CN214880230U - Fire tube type ammonia oxidation furnace - Google Patents

Abstract

The utility model relates to an ammonia oxidation furnace, which is the main equipment for producing nitric acid, in particular to a fire tube type ammonia oxidation furnace. The utility model discloses a solve the problem that current fire tube type ammonia oxidation furnace has the defect, a fire tube type ammonia oxidation furnace after improvement is provided, including the castable layer of heat-resisting takeover and adjacent upper surface of locating the tube sheet, the one end of heat-resisting takeover stretches down the outer wall that forms extension portion and stretch down portion and the sealed fixed connection of inner wall of heat exchange tube under the upper portion in the heat exchange tube, the bottom of extension portion is located between the below of tube sheet and heat exchange tube welding department and the bottom of heat exchange tube down, sealed fixedly connected with heat insulating part between the outer wall of extension portion and the inner wall of heat exchange tube down, the other end of heat-resisting takeover passes and outwards stretches in the castable layer and communicates with last furnace body. The fire tube type ammonia oxidation furnace of the utility model has simple structure, convenient installation, safety and reliability.

Description

Fire tube type ammonia oxidation furnace

Technical Field

The utility model relates to an ammonia oxidation furnace, which is a main device for producing nitric acid, in particular to a fire tube type ammonia oxidation furnace.

Background

Nitric acid is one of the important products of the basic chemical industry, the yield being second only to sulfuric acid among the various acids. Nitric acid can be used for manufacturing chemical fertilizers, nitrates, organic synthetic raw materials, TNT explosives, chemical reagents and the like. China is a big country for producing nitric acid and concentrated nitric acid at present, and with the rapid development of industries such as chemical fertilizers, civil explosion and the like, the demand of nitric acid in China in the industrial field still keeps increasing rapidly.

