Sulfur trioxide production device

Abstract

The utility model relates to the technical field of sulfur trioxide separation and evaporation, and discloses a sulfur trioxide production device, which aims to solve the problem in sulfur trioxide evaporation in the prior art, and comprises a fuming sulfuric acid storage tank, the fuming sulfuric acid storage tank is connected with a film evaporator, and the film evaporator is connected with a saturated steam or heat-conducting oil pipeline and a fuming acid pipeline. The top of the film evaporator is connected with a gaseous sulfur trioxide pipeline, the gaseous sulfur trioxide pipeline is connected with a condenser, the condenser is connected with a liquid sulfur trioxide tank, a swirler is arranged in the film evaporator and comprises a first-stage swirling vane arranged at the lower part in the film evaporator, and a second-stage swirling vane is arranged at the upper part in the film evaporator; the film evaporator is utilized to separate gas-phase sulfur trioxide from low-concentration fuming acid, so that the sulfur trioxide is evaporated quickly, the swirlers are arranged in the film evaporator, materials are prevented from being carried by gas, and the swirlers are arranged in an upper stage and a lower stage, so that the evaporation rate of the sulfur trioxide can be effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model belongs to sulfur trioxide separation evaporation technical field, concretely relates to a sulfur trioxide production device. BACKGROUND

[0002] In the liquid sulfur trioxide production in prior art, there are years of operation experience in China, and the technology is introduced in the sulfuric acid production processing and equipment practical manual.

[0003] There are falling film evaporator and horizontal evaporator (such as the anode protection sulfur trioxide evaporator disclosed in patent CN201110304706.3) in the oleum production, and both are shell and tube heat exchangers, and the heat transfer efficiency is far lower than 500w / m2.k.The falling film evaporator requires that oleum can be evenly distributed to each heat exchange pipe, and the outside of the pipe is heated by the reverse flow of conversion gas.The equipment has extremely high requirements for the distribution of oleum and installation, otherwise, the local heat exchange pipe will have less acid, the oleum will be evaporated, the local concentration of free sulfur trioxide is lower than 15%, and corrosion and leakage will occur; the shell of horizontal evaporator is provided with evaporation space, and the cylinder diameter is large, so the occupied area is large.

[0004] The thickness of the heat exchange pipe of the two forms of heat exchangers is generally greater than or equal to 2.0mm, the pipe wall is thin, and it is not easy to carry out corrosion design due to the multiple and dense pipe bundles.In addition, the evaporation efficiency of the prior art equipment is low, the evaporation capacity needs to be greatly increased, the pipe bundle area needs to be increased, and the equipment weight and the occupied area are increased.For the evaporation technology of conventional sulfur trioxide gas, the technical problem of accelerated corrosion of low-concentration oleum needs to be solved to realize rapid evaporation and improve the evaporation rate. UTILITY MODEL CONTENTS

[0005] The utility model discloses a sulfur trioxide production device to solve the technical problems in the prior art sulfur trioxide evaporation.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme:

[0007] The utility model relates to a kind of sulfur trioxide production device, including oleum storage tank, the oleum storage tank is connected with the outlet of thin film evaporator, thin film evaporator is also connected with saturated steam or heat conducting oil pipeline, oleum pipeline, the top of thin film evaporator is connected with gaseous sulfur trioxide pipeline, gaseous sulfur trioxide pipeline is connected with condenser, condenser is connected with liquid sulfur trioxide tank, the thin film evaporator is equipped with cyclone, cyclone includes the first stage cyclone blade installed in lower portion in thin film evaporator, thin film evaporator is equipped with second stage cyclone blade in upper portion, and the first stage cyclone blade, second stage cyclone blade are the blade of middle high, edge low, support column is equipped between the first stage cyclone blade, second stage cyclone blade, each blade of the first stage cyclone blade is equipped with multiple guide grooves, multiple guide columns are correspondingly equipped between the low point position of second stage cyclone blade, the first stage cyclone blade is also equipped with breaker.

[0008] Further, the guide groove is a plurality of guide grooves arranged through in horizontal and vertical on the first stage cyclone blade.

[0009] Further, the first stage cyclone blade is equipped with cofferdam plate on the side of downward inclination.

[0010] Further, the breaker is a plurality of spicules arranged on the first stage cyclone blade.

[0011] Further, the outlet of liquid sulfur trioxide tank is connected with liquid sulfur trioxide metering pump, and the liquid phase import pipeline of thin film evaporator is provided with flow regulating valve.

[0012] Further, the condenser is connected with vacuum pump by pipeline, and the pipeline of vacuum pump and condenser is provided with pressure regulating valve.

