and preheated natural gas to ensure uniformity and stability of subsequent reactions while avoiding excessive combustion reaction range affecting the gas production (hydrogen and carbon monoxide) effect. Thus, in embodiments of the present invention, the second reaction zone and the third reaction zone 48 are independent of each other, in other words, separated by a partition. In the embodiment, a partition for separating the second reaction zone from the third reaction zone 48 is further provided with a feed inlet 46, so that the third reaction zone 48 can be conveniently filled with the catalyst through the manhole 18 at the top of the outer cylinder 10 and the feed inlet 46.

It should be noted that the conversion catalyst in the first reaction zone 20 is outside the heat exchange unit 80 and can be added through the feed port 19, and the catalyst in the second reaction zone and the third reaction zone 48 can be added manually from the feed unit 90 and the mixed gas burner 96. And the discharge opening is easily unloaded from the bottom of the axial direction reactor 100 without the aid of an auxiliary tool. Therefore, compared with the prior art that the catalyst is arranged in the pipe, the adding and unloading difficulty of the catalyst is reduced.

In some embodiments, the second reaction zone further includes a high temperature reaction zone 44 disposed axially below the combustion zone 42. Specifically, the high temperature reaction zone 44 is provided with a porous plate (not shown) on which a high temperature catalyst is mounted. It should be understood that in order to ensure uniform reaction in third reaction zone 48, the reactant gas in the second reaction zone needs to be uniformly introduced into third reaction zone 48, and high temperature reaction zone 44 is provided to facilitate collection of unburned feed gas and high temperature reactant gas to facilitate delivery of high temperature gas to third reaction zone 48.

Further, the high temperature reaction zone 44 has a first end interfacing with the combustion zone 42 and a second end opposite to the first end, and the cross-sectional width of the high temperature reaction zone 44 gradually decreases from the first end to the second end. Specifically, the first end of the high temperature reaction zone 44 is open, i.e., the end in communication with the combustion zone 42, and the second end of the high temperature reaction zone 44 is closed, i.e., the aforementioned partition separates the high temperature reaction zone 44 from the third reaction zone 48. In a preferred embodiment, the high temperature reaction zone 44 has a reverse tapered cross-section, and the high temperature reaction zone 44 occupies about 1/4 to 1/3 of the second reaction zone.

Thus, a reaction gas collecting space can be formed to facilitate the collection and delivery of the high-temperature reaction gas to the third reaction zone 48.

Further, the axial-radial reactor 100 further comprises a porous central tube 50, wherein the porous central tube 50 is located in the third reaction zone 48, and one end of the porous central tube extends upwards along the axial direction to extend into the high-temperature reaction zone 44 so as to communicate the second reaction zone with the third reaction zone 48. Specifically, the lower end of the perforated center tube 50 is fixedly connected to the bottom head 16 of the outer cylinder 10, and the upper end thereof penetrates through the entire third reaction zone 48 and extends into the high temperature reaction zone 44. More specifically, the perforated center tube 50 is located at the center of the sleeve with its upper end at a distance from the perforated plate within the high temperature reaction zone 44 to facilitate the telescoping of the perforated center tube 50.

Further, the axial-radial reactor 100 further includes a central tube positioning frame 70 connected to the reaction gas distribution box 60, and the porous central tube 50 passes through and is fixed to the central tube positioning frame 70, so as to ensure that the porous central tube 50 is not easily deviated or damaged, thereby ensuring uniform reaction in the third reaction zone 48.

It should be emphasized that, due to the high reaction temperature in the outer cylinder 10 and the inner cylinder 30, the outer cylinder 10 and the inner cylinder 30 are also lined with refractory materials to ensure the safety and reliability of the axial-radial reactor 100.

