What is constant-pressure blasting purging?

The \"blasting method\" of purging involves using kraft paper to replace metal blind plates at the outlet of the main pipeline, while using steel blind plates or valves to seal off the connections between various branch pipes and the equipment. Then, an air compressor is used to gradually increase the pressure in the system. When the pressure in the equipment and pipelines reaches a certain value (0.6 MPa), the kraft paper at the outlet ruptures, allowing the gas inside the equipment and pipelines to be discharged at maximum velocity. This instantaneous release of gas helps to remove debris such as sediment, grease, welding slag, and rust from the pipelines and into the main pipeline. Close the intake valve, and rearrange the kraft paper at the outlet; use kraft paper of progressively greater thickness to increase the pressure step by step. The standard for determining whether the purging is successful is to place a white cloth target in the area where the equipment and process pipelines have been emptied, and to check it for 5 minutes; if there are no water droplets, rust spots, or debris on the white cloth target, then the purging is considered successful. Purging principles and preparations: (1) Steam shall not be used for purging pipelines. (2) Use circulating water to flush the tube sides of each cooler; after flushing, stop using it and drain the purified water. (3) Remove components such as filters, control valves, flow meters, and safety valves, which are prone to clogging or damage, and store them properly; reinstall them after the purging is completed. (4) All valves in the system should be opened as needed to prevent leakage. (5) Close the sampling valve, instrument lead valve, pressure gauge hand valve, and level gauge lead valve; after the equipment and pipelines have been purged, purge the aforementioned lead valves and pump nozzles as well. (6) For the pipelines connected to the pump, the inlet and outlet valves of the pump or the pump’s flanges must be removed, and blind plates or metal sheets must be inserted. After thorough purging, a filter screen can be installed, followed by the reinstallation of the flanges. (7) For the pipelines connected to the reaction materials as well as the high and low pressure networks, the blind plates on the corresponding flanges at the isolation valves must be removed, the flanges loosened, in order to enable purging. (8) During purging, no debris should be blown into the tower; the flanges at the equipment’s inlet and outlet should be removed in advance, purging should be carried out separately, and then the flanges reconnected. (9) When cleaning the lines, methods such as removing flanges or valves and inserting metal sheets for isolation should be employed. 10) Before the compressed air passes through the cooling equipment, the inlet flange must be removed; once the upstream pipeline has been cleaned, the upper flange can be moved further backward. (11) During purging of the pipelines and equipment connected to other positions by wind, all relevant positions must cooperate with each other, conduct thorough inspections, and keep proper records to avoid omissions that could affect operations. (12) When performing purging, it is essential to choose the appropriate specification for the blasting paper so that it will rupture on its own at a pressure of 0.6 MPa or higher. (13) Conduct thorough inspections to ensure the quality of purging for each piece of equipment and each pipeline; equipment and pipelines that do not pass the purging test must be subjected to repeated blasting and purging processes. (14) During purging, it is necessary to strictly follow the process flow and carefully check whether each stage of the purging process is unobstructed. (15) The raw material and product measurement instruments, as well as the removed orifice plates, nozzles, mixers, control valves, safety valves, etc., should be wiped clean and reinstalled after the process pipelines have been purged. (16) Introduce compressed air into the device to first purge the compressed air and nitrogen systems. (17) When using a compressed air blower for cleaning, start with the equipment and then move on to the pipelines, cleaning them one by one from largest to smallest. (18) After introducing compressed air into the equipment and ensuring that the pressure reaches the required level, purge each pipeline section from top to bottom, starting with shorter sections first and then longer ones, as well as from near to far; alternate methods such as closing valves to maintain pressure should be used.

This involves using kraft paper to replace metal blind plates at the outlet of the main pipeline; steel blind plates or valves are used to seal off the connections between various branch pipes and the equipment. Then, an air compressor is used to gradually increase the pressure in the system. When the pressure in the equipment and pipelines reaches a certain value (0.6 MPa), the kraft paper at the outlet ruptures, allowing the gas inside the equipment and pipelines to be discharged at maximum speed. The sudden release of this gas helps to remove debris such as sediment, grease, welding slag, and rust from within the pipelines and into the main pipeline. Close the intake valve, and rearrange the kraft paper at the outlet; use kraft paper of progressively greater thickness to increase the pressure step by step.