The ammonia oxidation furnace is the main equipment for producing nitric acid, and the reasonable structure of the ammonia oxidation furnace relates to the production cost and the consumption quota of the whole nitric acid, so that in order to adapt to the development of production and the large-scale of the device, the traditional ammonia oxidation furnace and the waste heat boiler are generally made into an integral equipment, the upper part of the equipment is the traditional ammonia oxidation furnace, and the lower part of the equipment is the waste heat boiler. The existing integral equipment is divided into a fire tube type ammonia oxidation furnace and a water tube type ammonia oxidation furnace, and the fire tube type ammonia oxidation furnace has the advantages of short-time power failure, no need of a water circulating pump and the like, so that the fire tube type ammonia oxidation furnace is widely used. As shown in figure 1, the prior fire tube type ammonia oxidation furnace comprises an upper furnace body and a lower furnace body which are distributed up and down, wherein the upper furnace body is provided with a hydrogen inlet 1, an igniter connector and an ignition hydrogen port, the top of the upper furnace body is provided with an ammonia-air mixed gas port 2, the bottom of the upper furnace body is open, the lower part of the hydrogen inlet 1 in the upper furnace body is sequentially provided with a platinum net 3, the furnace comprises a filler 4, a filler support ring plate 5 and a filler support, wherein the filler support ring plate 5 adopts a split structure (the area of the filler support ring plate 5 is larger due to the larger volume of an upper furnace body, so the filler support ring plate 5 generally adopts the split structure), the adjacent edges of each filler support ring plate (5) and the filler support ring plate (5) of the adjacent segment are vertically and fixedly connected with a partition plate 5-2 provided with a first fixing hole 5-1, and the adjacent two partition plates 5-2 are fixedly connected by screwing a nut after penetrating through the first fixing hole 5-1 through a bolt; the lower furnace body comprises a first cylinder body 6 and a second lower end socket 29, an opening at one end of the first cylinder body 6 is fixedly connected and communicated with the bottom of the upper furnace body in a sealing manner, an upper pipe plate 7 and a lower pipe plate 8 which are distributed up and down and fixedly connected with the inner wall of the first cylinder body 6 in a sealing manner are arranged in the first cylinder body 6, the upper pipe plate 7 and the lower pipe plate 8 form an upper sealing cavity with the first cylinder body 6, the lower pipe plate 8, the first cylinder body 6 and the second lower end socket 29 form a lower sealing cavity, air inlet holes and air outlet holes are respectively distributed in the upper pipe plate 7 and the lower pipe plate 8, heat exchange pipes 9 are distributed in the upper sealing cavity, the upper end of the outer wall of each heat exchange pipe 9 is welded with the air inlet holes in a sealing manner and communicated with the upper furnace body, the lower end of each heat exchange pipe 9 is fixedly connected with the air outlet holes in a sealing manner and communicated with the lower sealing cavity, a soft water inlet and a soft water outlet are arranged on the first cylinder body, and a nitric oxide outlet is arranged on the first cylinder body. The working process is as follows: hydrogen enters the upper furnace body from the hydrogen inlet 1 and then is distributed on the platinum net 3, and then the hydrogen is ignited through the igniter interface and the ignition hydrogen port to be combusted at the upper part of the platinum net 3; the ammonia air gas mixture gets into in the upper furnace body from ammonia air gas mixture mouth 2, make ammonia air gas mixture distribute in platinum net 3 upper portion of scorching heat, under the catalytic action of platinum net 3 of scorching heat, ammonia air gas mixture is oxidized into nitric oxide, release a large amount of heats simultaneously, last steam (have thermal nitric oxide) gets into in the heat exchange tube 9, and carry out heat exchange with the soft water outside the heat exchange tube 9, nitric oxide after the heat exchange gets into downstream equipment through the nitric oxide export, soft water after the heat exchange passes through the soft water export and carries in the steam pocket, so that follow-up recycle it. However, the existing fire tube type ammonia oxidation furnace has the following disadvantages: 1) the welding seam of the sealing welding position of the air inlet holes of the heat exchange tube 9 and the upper tube plate 7 is easy to crack, so that the equipment is frequently maintained, the running period of the equipment is short, the production rate of nitric oxide is reduced, and the welding seam cracks are mainly caused by the following reasons: the upper part of the heat exchange tube 9 does not substantially exchange heat or cold because the upper end of the outer wall of the heat exchange tube 9 is welded with the air inlet in a sealing way, but the temperature of the upper part of the heat exchange tube 9 is overhigh because nitric oxide before heat exchange directly flows to the upper part of the heat exchange tube 9 through the bottom opening of the upper furnace body and the nitric oxide is directly contacted with the upper part of the heat exchange tube 9, so that the welding seam at the sealing welding position of the heat exchange tube 9 and the air inlet of the upper tube plate 7 is overhigh, and the welding seam is cracked; because the upper tube plate 7 is directly exposed between the nitric oxide with heat, the temperature of the upper tube plate 7 is too high, so that the temperature of a welding seam at the sealing welding position of the heat exchange tube 9 and the air inlet of the upper tube plate 7 is too high, and the welding seam is cracked; the welding seam between the heat exchange tube 9 and the air inlet of the upper tube plate 7 is directly exposed to the nitric oxide with heat, so that the temperature of the welding seam at the sealing welding position of the heat exchange tube 9 and the upper tube plate 7 is overhigh, and the welding seam is cracked; 2) hydrogen plays an important role in the equipment, and enters from a hydrogen inlet 1, but because the fire tube type ammonia oxidation furnace has a large volume, the hydrogen is directly introduced into the upper furnace body from the hydrogen inlet 1 and then is redistributed on the platinum net 3, so that the hydrogen is unevenly distributed on the platinum net 3, the burning degree of the upper part of the platinum net 3 is uneven, and the ammonia-air mixed gas is not fully reacted with the burning platinum net 3, thereby influencing the production rate of nitric oxide; 3) because packing support ring board 5 adopts split type structure, realize fixed connection through the bolt between the adjacent two lamellas, but under the environment of last furnace body internal high temperature, often can take place the bolt and be burnt out by high temperature, when leading to need maintain or change packing support ring board 5, the problem of not dismantling between the adjacent two lamellas of packing support ring board 5 to extension maintenance or change time influences the productivity ratio of nitric oxide.

Disclosure of Invention

The utility model provides an improved fire tube type ammonia oxidation furnace, which aims to solve the problem that the prior fire tube type ammonia oxidation furnace has the defects.