It should be noted that the methane content in the reaction gas finally recovered by temperature reduction needs to reach a predetermined ratio, the methane content in the reaction gas after the reaction in the second reaction zone and the third reaction zone 48 is less than or equal to 0.5%, and the methane content in the reaction gas in the first reaction zone 20 is 1.2% -1.6%. Therefore, after the two reaction gases are mixed in the distribution chamber 68 and reach a predetermined ratio, the axial-radial reactor 100 can be drawn out, for example, in an embodiment, the reaction gas in the distribution chamber 68 has a methane content of 1.5%, and the axial-radial reactor 100 can be drawn out.

In one embodiment, the reaction gas distribution box 60 includes an upper plate 61, a lower plate 63 disposed facing each other, and an intermediate plate 65 disposed between the upper plate 61 and the lower plate 63; the intermediate plate 65 divides the reactant gas distribution box 60 into a distribution chamber 68 and an inlet chamber 64. More specifically, the reaction gas distribution box 60 further includes a side plate 67 connected to the upper plate 61, the lower plate 63 and the middle plate 65 to enclose a cavity, and the middle plate 65 is connected to the side plate 67 to divide the cavity into the gas inlet chamber 64 and the distribution chamber 68.

Further, the lower end of the outer sleeve 82 is fixed to the upper plate 61, and the upper end of the outer sleeve 82 extends into the first reaction zone 20 and is close to the top head 14 of the outer cylinder 10. The lower end of the inner tube is fixed to the intermediate plate 65, and the upper end of the inner tube extends upward into the outer sleeve 82, and is freely disposed at a distance from the upper end of the outer sleeve 82, and can be extended and retracted upward.

Wherein the outer sleeve 82 has a radial dimension greater than that of the inner sleeve 84 such that a gap is formed between the inner sleeve 84 and the outer sleeve 82 through which the air flow can pass, the gap communicating with the collecting and distributing chamber 68. The high-temperature reaction gas flowing out through the porous central tube 50 flows outwards in the radial direction and is merged with the raw material gas flowing in the air inlet gap 32 inwards in the radial direction and reacts, and the reacted reaction gas enters the air inlet cavity 64 through the air inlet, enters the inner sleeve 84 through the lower end of the inner sleeve 84 and flows upwards in the axial direction, and enters the outer sleeve 82 from the upper end of the inner sleeve 84. The reaction gas flows axially from top to bottom through the gap between the inner sleeve 84 and the outer sleeve 82, and finally merges into the collecting and distributing chamber 68.

It should be understood that outside the outer jacket 82 is the catalyst bed and that the gap between the outer jacket 82 and the inner jacket 84 allows for heating of the feed gas outside the outer jacket 82. And the upper end of the inner tube is freely disposed at a distance from the upper end of the outer tube 82 and is upwardly extendable. Therefore, the reaction temperature in the first reaction zone 20 is ensured, and compared with the structure that two ends of the heating pipe are provided with the pigtails in the existing design, the structure is simple and reliable, and the investment is low.

It is easy to understand that the lower end of the inner sleeve 84 is the air inlet end of the heat exchange unit 80, and the end of the gap formed between the outer sleeve 82 and the inner sleeve 84 at the lower end of the outer sleeve 82 is the air outlet end of the heat exchange unit 80.

The reaction gas distribution box 60 is fixed by welding the side plate 67 of one side to the outer wall of the inner tube 30 by the welding ring 130. Specifically, in some embodiments, the collecting and distributing chamber 68 is located above the intake chamber 64; of course, in other embodiments, the collecting and distributing chamber 68 may be located below the air inlet chamber 64, and is not limited herein.

In one embodiment, the gas collecting and heat exchanging structure further includes a gas collecting portion disposed on the upper plate 61 for collecting the reaction gas in the first reaction zone 20 into the collecting and distributing cavity 68. Specifically, the gas collecting part 61 is an air inlet hole or an air inlet pipe penetrating through the upper plate 61 of the reaction gas collecting box, and the reaction gas in the first reaction zone 20 flows downward from top to bottom along the axial direction and is collected into the collecting and distributing cavity 68 through the gas collecting part 61. Further, the gas collection and heat exchange structure further comprises a mesh plate 69, wherein the mesh plate 69 is arranged on one side of the upper plate 61, which is away from the middle plate 65, so that the reaction gas in the first reaction zone 20 can enter the collecting and distributing cavity 68 through the gas collection part 61 more uniformly.

