A steam flash device for hydrogen chloride synthesis furnace

Abstract

The utility model discloses a steam flash evaporation device for hydrogen chloride synthetic furnace, including jar body, the bottom of jar body is equipped with support leg, is equipped with liquid inlet on the lateral wall, is equipped with exhaust port at the top, is equipped with liquid outlet at the bottom, the inside of jar body is provided with vapour liquid primary separation mechanism, steam cyclone mechanism, demister from below to above in proper order, and the demister is located the top of steam cyclone mechanism, wherein, vapour liquid primary separation mechanism includes liquid inlet pipe, inverted conical hopper and conical disperser, one end of liquid inlet pipe is connected with liquid inlet, and the suspension end of liquid inlet pipe is located the just above of inverted conical hopper, the top of conical disperser is flat, and the centre is equipped with recess, and the circumferential side wall of recess is provided with a plurality of circumferentially distributed apertures, and inverted conical hopper is supported in recess through the column that sets up at its bottom. The utility model can separate vapour liquid efficiently, alleviate local erosion, and have higher operation safety.

Description

Technical Field

[0001] This utility model relates to the technical field of hydrogen chloride production equipment, and in particular to a steam flash evaporation device for a hydrogen chloride synthesis furnace. Background Technology

[0002] In the chlor-alkali industry, the combustion of chlorine and hydrogen in a synthesis furnace to produce hydrogen chloride gas is a strongly exothermic reaction. To recover and utilize this heat of reaction, modern industry commonly uses steel-jacketed or membrane-walled synthesis furnaces. High-temperature hot water is converted into steam through a steam flash evaporation device on the furnace body. This steam can be used for subsequent processes such as polymerization and drying, significantly reducing production energy consumption.

[0003] Existing flash steam evaporation devices are typically simple vertical tanks. High-temperature, high-pressure hot water enters the flash tank from the jacket of the synthesis furnace and rapidly vaporizes due to a sudden pressure drop. However, in actual operation, such traditional flash steam evaporation devices have several technical problems that urgently need to be solved: (1) The hot water entering the flash tank is often not sufficiently dispersed, resulting in incomplete flash evaporation. A large number of droplets are carried by the rising steam, resulting in low-quality steam (high humidity), which can easily cause water hammer and corrosion in the subsequent pipeline system. (2) High-temperature hot water is sprayed out at high speed from the inlet pipe and directly impacts the inner wall of the tank or a fixed point for a long time, causing the metal material in that area to thin rapidly, shortening the service life of the equipment, and posing a safety hazard. Utility Model Content

[0004] This invention provides a steam flash evaporation device for a hydrogen chloride synthesis furnace, which solves the problems of low efficiency in separating gas and liquid in traditional flash tanks, inability to effectively mitigate local erosion, and low operational safety.

[0005] This utility model provides a steam flash evaporation device for a hydrogen chloride synthesis furnace, comprising a tank body with legs at the bottom, a liquid inlet on the side wall, an exhaust port at the top, and a drain port at the bottom. Inside the tank body, from bottom to top, are arranged a vapor-liquid primary separation mechanism, a steam cyclone mechanism, and a demister. The demister is positioned above the steam cyclone mechanism. The vapor-liquid primary separation mechanism includes an inlet pipe, an inverted conical funnel, and a conical disperser. One end of the inlet pipe is connected to the liquid inlet, and the suspended end of the inlet pipe is located directly above the inverted conical funnel. The conical disperser is positioned below the inverted conical funnel and is fixed to the inner wall of the tank body by fixing rods. The top of the conical disperser is flat, with a groove in its center. Multiple circumferentially distributed notches are formed on the side walls of the groove. The inverted conical funnel is supported within the groove by a column at its bottom.

[0006] Furthermore, the steam swirling mechanism includes a swirler, which includes a central positioning block and a plurality of swirling plates inclined along the circumferential direction; the central positioning block is fixedly connected to the column in the groove by a support rod; the inner side of the plurality of swirling plates is connected to the central positioning block, and the outer side is fixedly connected to the inner wall of the tank.

[0007] Furthermore, the demister includes an upper positioning plate and a lower positioning plate arranged in parallel, and a plurality of guide tubes vertically installed therebetween; each guide tube is fixedly provided with a spiral blade.

[0008] Furthermore, the upper end of the guide tube is provided with a flange, and the guide tube is fixedly connected to the upper positioning plate through the flange; the lower end of the guide tube is embedded in the mounting hole on the lower positioning plate for positioning connection.

[0009] Furthermore, a remote dual level gauge is installed on the side wall of the tank.

