Gas generator overturning detection

Gas generator furnace sintering assessment: A. Large lumps form (different from large scars; the furnace bars are prone to breaking). 1. The total steam volume is low (the load is high). Features: (1) Numerous large gray slag lumps at the bottom; significant reduction in coking back in the earlier stages, with an excess of unreacted carbon thereafter ； (2) The carbon dioxide content in the gas is low ； (3) The top temperature is generally high, while the bottom temperature is on the high side or normal ； (4) High wind pressure ； (5) Warehouse temperature is high or normal ； (6) The fire layer is located higher up, it is sticky or even hard, and the slag layer is generally thick. Treatment: Add steam or reduce air flow based on the temperature at the bottom, top, and sides, as well as in the silo. (1) If the top temperature is high (above 50 degrees as per the standard), the bottom temperature is also high (above 100 degrees as per the standard), and the chamber temperature is high as well (above 150 degrees as per the standard), then reduce the air flow by 2–4 units, while increasing the lower blowing knob by 0. 5—1. 5 centimeters. Because the furnace conditions have already deteriorated at this point, it is not appropriate to further intensify gas production ； (2) If the top temperature is high (above 30 degrees as per the standard) and the low-temperature side temperature is also high (above 50 degrees as per the standard), with the warehouse temperature being slightly high or normal, it should be considered to increase the upper and lower blowing handwheels by 0 as well. 5—1. 5 centimeters, with blowing from above being the main method ； (3) If both the top and bottom are normal, an inversion of the top and bottom may occur occasionally; in such cases, increase the upper and lower blowing handwheels by 0 as well. 5—1. 5 centimeters, with blowing mainly from below; the rod machine can be set to 20–60 revolutions ； (4) After 40 minutes of adjustment, take samples for analysis and comparison, and pay attention to any changes in ash content in the next round. 2. Large amount of steam blown from above (small amount of steam blown from below; total steam volume is sufficient, but the speed of the furnace strip machine is low). Characteristics: (1) The ash lumps at the bottom are relatively thick, with obvious signs of fragmentation; they are not hard in texture and tend to be white in color. When the speed of the furnace strip machine is high, there is more foam, and it is easy for raw carbon to accumulate ； (2) The upward CO2% is high, while the downward CO2% is low or normal ； (3) High wind pressure (0 higher than normal). 5—1. 0) ； (4) The fire layer is located too high, and the slag layer is thick, making it difficult to penetrate ； (5) The top temperature is high, the bottom temperature is low or normal, and the bin temperature is normal or high. Treatment: (1) Decrease the upper blowing handwheel by 0. 5—1. 5 centimeters, while adding 0 to the downward blow. 5—1. 5 cm, plus 20–40 revolutions of the rod feeder ； (2) Subtract 1–2 numbers for blowing, and add 20–60 rotations for the rod feeder ； Or the use of both of the above methods in combination ； (3) Take samples for analysis and comparison after 40 minutes of adjustment. 3. The amount of steam blown downward is high (the amount of steam blown upward is low; the total amount of steam is sufficient, but the speed of the furnace strip machine is slow). Features: (1) The lower ash layer contains fewer voids in the slag lumps, is harder in texture, and has a dark gray color (not black spots) ； (2) The upper temperature is low or normal, the lower temperature is high, and the warehouse temperature is relatively high ； (3) The upward CO2% is significantly lower than the downward CO2% (greater than 2.0) ； (4) High wind pressure ； (5) When the furnace rod machine is accelerated, the temperature in the rear chamber tends to rise sharply on one side ； (6) The fire layer is located lower down, and the slag layer is thin and hard. Processing: (1) Turn the blower wheel to 0. 5—1. 5 cm, turn off the blower wheel to 0. 5—1. 5 cm, furnace rod adding machine: 20–60 revolutions ； (2) Add 1–2 blows, and operate the rod feeder at 20–40 revolutions ； (3) Turn the blower wheel to 0. 5—1. 5 cm, downward blowing; the furnace rod mechanism is temporarily inactive ； (4) Take samples for analysis and comparison after 40 minutes of adjustment. 4. The downward blowing ratio is too high (i.e., the upward blowing ratio is too low, causing the electrode machine to operate more slowly). Features: (1) The lower gray mass is larger in size, harder in texture, and grayish-black in color ； Items (2)–(6) are identical to the content of the “high steam volume” item. Treatment: (1) Add 1–3 blows (less than 34), and operate the rod feeder for 20–40 rotations ； (2) Adjust the upper blowing speed and coordinate it with the adjustment of the upper and lower blowing handwheels. If the total steam volume is too low, turn down the blowout handwheel by 0. 5—1. 5 centimeters ； If the total steam volume is too high, turn down the blowout wheel to 0. 5—1. 5 cm, with the rod adding machine at 20–40 revolutions ； (3) Take samples for analysis and comparison after 40 minutes of adjustment. 