The core of calcium hydroxide pneumatic conveying is to utilize the kinetic or static pressure energy of air to form a stable gas-solid two-phase flow of calcium hydroxide powder in a closed pipeline, completing the transportation from the storage bin to the point of use, and achieving gas separation and exhaust gas purification at the end.

Unlike ordinary mineral powder, calcium hydroxide has a fine particle size, high surface activity, and is prone to react with moisture in the air to form hard lumps. The key to its transportation principle lies in "preventing agglomeration, blocking pipes, and moisture absorption", rather than simply power transmission. The overall workflow still follows the three major stages of "feeding conveying separation", but each stage has a targeted principle adaptation. The mainstream is divided into three modes: positive pressure dilute phase, positive pressure dense phase, and negative pressure suction. The following is the general principle+core logic of the mode:

Arch breaking and bridge prevention - Calcium hydroxide is prone to forming "bridges" in storage due to moisture absorption and aggregation, making it difficult to cut naturally. Therefore, before starting the conveying process, it is necessary to use warehouse wall vibration or arch breaking devices to break the material aggregation structure, making the powder loose and laying the foundation for subsequent uniform feeding. This is the unique pre principle that distinguishes calcium hydroxide transportation from other dry powders.

Mixing of feed and gas - Loose calcium hydroxide is controlled and evenly fed into the conveying pipeline through a dedicated gas locking feeding device. At this point, the airflow enters the pipeline from the power source and is fully mixed with the material: the airflow breaks the adhesive force between the material particles, causing the calcium hydroxide particles to be carried or aggregated into loose clusters by the airflow, forming a gas-solid two-phase flow that can be transported. Key adaptation: The feeding device needs to have good airtightness to prevent external humid air from entering the pipeline and reacting with calcium hydroxide.

Pipeline transportation - Gas solid two-phase flow moves forward in pipelines relying on the kinetic or static pressure energy of the airflow. Calcium hydroxide particles are lightweight and strongly influenced by air flow, but due to their tendency to aggregate, they need to be designed through pipeline air supply and optimized bend curvature to avoid particle deposition and agglomeration in the pipeline, which can cause pipe blockage. The entire pipeline is sealed to isolate external moisture and dust leakage.

Gas material separation and exhaust gas purification - When the material reaches the endpoint, it enters the separation equipment. Calcium hydroxide particles separate from air under the action of gravity or centrifugal force and fall into the receiving bin; The exhaust gas carrying a small amount of fine dust enters the dust removal equipment for purification before being discharged. Key adaptation: Anti adhesive filter materials should be selected for dust removal equipment to prevent calcium hydroxide dust from adhering to the filter bag and causing blockage.

Preventing moisture absorption is a prerequisite: the entire process is enclosed and sealed, isolating the outside humid air to prevent calcium hydroxide from reacting and clumping, which is the core of smooth transportation;

Preventing agglomeration is key: by breaking the arch, replenishing air, optimizing flow rate, breaking the material agglomeration structure, and avoiding pipe blockage;

Low abrasion adaptation: Calcium hydroxide has weak abrasion resistance and does not require wear-resistant pipes. The focus is on the smoothness of the pipes to reduce particle adhesion.

1. The calcium hydroxide powder in the raw material warehouse is dispersed by the arch breaking device to prevent bridging, and is uniformly and continuously fed into the positive pressure conveying pipeline through the air lock feeder;

2. Positive pressure airflow wraps the material into a suspended state and transports it along the pipeline to the top of the desulfurization tower;

3. The material is directly sent into the desulfurization tower reaction zone through the injection device to participate in the flue gas desulfurization reaction;

4. A small amount of unreacted fine dust at the end is collected by the exhaust dust removal device to avoid polluting the environment.

Realize continuous and uniform supply of desulfurizer, stable reaction efficiency of desulfurization tower, precise control of calcium sulfur ratio, and reduce waste of calcium hydroxide;

The system structure is simple, without complex pressure vessels, and daily maintenance only requires checking the feeder and pipeline air supply device, with low operation and maintenance costs;

Fully enclosed transportation throughout the process, completely solving the dust problem in the desulfurizer feeding process and meeting the environmental protection requirements of power plants.

1.原料库内的氢氧化钙粉经破拱、保温处理后，分批装入发送罐；

2.发送罐加压后，以高压低速气流使物料形成松散料栓，靠静压能推动料栓沿主管输送；

3.物料到达分配器后，根据各车间投料指令，依次切换至对应接收仓卸料；

4.接收仓完成气料分离，物料落入车间缓存斗，尾气经除尘后达标排放。

采用密相栓流输送，风速低、能耗远低于稀相系统，适配长距离输送需求；

通过管道分配器实现「一仓供多车间」，无需为每个车间单独配置输送系统，大幅降低设备投资；

低速输送减少氢氧化钙颗粒间的摩擦生热与团聚，物料品质不受损，同时管道无磨损，使用寿命长。

1.负压风机启动，在总管内形成负压场；

2.料仓下料口的扬尘与筛选工位的不合格料，分别通过各自的吸嘴 / 吸料点被吸入支管，汇入总管；

3.气料混合物在终点分离器内完成分离，氢氧化钙粉沉降至回收料仓，重新送入生产系统加工；

4.净化后的尾气经负压风机排出，车间内无粉尘外泄。

负压环境下，粉尘仅向管道内吸入，车间内下料口、筛选工位无扬尘，生产环境大幅改善，符合职业健康标准；

实现「3 个下料口 + 3 个筛选工位」6 点同时取料、1 点集中卸料，无需人工清理扬尘与不合格料，节省人工成本；

系统仅在取料点少量吸入空气，可通过在吸嘴处设置干燥空气补风口，有效防止湿空气进入导致物料结块，输送顺畅无堵管。