Operation process of the backwash filter in the hydrogenation unit

At least 2 sets of backwash filters； Generally, a time and pressure difference are set; whichever comes first will trigger backwashing ； Backwashing involves allowing the oil to flow from a lower level to a higher one. During backwashing, the oil inlet and outlet valves are closed (in groups), and then the valve for the backwashing medium as well as the valve from the bottom to the waste oil are opened. Backwashing is generally set to be controlled sequentially and carried out automatically.

The backwash filter in the hydrogenation unit is used to remove solid impurities from the feed, thereby protecting downstream equipment and catalysts. Its working process is as follows: 1. Filtration stage: Feed inflow: The raw material enters the filter through the inlet and flows through the filtering medium (such as a filter screen or filter element). Impurity retention: Solid impurities are retained on the surface or within the filtering medium, while the clean liquid continues to flow toward the outlet. 2. Differential pressure monitoring: Differential pressure sensor: Monitors the pressure difference between the inlet and outlet of the filter in real time. Increasing pressure difference: As impurities accumulate, the pressure difference gradually increases. 3. Backwash trigger pressure difference threshold: When the pressure difference reaches the set value, the backwash procedure is triggered. Manual or automatic: Backwashing can be initiated manually or via an automatic control system. 4. Backwashing process: Close the feed valve: stop feeding and isolate the filter. Backwashing: A cleaning fluid (such as hydrogen or light hydrocarbons) is passed in the reverse direction through the filtering medium to wash away the trapped impurities. Waste discharge: The liquid and impurities after flushing are discharged from the system through the waste discharge valve. 5. Restore filtration: Close the drain valve: After backwashing is complete, close the drain valve. Re-feed: Open the feed valve to resume the filtration process. Differential pressure reset: When the differential pressure returns to the normal range, the filter resumes operation. 6. Automatic control system: PLC/DCS control – Modern hydrogenation units typically use PLC or DCS systems to automatically control the backwashing process. Parameter settings: Parameters such as pressure difference threshold, backwashing time, and frequency can be set. 7. Maintenance and Inspection: Regular inspections: Periodically check the filter media and pressure differential sensor. Replace the filter element: Replace the filter element or clean the filtering medium regularly based on usage. 8. Precautions: Operational safety: Strictly follow the operating procedures to ensure safety. System pressure: Pay attention to changes in system pressure during backwashing to avoid fluctuations. Waste treatment: Properly handle the impurities discharged during backwashing to prevent environmental pollution. Through the above steps, the backwash filter can effectively remove impurities, ensuring the stable operation of the hydrogenation unit.

I am a filter element manufacturer in this field. There are various types of brushes and scrapers used for backwashing, and backwashing can be done either online or offline. The reason for doing this is to prevent high pressure differences when the filter elements get clogged; after cleaning them, they can be used again