The utility model discloses an adopt following technical scheme to realize: a fire tube type ammonia oxidation furnace comprises an upper furnace body and a lower furnace body, wherein a hydrogen inlet and an ammonia-air mixed gas port are formed in the upper furnace body, and a platinum net and a filler supporting ring plate are arranged at the lower part of the hydrogen inlet in the upper furnace body; the lower furnace body comprises a first cylinder body, an upper tube plate is arranged in the first cylinder body, a lower tube plate, a heat exchange tube and a pouring material layer adjacent to the upper surface of the upper tube plate, the heat-resistant connecting tube (such as a stainless steel connecting tube) and the pouring material layer adjacent to the upper surface of the upper tube plate are further included, one end of the heat-resistant connecting tube extends downwards into the upper portion of the heat exchange tube to form a downward extending portion, the outer wall of the downward extending portion is fixedly connected with the inner wall of the heat exchange tube in a sealing mode, the bottom end of the downward extending portion is located between the upper tube plate and the upper surface of the heat exchange tube at the welding position, a heat insulation piece is fixedly connected between the outer wall of the downward extending portion and the inner wall of the heat exchange tube, and the other end of the heat-resistant connecting tube is inserted into the pouring material layer and communicated with the upper furnace body. The structure design of the heat-resistant connecting pipe ensures that nitric oxide flowing out from an opening at the bottom of the upper furnace body directly contacts with the heat-resistant connecting pipe, heat is directly transferred to the heat-resistant connecting pipe, and because a heat insulation piece which is fixed in a sealing way is arranged between the outer wall of the lower extension part of the heat-resistant connecting pipe and the inner wall of the upper part of the heat exchange pipe, the heat of the heat-resistant connecting pipe cannot be directly transferred to the upper part of the heat exchange pipe; due to the structural design of the casting material layer, the upper tube plate and the welding line cannot be directly exposed between nitric oxide with hot gas, so that the welding line cracking phenomenon at the sealing welding position of the heat exchange tube and the air inlet hole of the upper tube plate is reduced, the equipment maintenance rate is reduced, and the production rate of nitric oxide is improved.

Furthermore, the heat insulation piece is made of high silica cloth, so that the heat insulation effect is better.

Furthermore, the other end of the heat-resistant connecting pipe is inserted into and extends out of the pouring material layer, the other end of the heat-resistant connecting pipe is sealed and fixed with the inherent heat-resistant annular plate (such as a stainless steel annular plate) of the pouring material by the sealing sleeve, the bottom surface of the heat-resistant annular plate is sealed and fixed with the upper surface of the pouring material, the pouring material layer is convenient to shape, and meanwhile, the pouring material layer is fixed with the upper pipe plate better.

Furthermore, the upper furnace body is internally provided with a vertical folding pipe consisting of a horizontal pipe and a vertical pipe which are perpendicular to each other, one end of the vertical folding pipe is fixedly connected with a hydrogen inlet in a sealing manner, the other end of the vertical folding pipe is vertically downward and is positioned on the upper part of the platinum net, the other end of the vertical folding pipe is surrounded by a first ring pipe (the ring pipe is a pipe which is bent into a ring shape), a first connecting pipe is arranged between the first ring pipe and the other end of the vertical folding pipe, one end of the first connecting pipe is communicated and fixedly connected with the first ring pipe, the other end of the first connecting pipe is communicated and fixedly connected with the other end of the vertical folding pipe, and first distribution holes are distributed in the first ring pipe and/or the first connecting pipe. The working principle is as follows: the hydrogen gets into from the hydrogen entry and rolls over the pipe perpendicularly, then hydrogen from the other end of rolling over the pipe perpendicularly, get into first ring pipe behind first connecting pipe, at last through the hole that distributes on first ring pipe and/or the first connecting pipe with hydrogen distribution on the upper portion of platinum net, such structural design makes the distribution on platinum net upper portion of hydrogen even, the scorching hot degree on platinum net upper portion is even, the ammonia air mixture can fully take place the reaction with the platinum net of scorching hot to improve the productivity ratio of nitric oxide.

Furthermore, at least one second ring pipe coaxial with the first ring pipe is arranged outside the first ring pipe; be equipped with the second connecting pipe between first ring canal and the second ring canal, the one end and the first ring canal of second connecting pipe link up and sealed fixed connection, the other end and the second ring canal of second connecting pipe link up and sealed fixed connection, perhaps be equipped with the second connecting pipe between first ring canal and the second ring canal, the one end and the first ring canal of second connecting pipe link up and sealed fixed connection, the other end and the second ring canal of second connecting pipe link up and sealed fixed connection, all be equipped with the third connecting pipe between the adjacent second ring canal, the both ends of third connecting pipe link up and sealed fixed connection with adjacent second ring canal respectively, second ring canal and/or second connecting pipe, it has the second distribution hole to distribute on the third connecting pipe. Such structural design makes the distribution of hydrogen on platinum net upper portion more even, and the burning hot degree on platinum net upper portion is even, and the ammonia air gas mixture can fully take place the reaction with the platinum net of burning hot, further improves the productivity ratio of nitric oxide.

