阅读说明：本技术 一种高浓度二氧化硫气体的生产方法 (Production method of high-concentration sulfur dioxide gas ) 是由 张培清 潘木俊 于 2021-08-27 设计创作，主要内容包括：本发明公开了一种高浓度二氧化硫气体的生产方法,焚硫炉燃烧产生的二氧化硫烟气经降温冷却后,部分烟气进入下游工序,余下的烟气通过管道返回焚硫炉前与空气混合后一同进入焚硫炉,同时液硫在焚硫炉内喷雾燃烧,产生适当浓度的二氧化硫烟气,如此循环往复。该方法采用经余热锅炉冷却后的烟气回流方法,不仅可以把烟气中二氧化硫的浓度提得更高,同时避免了焚硫炉的超温,还可以回收大量的热量。(The invention discloses a production method of high-concentration sulfur dioxide gas, wherein sulfur dioxide flue gas generated by burning of a sulfur burning furnace is cooled, part of the flue gas enters a downstream process, the rest flue gas returns to the front of the sulfur burning furnace through a pipeline and is mixed with air to enter the sulfur burning furnace, meanwhile, liquid sulfur is sprayed and burned in the sulfur burning furnace to generate sulfur dioxide flue gas with proper concentration, and the steps are repeated in a circulating way. The method adopts a flue gas reflux method after cooling by the waste heat boiler, so that the concentration of sulfur dioxide in the flue gas can be improved to be higher, the overtemperature of the sulfur incinerator is avoided, and a large amount of heat can be recovered.)

1. A production method of high-concentration sulfur dioxide gas is characterized by comprising the following steps: and (3) cooling sulfur dioxide flue gas generated by combustion of the sulfur incinerator, then introducing part of the flue gas into a downstream process, returning the rest flue gas to the front of the sulfur incinerator through a pipeline, mixing the flue gas with air, then introducing the mixture into the sulfur incinerator, and simultaneously spraying and combusting liquid sulfur in the sulfur incinerator to generate sulfur dioxide flue gas with proper concentration, wherein the steps are repeated in a circulating manner.

2. The method for producing a high concentration sulfur dioxide gas as recited in claim 1, characterized in that: the sulfur dioxide flue gas generated by burning the sulfur incinerator is firstly cooled to 310-330 ℃ by a waste heat boiler and then enters a coal economizer to be cooled to 130-150 ℃ again, part of the flue gas sent out by the coal economizer returns to be mixed with air, and the rest flue gas enters a downstream process.

3. The method for producing a high concentration sulfur dioxide gas as recited in claim 1, characterized in that: the concentration of sulfur dioxide gas in the mixed gas is less than or equal to 5.36 percent.

4. The method for producing a high concentration sulfur dioxide gas as recited in claim 1, characterized in that: liquid sulfur is sent into the sulfur burning furnace through a liquid sulfur pump, and cooled part of flue gas is returned through a flue gas fan to be mixed with dry air sent out by an air fan and then sent into the sulfur burning furnace.

5. The method for producing a high concentration sulfur dioxide gas as recited in claim 1, characterized in that: and part of the cooled flue gas directly returns to the inlet end of the air fan to be mixed with dry air under the suction action of the air fan, and then is sent into the sulfur burning furnace by the air fan.

Technical Field

The invention relates to a production method of sulfur dioxide gas, in particular to a production method of high-concentration sulfur dioxide gas.

Background

The industrial production of sulphur dioxide is mainly obtained from the direct incineration of sulphur-containing raw materials. When sulfur dioxide is prepared by burning sulfur, if the concentration of the sulfur dioxide in the sulfur dioxide flue gas is to be increased to 18%, the burning temperature can reach more than 1600 ℃, and the concentration of the sulfur dioxide in the flue gas generated by burning the sulfur is not too high and is generally lower than 13% due to the limitation of the high temperature resistance of equipment (the operation temperature is less than 1150 ℃), so that the requirement of higher concentration of the sulfur dioxide in certain occasions can not be met. The oxygen-enriched or pure oxygen incineration of sulfur can produce high-concentration sulfur dioxide, but the cost is higher, the incineration temperature is also higher, and common equipment cannot bear the high-concentration sulfur dioxide. The existing oxygen-enriched smelting process can produce sulfur dioxide gas with concentration of more than 18%, but the process is often far away from the place using sulfur dioxide, safe transportation and use are extremely inconvenient, and even if separation, purification, compression, liquefaction, canning and transportation are adopted to obtain the sulfur dioxide gas with high concentration, the cost is extremely high. In addition, the general higher-concentration sulfur dioxide preparation process is to carry out water-cooling shock on high-temperature sulfur dioxide flue gas generated by sulfur combustion, does not recover heat, can be simpler in equipment, but has a large amount of waste heat waste and needs to consume a large amount of cooling water.

