SDA rotary spray drying desulfurization system
By fine grinding the lime mortar with colloid mill in the SDA deacidification system, the problem of limited addition of lime mortar when dealing with high concentrations of acid gases in traditional processes is solved, and a more efficient deacidification reaction and lime utilization rate is achieved, which meets strict emission standards and reduces costs.
Patent Information
- Application Number
- CN202421371408.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-17
- Publication Date
- 2025-03-25
- Estimated Expiration
- 2034-06-17
AI Technical Summary
When the traditional SDA rotary spray drying and desulfurization process treats high concentrations of acid gas, the amount of lime mortar is limited, which leads to the inability to guarantee the emission of acid gases to meet standards, and the utilization rate of lime slurry is low, resulting in a large amount of fly ash, which increases the cost and difficulty of processing.
By introducing colloid mill into the SDA deacidification system, the lime mortar is finely grounded, which significantly reduces the size of particles in the lime mortar, thereby improving the dissolution rate of Ca(OH)2 and deacidification efficiency.
The specific surface area and dissolution speed of lime mortar are improved, the contact and reaction capacity with acid gases are enhanced, the efficiency of deacidification reaction and lime utilization rate are significantly improved, the increasingly stringent pollutant emission standards are met, and the amount of lime mortar and the generation of fly ash are reduced.
Smart Images
Figure CN222658309U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of flue gas environmental protection purification, and specifically relates to an SDA rotary spray drying desulfurization system. Background Art
[0002] With the increasing awareness of environmental protection and increasingly stringent pollutant emission standards, domestic waste incinerators are facing the challenge of reducing acid gas emissions in flue gas while processing waste and generating energy. The mainstream deacidification process for domestic waste incinerators is the lime slurry rotary spray desulfurization process (SDA), which uses slaked lime as a desulfurizer and atomizes the lime slurry into fine droplets through a high-speed rotating atomizer. After mixing with the flue gas, the acid gas is absorbed by the lime slurry to achieve the purpose of flue gas purification.
[0003] However, with the increase in the incineration of industrial waste in municipal solid waste incinerators, the acid gas composition in the flue gas has become more complex and the concentration has become higher, which poses a higher challenge to the SDA process. The traditional SDA process is limited by the temperature requirements of the bag filter, and there is an upper limit on the amount of lime slurry added. When the concentration of acid gas is too high and the amount of lime slurry added is difficult to increase, the emission of acid gas cannot be guaranteed to meet the standards. The countermeasure at this time is to increase the amount of slaked lime powder added. However, the deacidification efficiency of ordinary slaked lime powder is low, resulting in low utilization of slaked lime. A large amount of unreacted slaked lime will be converted into fly ash, which is classified as hazardous waste and requires further treatment, increasing the cost and difficulty of treatment.
[0004] In the SDA process, the dissolution of Ca(OH)2 in the droplets is an important mass transfer process, which has a direct impact on the efficiency of the deacidification reaction. The size of the lime particles is a key factor affecting the dissolution rate of Ca(OH)2. The smaller the particle size, the larger the specific surface area and the faster the dissolution rate, thereby improving the deacidification efficiency and lime utilization. However, the current technology lacks equipment and methods that can effectively reduce the particle size in the lime slurry, which limits the performance of the SDA process in dealing with high-concentration acid gas emissions. Utility Model Content
[0005] In view of the deficiencies in the prior art, the utility model provides an SDA rotary spray drying desulfurization system, which can effectively reduce the particle size in the lime slurry, thereby improving the deacidification efficiency and lime utilization rate.
[0006] The utility model is realized through the following technical solutions:
[0007] A SDA rotary spray drying desulfurization system comprises a slurry preparation tank, a colloid mill, a finished product tank and an SDA deacidification tower; wherein a pipeline is provided at the bottom outlet of the slurry preparation tank to be connected to the inlet of the colloid mill, a pipeline is provided at the outlet of the colloid mill to be connected to the top inlet of the finished product tank, and the bottom outlet of the finished product tank is connected to the rotary atomizer of the SDA deacidification tower through a pipeline.
[0008] Preferably, a delivery pump is provided on the pipeline between the finished product tank and the SDA deacidification tower.
[0009] Preferably, a return pipe is provided at the outlet of the delivery pump to be connected back to the top inlet of the slurry mixing tank.
[0010] Preferably, a circulation pump is also included, and a return pipe is provided at the bottom outlet of the finished product tank to be connected to the inlet of the circulation pump, and a pipe is provided at the outlet of the circulation pump to be connected back to the top inlet of the slurry mixing tank.
[0011] Preferably, a valve is provided on the reflux pipe.
[0012] Preferably, there are more than one slurry preparation tanks, all of which are connected to the colloid mill through pipelines.
