injection tank

Powder Injection Tank
Xiangye Environmental Protection provides a detailed introduction to the powder injection tank (also known as the coal injection tank). A coal injection tank generally consists of the following components: elliptical or dished heads, a straight cylindrical section, a conical lower head, supports, and a manhole. It is a typical internal pressure vessel, designed in accordance with specifications, with a pressure requirement higher than the maximum working pressure. However, for safety reasons, especially when injecting bituminous coal, the design pressure should be appropriately increased.

The powder injection system is composed of different types of powder injection tank groups, as well as corresponding bell valves, fluidization devices, and other components. Inside the powder injection tank group, compressed air is usually filled, and secondary compressed air is introduced through a self-mixer, to inject pulverized coal into the blast furnace tuyere via pipelines and lances, realizing the powder injection process.

The arrangement of the powder injection tank group is flexible and diverse. A parallel layout can be adopted to realize the alternation of coal charging and coal injection; a stacked layout can also be selected, where the bottom tank is dedicated to powder injection, while coal charging is completed through the upper tank and its pressure equalization and discharge device. This design is both efficient and practical.

At the bottom of the powder injection tank, a fluidized bed is installed, and on the conical section of the lower part of the tank, fluidization nozzles are mounted. Both the fluidized bed and the fluidization nozzles are connected to the fluidization gas source through control valves. This design effectively improves the conveying performance of the powder in the powder injection tank and optimizes the fluidization effect of the powder through the agitation of the fluidization nozzles. This new type of powder injection tank is not only suitable for newly built powder injection systems but also can be used for the transformation and upgrading of existing powder injection systems, so as to enhance the performance and efficiency of the system.

In terms of powder injection methods, we can divide them into two types: direct injection and indirect injection. The direct injection method sets the powder injection tank directly below the coal bunker of the pulverizing system, and injects pulverized coal directly into the blast furnace tuyere. The advantage of this method is that it saves the investment of the powder injection station and the corresponding operation and maintenance costs, and is especially suitable for small blast furnaces. The indirect injection, however, requires that the prepared pulverized coal is sent to the powder injection station near the blast furnace through a special coal conveying pipeline or tank truck, and then injected into the blast furnace. Although this method has a larger investment and complex equipment configuration, it can be equipped with corresponding powder recovery and dust removal devices to ensure the cleanliness and safety of the powder injection process.

In terms of the arrangement form of the powder injection tanks, we can divide them into parallel injection and series tank injection. Parallel injection ensures uninterrupted coal injection into the blast furnace through sequential or alternate switching of the tanks. Usually, to facilitate handling possible powder injection accidents, it is recommended that the number of parallel tanks be 3. Although sequential tank switching may have a certain impact on the stability of powder injection, this problem can be effectively improved through precise measurement and control methods. In addition, although parallel injection has a large land occupation, the powder injection weighing is simple and the investment is relatively small, so it is often used in the direct injection process systems of small blast furnaces.

Through the above introduction, we can see that the powder injection tank designed by Xiangye Environmental Protection not only focuses on safety and stability but also optimizes efficiency and practicality. Whether it is a new project or the transformation and upgrading of an existing system, our products can provide you with reliable solutions.