Who has the operating procedures for modified diaphragm sintering furnaces? Please upload and share them

Reply 1# YBTYJB@163.com

Reply 1# YBTYJB 1.1 First, the production of the anode; second, the cleaning and decomposition of the anode. After the electrolyzer is disassembled, the anode must be rinsed thoroughly with tap water; once dried, the anode plates and bottom plate should be removed one by one for further processing and storage. Second, pre-treatment before installing the contact points. The titanium plates of the anode sheets must be leveled, with the levelness deviation not exceeding +1mm. The screws need to have their rust removed, and the copper caps should be polished and smoothed using sandpaper. After the contact surface between the conductive copper plate and the steel base plate is rust-removed, a conductive paste is applied for conductive and anti-rust treatment. Third, anode assembly. First, fix the conductive copper plate to the steel base plate in their original positions using new screws, ensuring that there is no gap at the contact surface between the copper plate and the steel base plate, with a firm connection. Check whether the rubber gaskets of the anode plates are aged; replace those that are damaged with new gaskets. Install each anode plate onto the base plate and then secure it with copper caps. Fourth, fine-tuning of the anode sheet. After the anodes are assembled, a ruler and calipers are used to measure the front-to-back, left-to-right distances as well as the verticality of each anode plate. Any deviations are adjusted slightly to ensure that the anode plates are perpendicular to the steel base plate, with an angle deviation of ≤0.5 degrees. The vertical spacing deviation between adjacent rows in each row shall be ≤1 mm, and the overall dimensional deviation shall be ≤2 mm. Each copper cap should be tightened using an electric wrench, with a torque of ≥800 N•M. The sealing quality between the anode sheet gasket and the titanium plate should be checked; if the sealing is inadequate, the copper cap should be tightened until proper sealing is achieved. 1.2 Fabrication of the cathode and diaphragm 1.2.1 The cathode box shall meet the following requirements: The welds of the cathode box must be even and secure; this is especially true for the connections between the copper conductors and the box body. The welding must be smooth and solid, without any pores or cracks. The upper and lower flanges of the box shall be straight, with a flatness deviation not exceeding +2mm. The diagonal error of the box body must not exceed +2mm, and the center deviation between any two mesh bags must not exceed +1mm. The mesh bag should be flat, without any damage or broken strands; its unevenness should be less than 1 mm. The number of welding points between the internal support framework and the mesh bag should not exceed 2 per mesh cell ； When splicing wire mesh, the wires should be welded in pairs; it is not allowed to weld more than two wires together. The mesh size must not exceed 4X4 mm. The cathode mesh bag to be adsorbed must be free of residual fluff and rust. 1.2.2 Preparation of asbestos slurry: The density of the asbestos in the slurry is 14 kg/m3. The amount of asbestos fibers used is generally around 1.3–1.4 kilograms per square meter, based on a current density of 1700–2000 amperes per square meter; the exact amount should be adjusted accordingly depending on the current density and the type of asbestos fibers used. The asbestos slurry contains 115–125 grams per liter of sodium hydroxide, and 180–200 grams per liter of sodium chloride. The initial amount of modifier added is 3 kg/m3; thereafter, it is added at 18% of the amount of asbestos used. For the replacement slurry, 2.5 kg/m3 of modifier must be added based on the volume of the slurry. 1.2.3 Process conditions for cathodic adsorption: The causticization time required for the first adsorption of asbestos fibers using freshly prepared slurry is 120 hours, while the optimal causticization time for normal adsorption of asbestos fibers is 48 hours. The freshly prepared slurry must be at room temperature before asbestos is added (the mixing temperature should be ≤30°C); it is strictly prohibited to add asbestos when the temperature of the slurry exceeds 30°C. In summer, efforts should be made to avoid using freshly prepared slurry due to high temperatures. Before adsorption, the cathode mesh bags should be descaled using a high-pressure water gun; for cathode boxes that have been in use for an extended period, 20% hydrochloric acid with a corrosion inhibitor should be used for descaling, followed by rinsing with water. Individual defective mesh bags should be adjusted using a flat shovel, and those with blocked mesh holes need to be cleared. Prepare the new slurry: Draw all the alkali-treated slurry from the adsorption tank into the vacuum tank and subject it to vacuum stirring for 1 minute before returning it to the adsorption tank. Repeat this process of drawing the slurry into the vacuum tank, stirring it there for 1 minute, and then returning it to the adsorption tank 3–4 times, until the desired adsorption level is achieved. Normal adsorption: Before adsorption, the asbestos that has been alkali-treated in the alkali treatment tank for 48 hours is drawn into the vacuum tank (containing the old adsorption solution) and subjected to vacuum stirring for 1 minute