Disclosure of Invention

The invention aims to provide a method for producing high-concentration sulfur dioxide gas. When the method is used for preparing the high-concentration sulfur dioxide gas, the flue gas cooled by the waste heat boiler flows back to the sulfur incinerator, the backflow flue gas absorbs heat generated in the combustion process of sulfur to avoid high temperature, so that the internal temperature of the sulfur incinerator is less than 1150 ℃, the high-concentration sulfur dioxide gas can be prepared, meanwhile, the internal overtemperature of the sulfur incinerator is avoided, and a large amount of heat can be recovered.

The technical scheme of the invention is as follows: a method for producing high-concentration sulfur dioxide gas includes cooling sulfur dioxide flue gas generated by combustion of a sulfur burner, enabling part of flue gas to enter a downstream process, enabling the rest flue gas to return to the front of the sulfur burner through a pipeline and to enter the sulfur burner together with air after being mixed with the air, enabling liquid sulfur to be sprayed and combusted in the sulfur burner to generate sulfur dioxide flue gas with proper concentration, and repeating the steps in a circulating mode.

In the production method of the high-concentration sulfur dioxide gas, the sulfur dioxide flue gas generated by burning the sulfur burning furnace is firstly cooled to 310-330 ℃ by the waste heat boiler and then enters the economizer to be cooled to 130-150 ℃ again, part of the flue gas sent by the economizer returns to be mixed with air, and the rest flue gas enters a downstream process.

In the production method of the high-concentration sulfur dioxide gas, the concentration of the sulfur dioxide gas in the mixed gas is less than or equal to 5.36 percent.

In the production method of the high-concentration sulfur dioxide gas, liquid sulfur is sent into the sulfur incinerator through the liquid sulfur pump, and part of cooled flue gas is returned through the flue gas fan to be mixed with dry air sent out by the air fan and then sent into the sulfur incinerator.

In the production method of the high-concentration sulfur dioxide gas, part of the cooled flue gas directly returns to the inlet end of the air fan under the suction action of the air fan to be mixed with the dry air, and then is sent into the sulfur incinerator by the air fan.

The invention has the beneficial effects that: compared with the prior art, the system and the production process for producing the sulfur dioxide gas by the existing sulfur incinerator are simply improved, part of the flue gas containing the sulfur dioxide gas after being burnt, cooled and output is returned to the front end of the system to be mixed with air and then is input into the sulfur incinerator, the returned sulfur dioxide flue gas does not participate in combustion, and the returned sulfur dioxide flue gas absorbs a large amount of heat in the heating process inside the sulfur incinerator, so that the temperature inside the sulfur incinerator is reduced, the high temperature generated in the process of preparing the high-concentration sulfur dioxide gas by burning liquid sulfur is prevented from damaging the sulfur incinerator, and the generation of the high-concentration sulfur dioxide gas is facilitated.

The production practice shows that the method of refluxing the flue gas cooled by the waste heat boiler to the front end of the sulfur burning furnace can improve the concentration of sulfur dioxide gas in the flue gas to 18 percent, simultaneously avoid the overtemperature of the sulfur burning furnace and recover a large amount of heat.

Drawings

FIG. 1 is a schematic structural view of a device for producing sulfur dioxide gas according to the present invention;

Detailed Description

The invention will be further described with reference to the accompanying fig. 1 and examples, but is not to be construed as being limited thereto.