Furthermore, the packing support ring plate is of a split structure, the adjacent edges of each section of packing support ring plate and the adjacent sections of packing support ring plates of the adjacent sections are vertically and fixedly connected with partition plates provided with first fixing holes, gaps are formed between the adjacent two partition plates, omega-shaped connecting channel steel (the middle of the omega-shaped connecting channel steel is bent into circular arc-shaped connecting channel steel with smooth transition at two ends) with packing holes distributed on the gaps is arranged between the gaps, two ends of the connecting channel steel are respectively supported on the upper surfaces of the adjacent two sections of packing support ring plates, a second fixing hole matched with the first fixing hole is formed in the circular arc portion of the connecting channel steel, and the adjacent two sections of packing support ring plates penetrate through the first fixing holes through pins and are fixedly connected with the second fixing holes after spot welding. By adopting the structure, when the packing support ring plate needs to be maintained or replaced, the pin can be taken down only by taking the hammer, and the disassembly of the packing support ring plate can be completed.

Further, the packing supporting ring plate adopts a split structure, the adjacent edge of each section of packing supporting ring plate and the adjacent edge of the packing supporting ring plate of the adjacent section of packing supporting ring plate are respectively and fixedly connected with a partition plate provided with a first fixing hole, a gap is arranged between every two adjacent partition plates, U-shaped connecting channel steel is arranged between the gaps, the two adjacent partition plates are clamped between two vertical arms of the U-shaped connecting channel steel, the two vertical arms are provided with second fixing holes matched with the first fixing holes, the two adjacent partition plates pass through the first fixing holes through pins, and the two ends of the pins are bent downwards to realize fixed connection after the second fixing holes. By adopting the packing support ring plate with the structure, when the packing support ring plate needs to be maintained or replaced, the packing support ring plate can be detached only by bending and straightening the pin.

The utility model discloses produced beneficial effect as follows: 1) the structural design of the heat-resistant connecting pipe not only ensures that the temperature of the upper part of the heat exchange pipe cannot be overhigh, but also ensures the essential effect of cold and heat exchange between the heat exchange pipe and soft water; 2) The first ring pipe, the second ring pipe, the first connecting pipe and the second connecting pipe are structurally designed, so that hydrogen is uniformly distributed on the upper part of the platinum net, the burning degree of the upper part of the platinum net is uniform, and the ammonia-air mixed gas can fully react with the burning platinum net, so that the utilization rate of the hydrogen is improved, and the production rate of nitric oxide is improved; 3) the structural design of the pin and the omega-shaped/U-shaped connecting channel steel is as follows: the structure of bolt fixing is avoided, and the structure is simple, the installation is convenient, the disassembly is convenient, and the safety and the reliability are realized. To sum up, the utility model discloses a fire tube formula ammoxidation stove when guaranteeing to be connected conveniently with upper and lower reaches equipment, has realized the production of nitric oxide, and equipment structure is compact, and production intensity is high, and the loss of ammonia and the loss of hydrogen are low, low in production cost, and the output of nitric oxide is high, and energy recovery comprehensive utilization is reasonable, simple structure moreover, simple to operate, safe and reliable.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

FIG. 3 is a schematic structural view of a packing support ring plate;

FIG. 4 is a cross-sectional view taken along line B-B of FIG. 3;

FIG. 5 is a cross-sectional view taken at C-C of FIG. 3;

FIG. 6 is an enlarged view of a portion of FIG. 1 at D;

FIG. 7 is a top view of FIG. 6;

FIG. 8 is a schematic structural view of a curved pipe made of shrimp;

FIG. 9 is a view in the direction E of FIG. 8;

fig. 10 is a partial enlarged view of F in fig. 1.

In the figure: 1-a hydrogen inlet, 2-an ammonia-air mixture gas port, 3-a platinum net, 4-a filler, 5-a filler support ring plate, 5-1-a first fixing hole, 5-2-a partition plate, 5-3-a connecting channel steel, 5-4-a second fixing hole, 5-a pin, 6-a first cylinder, 7-an upper tube plate, 8-a lower tube plate, 9-a heat exchange tube, 10-a heat-resistant connecting tube, 11-a casting material layer, 12-a heat-insulating member, 13-a heat-resistant ring plate, 14-a vertical folded tube, 14-1-a horizontal tube, 14-2-a vertical tube, 15-a first circular tube, 16-a first connecting tube, 17-a second circular tube, 18-a second connecting tube, 19-a third connecting tube, 20-an inclined strut, 21-a first distribution plate, 22-a first connecting tube, 23-a second distribution plate, 24-a second connecting rod, 25-a shrimp elbow, 26-a cone, 27-a second cylinder, 28-a first lower end enclosure, 29-a second lower end enclosure and 30-a guide plate.