[0013] Compared with the prior art, the utility model has the following beneficial effects:

[0014] The utility model can realize the quick evaporation of sulfur trioxide, improve evaporation efficiency, and increase the evaporation capacity of unit circulation flow. By using the thin film evaporator, the separation of gaseous sulfur trioxide and low-concentration oleum is realized. Under the action of gravity and the rotating movable scraper of the thin film evaporator, the oleum forms a downward rotating film on the inner wall of the cylinder, and the liquid is distributed into a uniform film, so that the sulfur trioxide is quickly evaporated, and the evaporation capacity per unit area can be more than 6 times that of the traditional evaporator. At the same time, under the action of the thin film evaporator, the heating time is short, the residence time of low-concentration oleum on the wall surface is reduced, and the corrosion of low-concentration oleum on the inner wall of the cylinder under high temperature is avoided. The equipment evaporation efficiency can be improved, the heat transfer temperature difference is increased, and compared with the prior art, the heat exchange area can be effectively reduced under the same production capacity, which is more conducive to reducing the corrosion rate of oleum.

[0015] The utility model discloses a cyclone is set up in thin film evaporator, avoid material to be carried by gas, and cyclone is set up to two levels, can effectively improve the evaporation rate of sulfur trioxide. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is the structure flow schematic diagram of the utility model.

[0017] Figure 2 It is the schematic diagram of cyclone of the utility model.

[0018] Figure 3 It is the structure schematic diagram of primary cyclone vane of the utility model.

[0019] Figure 4 It is the structure schematic diagram of secondary cyclone vane of the utility model.

[0020] Figure 5 It is the structure schematic diagram of single vane of secondary cyclone vane of the utility model.

[0021] The meaning of the figure mark is as follows: 1. fuming sulfuric acid storage tank, 2. thin film evaporator, 3. saturated steam or heat conducting oil pipeline, 4. fuming acid pipeline, 5. gaseous sulfur trioxide pipeline, 6. pressure regulating valve, 7. condenser, 8. liquid sulfur trioxide tank, 9. primary cyclone vane, 10. flow guide column, 11. secondary cyclone vane, 12. support column, 13. flow guide groove, 14. breaker, 15. liquid sulfur trioxide metering pump, 16. flow regulating valve, 17. vacuum pump, 18. cofferdam plate. DETAILED DESCRIPTION

[0022] The utility model will be further explained in connection with the drawings and specific implementation.

[0023] For example, Figures 1-5As shown, a kind of sulfur trioxide production device, including oleum storage tank 1, oleum storage tank 1 is connected with the outlet of membrane evaporator 2, the oleum line 4 of membrane evaporator 2 is provided with flow regulating valve 16, membrane evaporator 2 is also connected with saturated steam or heat conducting oil line 3, the top of membrane evaporator 2 is connected with gaseous sulfur trioxide line 5, gaseous sulfur trioxide line 5 is connected with condenser 7, condenser 7 is connected with liquid sulfur trioxide tank 8, condenser 7 is connected with vacuum pump 17 by pipeline, pressure regulating valve 6 is provided on the pipeline of vacuum pump 17 and condenser 7, the outlet of liquid sulfur trioxide tank 8 is connected with liquid sulfur trioxide metering pump 15, cyclone is installed in membrane evaporator 2, cyclone includes the first stage cyclone blade 9 installed in the lower part in membrane evaporator 2, the second stage cyclone blade 11 is installed in the upper part in membrane evaporator 2, and the first stage cyclone blade 9, second stage cyclone blade 11 are all the blade of middle high, edge low, support column 12 is fixedly installed between the first stage cyclone blade 9, second stage cyclone blade 11, a plurality of guide grooves 13 are provided on each blade of the first stage cyclone blade 9, the guide groove 13 is the multiple guide grooves arranged in the first stage cyclone blade 9 in transverse and longitudinal, a plurality of guide columns 10 are correspondingly installed between the guide groove 13 and the low point position of second stage cyclone blade 11, breaker 14 is also provided on the first stage cyclone blade 9, and the breaker 14 is the multiple spines arranged on the first stage cyclone blade 9, the side of the first stage cyclone blade 9 that is inclined downward is equipped with cofferdam plate 18.(the edge of the first stage cyclone blade 9, second stage cyclone blade 11 is welded and fixed with the inner wall of membrane evaporator 2, support column 12 is connected with scraper shaft sleeve, scraper shaft rotates, and support column 12 does not rotate.The scraper and scraper shaft are prior art, not shown in the drawing)

[0024] Oleum enters from the liquid inlet of membrane evaporator 2, which is provided with acid washing replacement pipeline, heat conducting oil or steam is passed in the jacket of membrane evaporator, and the inner wall is polished, and the scraper is installed on the rotatable scraper shaft, in membrane evaporator 2, high concentration oleum realizes the separation of gaseous sulfur trioxide and low concentration oleum after heating.Gaseous sulfur trioxide enters condenser 7 through pipeline, the bottom of condenser 7 is provided with liquid outlet, which is connected with liquid sulfur trioxide tank 8 through pipeline.Liquid phase sulfur trioxide after condensation flows into liquid sulfur trioxide tank 8 by gravity, and liquid sulfur trioxide tank 8 is used one by one.

