Catalyst loading

This is a lot. First of all, when filling, make sure the catalyst is clean, wash it with water and screen it.； The second is to weigh and prepare all kinds of tools when installing. The third is to rake and shake well when installing to prevent the catalyst from being installed unevenly. When the time comes, phenomena such as gas deviation and uneven bed temperature will not occur. This post was last published by * Edited by aoye613 on 2009-3-11 17:34 ]

The quality of catalyst filling directly affects the resistance of the bed and the distribution of air flow, so special attention should be paid when filling.； 1. In order to prevent the catalyst from getting damp, it should be loaded on a sunny day. 2. Remove debris from the furnace and check whether the inner wall, refractory bricks, grate, etc. are intact. 3. Lay stainless steel wire mesh on the grate, spread refractory balls evenly, and mark the planned filling height. 4. Prepare loading tools and protective tools. 5. Screening should be performed before filling to remove dust and broken particles. 6. The filling height should be less than 0.5m. 7. The loading personnel should step on the wooden board. It is strictly forbidden to step directly on the catalyst to avoid crushing the catalyst. 8. After filling, use wooden boards to smooth the catalyst. Install the manhole immediately.

1. Prevent the catalyst from getting damp, so the catalyst must be waterproof, moisture-proof and rain-proof before filling. 2. The density and uniformity of the catalyst filling. The higher the density, the greater the resistance. The smaller the density, the less the catalyst will be filled. This will cause the catalyst to sink after production and reduce the production capacity. 3. Sieve the catalyst. All catalysts will inevitably have dust and must be screened to prevent them from being blown clean after filling. 4. Prevent The catalyst is broken. Some catalysts have poor strength and are easy to pulverize, so you must be careful when filling. You can lay wooden boards and reduce the free fall height of the catalyst. 5. For pre-reduced catalysts, pay attention to the protection issues during filling to prevent the temperature from flying and the catalyst from burning. 6. The refractory ball filling height, the lower refractory ball must be installed above the outlet pipe distributor to prevent the catalyst from leaking into the pipe.

It depends on what kind of catalyst it is, methanol, synthesis, conversion (medium change, low change) conversion, etc. The ones discussed above are only transformation catalysts. There are still differences in the filling of other catalysts.

Special care should be taken when loading the pre-reduction catalyst in the ammonia synthesis tower of an ammonia plant. Large ammonia plants usually use mechanical oscillators to fill catalysts to ensure tight filling and uniform air flow during production. The vibration should not be too violent, otherwise the oxide film on the outside of the particles will be worn. Workers in the tower must have adequate safety protection measures, such as wearing oxygen masks to supply oxygen. This is because when a small amount of reduced α-Fe microcrystals are exposed, they will form a new oxide film with the oxygen in the air, resulting in less and less oxygen in the surrounding space. Workers working in the tower will be in danger of suffocation if they do not have special safety tools for oxygen supply. Another danger during loading is that the oscillator is too strong. After a large amount of oxide film is destroyed, a new oxide film is quickly formed, causing the temperature to rise rapidly. This is because the exothermic reaction of 2Fe + O2 = 2FeO can increase the temperature of the catalyst bed. ； The rise in temperature in turn accelerates the oxidation of Fe, forming a vicious cycle, causing the temperature to rise to 1000°C or higher. As a result, the catalyst will sinter and the high-pressure cylinder of the ammonia synthesis tower will also be damaged. Therefore, when filling the pre-reduction catalyst, necessary inert gas (such as N2) should be reserved and the catalytic bed temperature should be closely monitored. If there is a rapid upward trend, the staff should first evacuate immediately and introduce N2 into the ammonia synthesis tower. Wait until the temperature drops to normal before continuing to fill.

This question is relatively low-level, haha:) I am engaged in teaching. After installing the catalyst, do I need to cover the top of the catalyst with refractory balls or steel mesh? How? Barbed wire at the top? The book says that refractory balls and steel wire mesh need to be placed above the catalyst, but the order of the two is not clearly stated. I hope you can give me an answer. Thank you.

1. Before loading the catalyst, lay several layers of wire mesh at the bottom of the inner catalyst basket (depending on the particle size of the catalyst), and then put in refractory balls (or not, depending on the mechanical strength of the catalyst). The refractory ball has greater mechanical strength and can prevent the catalyst from being pulverized and blocking the heat exchanger tubes in the tower. The function of the wire mesh is to prevent smaller particles of catalyst from entering the heat exchanger tubes and affecting the heat transfer efficiency. Therefore, although the functions of the two are different, the purpose is the same. 2. After the catalyst loading is completed, the upper part is covered with several layers of wire mesh. The purpose is to prevent the catalyst from being brought into the central tube caused by improper operation (such as pressure relief in front of the tower). Generally, there is no need to install refractory balls. This is zero meter, which is also the lowest point of the bed temperature.