[0010] Furthermore, a manhole is provided on the side wall of the tank, and a manhole cover is provided on the outside of the manhole.

[0011] Compared with the prior art, the beneficial effects of this utility model are: 1. This utility model removes moisture from steam step by step through primary dispersion flash evaporation, cyclone centrifugal dehydration, and spiral flow guidance, resulting in steam with extremely high dryness, which effectively solves the problems of water hammer and corrosion in subsequent pipelines.

[0012] 2. This utility model, through the structure of an inverted conical funnel and a conical disperser with notches and grooves, transforms the concentrated, high-speed impact of fluid on the tank into a dispersed and gentle overflow, eliminating local erosion hotspots and significantly improving the service life, operational safety, and stability of the tank. Attached Figure Description

[0013] To more clearly illustrate the technical solution of this utility model, the drawings used in the implementation examples will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0014] Figure 1 This is a schematic diagram of the overall structure of a steam flash evaporation device for a hydrogen chloride synthesis furnace proposed in this utility model. Figure 2 This is a cross-sectional schematic diagram of the overall structure of a steam flash evaporation device for a hydrogen chloride synthesis furnace proposed in this utility model. Figure 3 This is a partial structural schematic diagram of a steam flash evaporation device for a hydrogen chloride synthesis furnace proposed in this utility model. Figure 4Appendix to this utility model Figure 3 A magnified schematic diagram of the structure at position I.

[0015] In the diagram: 1-Tank body; 11-Support leg; 12-Liquid inlet; 13-Manhole; 14-Remote dual level gauge; 15-Exhaust port; 16-Drain port; 2-Liquid inlet pipe; 3-Hydrocyclone; 31-Inverted conical funnel; 32-Conical disperser; 320-Fixing rod; 321-Groove; 322-Notch; 33-Column; 34-Center positioning block; 35-Hydrocyclone plate; 36-Support rod; 4-Demister; 41-Upper positioning plate; 42-Lower positioning plate; 43-Guide tube; 44-Helical blade; 45-Flange. Detailed Implementation

[0016] To enable those skilled in the art to better understand the technical solutions of this utility model, the technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings.

[0017] Example 1: Please see Figure 1-4 The present invention provides a steam flash evaporation device for a hydrogen chloride synthesis furnace, the main body of which is a vertical cylindrical tank 1, made of corrosion-resistant materials such as stainless steel or carbon steel lined with stainless steel. At least three legs 11 are welded to the bottom of the tank 1 to support the entire device. An inlet 12 is provided on the upper part of the side wall of the tank 1 for connecting to a high-temperature, high-pressure water pipeline from the synthesis furnace jacket. An exhaust port 15 is located at the center of the top of the tank 1, and the exhaust port 15 is connected to an exhaust pipe, which is connected to a by-product steam output pipeline. A drain port 16 is provided at the bottom of the tank 1 for discharging unflashed saturated water. In addition, a manhole 13 is provided on the side wall of the tank 1 for facilitating the installation and maintenance of internal components, and a remote dual level gauge 14 is provided for real-time monitoring of the liquid level inside the tank.

[0018] Please combine Figure 1 and Figure 2 The lowest part of the tank body 1 contains a vapor-liquid separation mechanism. This mechanism includes a horizontally suspended inlet pipe 2 suspended in the middle of the tank body 1. Its inlet end is welded to the inlet port 12, and its outlet end is open, facing an inverted conical funnel 31. Below the inverted conical funnel 31 is a conical disperser 32, which is fixedly connected to the inner wall of the tank body 1 by four fixing rods 320, thus suspending and supporting the disperser 32. The top of the conical disperser 32 is machined to be flat, and a circular groove 321 is machined in its middle. Figure 3 , 4 As shown, multiple rectangular notches 322 are evenly distributed along the circumference on the four side walls of the groove 321. The bottom of the inverted conical funnel 31 is fixedly supported inside the groove 321 by three or four evenly distributed columns 33, so that its bottom outlet is kept at a certain distance from the bottom of the groove 321.

[0019] During operation, high-temperature hot water falls vertically from the end of the inlet pipe 2 into the inverted conical funnel 31, is collected, and flows into the groove 321 below. When the liquid level in the groove 321 exceeds the bottom of the opening 322, the hot water overflows evenly and radially from each opening 322, spreading into a thin liquid film along the conical surface of the conical disperser 32. This process greatly increases the evaporation surface area of ​​the fluid and releases pressure instantaneously, thereby achieving intense and thorough primary flash evaporation. The angle between the conical surface of the conical disperser 32 and the horizontal plane is preferably 45°, which ensures smooth liquid flow without stagnation and provides sufficient spreading area.