Detailed Description

As shown in fig. 1, 2 and 10, a fire tube type ammonia oxidation furnace comprises an upper furnace body and a lower furnace body, wherein the upper furnace body is provided with a hydrogen inlet 1 and an ammonia-air mixture port 2, and the lower part of the hydrogen inlet 1 in the upper furnace body is provided with a platinum net 3 and a filler support ring plate 5; the lower furnace body comprises a first cylinder body 6, an upper tube plate 7 is arranged in the first cylinder body 6, a lower tube plate 8 and a heat exchange tube 9, and further comprises a heat-resistant connecting tube 10 and a casting material layer adjacent to the upper surface of the upper tube plate 7, one end of the heat-resistant connecting tube 10 extends downwards into the heat exchange tube 9, the outer wall of the lower extension part and the inner wall of the heat exchange tube 9 are fixedly connected in a sealing mode, the bottom end of the lower extension part is located between the welding position of the upper tube plate 7 and the heat exchange tube 9 and the upper surface of the lower tube plate 8, a heat insulation part 12 is fixed between the outer wall of the lower extension part and the inner wall of the heat exchange tube 9 in a sealing mode, and the other end of the heat-resistant connecting tube 10 is inserted into the casting material layer 11 and communicated with the upper furnace body. The structure design of the heat-resisting connecting pipe 10 ensures that nitric oxide flowing out from the opening at the bottom of the upper furnace body directly contacts with the heat-resisting connecting pipe 10, heat is directly transferred to the heat-resisting connecting pipe 10, and the heat of the heat-resisting connecting pipe 10 cannot be directly transferred to the upper part of the heat exchange pipe 9 because the heat insulation piece 12 is sealed and fixed between the outer wall of the lower part of the heat-resisting connecting pipe 10 and the inner wall of the upper part of the heat exchange pipe 9; due to the structural design of the castable layer 11, the upper tube plate 7 and a welding seam cannot be directly exposed between nitric oxide with hot gas, so that the phenomenon of welding seam cracking at the sealing welding position of the heat exchange tube 9 and the air inlet of the upper tube plate 7 is reduced, the equipment maintenance rate is reduced, and the production rate of nitric oxide is improved. In specific implementation, the heat insulation piece 12 is made of high silica cloth, so that the heat insulation effect is better.

During specific implementation, the other end of the heat-resistant connecting pipe 10 is inserted into and extends out of the castable layer 11, the other end of the heat-resistant connecting pipe 10 is sealed and fixed by the inherent heat-resistant annular plate 13, the bottom surface of the heat-resistant annular plate 13 is sealed and fixed with the upper surface of castable, the castable layer 11 is convenient to shape, and meanwhile, the castable layer 11 is better fixed with the upper pipe plate 7.

As shown in fig. 1, 6 and 7, in specific implementation, a vertical folded pipe 14 composed of a horizontal pipe 14-1 and a vertical pipe 14-2 perpendicular to each other is further disposed in the upper furnace body, one end of the vertical folded pipe 14 is fixedly connected to the hydrogen inlet 1 in a sealing manner, the other end of the vertical folded pipe 14 faces downward and is located at the upper portion of the platinum mesh 3, the other end of the vertical folded pipe 14 is sleeved with a first loop pipe 15, a first connection pipe 16 is disposed between the first loop pipe 15 and the other end of the vertical folded pipe 14, one end of the first connection pipe 16 is communicated and fixedly connected to the first loop pipe 15, the other end of the first connection pipe 16 is communicated and fixedly connected to the other end of the vertical folded pipe 14, and first distribution holes are distributed on the first loop pipe 15 and/or the first connection pipe 16. The working principle is as follows: the hydrogen enters the vertical folding pipe 14 from the hydrogen inlet 1, then the hydrogen enters the first ring pipe 15 from the other end of the vertical folding pipe 14 after passing through the first connecting pipe 16, and finally the hydrogen is distributed on the upper part of the platinum net 3 through the first distribution holes distributed on the first ring pipe 15 and/or the first connecting pipe 16.

In specific implementation, at least one second ring pipe 17 coaxial with the first ring pipe 15 is arranged on the outer side of the first ring pipe; a second connecting pipe 18 is arranged between the first ring pipe 15 and the second ring pipe 17, one end of the second connecting pipe 18 is communicated with the first ring pipe 15 and is in sealing fixed connection, the other end of the second connecting pipe 18 is communicated with the second ring pipe 17 and is in sealing fixed connection, or a second connecting pipe 18 is arranged between the first ring pipe 15 and the second ring pipe 17, one end of the second connecting pipe 18 is communicated with the first ring pipe 15 and is in sealing fixed connection, the other end of the second connecting pipe 18 is communicated with the second ring pipe 17 and is in sealing fixed connection, a third connecting pipe 19 is arranged between every two adjacent second ring pipes 17, two ends of the third connecting pipe 19 are respectively communicated with the adjacent second ring pipes 17 and is in sealing fixed connection, and second distribution holes are distributed on the second ring pipe 17 and/or the second connecting pipe 18 and the third connecting pipe 19. Such structural design makes hydrogen more even in the distribution on platinum net 3 upper portion, and the burning hot degree on platinum net 3 upper portion is even, and the ammonia air gas mixture can fully take place the reaction with platinum net 3 of burning hot, further improves the productivity ratio of nitric oxide.