before being placed in the adsorption tank. Then, both the old and new slurries are drawn into the vacuum tank and stirred for 1 minute again before being put into the adsorption tank. Repeating this process 1–2 times will meet the adsorption requirements. Lift the rinsed cathode box into the adsorption tank, and raise and lower it above and below the slurry surface 3 to 5 times to ensure even distribution of the asbestos in the adsorption tank. Start the vacuum pump and open the vent valve; the pumping capacity of the vacuum pump must be at least 0.09 MPa (680 mmHg). For adsorption: close the vent valve, wait until the vacuum level reaches 0.04 MPa, then open the adsorption valve. Keep the cathode box in a suspended position for 1 minute and 20 seconds, followed by dynamic adsorption. Throughout the adsorption process, the cathode box must be raised and lowered 3 times every 30 seconds, with the range of movement being as large as possible. It should also be moved horizontally 3 times every 3 minutes. At the end of each cycle of dynamic adsorption, the cathode box must remain in a suspended position. Pay attention to the condition of the slurry during adsorption, and replenish it if necessary. For the first adsorption, it lasts 6 minutes; no raking is performed, followed by lifting (to check for any bridging, and if bridging is present, it is broken). Dry adsorption for 8 minutes; the vacuum degree of the modified membrane is 0.055±0.004 MPa. During dry adsorption, slurry is added to the adsorption tank, and bubbling is carried out for 1 minute. After 8 minutes of dry adsorption, the cathode box is lifted into the adsorption tank for a second adsorption process (via the hydraulic membrane). Dynamic adsorption takes place for 1.5 minutes without using a rake; after that, the box is lifted out. Once the adjustments are complete, the vacuum level a is recorded, and then the system is subjected to 4 hours of dry pumping before water is drained. (Release water every half hour for half a minute each time), record the vacuum level b, and then move it into the drying room. The temperature in the steam drying chamber should be maintained between 90 and 110 degrees, with a drying time of 40 to 15 hours. To prevent silicate reactions from occurring over an extended period due to asbestos, which could affect the current efficiency of the electrolytic cell, the diaphragm must be thoroughly dried within 40 hours after it has been cleaned by vacuum, and then assembled and installed in the cell immediately. (Compare the vacuum levels of the two times; if a exceeds 0.07 MPa, the alkali concentration of the slurry can be appropriately reduced) ； If there is a large difference between a and b, the salt concentration of the slurry can be increased appropriately. ) The absorbed diaphragms should be numbered and registered, kept dry, properly insulated, and securely cleaned. Generally, absorbed diaphragms should not be left for too long to prevent rusting, as this can result in a high hydrogen content once they are put into use. 1.3 The mixing ratio of the soft-sealing material is: talcum powder: tung oil: asbestos fluff = 50 kg: 20 kg: 1.5 kg. Mix talcum powder with asbestos fluff, then add tung oil and mix well. 1.4 Disassembly and assembly of the electrolyzer: Stop feeding saline before powering down the electrolyzer ； After power is cut off, promptly remove the chlorine and hydrogen branch pipes and seal the main pipe connections. When dismantling the electrolytic cell, it is necessary to recover the mild alkali and brine inside the cell in order to reduce consumption and prevent pollution; safety must be taken into account during the dismantling process. The removed parts are cleaned thoroughly for reuse. The cathode assembly must be lowered smoothly, accurately, and vertically, to prevent the metal anode from damaging the diaphragm. When assembling the electrolyzer, the distance between the anode and cathode should be even and appropriate; if there is a significant deviation, use a Ф6-8mm glass rod to adjust it to evenness. Short circuits caused by contact between the anode and cathode are strictly prohibited. When assembling the cell, proceed carefully to avoid damaging the diaphragm. When lifting the trough, strict attention must be paid to the safety of personnel and equipment; it is necessary to move it smoothly, lift and place it gently, and proceed at a slow pace to prevent collisions or electrical damage to the trough, as well as to the wire ropes and crane components. When lifting the cell, strictly control the position of the cell relative to the porcelain base. Ensure that the distance between each platform is consistent, with each row arranged in an orderly line. The installation of the electrolytic cells and accessories must be firm, correct, complete, sensitive, and functional, with consistent dimensions. When loading and unloading the groove, the rule of operating with one hand must be strictly followed. It is strictly prohibited to use wrenches or the body to connect to both rows of cells simultaneously, or to connect one end to a cell and the other end to ground. Before powering on, saline is injected. During the first 15 minutes, the flow rate of the saline injection is controlled at half of the normal rate; during the next 15 minutes, it is maintained at the normal rate. Thereafter, the injection flow rate is increased to 2.5 times the normal rate, until saline starts to overflow from the weak-alkali pipe, at which point power is supplied. When injecting saline, be careful not to direct it at the diaphragm, as this could damage it. To connect the slot-connected copper plates and the cross-slot copper plates, it is necessary to have large contact areas that are smooth and free of any contaminants; conductive paste should be applied afterward, the connection must be secure, the temperature of the copper plates should be below 700°C, and the voltage drop at the joints should be less than 20 millivolts. After power is supplied to the new slot, clean the surrounding area to maintain hygiene, inform the pipeline maintenance staff, and conduct a daily acceptance handover with the person in charge of the electrolysis operation. . 