Regarding oven drying

Heating Plan for the Refractory Lining of KEY EQUIPMENT in SHELL Vaporizers I. Purpose of Heating 1. To evaporate the crystalline water and free water contained in the lining material. 2. The binder in the cured lining material. Baking of the furnace can only begin 48 hours after the completion of the lining material installation. To prevent hydration reactions of the SICL3001D material, the lining must be kept dry after installation, and baking should start within 28 days. II. Types of refractory materials for membrane walls: 1. Plibrico—Pliram SICL3001D; 2. Resco-Rescocast AA-22s; 3. Karaplan-RGB siC-F85LC. In the event of conflicts between the drying curves of these three refractory materials, Plibrico—Pliram SICL3001D shall be given priority. III. Heating of the thermal insulation lining of pressure vessels: The heating of the thermal insulation lining of pressure vessels is carried out simultaneously with the heating of the refractory lining of the internal components. Temperature measurement points are installed at the thermal insulation lining of the pressure vessels to ensure that this lining can reach the appropriate heating temperature for that material during the heating process. The drying of the lining of the vaporization furnace pressure vessel is carried out by introducing hot air through the openings in internal components such as coal burners, ignition burners, and startup burners, with the air being discharged through the A10 manhole ； The shell of the SGC is discharged from the lower end of the SGC to the annular space at A12. It ensures that the water vapor evaporated in the thermal insulation lining is discharged out of the furnace along with the hot flue gas, and does not re-condense on the surface of the pressure vessel lining. IV. Preparations before furnace drying 1. Preliminary preparations for furnace drying 1) Pressure testing and sealing testing of the liquefied gas pipelines. Fuel supply, stability of fuel pressure. 2) Insulation and sealing of the pipes connected to the gasifier. 3) All temporary installation devices, auxiliary equipment, and tools must be removed in a timely manner. It must be carefully inspected to ensure that no foreign objects remain inside the container. And document this work. Otherwise, foreign objects may restrict the free expansion of the internal components and damage them. 4) During the drying process, the A10 manhole must be opened to allow gas to flow in the annular space, thereby controlling the temperature difference between the metal wall of the pressure vessel and the metal walls of the internal components. 5) The thickness of the insulation layer on the inner wall of the pressure vessel, which is a key component in the gasification process, is only 40–50 mm. The large external surface area of the pressure vessel results in high heat dissipation (large heat losses). The relatively low temperature of the vessel’s wall walls can cause the temperature difference between the metal walls of the pressure vessel and those of the components inside the gasification furnace to exceed 75 degrees. The expansion of the internal components, in coordination with the expansion-induced displacement of the casing, results in significant temperature differential stresses that damage the internal components. Therefore, special attention should be paid to the temperature difference between the metal wall of the gasifier and the temperatures of its internal components. 6) The pressure test of the water vapor system should be completed in advance to prevent leaks during the hydrostatic test from wetting the refractory mortar. The pressure testing of the internal components at Zhongyuan Dahuahua has been completed, and the pressure testing of the outer tube will not cause damage to the refractory materials. 7) All temporary installation devices, auxiliary equipment, and tools must be removed in a timely manner. It must be carefully inspected to ensure that no foreign objects remain inside the container. 8) There shall be no lifting lugs, shafts, beams, scaffolding, or other temporary structures that could prevent the pressure vessel from moving up and down freely, as well as the movement up and down of the guide frames for the syngas cooler; records must be kept of this work. 9) The external insulation work must be completed; otherwise, it will affect the heating time of the gasification furnace as well as the temperature difference between the metal walls of the pressure vessel and its internal components, leading to the failure of the expansion joints that connect these internal components. 