During specific implementation, two inclined support rods 20 are arranged between the outer wall of the second annular pipe 17 adjacent to the first annular pipe 15 and the vertical pipe 14-2, the bottom ends of the two inclined support rods 20 are 180 degrees based on the central angle of the axial lead of the second annular pipe 17, one end of each inclined support rod 20 is fixedly connected with the vertical pipe 14-2, the other end of each inclined support rod 20 is fixedly connected with the outer wall of the second annular pipe 17, the structure is specific, meanwhile, the structural design of the inclined support pipes increases the level state of the first annular pipe 15 and the second annular pipe 17 as much as possible, and hydrogen is distributed more uniformly on the upper portion of the platinum net 3.

In specific implementation, the upper part of the horizontal pipe 14-1 in the upper furnace body is provided with a first distribution disc 21 which is fixedly connected with the inner wall of the upper furnace body and is provided with first holes, and a first connecting rod 22 is vertically and fixedly connected between the bottom of the first distribution disc 21 and the outer wall of the horizontal pipe 14-1; the lower part of the horizontal pipe 14-1 in the upper furnace body is provided with a second distribution disc 23 which is fixedly connected with the inner wall of the upper furnace body and is provided with second holes, two second connecting rods 24 are vertically fixed between the outer wall of the second ring pipe 17 at the outermost side and the second distribution disc 23, the central angle of the shaft axis of the second ring pipe 17 is 180 degrees based on the two second connecting rods 24, one end of each second connecting rod 24 is fixedly connected with the bottom surface of the second distribution disc 23, the other end of each second connecting rod 24 is fixedly connected with the outer wall of the second ring pipe 17 at the outermost side, and the first distribution disc 21 and the second distribution disc 23 are structurally designed to enable ammonia-air mixed gas to be uniformly distributed on the platinum net 3 after passing through the first distribution disc 21 and the second distribution disc 23, so that the ammonia-air mixed gas and the scorching platinum net 3 can react more fully. Meanwhile, the first ring pipe 15 and the second ring pipe 17 are better fixed by the structural design of the first connecting rod 22 and the second connecting rod 24.

As shown in fig. 3, 4 and 5, in specific implementation, the packing support ring plate 5 adopts a split structure, the adjacent edge of each packing support ring plate 5 and the packing support ring plate 5 of the adjacent split is vertically and fixedly connected with a partition plate 5-2 provided with a first fixing hole 5-1, a gap is arranged between two adjacent partition plates 5-2, and when the gap is large, the following structure is adopted: the gap is provided with omega-shaped connecting channel steel 5-3 (the omega-shaped connecting channel steel is the connecting channel steel which is bent into an arc shape in the middle and smoothly transits with two ends), two ends of the connecting channel steel 5-3 are respectively supported on the upper surfaces of two adjacent sections of packing support ring plates 5, the arc part of the connecting channel steel 5-3 is provided with a second fixing hole matched with the first fixing hole 5-1, two adjacent sections of packing support ring plates 5 pass through the first fixing hole 5-1 and the second fixing hole through a pin 5-5, the second fixing hole and the pin 5-5 are subjected to spot welding to realize fixed connection, and the packing support ring plate 5 adopting the structure, when the packing support ring plate 5 needs to be maintained or replaced, the pin 5-5 can be taken down only by taking a hammer, and the dismounting of the packing support ring plate 5 can be completed; when the clearance is small, the following structure is adopted: u-shaped connecting channel steel 5-3 is arranged between the gaps, two adjacent partition plates 5-2 are clamped between two vertical arms of the U-shaped connecting channel steel 5-3, second fixing holes matched with the first fixing holes 5-1 are formed in the two vertical arms, and two ends of each pin 5-5 are bent downwards to achieve fixed connection after each two adjacent partition plates 5-2 penetrate through the first fixing holes 5-1 and the second fixing holes through the pins 5-5. By adopting the packing support ring plate 5 with the structure, when the packing support ring plate 5 needs to be maintained or replaced, the packing support ring plate 5 can be detached only by bending and straightening the pins 5-5.