10. Change the medium-change catalyst filling plan 10.1 Catalyst filling distribution 10.1.1 Calculate the filling amount of catalyst. Before loading the catalyst, the demand and distribution method of the catalyst should be determined based on production needs. 10.1.2 Model specifications of the filling distribution parts Weight/t Height/mm One section of top refractory balls, steel wire mesh Φ50, 8 mesh 50~100 Refractory balls at the middle bottom, steel wire Φ50, 8 mesh 50~100 Refractory balls at the top of the second section, steel wire Φ50, 8 mesh 50~100 Refractory balls at the middle bottom, steel wire Φ50, 8 mesh 50~100 Three sections of top refractory balls, steel wire mesh Φ50, 8 mesh 50~100; middle bottom refractory balls, steel wire Φ50, 8 mesh 50~100 10.2 Notes 2.1 Before loading, check the lining, furnace wall and grate of the medium conversion furnace for damage or damage, clean up the debris in the furnace, mark the catalyst filling height, measure and fix the position of the thermocouple. 2.2 Lay Φ50 refractory balls and 8-mesh steel wire mesh on the supporting plate, and seal them tightly around them. 2.3 It is best to sift the catalyst when loading it. When loading it into the furnace, it should be poured lightly and dispersed, not concentrated in a pile. 2.4 The loading personnel should not step on the catalyst to prevent it from being crushed. They should place the wooden board on it and operate on it. 2.5 Do not load on rainy days. 2.6 After the catalyst is installed, the upper part should be raked and leveled, and then covered with steel wire mesh and refractory balls. 2.7 The installation must be completed at one time, and the manholes and inlets and outlets must be quickly closed to prevent the catalyst from absorbing moisture. 2.8 When loading catalyst, operators should wear protective equipment and pay attention to safety. 2.9 Before loading, prepare a long and short iron rake, a flat-blade shovel, and 4 to 5 iron buckets. 11. Change the low-variation catalyst filling plan 11.1 Catalyst filling distribution 11.1.1 Calculate the filling amount of catalyst. The filling amount of catalyst is calculated from the airspeed. When the steam-gas ratio, operating temperature, and CO conversion load are selected, the airspeed can be determined by the operating pressure. 11.1.2 Model specifications of the filling distribution parts Weight/t Height/mm One section of top refractory balls, stainless steel wire mesh Φ50, 8 mesh 50～100 Refractory balls at the middle bottom, stainless steel wire mesh Φ50, 10 mesh 50～100 Two sections of top refractory balls, stainless steel wire mesh Φ50, 8 mesh 50～100 Refractory balls at the middle bottom, stainless steel wire mesh Φ50, 10 mesh 50～100 11.2 Operation and Precautions 11.2.1 Before filling, the lining, furnace wall and grate of the low-variation furnace should be checked for damage or damage, debris in the furnace should be cleaned, the catalyst filling height should be marked, and the position of the thermocouple should be measured and fixed. 11.2.2 In order to prevent gas deviation, the bed diameter-to-height ratio (diameter to total assembly height) is preferably 0.5 to 1.0. This is used to select the height of each bed section to facilitate uniform gas distribution. 11.2.3 After the low-variation catalyst is loaded into the low-variation furnace, the active components are often lost due to water leakage from the inlet and outlet valves. Therefore, the catalyst should be loaded into the low-variation furnace before vulcanization. Generally, the catalyst can be vulcanized after being loaded 1 to 2 days in advance. 11.2.4 Lay Φ50 refractory balls and 10-mesh steel wire mesh on the supporting plate, and seal them tightly around them. 11.2.5 It is best to sift the catalyst when loading it. When loading it into the furnace, it should be poured lightly and dispersed, not concentrated in a pile. 11.2.6 The loading personnel should not step on the catalyst to prevent it from being crushed. They should place the wooden board on it and operate on it. 11.2.7 Do not load on rainy days. 11.2.8 After the catalyst is installed, the upper part should be raked and leveled, and then covered with steel wire mesh and refractory balls. 11.2.9 Try to leave a certain space in the upper part of each section of the low-temperature furnace so that after a certain period of operation, some new catalyst can be added to the upper section (or upper part) as appropriate due to the deactivation of the catalyst. The new catalyst has good activity and significant temperature rise. The new catalyst can be added directly from the upper manhole, but it must be done with N2 to maintain a slight positive pressure (note that the downstream valves and diversion of the system are closed to prevent the "chimney effect" from entering the air). 11.2.10 The installation must be completed at one time, and the manholes and inlets and outlets must be closed quickly to prevent the catalyst from absorbing moisture. 11.2.11 When loading catalyst, operators should wear protective equipment and pay attention to safety. 11.2.12 Before loading, prepare a long and a short iron rake, a flat-blade shovel, and 4 to 5 iron buckets. This post was last edited by bdx-345 on 2009-3-12 12:37 ]