10) All openings on the pressure vessel must be sealed, with the exception of the exhaust vent at the top of the return chamber, the exhaust vent A12 on the syngas cooler via the manhole, and the 4 nitrogen inlet holes located above the sealing plate in the annular space of the gasifier which need to be opened as required. In particular, the slag discharge port at the lower part of the gasifier should be blocked using aluminum silicate fiber filled in a cylindrical basket, and the connecting pipe below it should also be insulated. Nozzles with cooling water jackets should be sealed using ceramic inserts, while other nozzles are sealed with mineral wool; the flange side is covered with a flange cover. The cold shock gas inlet pipeline and the nitrogen outlet purge port must be sealed. 11) Thermocouples used to measure the metal temperature of the outer wall of pressure vessels must be installed and inspected. 12) Has the clamping block of the constant-force hoist been removed? 13) Use insulating materials to insulate the manholes, pilot burners, and start-up burner connection plates; the insulation length of external connection pipes should be at least 200 mm. Otherwise, excessive energy loss will affect the drying time. 14) Adjustment of pipe clamps and removal of fixing elements. 15) The gap between the slag pool and the thermal skirt must be strictly sealed using asbestos rope or other insulating materials, and measures must be taken to prevent it from being blown open. 16) The thermocouple used to measure the gas temperature on the surface of the refractory mortar must be exposed outside the refractory layer, while the thermocouple used to measure the temperature of the metal components must be in contact with the metal; furthermore, the connections and performance of the thermocouples must be checked. Measures should be taken for thermocouples to prevent damage. If the thermocouple is placed after the vaporization furnace, a compensation wire is used for connection. 17) Determination of the power of the hot gas generator: The power of the hot gas generator is calculated in terms of 1 million kcal. The air flow rate must ensure that the velocity of the hot gas flowing over the surface of the refractory materials in the gas reaction chamber is greater than 1 m/s. 18) Pressure testing and sealing tests for the fuel supply system. Inspection of the nitrogen purge system, inspection of the pressure gauge. 19) Inspection of fire protection and safety measures. 20) The outlet port of the syngas cooler is sealed. 21) Lighting for night operations. 22) Examine the structure of the gas distributor to ensure uniform distribution in the circumferential direction. 23) Manhole insert 2. Key points to pay attention to during baking: 1) The temperature of the shell wall may differ from that of the internal components of the gasification furnace by more than 75 degrees. Therefore, special attention should be paid to the temperature difference between the metal wall of the gasifier and the temperatures of its internal components. Based on the experience of previous manufacturers in heating up the furnaces, it can be increased to 125 degrees. 2) The four tie rods of the constant-force hoists on the upper part of the support beam must be located at the center of the holes. Monitor the travel and swinging motion of the constant-force hoists; if the tie rods come into contact with the box girder, it is necessary to lower the temperature, either by readjusting the position of the tie rods or by increasing the diameter of the holes at the lower end of the box girder. 3) Observe whether the guide rod can move up and down, and whether the syngas cooler can move up and down freely. 4) Observe the deflection angle of the syngas cooler. 5) The temperature of the hot gas at the burner outlet must not exceed 530 degrees. Control is achieved by adjusting the pressure and flow rate of the feed gas; in particular, during the ignition phase, concern over the possibility of failure to ignite results in a very low air flow, which causes temporary high temperatures. It is therefore necessary to immediately increase the air flow to keep the temperature of the hot gases entering the gasification furnace below 110 degrees. Under normal circumstances, the amount and pressure of the feed gas should be reduced during the ignition phase, and air should be introduced at the rear part of the hot gas generator to prevent sudden high temperatures from occurring in the hot gas within the gasifier, which could damage the surface of the refractory material. During the curing process of refractory materials, fluctuations in the volume and pressure of the feed gas, which can cause temperature variations, must be taken into account during the constant-temperature stage; the temperature of the hot gas entering the gasification furnace should be kept below 530 degrees. 7) The constant temperature time at 110°C should be determined based on the water content of the external insulation material of the pressure vessel. The insulation material must be dried before the temperature can be increased; otherwise, it will affect the temperature of the metal walls of the pressure vessel during heating. 