As shown in fig. 1, 7 and 8, in specific implementation, the upper furnace body is formed by sequentially distributing, sealing and welding a shrimp elbow 25, a conical cylinder 26, a cylindrical second cylinder 27 and a first lower end enclosure 28 from top to bottom, non-connecting ports of the shrimp elbow 25 and the conical cylinder 26 are ammonia-air mixed ports, strip-shaped guide plates 30 are distributed in the shrimp elbow 25, two opposite end faces of the guide plates 30 are fixedly connected with the inner wall of the shrimp elbow 25, and the bending direction of the guide plates 30 is the same direction as that of the shrimp elbow 25, so that the space in the shrimp elbow 25 is divided into a plurality of cavities distributed along the non-circumferential direction, and the ammonia-air mixed gas is uniformly distributed in the upper furnace body after passing through the cavities of the shrimp elbow 25.

In this embodiment, the first cylinder 6 is provided with a heating steam inlet for introducing steam, so that the equipment can operate normally and quickly. The upper furnace body wall is provided with a sight glass pipe orifice for observing the ignition condition and a thermocouple pipe orifice for measuring the internal temperature of the upper furnace body. A shell pass water supplementing inlet is arranged between the lower tube plate 8 and the second lower end socket 29 of the first barrel 6, a spare pipeline which penetrates through the lower tube plate 8 and extends into the upper seal cavity is fixed at the shell pass water supplementing inlet in a sealing mode, and a water spray pipe which is communicated with the spare pipeline and is provided with water spray holes is arranged in the upper seal cavity, so that equipment damage caused by water shortage in the upper seal cavity is prevented. The bottom of the second lower end enclosure 29 is provided with a drain port.

Claims (10)

1. A fire tube type ammonia oxidation furnace comprises an upper furnace body and a lower furnace body, wherein the upper furnace body is provided with a hydrogen inlet (1) and an ammonia-air mixed gas port (2), and the lower part of the hydrogen inlet (1) in the upper furnace body is provided with a platinum net (3) and a filler support ring plate (5); the lower furnace body comprises a first barrel body (6), an upper tube plate (7) is arranged in the first barrel body (6), a lower tube plate (8) and a heat exchange tube (9), and the lower furnace body is characterized by further comprising a heat-resistant connecting tube (10) and a casting material layer (11) which is arranged on the upper surface of the upper tube plate (7) in an adjacent mode, one end of the heat-resistant connecting tube (10) extends downwards to the upper portion in the heat exchange tube (9) to form a downward extending portion, the outer wall of the downward extending portion is fixedly connected with the inner wall of the heat exchange tube (9) in a sealing mode, the bottom end of the downward extending portion is located between the welding position of the upper tube plate (7) and the heat exchange tube (9) and the upper surface of the lower tube plate (8), a heat insulation piece (12) is fixedly connected between the outer wall of the downward extending portion and the inner wall of the heat exchange tube (9) in a sealing mode, and the other end of the heat-resistant connecting tube (10) penetrates through the casting material layer (11) and is communicated with the upper portion.

2. The fire tube type ammoxidation furnace according to claim 1, wherein the heat insulator (12) is a high silica cloth.

3. The fire tube type ammoxidation furnace according to claim 2, wherein the other end of the heat-resistant connection tube (10) is inserted into and extended out of the castable layer (11), the other end of the heat-resistant connection tube (10) is sealed and sealed with an inherent heat-resistant annular plate (13), and the bottom surface of the heat-resistant annular plate (13) is sealed and fixed with the upper surface of the castable layer (11).

4. The fire tube type ammoxidation furnace according to claim 3, wherein the upper furnace body is further provided with a vertical folded tube (14) consisting of a horizontal tube (14-1) and a vertical tube (14-2) which are perpendicular to each other, one end of the vertical folded tube (14) is fixedly connected with the hydrogen inlet (1) in a sealing manner, the other end of the vertical folded tube (14) faces downward vertically and is located at the upper part of the platinum mesh (3), the other end of the vertical folded tube (14) is surrounded by a first circular tube (15), a first connecting tube (16) is arranged between the first circular tube (15) and the other end of the vertical folded tube (14), one end of the first connecting tube (16) is communicated and fixedly connected with the first circular tube (15), the other end of the first connecting tube (16) is communicated and fixedly connected with the other end of the vertical folded tube (14), and first distribution holes are distributed on the first circular tube (15) and/or the first connecting tube (16).