In one embodiment, the gas-collecting and heat-exchanging structure further comprises a reaction gas inlet 66 communicating the gas inlet chamber 64 with the third reaction zone 48, so as to introduce the reaction gas in the third reaction zone 48 into the gas inlet chamber 64.

In one embodiment, the reaction gas distribution box 60 is further provided with a mixed gas outlet 68 communicated with the distribution cavity 68; a portion of the bottom of the outer tub 10 between the outer tub 10 and the inner tub 30 is provided with a reformed gas outlet 110 for delivering the gas flow flowing out from the mixture gas outlet hole 68 outward. Specifically, the mixed gas outlet 68 is provided in the reaction gas distribution box 60 near the side plate 67 of the outer tub 10, and the reaction gas mixed in the distribution chamber 68 is led out through the reformed gas outlet 110 through a space between the distribution box of the axial-radial reactor 100 and the bottom of the outer tub 10.

It should be understood that, particularly in some embodiments, the reformed gas outlet 110 for feeding the reaction gas outward is provided in the bottom portion of the outer cylindrical housing 10 at a portion between the outer cylindrical housing 10 and the inner cylindrical housing 30; that is, the axial-radial reactor 100 achieves the final collection and discharge of the reaction gas through the space between the reaction gas distribution box 60 and the bottom of the outer tub 10. Therefore, the space between the reaction gas distribution box 60 and the bottom of the outer tub 10 is a non-reaction area. For example, in some embodiments, the portion of the porous central tube 50 below the plane of the reaction gas distribution box 60 is not perforated, and the space between the reaction gas distribution box 60 and the bottom of the outer tub 10 is provided with a refractory aluminum ball 21 to ensure that the reaction gas finally output from the space through the reformed gas outlet 110 meets the set standard.

In an embodiment, the axial-radial reactor 100 further comprises a support block 74, wherein the support block 74 is fixedly connected to the inner wall of the outer cylinder 10 and is used for supporting the lower plate 63 of the reaction gas distribution box 60 so as to support the reaction gas distribution box 60 as a whole, thereby further improving the connection reliability and stability of the reaction gas distribution box 60. It is to be noted that the catalyst bed of the first reaction zone 20 is located above the upper plate 61 of the reaction gas collection box, so that the support block 74 also serves to support the catalyst bed located above the reaction gas collection box 60 and the catalyst loaded thereon.

It is particularly emphasized that in embodiments of the present invention, where the exothermic oxidation reaction is combined with the endothermic reforming reaction gas in an axial-radial reactor 100, the lower temperature endothermic reforming reaction (first reaction zone 20) surrounds the high temperature exothermic oxidation reaction (second and third reaction zones 48). After the reaction gas passes through the second reaction zone and the third reaction zone 48, the pressure value is reduced, so that only one outer cylinder 10 with lower temperature and pressure is used as a pressure cylinder. That is, the bearing threshold of the inner cylinder 30 is smaller than that of the outer cylinder 10, for example, in some embodiments, the inner cylinder 30 bears a pressure of about several kilograms.

Further, the outer cylinder 10 is a pressure-bearing thick-walled cylinder, and the inner cylinder 30 is a high-temperature-resistant and non-pressure-bearing thin-walled cylinder.

Thus, the investment in valuable materials is reduced compared to the conventional two pressed thick-walled cylinders 12. In addition, the thin-walled inner cylinder 30 can serve the dual function of heating the reforming catalyst and the reaction gas in the first reaction zone 20, and accordingly, the heat exchange jacket of the heat exchange unit 80 is reduced, thereby further saving investment.