8) Due to the high heat dissipation, can the heat provided by the hot gas generator maintain the hot gas temperature at 450°C for 12 hours? 9) It is necessary to ensure that the metal wall temperature at the outlet of the syngas cooler does not exceed 380 degrees; otherwise, 40 mm of mineral wool should be placed on top of 4 mm thick stainless steel plates. 10) The drying process is carried out at a constant temperature of over 110 degrees for 16 hours, during which the average temperature of the hot surface metal of the internal components does not exceed 150 degrees. When the temperature is above 225–230 degrees, the holding time is 12 hours, and the temperature of the metal wall of the pressure vessel should be between 185–200 degrees. At 450 degrees, the holding time is 12 hours; during this time, the metal temperature of the hot surface of the pipeline’s internal components must not be lower than 350 degrees, and the holding time must be at least 6 hours. 11) Strictly control the heating rate and follow the heating curve. Especially when the drying temperature is above 110 degrees. 12) The evaluation of the drying effect of the internal components is primarily based on the following temperatures and their corresponding holding times: TsH1.1∽TsH1.3; TwH1.1~TwH1.3 ； TsB1.1~TsB1.3 ； TwT2.1~TwT2.3 TsG1.1~TsG1.4 ； TsQ1.1~TsQ1.2 ； TwR1, TwR2 13) If the metal temperature of the gas pipeline is too low, it is necessary to open the A10 manhole. 14) When there are conflicts in temperature control during the baking of the three types of refractory materials, Plibrico—Pliram SICL3001D should be given priority. 3. Advantages and disadvantages of using a two-step drying method: 1) The approach of using steam drying in the first step and hot air drying in the second step is advantageous for cleaning the water vapor system and reducing foreign substances within the pipes. This prevents soil, metal powder, and fine metal wires from sticking together during the high-temperature drying process with hot air, thereby avoiding blockages in the internal components such as Lamont nozzles (throttle orifice plates). 2) Steam drying is used, featuring a large heating surface, uniform drying, and short drying time. Lower temperature control is required during the drying process. 3) Steam drying is used; the steam system must be purged, and the boiler has been cooked and tested. At the same time, flow tests were conducted on the steam system of the heat transfer surfaces inside the gasifier. 4) During the flow rate testing of the vapor system on the heat transfer surface, if it is found that the flow rate in the tubes differs significantly from the design value, the tubes can be repaired to remove any blockages, without affecting the performance of the refractory lining inside the tubes. 4. Advantages and disadvantages of using only hot air drying: Using only hot air drying can reduce the pressure on the installation schedule of the steam system, as it is not affected by the progress of piping work; thus, the drying of the steam system can be completed 15–20 days earlier. However, due to the use of hot air convection and radiation heat transfer, the heat transfer rate is low, resulting in uneven drying, especially for the fire-resistant lining on the inner wall of the pressure vessel shell, which takes a long time to dry. High control requirements are needed for temperature during the drying process. Usage conditions for heat-only drying: a) The refractory materials for the internal components have already been shipped; these materials have a limited shelf life, and the installation, piping, and commissioning of the steam system equipment cannot be completed in time. b) Due to schedule requirements, the application of the refractory mortar for the internal components must be carried out in winter, when the ambient temperature is below 5 degrees Celsius. Drying must begin immediately 48 hours after the application of the refractory mortar is completed. The internal components manufacturers and pressure vessel manufacturers ensure proper quality control within the on-site assembly facilities, and the owner, contractors, and manufacturers can take measures to maintain cleanliness inside the pipes of the steam system.

1. Instrument air is available. 2. Compressed air is available. 3. Fuel gas is available. 4. The preheating water pump is in working condition. 5. The corresponding valves have been checked. 6. Fresh water is available. During the furnace drying process, pay attention to: 1. The heating curve. 2. The principles of heating. 3. The temperature difference between the upper and lower parts. 4. The liquid level in the gasification furnace. 5. The temperature at the syngas outlet