Where is the location of the small feeder?

We have both types of processes here; generally, they are combined into a single dense phase process. This is probably because the temperature difference between the two is relatively small. (Repeatedly, the low-oxygen charring method only handles 15-20% of the charring load.) ） ； If it is necessary to relatively increase the catalyst activity, add it to the bottom of the secondary calcination tank instead.

3# liaifeng: I asked 2 experienced teachers about this issue, and their answers were similar to what you said. One explanation is that it is added repeatedly in order to achieve thorough mixing, so as to prevent significant changes in the catalyst’s activity and to maintain the activity of the equilibrium agent at a constant level. Another explanation is that adding it twice is to take advantage of the high reactivity of the activator.

Our equipment has additive lines both for once and twice. Just like on the 3rd floor, it only requires repeated addition lines. I think the reason is that a low bed temperature helps to protect the cold catalyst added, and another reason is that after adding the cold catalyst, it is necessary to raise the temperature to around 700 degrees; this heating process should not be too rapid, and the time taken to go from one temperature to another is generally appropriate. As for the catalyst activity mentioned on the 4th floor, once a fresh catalyst is added, as long as it does not come into contact with the raw materials and the bed temperature does not become excessively high, its activity should remain unaffected.

We add it to two, and the regenerator of this type is a coke-fired one; the residence time of the flue gas is short. In some refineries, the coking process operates at the limit, and once cold catalyst is added, the temperature difference between the dense and dilute phases increases, leading to post-combustion phenomena. Such catalytic devices seem to have a certain degree of universality.

I have both circuits installed; since they are arranged in a coaxial overlapping pattern, to account for changes in wind pressure and ensure proper feeding, I chose to add them at the lower part. Each device should be treated differently, as appropriate.

The automatic feeder, the LT150 type FCC catalyst small-scale automatic metering and feeding device developed by Beijing Licheng Petrochemical Technology Co., Ltd. by introducing advanced German technology, is a tank-type positive-pressure dense-phase pneumatic powder transfer system. This system features advantages such as long transportation distance, low energy consumption, no clogging, environmental friendliness and energy efficiency, as well as safety and reliability. It is at the leading level in China and matches the standards of international similar technologies, enabling the timed, quantitative, balanced, and automatic addition of solid powder materials. The basic process flow of this system is as follows: The materials to be added to the system are fed into hoppers equipped with electronic measuring devices, and the PLC system is used to accurately measure the amount of material that passes through. During transportation, a metering device feeds material into the pressing tank according to a set weight value, with the feed inlet being controlled by a pneumatic butterfly valve. The pusher tank is equipped with level and pressure transmitters; when the material reaches a specified level, the feed valve is closed and air is introduced into the tank to fluidize the material. Inflate to the set pressure, then open the discharge valve to start conveying. By programmatically controlling the opening and closing of various valves in the pressure feed tank, the material is smoothly transported through the pipes to the receiving end. To ensure smooth and stable transportation, a fluidization nozzle is installed at the air supply inlet, which serves to stabilize the air pressure and airflow. Pressure transmitters can be installed in the transfer tank, the acceleration pipeline, and the end section of the transfer pipeline according to user requirements, allowing for timely monitoring of the system’s status and ensuring its normal and reliable operation. Measurement is carried out using a cumulative decrement method. This system features the following technical advantages: (1) It adopts a solution of weighing first and then transporting, which allows the electronic sensors to be placed on the outside of the container, facilitating maintenance and calibration. This approach also reduces factors that can affect measurement accuracy and improves it ； 　　(2) The fluidization tank uses a bottom-discharge conveying method, which facilitates the clean transfer of materials ； 　　(3) Measurement and delivery are separated; all pipelines connected to the fluidization tank are rigidly connected, which extends the system’s service life and reduces maintenance workload ； 　　(4) The fluidization tank is equipped with fluidization nozzles installed on the outside of the tank, allowing for easy replacement. Lafayette nozzles are used for air intake in the fluidization tank to accelerate the airflow and generate a stable stream of air ； 　　(5) Special wear-resistant valves are used for the main valves, thereby increasing their service life ； 　　(6) The device features a modular design, facilitating installation and maintenance. 　　 This device has been applied in various petrochemical companies belonging to CNPC and Sinopec. Figure: Catalyst small feeding device of Jilin Petrochemical Company, China National Petroleum Corporation. Feel free to call for inquiries. He Yongtai: 010-82897100, 13911867696; hyt_a2@163.com

Our two regeneration units have two feeding lines, but generally, it is chosen to feed them together. The main goal is to avoid situations where, when adding the reagent again, the amount used varies, which leads to fluctuations in the bed temperature and consequently fluctuations in the reaction temperature, thereby affecting the stability of production. Under stable operating conditions, adding secondary reagents can increase the content of fine powder in the secondary catalyst, thereby ensuring stable fluidization.