Example 1 of the invention: a production method of high-concentration sulfur dioxide gas is disclosed, as shown in figure 1, after high-temperature sulfur dioxide flue gas generated by combustion of a sulfur burning furnace is cooled, part of the flue gas returns to the front end of the whole production system through a pipeline after being acted by a flue gas fan and is mixed with air to enter the sulfur burning furnace, the concentration of the sulfur dioxide gas in the mixed gas is less than or equal to 5.36 percent, the rest sulfur dioxide flue gas enters a downstream process, meanwhile, liquid sulfur is sent into the sulfur burning furnace under the action of a liquid sulfur pump to be sprayed and combusted, and the generated sulfur dioxide flue gas is discharged in a circulating way.

The high-temperature sulfur dioxide flue gas generated by combustion of the sulfur incinerator is firstly cooled to 310-330 ℃ by a waste heat boiler and then enters the economizer to be cooled to 130-150 ℃ again, part of the sulfur dioxide flue gas sent out by the economizer returns to be mixed with air, and the rest sulfur dioxide flue gas enters a downstream process.

In the whole production process, liquid sulfur is pumped into the sulfur incinerator through the liquid sulfur pump, and part of cooled flue gas is returned through the flue gas fan and mixed with dry air sent out by the air fan and then sent into the sulfur incinerator.

As can be seen from the attached figure 1, when the flue gas fan fails, in order to ensure that the cooled flue gas circulates normally, the cooled part of the flue gas can also be directly returned to the inlet end of the air fan to be mixed with dry air under the action of the air fan, and then the mixed flue gas is sent into the sulfur burning furnace. The circulation of the cooling flue gas is realized through a double system.

The principle of the production method of the invention is as follows: in order to conveniently obtain sulfur dioxide gas with higher concentration, the method adopts a flue gas reflux technology after indirect heat exchange cooling, avoids the problem of high temperature resistance of equipment, can even adjust the concentration of sulfur dioxide in the sulfur dioxide flue gas within the range of 5-18 percent, and is convenient for downstream use.

Taking the sulfur dioxide gas with the production concentration of 18% as an example, the production method of the high-concentration sulfur dioxide gas is introduced, dry air is sent into a sulfur incinerator through an air fan, the returned flue gas is mixed with dry air under the action of a flue gas fan and enters the sulfur incinerator, at the moment, the concentration of sulfur dioxide in the mixed gas is 5.36%, liquid sulfur is sent into the sulfur incinerator for spray combustion under the action of a liquid sulfur pump to generate the flue gas with the concentration of 18% of sulfur dioxide, the temperature of which reaches about 1100 ℃ (depending on the heat dissipation condition of equipment), the flue gas is cooled to about 320 ℃ through a waste heat boiler and then enters an economizer to be cooled to about 140 ℃ again, part of the flue gas is returned through the flue gas fan to be uniformly mixed with fresh air and then enters the sulfur incinerator to participate in sulfur combustion, and the rest of the flue gas enters a downstream process and is circulated in a reciprocating mode.

The waste heat boiler generates saturated steam of about 3.5MPa, boiler feed water comes from a deoxygenation water system and is sent to an economizer through a feed water pump to be heated to about 243 ℃, and the steam enters a steam pocket of the waste heat boiler.

The process has the advantages that: the concentration of the carbon dioxide stream can reach 18 percent at most and can be adjusted in a certain range, and the sulfur incinerator can generate flue gas with the concentration of 5 to 18 percent and the temperature of about 500 ℃ and 1100 ℃. When the concentration of sulfur dioxide in the flue gas to be produced is lower than 13%, the cooling flue gas can be returned to the system without starting the cooling flue gas, and the original system can be used for production. When the sulfur dioxide gas with the concentration of more than 13% needs to be produced, the backflow amount of the flue gas fan can be adjusted according to the prepared flue gas concentration, and when the produced concentration is 18%, the backflow amount is the largest, so that the concentration of the sulfur dioxide gas in the mixed gas is the highest and reaches 5.36% after the backflow flue gas is mixed with dry air.

In the system, the flue gas waste heat generated by the sulfur incinerator can be fully utilized, the waste heat boiler has simple and reliable flow and convenient operation, and can generate steam of various grades.

TABLE 1 control parameter table for each step in the production of 18% sulfur dioxide gas