In order to better understand the technical solution and technical effects of the axial-radial reactor 100 of the present invention, the following description will be made on the reaction flow of the axial-radial reactor 100:

the refined and preheated natural gas is divided into two streams, one stream of raw gas enters the pressure-bearing sleeve 92 from the raw gas inlet on the pressure-bearing sleeve 92 and enters the gas inlet gap 32 through the second gas inlet on the outer cylinder 10, so as to perform an oxidation combustion reaction with the mixed gas (oxygen and steam) ejected from the mixed gas burner 96 in the combustion zone 42. At this time, the temperature at the top of the axial-radial reactor 100 reached 1200 ℃ to 1300 ℃.

The reactant gas then passes through the high temperature reaction zone 44 in turn and through the perforated central tube 50 into the third reaction zone 48 to continue reacting with the feed gas flowing from the inlet gap 32 and finally through the reactant gas inlet 66 into the inlet chamber 64. At the moment, the temperature of the reaction gas is reduced to 950-1050 ℃, and the content of methane after the reaction is less than or equal to 0.5 percent.

Further, the reaction gas flows from bottom to top along the inner sleeve 84 to the upper end of the inner sleeve 84, enters the outer sleeve 82, flows from top to bottom along the gap between the outer sleeve 82 and the inner sleeve 84, and converges into the collecting and distributing cavity 68. Meanwhile, another raw material gas + steam entering the first reaction zone 20 from the first gas inlet 13 at the top of the outer cylinder 10 passes through the catalyst bed with the double-pipe arranged from top to bottom, and is heated by the heat exchange unit 80 to perform a conversion reaction. The content of methane after reaction is 1.2-1.6%. Finally, the reaction gas enters the collecting and distributing chamber 68 through the mesh plate 69 above the upper plate 61 of the reaction gas collecting and distributing box 60 and the gas collecting part 61.

After the two reaction gases are mixed in the distribution cavity 68, the methane reaches a predetermined index, and flows downwards through the mixed gas outlet hole 68 formed in the side plate 67 of the reaction gas distribution box 60, and is finally discharged through the converted gas outlet 110 formed in the bottom of the outer cylinder 10, so that the temperature reduction and recovery are facilitated.

Compared with the prior art, the gas collection and heat exchange structure and the reaction gas distribution box have the following advantages:

(1) combining the exothermic and endothermic conversion reactions of oxidation in one axial-radial reactor 100 reduces the footprint and weight compared to a conventional two axial-radial reactor 100.

(2) The raw material gas is divided to enter the axial-radial reactor 100, the axial-radial reactor 100 is of an axial-radial structure, the arrangement of large-diameter high-temperature pipelines can be greatly reduced, the investment of the pipelines is reduced, the cost is reduced, and the flow of reaction gas is reduced, so that the system resistance is reduced, and the gas compression power consumption and heat loss are reduced.

(3) The endothermic conversion reaction (the first reaction zone 20) with lower temperature surrounds the high-temperature oxidation exothermic reaction (the second reaction zone and the third reaction zone 48), only one pressurized outer cylinder 10 is a thick-wall cylinder 12, and the high-temperature resistant, expensive and non-pressurized inner cylinder 30 is a thin-wall cylinder 12, so that the investment of valuable materials is reduced.

(4) The thin-walled inner cylinder 30 can serve the dual function of heating the reforming catalyst and the reaction gas in the first reaction zone 20, and accordingly, the heat exchange jacket of the heat exchange unit 80 is reduced, thereby further saving the investment.

(5) The heat exchange tube is a double-sleeve tube, the catalyst is arranged outside the tube, one end of the heat exchange tube can freely extend upwards, and the heat exchange tube is simpler and more reliable than the traditional heating tube with two ends provided with pigtails and has less investment.