2　Main safety control indicators (see Tables 1 and 2 for details) 3　Abnormal phenomena affecting safety and countermeasures 3.1 Saltwater leakage from the anode chassis: Aging of sealing gaskets or loose fixing of copper caps ； No rubber pad. Solution: Replace the sealing gasket, or tighten the copper cap ； Enclosed sealing gasket. Table 1: Process Parameter Names, Units, Control Ranges, Measuring Instruments, and Remarks
Asbestos causticization time: h; 48 hours; Clock
Rate of increase in adsorption vacuum: Pa/s; 6.6; Stopwatch
Adsorption vacuum pressure: Pa; 9×10³–9.6×10³ or (680–720 mmHg); Pressure gauge
Adsorption time: s; 1.5×10³–1.8×10³ seconds; Stopwatch
Drying time: h; 4 hours; Clock
Drying vacuum pressure: Pa; 9×10³; Pressure gauge

Table 2: Sequence Number, Control Parameter, Control Criteria, Sampling Location, Sampling Frequency, and Analysis Method
1. Adsorption of asbestos slurry: NaOH: 115–125 g/l; NaCl: 180–200 g/l; Sampling location: Film-forming tank; Sampling frequency: Once a week; Analysis method: Chemical method
2. Tank operation conditions: When the current density is 1800 A/m², the tank voltage should be greater than 3.30 V. Electrolyzer – Chemical method: Cells with a sodium hydroxide concentration in the dilute alkali solution of more than 145 g/L or less than 90 g/L, and for which the liquid level cannot be adjusted. Electrocell, physical method: oxygen content in chlorine is greater than 3%, and current efficiency is less than 90%. Electrocell chemical method: applicable to cases where the hydrogen content in chlorine is greater than 3% and treatment is ineffective. Electrolyzer, chemical method – for cases where the flow rate is too high and the liquid level cannot be adjusted. Cell: Physical method – In the case of cell leakage or when treatment is ineffective. Cell: Physical method – In cases of abnormally low voltage, indicating a short circuit. Chemical method: Three times a week. 3.2 Low vacuum level when absorbing the diaphragm: Causes include vacuum leaks and valves that are not fully open ； The valve core has fallen off ； The rubber tube is broken or blocked ； Blockage in the outlet pipe of the anode box ； The vent valve is not closed. Solution: Check the cause of the air leak and address it promptly ； Repair the valve ； Replace the rubber hose ； Unblock the obstruction ； Close the vent valve. 3.3 Causes of poor diaphragm adsorption: too low vacuum ； Cathode mesh clogging ； The asbestos fiber quality is poor. Solution: Check the vacuum system ； Clear the cathode mesh ； The proportion of short and long asbestos fibers is appropriate. 3.4 Causes of excessive temperature in copper conductors: poor contact ； The contact surface is too small. Solution: Clean the copper plate joints and tighten the screws ； Increase the contact surface. 4 Safety Protection Measures 4.1 A sufficient number of small fire extinguishers and other firefighting equipment are available on the factory premises, placed in easily accessible locations; it is strictly prohibited to use them for any other purpose. Special fire hydrants should be installed in the production area, and fire extinguishers as well as other fire-fighting equipment must be under the supervision of designated personnel who are responsible for their regular inspection. Replace and maintain in a timely manner to keep them in good condition. 4.2 Pits, ditches, ponds, and holes created for production purposes shall be enclosed or covered. 4.3 Wear protective equipment before going to work, such as work clothes and gloves. Wear glasses at all times during adsorption, and use lined gloves when handling glass products. 4.4 When assembling or disassembling, multiple people should work together closely, taking care of one another; it is strictly prohibited to operate with one hand while touching a grounded surface with the other hand. During lifting, the load must be secured properly; regularly check the crane, hook, and steel cables for any damage ； No one is allowed to stand under the lifted heavy objects. There must be a dedicated person to operate the crane, and its power supply should be turned off when it is not in use. 4.5 For equipment operating at high speeds, the moving parts must be equipped with protective covers. When the equipment is in operation, its moving parts are generally not cleaned; gloves should not be worn when filling it with oil. Before starting the equipment, check to ensure that no maintenance personnel are working on it. 4.6 When operating electrical switches, do not use wet hands; wear rubber gloves on cloudy or rainy days. The motor and electrical panel must have grounding wires. Prevents electric shock, chlorine poisoning, and hydrogen fires. 