[0020] In this embodiment, the steam swirling mechanism mainly consists of a swirler 3. The swirler 3 includes a cylindrical central positioning block 34 and multiple (e.g., 16) swirling plates 35 with fixed inclination angles. Figure 2 , 3 As shown, these swirl plates 35 are fixed by welding the inner side to the circumference of the central positioning block 34 and the outer side to the inner wall of the tank 1. The one-piece welded structure ensures the overall robustness. The bottom of the central positioning block 34 is welded to the bottom of the groove 321 of the lower conical diffuser 32 by a support rod 36, thereby connecting the upper and lower structures into a stable whole.

[0021] The steam generated by the primary flash evaporation flows upward and is forced through the swirl plate 35. The preferred inclination angle of the swirl plate 35 is 30°, which generates sufficient rotational intensity while avoiding excessive flow resistance. Guided by the swirl plate 35, the steam changes from linear motion to intense rotational motion, forming a swirling flow field. Larger droplets entrained in the steam are thrown against the tank wall by centrifugal force, condense upon impact, and fall, achieving secondary dehydration and homogenization mixing of the steam.

[0022] Please see Figure 2 At the very top of tank 1, a demister 4 is installed as a third-stage separator. The demister 4 includes an upper positioning plate 41 and a lower positioning plate 42 welded to the inner wall of the tank, connected by multiple guide tubes 43. Figure 3 As shown, each guide tube 43 has a flange 45 at its upper end, which is fixed to the upper positioning plate 41 by bolts; its lower end is directly inserted into the corresponding mounting hole of the lower positioning plate 42 for positioning. Inside each guide tube 43, a spiral blade 44 is fixedly installed. The pitch of the spiral blade 44 is preferably 0.8 times the diameter of the guide tube 43, which achieves a good balance between separation efficiency and pressure drop.

[0023] In the above embodiment, the steam after swirling is distributed into each guide tube 43, where it undergoes a forced spiral upward motion under the constraint of the spiral blades 44. This design greatly extends the purification path of the steam, and the fine droplets are subjected to strong centrifugal force inside the tube, being thoroughly thrown against the tube wall and flowing down the inner wall, thereby achieving deep fine separation. Finally, the extremely dry clean steam is discharged from the top exhaust port 15.

[0024] In the above embodiment, a remote dual-level gauge 14 is installed on the side wall of tank 1. The remote dual-level gauge 14 is a commercially available product and employs two independent measurement systems (e.g., one using a differential pressure transmitter principle and the other using radar or radio frequency admittance principle). Their signals are simultaneously transmitted to the DCS or SIS system in the central control room. The system is equipped with a comparison program. When the difference between the two level signals exceeds the normal range (e.g., 5%), an audible and visual alarm is triggered to remind the operator to check the instrument status. This provides critical safety redundancy in case the level gauge becomes inaccurate due to freezing in winter or other reasons, avoiding accidents such as dry burning or overfilling caused by misjudgment.

[0025] The workflow of this utility model is as follows: Hot water at approximately 175°C and 0.80 MPa, sourced from the jacket of the hydrogen chloride synthesis furnace, enters the horizontally suspended inlet pipe 2 through inlet 12 and falls vertically from its suspended end. It is first received by an inverted conical funnel 31, which guides and concentrates the fluid in the central groove 321 at the top of the conical disperser 32. Once the liquid level in the groove 321 has accumulated, the hot water overflows evenly through the surrounding openings 322 onto the conical inclined surface of the conical disperser 32. During this process, the fluid transforms from a concentrated columnar flow into multiple streams and thin liquid films, resulting in a rapid increase in surface area. Simultaneously, under reduced pressure, the vapor dissolved in the water is fully and violently released, completing the initial flash evaporation.

[0026] The released saturated steam flows upward, first passing through hydrocyclone 3. The inclined cyclone plates 35 force the steam to change from a straight upward motion to a rotating upward motion, forming a swirling flow field. Under the action of centrifugal force, the denser droplets entrained in the steam are thrown towards the tank wall, colliding and condensing into larger droplets before falling, achieving secondary separation. At the same time, the swirling effect ensures that the temperature and composition of the steam are fully mixed, producing steam with more uniform quality.

[0027] The steam, purified by the cyclone, continues to rise and enters the demister 4. The steam is distributed into various guide tubes 43, where it undergoes forced spiral motion under the guidance of the spiral blades 44. This significantly extends the residence path and time of the steam within the demister 4, causing fine droplets to be thrown against the tube wall by strong centrifugal force and fall along the wall surface, thus achieving deep dehydration and fine filtration. Finally, the highly dry, clean steam is discharged from the exhaust port 15 at the top and transported to subsequent processes.