Catalyst filling plan for the first-stage reformer Preparation work for catalyst filling 1. The conversion tube has been replaced and the tray has been installed in place. 2. φ25 low silicon refractory balls and Z-111B catalyst are ready. 3. The working area for catalyst stacking, screening, weighing and bagging has been arranged. 4. The weighing tool has been calibrated and passed the test. 5. The filling tools such as sieves, funnels, hanging baskets, and dustpans are in place. 6. Prepare relevant filling records and diagrams. 7. The filling personnel will be determined according to the situation. 3. Tools 1. Canvas bags φ140×1200, more than 50 pieces. 2. A set of filling funnel and bracket. 3. Two 50kg scales. 4. One sieve (10×10). 5. One crane or one winch of over 20 tons. 6. A 30m tape measure (with weight). 7. A four-section flashlight. 8. 10 pieces of cover plates. 9. Two measuring cylinders. 10. 5 wooden hammers and 2 copper hammers. 11. 20m each of φ10 and φ2 nylon ropes (with hooks and safety buckles). 12. A set of resistance measuring devices. 13. Several kinds of protective equipment. 4. Filling method and steps 1. Determination of bulk density (1) Use a φ152×2000 measuring cylinder to measure. First, measure the empty tube weight G1 (kg) of the φ152×2000 measuring cylinder. (2) Fill the measuring cylinder with water, measure the water temperature with a thermometer, and check the corresponding density d. Then weigh the weight of the full water in the measuring cylinder G2 (kg). (G2 - G1)/d can obtain the volume of the measuring cylinder. Repeat three times and take the average value V. (3) Use a small measuring cylinder to install the catalyst, pour it into a φ152×2000 measuring cylinder, and tap it with a wooden hammer while pouring. After filling and leveling, weigh the catalyst and weigh it as G3 (kg). The bulk density of the catalyst is: (G3-G1)/V. (4) Use the same method to measure three times and keep records. Take the average bulk density as the filling density, and compare this value with the bulk density measured in November 2003. If the difference is too large, it should be reported in time. 2. Measurement of empty pipe resistance (1) Install the tray in place. (2) Discharge the factory air for a period of time, make sure there is no water and is clean, and then close it. (3) Connect the resistance measuring device, slowly open the air valve and stabilize the pressure of the pressure gauge in front of the orifice plate at 0.4Mpa. At the same time, read and write down the pressure indication behind the orifice plate. (4) When measuring, be careful not to damage the sealing surface of the conversion tube. The measured value should be compared with other tubes. If the difference is too large, check the reason. 3. Filling of refractory balls (1) Use a handful of dustpans to weigh the refractory balls. Pick up about 130 φ25 refractory balls each time and weigh them about 3.720kg. (2) After weighing, put it into a canvas bag, tie the openings, put it into a hanging basket, and hang it on the stove top. (3) Loading is done in groups of three. (4) Use the safety buckle on the φ10 rope to fasten the buckle of the canvas bag, use the iron hook on the φ2 rope to hook the mouth of the bag, and fold it over 200mm. After the two ropes are aligned, slowly put the bag into the bottom of the conversion tube, loosen the 2mm rope, and lift the 10mm rope. When your hand feels very light or you hear the sound of pouring, lift up the two ropes at the same time. (5) After the bags are lifted out, they should be hung on the hanger of the conversion tube and collected by a dedicated person, and records should be kept to prevent over-packing or under-packing. (6) After installing the refractory balls, measure the height of the conversion tube and make a record. 4. Catalyst filling (1). Use a winch to hoist the bag containing the catalyst to the top of the furnace and manually move it into place. (2) Install half of the catalyst first: Installed in 5 times. Each filling height is 1150mm. After each filling, put down the tape measure and use a vibrating tool to vibrate to the predetermined height and make a record. (3) After the half pipe is installed, measure the resistance of the half pipe and make a record of it, and adjust the filling height so that it is within the allowed range. (4) Use the same method to fill the other half of the catalyst. (5) As the filling height increases, the inertia becomes larger, and the impact of the hammer hammer will not be obvious. You can use a copper hammer to knock the lifting lugs of the conversion tube, but be careful not to hit the sealing surface of the upper flange or knock off the furnace top refractory material. (6) After the catalyst is installed, measure the resistance of the whole tube and record it. The error shall not exceed ±3%. Adjust the filling height to make it within the allowable range, and compare the filling height and the resistance of the whole tube with the original values. 5. Finishing work (1) After the loading work is completed, collect all the tools and equipment used this time, take them back to the designated location, and manage them uniformly for reuse next time. (2) Inform the relevant units to install the flange.

Please tell me, what is the bulk density of Z111B?