5. The fire tube type ammoxidation furnace according to claim 4, wherein the first ring tube (15) has at least one second ring tube (17) coaxially provided outside thereof; a second connecting pipe (18) is arranged between the first ring pipe (15) and the second ring pipe (17), one end of the second connecting pipe (18) is communicated with the first ring pipe (15) and is fixedly connected in a sealing way, the other end of the second connecting pipe (18) is communicated with the second ring pipe (17) and is fixedly connected in a sealing way, or be equipped with second connecting pipe (18) between first ring canal (15) and second ring canal (17), the one end and first ring canal (15) of second connecting pipe (18) link up and sealed fixed connection, the other end and second ring canal (17) of second connecting pipe (18) link up and sealed fixed connection, all be equipped with third connecting pipe (19) between adjacent second ring canal (17), the both ends of third connecting pipe (19) link up and sealed fixed connection with adjacent second ring canal (17) respectively, second ring canal (17) and/or second connecting pipe (18), it has the second to distribute the hole on third connecting pipe (19).

6. The fire tube type ammonia oxidation furnace according to claim 5, wherein two diagonal braces (20) are arranged between the outer wall of the second ring tube (17) adjacent to the first ring tube (15) and the vertical tube (14-2), the bottom ends of the two diagonal braces (20) are 180 degrees based on the central angle of the axis of the second ring tube (17), one end of each diagonal brace (20) is fixedly connected with the vertical tube (14-2), and the other end of each diagonal brace (20) is fixedly connected with the outer wall of the second ring tube (17).

7. The fire tube type ammoxidation furnace according to claim 6, wherein the upper part of the horizontal tube (14-1) in the upper furnace body is provided with a first distribution plate (21) fixedly connected to the inner wall of the upper furnace body and having first holes distributed thereon, and a first connecting rod (22) is vertically and fixedly connected between the bottom of the first distribution plate (21) and the outer wall of the horizontal tube (14-1); the lower part of a horizontal pipe (14-1) in the upper furnace body is provided with a second distribution disc (23) which is fixedly connected with the inner wall of the upper furnace body and is provided with second holes, two second connecting rods (24) are vertically and fixedly connected between the outer wall of the second ring pipe (17) at the outermost side and the second distribution disc (23), and the central angle of the two second connecting rods (24) based on the axial lead of the second ring pipe (17) is 180 degrees.

8. The fire tube type ammoxidation furnace according to any one of claims 1 to 7, wherein the packing support ring plate (5) has a split structure, each segment of the packing support ring plate (5) is vertically and fixedly connected with a partition plate (5-2) having a first fixing hole (5-1) at the edge adjacent to the adjacent segment of the packing support ring plate (5), a gap is provided between two adjacent partition plates (5-2), an omega-shaped connecting channel steel (5-3) having a packing hole is provided between the gaps, two ends of the connecting channel steel (5-3) are respectively supported on the upper surfaces of two adjacent segments of the packing support ring plate (5), a second fixing hole (5-4) matched with the first fixing hole (5-1) is provided at the arc portion of the connecting channel steel (5-3), and two adjacent segments of the packing support ring plate (5) pass through the first fixing hole (5-1) through a pin (5-5), The second fixing hole (5-4) is connected with the pin (5-5) in a fixed mode after spot welding is carried out on the second fixing hole (5-4).

9. The fire tube type ammoxidation furnace according to any one of claims 1 to 7, wherein the packing support ring plate (5) has a split structure, the adjacent edge of each section of the packing support ring plate (5) and the adjacent section of the packing support ring plate (5) is vertically and fixedly connected with a partition plate (5-2) having a first fixing hole (5-1), a gap is provided between two adjacent partition plates (5-2), a U-shaped connecting channel steel (5-3) is provided between the gaps, the two adjacent partition plates (5-2) are clamped between two vertical arms of the U-shaped connecting channel steel (5-3), the two vertical arms are provided with second fixing holes (5-4) adapted to the first fixing holes (5-1), and the two adjacent partition plates (5-2) pass through the first fixing holes (5-1) through pins (5-5), After the second fixing hole (5-4), the two ends of the pin (5-5) are bent downwards to realize fixed connection.

10. The fire tube type ammoxidation furnace according to claim 8, wherein the upper furnace body is formed by sequentially distributing and welding a shrimp elbow (25), a cone (26), a cylindrical second cylinder (27) and a first lower end enclosure (28) from top to bottom in a sealing manner, the non-connecting ports of the shrimp elbow (25) and the cone (26) are ammonia-air mixture ports (2), strip-shaped guide plates (30) are distributed in the shrimp elbow (25), the two opposite end faces of each guide plate (30) are fixedly connected with the inner wall of the shrimp elbow (25), the bending direction of each guide plate (30) is the same as the bending direction of the shrimp elbow (25), and thus the space in the shrimp elbow (25) is divided into a plurality of cavities distributed along the non-circumferential direction.

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