[0028] The saturated water that fails to flash evaporate, along with the separated liquid, falls down the tank wall to the bottom and returns to the circulation system or is discharged through drain port 16. The remote dual-level gauge 14 on the tank monitors the liquid level in real time. The two systems serve as backups and calibrations for each other. If the reading deviation exceeds the set range, the system will issue an alarm, prompting the operator to intervene, thus fundamentally avoiding safety accidents caused by single-point instrument failure. After three-stage separation, it becomes saturated vapor at approximately 0.80 MPa with a dryness higher than 98%, which is discharged from exhaust port 15 for use in polymerization drying or hydrochloric acid desorption processes. The unvaporized saturated water collects at the bottom of the tank and returns to the system for circulation through drain port 16. Throughout the process, the remote dual-level gauge 14 provides dual-channel monitoring to ensure the liquid level remains stable at around 50%, guaranteeing the safe, stable, and efficient operation of the system.

[0029] As the load on the synthesis furnace increases and the flash tank pressure rises to 0.87 MPa, a vent pipe is connected in parallel to the side of the exhaust pipe at the top of the flash tank. A vent regulating valve is installed on the vent pipe and is automatically opened by electrical control, releasing steam. Simultaneously, the boiler feedwater pump replenishes soft water to the evaporation section of the synthesis furnace through an automatic regulating valve to maintain a stable liquid level in the flash tank. To improve steam utilization, an automatic regulating valve and a check valve are added to the existing by-product steam vent pipe, and a steam recovery pipe is laid. When the flash tank pressure reaches 0.75 MPa, the by-product steam is switched and transported to the recovery process through the pipeline.

[0030] Other embodiments of the present invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The present invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope of the invention is indicated by the claims.

[0031] It should be understood that this utility model is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model.

Claims

1. A steam flash evaporation device for a hydrogen chloride synthesis furnace, comprising a tank (1), wherein the tank (1) is provided with a support leg (11) at the bottom, a liquid inlet (12) on the side wall, an exhaust port (15) at the top, and a liquid outlet (16) at the bottom, characterized in that, The tank body (1) is provided with a vapor-liquid primary separation mechanism, a steam cyclone mechanism, and a demister (4) arranged sequentially from bottom to top inside the tank body (1). The demister (4) is located above the steam cyclone mechanism. The vapor-liquid primary separation mechanism includes an inlet pipe (2), an inverted conical funnel (31), and a conical disperser (32). One end of the inlet pipe (2) is fixedly connected to the inlet port (12), and the suspended end of the inlet pipe (2) is located directly above the inverted conical funnel (31). The conical disperser (32) is located below the inverted conical funnel (31). The conical disperser (32) is connected and fixed to the inner wall of the tank (1) by a fixing rod (320). The top center of the conical disperser (32) is provided with a groove (321). The side walls of the groove (321) are provided with multiple circumferentially distributed notches (322). The inverted conical funnel (31) is supported in the groove (321) by a column (33) provided at its bottom.

2. The steam flash evaporation device for a hydrogen chloride synthesis furnace according to claim 1, characterized in that, The steam swirling mechanism includes a swirler (3), which includes a central positioning block (34) and multiple swirling plates (35) inclined along the circumferential direction. The central positioning block (34) is fixedly connected to the column (33) in the groove (321) by a support rod (36). The inner side of the multiple swirling plates (35) is connected to the central positioning block (34), and the outer side is fixedly connected to the inner wall of the tank (1).

3. The steam flash evaporation device for a hydrogen chloride synthesis furnace according to claim 1, characterized in that, The demister (4) includes an upper positioning plate (41) and a lower positioning plate (42) arranged in parallel, and a plurality of guide tubes (43) installed vertically therebetween; each guide tube (43) is fixedly provided with a spiral blade (44).

4. A steam flash evaporation device for a hydrogen chloride synthesis furnace according to claim 3, characterized in that, The upper end of the guide tube (43) is provided with a flange (45), and the guide tube (43) is fixedly connected to the upper positioning plate (41) through the flange (45); the lower end of the guide tube (43) is embedded in the mounting hole on the lower positioning plate (42) for positioning connection.

5. A steam flash evaporation device for a hydrogen chloride synthesis furnace according to claim 1, characterized in that, The tank (1) is equipped with a remote dual level gauge (14) on its side wall.

6. A steam flash evaporation device for a hydrogen chloride synthesis furnace according to claim 1, characterized in that, A manhole (13) is provided on the side wall of the tank (1), and a manhole cover is provided on the outside of the manhole (13).

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