4.7 For equipment and pipelines that use polytetrafluoroethylene as packing or gaskets, it is strictly prohibited to use an open flame for disassembly and handling. 4.8　When repairing or maintaining alkali pipes and equipment, it is necessary to wear appropriate personal protective equipment; in particular, glasses should be worn, and rubber gloves must be used when handling alkali substances with the hands. When maintaining equipment and pipelines, the alkaline solution inside must be thoroughly removed, and the pressure within the equipment should be released to prevent burns caused by the alkali. 5 Emergency first-aid measures for personal injuries 5.1 First-aid treatment for electric shock victims: Quickly disconnect the victim from the power source and carry out first-aid measures such as artificial respiration. 5.2 In the event of skin contact with caustic soda, immediately remove the contaminated clothing, rinse the affected area thoroughly with plenty of flowing water for at least 15 minutes, and then seek medical treatment. Eye contact: Immediately lift the eyelids and rinse thoroughly with plenty of flowing water or saline for at least 15 minutes, then seek medical treatment. Ingestion: Rinse mouth with water, give milk or egg white to drink, and seek medical attention. Inhalation: Quickly move to a place with fresh air. Keep the airway clear. If there is difficulty breathing, administer oxygen. If breathing stops, perform artificial respiration immediately and seek medical attention. First-aid medication: 3% boric acid solution (for external washing). 5.3 In the case of chlorine inhalation poisoning, first move the poisoned person to a place with fresh air, immediately perform artificial respiration and chest compressions, and promptly call medical personnel for emergency treatment. Those with skin or eye contact should immediately remove the contaminated clothing, or lift the eyelids and rinse with flowing water or saline. Seek medical attention. First-aid medications: Those who have inhaled a large amount should rest in bed, receive oxygen therapy, and be given nebulized inhalations of Albuterol, Ventolin, or 5% sodium bicarbonate combined with dexamethasone; oral administration of Acetaminophen and Bromhexine syrup may also be used. 6 Labor protection and occupational health requirements 6.1 Wear appropriate labor protection equipment, such as work uniforms, before starting work. Personnel working with acids and bases must use protective glasses and other protective equipment. 6.2 For cell maintenance, at least three people must be on duty per shift, and two persons should be assigned to carry out the maintenance work while supervising each other. 6.3 Maintenance personnel who have direct contact with chlorine must have oxygen respirators and gas masks available at their workstations; in particular, crane operators in electrolysis plants must carry gas masks with them at all times. 6.4 The concentration of toxic substances in the air at the production sites should be measured regularly; the maximum allowable concentrations are 1 mg/m3 for chlorine, 7.5 mg/m3 for hydrochloric acid, and 2 mg/m3 for sodium hydroxide. The total asbestos dust concentration is 1.5 mg/m3. The health limit for industrial noise is 85 dB(A). 7 Safety Education 7.1 Safety education is a fundamental aspect of safety management; it plays an important role in fostering among employees a mindset that places safety first, as well as improving their technical skills in safety matters. It also helps to prevent injuries, accidents, and occupational diseases. 7.2 New employees joining the factory (including contract workers, temporary workers, personnel transferred from other units, and those on training or internship visits) must receive safety training at three levels (i.e., company level, branch/department level, and work section (team) level). 7.3 New employees must receive three levels of safety training before they can be issued personal protective equipment to allow them to work in production teams or visit work sites for learning purposes. 7.4 Leaders at all levels should regularly provide workers with ideological and technical education on safe production and labor protection, foster the mindset of \"safety first, prevention foremost,\" and encourage workers to voluntarily fulfill their responsibilities regarding safe production in order to ensure it. 7.5 The content of safety education includes basic theoretical knowledge regarding safe production and labor protection, specialized safety technical knowledge, as well as typical accident cases. 7.6 Employees shall receive safety and technical training at least once a year, and assessments shall be conducted. The results of these assessments shall be recorded on their work permit; only those who pass the assessments are allowed to continue working. 7.7 Special operation personnel must receive professional safety and technical training organized by their respective competent departments. Only after passing the assessment and obtaining a special operation safety permit may they take up their posts. 7.8 Special operation personnel must undergo weekly inspections in accordance with the relevant regulations; only after passing these inspections can they continue to perform work in such special roles. I hope this can be helpful to you