CN-122006443-A - Transformation method for changing calcium desulfurization system into ammonia desulfurization system

Abstract

The invention provides a modification method for changing a calcium desulfurization system into an ammonia desulfurization system, which comprises the step of modifying a calcium desulfurization tower in the calcium desulfurization system into the ammonia desulfurization tower of the ammonia desulfurization system, so that the ammonia desulfurization tower sequentially comprises an oxidation section, a cooling section, an absorption section, a water washing section and a demisting section from bottom to top, and the absorption section is subjected to diameter expansion modification so as to reduce the gas velocity and improve the ammonia desulfurization absorption effect, thereby meeting the working condition requirement of the ammonia desulfurization system. The transformation method fully utilizes the original calcium desulfurization system, can improve the utilization rate, can improve the transformation utilization rate by more than 80 percent, reduces the cost and improves the transformation effect.

Inventors

• XU JUNSHENG

Assignees

• 江苏江南生态碳科技(集团)股份有限公司
• 江南环境科技公司

Dates

Publication Date

20260512

Application Date

20260403

Claims (6)

1. 1. A retrofitting method for changing a calcium desulfurization system into an ammonia desulfurization system, the retrofitting method comprising: The method comprises the steps of modifying a calcium desulfurization tower in a calcium desulfurization system into an ammonia desulfurization tower of an ammonia desulfurization system, wherein the ammonia desulfurization tower sequentially comprises an oxidation section, a cooling section, an absorption section, a washing section and a demisting section from bottom to top, and the absorption section is subjected to diameter expansion modification so as to reduce the gas velocity and improve the ammonia desulfurization absorption effect.
2. 2. The modification method according to claim 1, wherein, for the absorption section of the ammonia desulfurization tower, the tower diameter of the absorption section satisfies the formula ; Wherein D is the tower diameter of the absorption section, the unit is m, Q is the desulfurization flue gas amount under the ammonia desulfurization working condition, the unit is m 3 /s, and u is the air tower air speed under the ammonia desulfurization working condition, the unit is m/s.
3. 3. The improvement method according to claim 1 or 2, characterized in that said diameter-enlarging improvement comprises dividing the tower body of said calcium desulfurization tower above the top of the original flue gas inlet, and inserting a newly added diameter-enlarging absorption section as the absorption section of said ammonia desulfurization tower.
4. 4. The improvement according to claim 1, characterized in that said improvement further comprises using a main pipe split control for the absorption circulation pump in the calcium desulfurization system to achieve one pump to multiple spray levels.
5. 5. The improvement method according to claim 1, further comprising the steps of adopting a parent pipe for an oxidation fan in the calcium desulfurization system, and adding at least one oxidation fan according to actual conditions.
6. 6. The improvement method according to claim 1, further comprising the step of improving a gypsum treatment module in the calcium desulfurization system to an ammonium sulfate treatment module in the ammonia desulfurization system, wherein an original cyclone is improved, and a centrifuge, a dryer and a packaging machine are sequentially added at the outlet of the cyclone.

Description

Transformation method for changing calcium desulfurization system into ammonia desulfurization system Technical Field The invention relates to the technical field of flue gas desulfurization, in particular to a modification method for changing a calcium desulfurization system into an ammonia desulfurization system. Background At present, a flue gas desulfurization device of a thermal power generating unit mostly adopts a limestone-gypsum wet method (also called a calcium method), namely limestone superfine powder is prepared into slurry to be used as a desulfurization raw material, and a desulfurization product is desulfurization gypsum (CaSO 4·2H2 O). However, the limestone-gypsum wet method has the following problems that (1) the calcium method desulfurization is a process of removing waste to produce three wastes, namely, solid waste gypsum, desulfurization waste water and greenhouse gas CO 2 are produced while SO 2 is removed, (2) the national calcium method desulfurization annual production desulfurization gypsum is about 9000 ten thousand tons, most of the desulfurization gypsum is used as solid waste for storage or landfill under the condition of no anti-seepage treatment except for a small part of the desulfurization gypsum is applied by the construction industry, a large amount of desulfurization gypsum is easy to cause secondary pollution in the stacking process, (3) the calcium method desulfurization relies on limestone (CaCO 3) as a desulfurizing agent, the limestone reacts with SO 2 to produce CO 2, each 1 ton of SO 2 is removed to produce 0.7 ton of CO 2, the extra carbon emission is contrary to the national carbon peak and carbon neutralization strategic targets, (4) the large-scale exploitation of the limestone damages green mountain water, the shortage of resources is further increased, and a large amount of high salt is produced in the desulfurization cost in the calcium method process, and the zero emission is realized. In contrast, ammonia desulfurization is carried out by taking liquid ammonia or ammonia water as a desulfurizing agent for flue gas desulfurization, the route has no waste water, waste residue and waste gas, no additional carbon dioxide emission is increased, and the byproduct ammonium sulfate can be sold as fertilizer, so that the development of agriculture can be supported. Moreover, the electricity consumption of the ammonia process technology is reduced by four times compared with that of a calcium process, and the whole operation cost is reduced to be positive. Therefore, for the flue gas desulfurization system of the thermal power generating unit, in order to pursue the minimization of the reconstruction cost and the maximization of the environmental protection benefit and the economic benefit after reconstruction, a reconstruction method for changing the calcium desulfurization system into the ammonia desulfurization system needs to be developed. Disclosure of Invention In view of the problems existing in the prior art, the invention provides a modification method for changing a calcium desulfurization system into an ammonia desulfurization system, which comprises the step of modifying a calcium desulfurization tower in the calcium desulfurization system into an ammonia desulfurization tower of the ammonia desulfurization system, so that the ammonia desulfurization tower sequentially comprises an oxidation section, a cooling section, an absorption section, a washing section and a demisting section from bottom to top, and the absorption section is subjected to diameter expansion modification so as to reduce the gas velocity and improve the ammonia desulfurization absorption effect, thereby meeting the working condition requirements of the ammonia desulfurization system. The transformation method fully utilizes the original calcium desulfurization system, can improve the utilization rate, can improve the transformation utilization rate by more than 80 percent, reduces the cost and improves the transformation effect. To achieve the purpose, the invention adopts the following technical scheme: the invention aims to provide a transformation method for changing a calcium desulfurization system into an ammonia desulfurization system, which comprises the step of transforming a calcium desulfurization tower in the calcium desulfurization system into an ammonia desulfurization tower of the ammonia desulfurization system, wherein the ammonia desulfurization tower sequentially comprises an oxidation section, a cooling section, an absorption section, a washing section and a demisting section from bottom to top, and the absorption section is subjected to diameter expansion transformation so as to reduce the gas velocity and improve the ammonia desulfurization absorption effect. The ammonia desulfurization tower is characterized in that an oxidation section and a cooling section in the tower are completely isolated through a partition plate, a gas-liquid separator is respectively