(6) The reforming catalyst is added outside the heat exchange sleeve through the feed port 19, and the catalyst in the second reaction zone and the third reaction zone 48 can be added manually from the feed unit 90 and the mixed gas burner 96. And the discharge opening is easily unloaded from the bottom of the axial direction reactor 100 without the aid of an auxiliary tool. Compared with the prior art, the catalyst is arranged in the pipe, so that the adding and unloading difficulty of the catalyst is reduced.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims (10)

1. The gas collection and heat exchange structure is characterized by comprising a heat exchange unit and a reaction gas distribution box;

the reaction gas collecting and distributing box is provided with an air inlet cavity and a collecting and distributing cavity which are mutually independent;

the heat exchange unit comprises a plurality of heat exchange sleeves; the heat exchange sleeve comprises an outer sleeve and an inner sleeve positioned on the inner side of the outer sleeve; the outer sleeve is positioned on the reaction gas distribution box and communicated with the distribution cavity; the inner sleeve is positioned on the reaction gas collecting and distributing box, and two ends of the inner sleeve are respectively communicated with the outer sleeve and the gas inlet cavity.

2. The gas collecting and heat exchanging structure of claim 1, wherein the reaction gas collecting and distributing box comprises an upper plate, a lower plate and a middle plate, wherein the upper plate and the lower plate are arranged in a facing manner, and the middle plate is positioned between the upper plate and the lower plate;

the lower end of the outer sleeve is fixed on the upper plate; the lower end of the inner sleeve is fixed on the middle plate, and the top end of the inner sleeve extends into the outer sleeve and is freely arranged.

3. The gas collecting and heat exchanging structure of claim 2, wherein the reaction gas collecting and distributing box further comprises a side plate connected between the upper plate and the lower plate to form a cavity;

the middle plate is connected to the side plates and located between the upper plate and the lower plate, and is used for dividing the cavity into the collecting and distributing cavity and the air inlet cavity.

4. The gas collecting and heat exchanging structure of claim 3, wherein the side plate is further provided with a reaction gas inlet communicated with the gas inlet cavity.

5. The gas collecting and heat exchanging structure of claim 2, wherein the upper plate is further provided with a gas collecting part communicated with the collecting and dispersing cavity.

6. The gas collecting and heat exchanging structure of claim 5, further comprising a mesh plate disposed on a side of the upper plate away from the middle plate.

7. A gas collection and heat exchange structure as claimed in claim 3, wherein the side plate is further provided with a mixed gas outlet communicated with the collecting and distributing cavity;

the reaction gas inlet and the mixed gas outlet are arranged oppositely.

8. A reaction gas collecting and distributing box is used for being connected with a heat exchange unit, and the heat exchange unit comprises a plurality of heat exchange sleeves; the heat exchange sleeve comprises an outer sleeve and an inner sleeve which is positioned on the inner side of the outer sleeve and communicated with the outer sleeve, and is characterized in that the reaction gas distribution box comprises an upper plate, a lower plate and a middle plate, wherein the upper plate and the lower plate are arranged in a facing manner, and the middle plate is positioned between the upper plate and the lower plate;

the middle plate divides the reaction gas distribution box into an air inlet cavity and a distribution cavity which are independent of each other;

the upper plate is provided with a first mounting hole for mounting the outer sleeve, and the middle plate is provided with a second mounting hole for mounting the inner sleeve.

9. The reactant gas distribution box of claim 8, further comprising a side plate connected between the upper plate and the lower plate to enclose a cavity;

the middle plate is connected to the side plates, is positioned between the upper plate and the lower plate and is used for dividing the cavity into the collecting and distributing cavity and the air inlet cavity;

and the side plate is provided with a reaction gas inlet communicated with the gas inlet cavity and a mixed gas outlet communicated with the collecting and distributing cavity.

10. The reactant gas distribution box of claim 8, wherein the upper plate is further provided with a gas collector communicating with the distribution chamber.