[0025] The bottom of the membrane evaporator is provided with a liquid outlet, and the liquid outlet is connected with a liquid storage tank through a pipeline.

[0026] The vacuum pump is connected with the condenser through a pipeline, and a pressure regulating valve is arranged on the pipeline connecting the vacuum pump and the condenser.

[0027] When working, the following steps are carried out.

[0028] Step 1, introduce 109%-109.6% of nicotinic acid into the thin film evaporator 2, and set the working parameters of the thin film evaporator 2 (in this embodiment, the heating medium pressure of the thin film evaporator 2 is 0.8 MPa, the temperature of the saturated steam or conductive oil is 175℃, and the temperature control of the thin film evaporator 2 is 100-120℃).

[0029] Step 2, when the nicotinic acid in the thin film evaporator 2 passes through the first cyclone vane 9, the nicotinic acid is broken into small droplets by the defoamer 14, collected in the flow guide groove 13, flows to one side of the cofferdam plate 18, and finally contacts the heating wall of the thin film evaporator 2 for evaporation.

[0030] Step 3, small particle size droplets that cannot be captured by the first cyclone vane 9 pass through the second cyclone vane 11, collect, and flow to the flow guide groove 13 of the first cyclone vane 9 through the flow guide column 10, flow to one side of the cofferdam plate 18 with the collected liquid of the first cyclone vane 9, and then evaporate.

[0031] Step 4, the liquid sulfur trioxide at the bottom is discharged into the closed liquid sulfur trioxide tank 8 by gravity through the condenser 7.

[0032] Step 5, the vacuum degree is stabilized in the system pressure range of the thin film evaporator 2, and the continuous evaporation is completed.

Claims

1. A sulfur trioxide production plant comprising a fuming sulfuric acid reservoir (1), characterized by: The fuming sulfuric acid tank (1) is connected with the acid outlet of the membrane evaporator (2), and the membrane evaporator (2) is further connected with a saturated steam or heat conducting oil pipeline (3) and a fuming acid pipeline (4). The top of the membrane evaporator (2) is connected with a gaseous sulfur trioxide pipeline (5), the gaseous sulfur trioxide pipeline (5) is connected with a condenser (7), the condenser (7) is connected with a liquid sulfur trioxide tank (8), and the membrane evaporator (2) is provided with a cyclone therein. The cyclone comprises a first-stage cyclone blade (9) arranged at the lower part of the membrane evaporator (2), and a second-stage cyclone blade (11) arranged at the upper part of the membrane evaporator (2). The first-stage cyclone blade (9) and the second-stage cyclone blade (11) are both blades with a middle part being higher than the edges. A support column (12) is arranged between the first-stage cyclone blade (9) and the second-stage cyclone blade (11). A plurality of guide grooves (13) are arranged on each blade of the first-stage cyclone blade (9). A plurality of guide columns (10) are arranged between the guide grooves (13) and the low point positions of the second-stage cyclone blade (11). A breaker (14) is further arranged on the first-stage cyclone blade (9).

2. A plant for the production of sulfur trioxide according to claim 1, characterized in that The guide grooves (13) are a plurality of guide grooves arranged on the first-stage cyclone blade (9) in a transverse and longitudinal manner.

3. A plant for the production of sulfur trioxide according to claim 2, characterized in that: The first-stage cyclone blade (9) is provided with a cofferdam plate (18) on the side inclined downward.

4. A plant for the production of sulfur trioxide according to claim 1, characterized in that: The breaker (14) is a plurality of spines arranged on the first-stage cyclone blade (9).

5. A plant for the production of sulfur trioxide according to claim 1, characterized in that: The outlet of the liquid sulfur trioxide tank (8) is connected with a liquid sulfur trioxide metering pump (15), and a flow regulating valve (16) is arranged on the liquid phase inlet pipeline of the membrane evaporator (2).

6. A sulfur trioxide production apparatus according to claim 1, characterized in that: The condenser (7) is connected with a vacuum pump (17) through a pipeline, and a pressure regulating valve (6) is arranged on the pipeline between the vacuum pump (17) and the condenser (7).

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