Explore the precautions for replacing the coke oven rising pipe?

1. Ensure that the flap of the valve body remains closed throughout the replacement process. 2. During the replacement process, the plant dispatcher and fan operators ensure a slight positive pressure in the gas collection duct (30–50 Pa). 3. All personnel must wear complete personal protective equipment to prevent burns, scalds, and injuries from falling objects. 4. The factory’s safety department must assign dedicated personnel to oversee safety throughout the entire process. 5. When replacing, ensure that the furnace lids within a 10-meter radius are tightly sealed, and that all rise tube lids are properly sealed. Open flames are strictly prohibited, and no welding or similar operations shall be carried out at the site. 6. The replacement work can only begin after all fire-fighting equipment is ready and personal protective gear is fully worn. 7. Thermal direction switching is strictly prohibited during replacement. ……

Discussion on the Construction Plan for Replacing the Valve Body – Following the Step Before Replacing the Bridge Tube Yan Haojie, Gao Xiaobing (Pingyao Coal Chemical Group No.1 Mine Coking Co., Ltd.) 【Abstract】This paper focuses on the preparatory work, replacement steps, and emergency plans for replacing the valve body. 【Keywords】Valve body; Steps; Emergency plan 0. Introduction Our company’s No. 2 coke oven was put into operation on September 26, 2004, while No. 1 coke oven was commissioned on November 19, 2005. Due to quality issues with the cast components, as well as frequent power outages and interruptions in the operation of blowers at the time of commissioning, the valve bodies suffered varying degrees of damage; some of them developed cracks, resulting in serious problems such as leakage, which affected their normal functionality. In addition, due to environmental regulations, it was necessary to replace these valve bodies. Hence, this plan was formulated for reference. 1. Determination of the organizational structure 2. Construction personnel: Maintenance team, Thermal repair team members 3. Preparatory work 3.1 Fabricate a dummy chimney with a diameter of 550 mm, a height of 1500 mm, and a thickness of 2 mm. 3.2 Prepare all necessary tools, including welding equipment, oxyacetylene welding gear, wrenches, crowbars, etc. 3.3 Prepare 3 steel wire ropes with a diameter of 20 mm, several crowbars, and several spare replacement screws. (Some extra steel cables should be kept on hand for emergency use.) 3.4 Prepare (3mm, 5mm) asbestos sheets, lead paint, and asbestos cloth. 3.5 Select the furnace numbers with a coking time of over two-thirds for replacement. 3.6 First, remove the bolts at the connections between the valve body and the gas collection pipe one by one, and install four new bolts on the two diagonals to get everything ready. (Loosen bolts at intervals) 3.7 Prepare a fire mask, fire-resistant clothing, and heat-resistant gloves. It would be best to have a full-face mask; two spare sets will suffice. 3.8 Contact Tools 4. Replacement Steps 4.1 First, lift out the bridge pipe and straight pipe: 4.1.1 Remove the sealing material from the socket and the base of the straight pipe. 4.1.2 First, close the low-pressure ammonia water valve for that furnace number, shut off the water seal inlet valve, and disconnect its connection flange. 4.1.3 After securing the bridge tube and straight tubes in place, close the flap and simultaneously open the cover of furnace No. 3, then install the fake chimney. Change the regulation of the collector pipe pressure to manual control; the riser operator should closely monitor the pressure in the collector pipe and is strictly prohibited from making large adjustments. They must maintain communication with the dispatching and blower teams, and (the riser operator should rely on the readings from the inclined micromanometer) ensure that the pressure in the collector pipe remains around 5–10 Pa, i.e., in a slightly positive pressure state. 4.1.4 Before preparing to lift the valve body, stop reversing operations for 1# and 2#, and ensure that the pressure in the main pipe remains stable at around 5500 Pa, with the pressure in the gas collection pipe maintained at a slight negative pressure. 4.1.5 Select an appropriate location to fasten the rope buckle to ensure smooth lifting. After the crane lifts the straight pipe and bridge pipe, turn off the compressed air supply to extinguish the flame, and at the same time use ammonia to seal the valve body. 4.1.6 Clean the base of the straight pipe, cover its opening with a furnace lid, and seal it with loess slurry. 4.2 Replacing the valve body: 4.2.1 Cut the bolts one by one using a diagonal cutting method; it is advisable to use a crane to hold the valve body steadily. The entire process of removing and installing the valve body requires caution, speed, as well as a strong sense of self-protection and mutual protection. 4.2.2 Close the ammonia water valve. 4.2.3 After lifting, quickly cover the gas collection port from top to bottom with a wet asbestos cloth (dipped in water). 4.2.4 When installing a new valve body and removing the asbestos cloth, keep the pressure in the gas collection pipe at around -15 Pa. 4.2.5 After installing the valve body, open the ammonia valve to seal it. Restore automatic adjustment of the gas collector pressure. 4.2.6 Install in reverse order. 4.2.7 Pour thin mud material at the base of the sealed straight pipe and at the socket joints, cover it with the No. 3 furnace lid, open the flap, and check whether the system is functioning properly. 4.2.8 Clean the work site, and recheck the system after four hours. 5. Acceptance Criteria 5.1 The flange connections shall be properly tightened, with no leaks. 5.2 All plug and socket connections shall be inserted to a sufficient depth to ensure a tight seal. 5.3 All systems are operating normally. 6. Safety Precautions 6.1 It is advisable to carry out replacements after 8:00 in the morning, with factory management present on site to oversee the process. 6.2 The workshop shall designate a specific person to be responsible for on-site command and coordination. 6.3 The persons in charge of various relevant positions throughout the plant must set their walkie-talkies on the same channel and follow the instructions of the on-site supervisor. 6.4 Provide specialized technical training in advance to all personnel involved in the replacement, so that they are familiar with every detail of the replacement process. 6.5 All participants must wear complete and proper personal protective equipment; repair workers must wear masks. 6.6 It is strictly prohibited for personnel to stand directly in front of the gas collection opening after the valve body is lifted and during the period when no new valve body is installed. 6.7 The shutdown shall be notified in advance by the scheduler. 6.8 The on-duty safety officer is responsible for safety supervision. 6.9 After the valve body is moved, all hot work in the vicinity is strictly prohibited. 6.10 The site is equipped with connected steam hoses and 16-kilogram fire extinguishers, which are under the responsibility of a designated person. 6.11 Standing under the crane is strictly prohibited. 6.12 When using steel wire ropes to tie the valve body and the straight pipe connected to it, it is essential to lift them vertically. 7. Emergency Procedures 7.1 Fire around the socket of the valve body: First, extinguish the fire using a fire extinguisher or steam before proceeding with further actions. 7.2 When the valve body has not been lifted: it is best to adjust the pressure so that it shuts off automatically; wait until there are no sources of fire in the vicinity before proceeding with the next steps. 7.3 Internal ignition in the collector pipe pressure: It is best to maintain stable pressure in the collector pipe (under negative pressure) and address the issue as soon as possible by installing a new valve body. 8. Remarks: Any unspecified matters will be determined on-site.