We need to understand the mechanism of sublimed sulfur production before analyzing the causes, in order to understand this problem more clearly, so as to better solve it.

Mechanism of sublimation sulfur production

In the process of sulfur acid production, due to the low local oxygen-sulfur ratio, sulfur is not fully burned, and it is easy to vaporize into sublimed sulfur (sulfur boiling point 444.6 ℃; Sulfur burning furnace temperature above 800 ℃).

The combustion rate of unburned or unvaporized liquid sulfur at this time (the average free combustion rate of liquid sulfur is 15kg/ (h• m²) Much less than the atomized liquid sulfur will accumulate at the bottom of the furnace and enter the thermal insulation layer through the gaps between the refractory bricks of the furnace. At this time, the insulation effect of the insulation layer will be reduced, and the reaction in the production is the reduction of steam, while sulfur will react with iron, as follows:

The generated ferrous sulfide is dark brown or gray black flake or granular matter, the density is 4.84g/cm3 (iron is 7.8g/cm3), at this time the volume will expand, so that the appearance of the sulfur furnace deformation, at the same time, there will be a bell sulfur column outside the sublimed sulfur cooling.

The harm of producing sublimed sulfur

1. Part of sublimed sulfur is not burned and enters the subsequent section with high temperature gas, condenses into sulfur during cooling, deposits and corrodes equipment and pipelines, causing problems such as increased resistance and blockage of valves and pipelines, thereby increasing the blower load and reducing the system production load. In serious cases, it will lead to system blockage and forced shutdown;

2, condensed sulfur into the finished sulfuric acid and sulfuric acid in the circulation tank will cause acid turbidity, reduce transparency, product quality decline; One of the most serious is the boiler, because in order to better heat exchange in the boiler, the contact area is larger, then the sublimed sulfur and the fire tube in the boiler contact area is also larger, the production of iron sulfide will increase, aggravate the corrosion of the boiler;

3, the generated ferrous sulfide is also easy to enter the converter section, which aggravates the blockage of the boiler and a section of packing.

Reason analysis

After understanding the sources and hazards, we analyze why the device produces this reason:

1. The atomization effect of the sulfonate gun is not good or does not meet the design standards of the sulfur burner

For example: the spray effect of the sulfonate gun is not good, resulting in insufficient combustion, which accumulates at the bottom. Although the oxygen to sulfur ratio is in line with the process, its combustion rate is not enough, which will lead to sublimed sulfur entering the subsequent section with high temperature gas.

2. Excessive amount of sulfonation or insufficient air volume destroys the oxygen-sulfur ratio of the production process

For example, due to the increase of pressure drop in the subsequent section, the intake air volume of the fan is reduced, and the oxygen-sulfur ratio of the normal production process is destroyed. Although the indicators are not changed at the time of operation, the excess liquid sulfur has begun to accumulate in the sulfur burner and enter the subsequent section with the high-temperature gas.

3. Instrument data is not accurate

Improper use of some remote instrumentation, accuracy and process production standards do not meet, will make some instrument data deviation, affect the operation of the process.

Solution

1. For the problem of atomization or standard of the sulfonate gun, the sulfonate gun that meets the design standard is used to ensure the smooth progress of the production process.

2. Real-time monitoring of the relationship between oxygen and sulfur to prevent the ratio from changing and sublimating sulfur.

3. Normalize the instrument to ensure normal and compliant use of the instrument.