[0013] The beneficial effects of the utility model are as follows:
[0014] The SDA rotary spray drying desulfurization system of the utility model can significantly reduce the size of the particles in the lime slurry by finely grinding the lime slurry with a colloid mill. Due to the reduction in particle size, the specific surface area of the lime slurry is greatly improved, thereby accelerating the dissolution rate of Ca(OH)2 in the droplets, thereby ensuring the rapid and effective deacidification reaction. At the same time, due to the reduction in the particle size of the lime slurry, it can better contact with the acidic gas in the flue gas during the deacidification process, increasing the contact area and reaction opportunities. This makes the deacidification reaction more thorough, and the removal efficiency of the acidic gas is significantly improved, which can meet the increasingly stringent pollutant emission standards. In addition, the implementation of this system can also reduce the amount of lime slurry used. Due to the improvement in deacidification efficiency, the amount of lime slurry required to be invested under the same conditions is reduced, reducing the operating cost. At the same time, since the generation of fly ash is reduced, the cost and difficulty of subsequent fly ash treatment are also reduced. The system structure of the utility model is simple, easy to operate, and easy to integrate and transform with the existing domestic waste incinerator, and has good application prospects and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the structure of the SDA rotary spray drying desulfurization system;
[0016] In the figure: 1. slurry preparation tank; 2. colloid mill; 3. finished product tank; 4. SDA deacidification tower; 5. delivery pump; 6. valve; 7. reflux pipeline. DETAILED DESCRIPTION
[0017] The utility model is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0018] Example 1
[0019] A SDA rotary spray drying desulfurization system, such as Figure 1 As shown, it includes a slurry preparation tank 1, a colloid mill 2, a finished product tank 3 and an SDA deacidification tower 4; wherein, a pipeline is provided at the bottom outlet of the slurry preparation tank 1 to be connected to the inlet of the colloid mill 2, and a pipeline is provided at the outlet of the colloid mill 2 to be connected to the top inlet of the finished product tank 3, and the bottom outlet of the finished product tank 3 is connected to the rotary atomizer of the SDA deacidification tower 4 through a pipeline.
[0020] like Figure 1 As shown, a delivery pump 5 can be provided on the pipeline between the finished product tank 3 and the SDA deacidification tower 4 to pump the lime slurry ground by the colloid mill 2 into the SDA deacidification tower 4. At the same time, a reflux pipeline 7 (a valve 6 is provided on the pipeline to control the reflux amount) is provided at the outlet of the delivery pump 5 and is connected back to the top inlet of the slurry preparation tank 1, so that a part of the pumped lime slurry can be refluxed into the slurry preparation tank 1, and the refluxed lime slurry is ground by the colloid mill 2 and then returned to the finished product tank 3.
[0021] A preferred solution is to set up a separate circulating pump to circulate the ground lime slurry, that is, a reflux pipe 7 is set at the bottom outlet of the finished product tank 3 to connect back to the top inlet of the slurry mixing tank 1, and a circulating pump and a valve 6 are set on the pipe, and the valve 6 is used to control the reflux amount.
[0022] like Figure 1 As shown, in this embodiment, there can be multiple slurry preparation tanks 1, and all of them are connected to the colloid mill 2 through pipelines.
[0023] The operating process of the above-mentioned SDA rotary spray drying desulfurization system has the following specific steps:
[0024] First, slaked lime (or quicklime) and water are added to the slurry preparation tank 1 to prepare lime slurry. When the SDA process is required, the outlet at the bottom of the slurry preparation tank 1 is opened, and the lime slurry therein enters the colloid mill 2. The lime particles in the lime slurry are ground to less than 1 μm (preferably less than 0.5 μm). The lime slurry ground by the colloid mill 2 is sent to the finished product tank 3, and then pumped into the high-speed rotating atomizer through the delivery pump 5, and finally sprayed into the SDA deacidification tower 4 to carry out the SDA rotary spray drying desulfurization process.
[0025] The lime slurry can also be repeatedly ground by the colloid mill 2 in a circulating manner. The lime slurry pumped into the SDA deacidification tower 4 is partially refluxed to the slurry preparation tank 1 through the reflux pipe 7 by the delivery pump 5, or the lime slurry is directly pumped back from the finished product tank 3 to the slurry preparation tank 1 by setting up a reflux pipe 7 and a circulation pump. The reflux amount can be controlled according to the opening of the valve 6 on the reflux pipe 7. The refluxed lime slurry is ground by the colloid mill 2 and then returned to the finished product tank 3. The lime slurry is ground multiple times to form finer lime particles, which has a better deacidification effect.
[0026] The embodiments described above are only some embodiments of the utility model, not all embodiments. The detailed description of the embodiments of the utility model is not intended to limit the scope of the utility model for which protection is sought, but merely represents selected embodiments of the utility model. The scope of protection of the utility model shall be subject to the scope required by the claims. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work shall fall within the scope of protection of the utility model.
Claims
1. An SDA rotary spray drying desulfurization system, characterized in that: It includes a slurry preparation tank, a colloid mill, a finished product tank and an SDA deacidification tower; wherein, a pipeline is provided at the bottom outlet of the slurry preparation tank to be connected to the inlet of the colloid mill, a pipeline is provided at the outlet of the colloid mill to be connected to the top inlet of the finished product tank, and the bottom outlet of the finished product tank is connected to the rotary atomizer of the SDA deacidification tower through a pipeline.
2. The SDA rotary spray drying desulfurization system according to claim 1 is characterized in that: A delivery pump is provided on the pipeline between the finished product tank and the SDA deacidification tower.
3. The SDA rotary spray drying desulfurization system according to claim 2 is characterized in that: A return pipe is arranged at the outlet of the delivery pump and is connected back to the top inlet of the slurry mixing tank.
4. The SDA rotary spray drying desulfurization system according to claim 2, characterized in that: It also includes a circulation pump. A return pipe is arranged at the bottom outlet of the finished product tank and connected to the inlet of the circulation pump. The outlet of the circulation pump is provided with a pipe back to the top inlet of the slurry mixing tank.
5. The SDA rotary spray drying desulfurization system according to claim 3 or 4, characterized in that: The reflux pipeline is provided with a valve.
6. The SDA rotary spray drying desulfurization system according to claim 1, characterized in that: There are more than one slurry mixing tank, all of which are connected to the colloid mill through pipelines.