5. Equipment issues. Category: (1) Uneven air distribution over the grate cloth ； (2) Valve issues result in reduced steam flow to the furnace ； (3) Poor slag breaking capacity of the furnace grates ； (4) Instrument failure, misjudgment, etc. Handling: Take appropriate actions depending on the situation. 6. Material issues. Category: (1) During normal production, some batches contain a higher amount of carbonaceous gangue, which easily leads to the formation of large lumps ； (2) The raw coal has a low ash melting point, low fixed carbon, and high ash content. Larger clumps form at slightly lower steam levels ； (3) The particle size of the raw material is relatively small (more than 50% are between 10–16 millimeters), resulting in a large specific surface area and making it easy for large lumps to form. 7. Other factors. For example: in the process design, the top temperature is too low while the bottom temperature is too high ； Imbalanced blending ratio ； Large fluctuations in the temperature of the incoming steam, or excessive pressurized steam after the boiler is shut down ； Excessive powder in the raw coal, among other factors, can easily lead to localized overheating and the formation of large lumps. B. Formation of large scars (different from large lumps; difficult to break apart; does not refer to scars on the furnace surface). The cause of large scar formation is the same as that of large lump formation, being a result of further deterioration. That is, local overheating inside the furnace leads to reduced steam production; after slag formation, solid black patches are created. The smaller ones can be discharged along with the slag, while the larger ones move around irregularly inside the furnace (sometimes moving and sometimes staying still). The external characteristics are: (1) the furnace is prone to fluidized carbon collapse, with high coking ； (2) After the furnace load is increased, it is difficult to maintain stability and the furnace tends to reverse its operation ； (3) The current of the furnace rod machine is on the high side ； (4) Initially, small, dark, solid, and hard scars appear (usually without sharp edges and difficult to break). Ovens used to deal with large scars can generally only operate at a light load in order to gradually reduce the size of these large scars or break them down into smaller ones before removing them; however, if too large scar formations remain on the grate, it is difficult to remove them, and the only option is to shut down the oven and remove the scars. In short, large deposits form inside the furnace more often, while large scars form less frequently. It is mainly caused by improper adjustment of steam and burner bars, leading to localized overheating inside the furnace and thus scaling. In mild cases, it can be dealt with gradually; in severe cases, most of the furnace is covered with deposits, the carbon layer is less than one meter thick, it’s impossible to increase the load, and the furnace rods cannot be lowered either. Therefore, specifying “anti-caking” in the operating procedures is an important principle

Judgment of high ash return and coking degree A: Steam factors. 1. Low steam consumption: Characteristics: (1) Many ash lumps at the bottom, including black, solid ash lumps; there is a lot of unburned carbon which can cause uneven distribution ； 　　　　　　　　　　(2) The top temperature is high and fluctuates greatly, showing a serrated pattern; the furnace is prone to overturning when there is a slight carbon deficiency ； 　　　　　　　　　(3) Normal top and bottom temperatures but furnace turnover ； 　　　　　　　　　　　　　　　　　　　　(4) The bottom temperature rises slowly after adding furnace rods, while the bin temperature rises quickly, resulting in a large temperature difference ； 　　　　　　　(5) High wind pressure, low CO2 level ； 　　　　　　　　　　　　　　　　　　　　(6) The gasification layer is sticky and hard, and concentrated. Treatment: Adjust the total steam supply accordingly based on the temperature at the top, bottom, and in the furnace, as well as the speed of the rod drive mechanism; adjust the ratio of upper to lower blowing, or use the handwheel and the speed control of the rod drive mechanism. (1) When the top temperature is high and the bottom temperature is low, increase the lower blowing handwheel by 0. 5—1. 5 cm, furnace rod adding machine: 20–80 revolutions ； (2) When the top temperature is low and the bottom temperature is high, add 0 to the blower wheel setting. 5—1. 5 cm – Adjust the heating rods gradually based on temperature changes ； (3) When the top temperature, bottom temperature, and chamber temperature are high, reduce the blowing speed by 2–4 levels, and reduce the rotation of the rod feeder by 20–60 revolutions or stop it altogether ； (4) If the top and bottom temperatures are normal but the wind pressure is high and the CO2% level is low, causing the furnace to tip over, then increase the upper and lower blowing handwheels by 0 simultaneously. 5—1. 5 cm, with the rod adding machine at 20–80 revolutions. 2. High steam consumption. Features: (1) The bottom ash is grayish-white; there are hardly any large pieces of ash, plenty of foam and powder, a lot of charcoal, and the ash content is either high or normal, with no bias to one side ； (2) The top and bottom temperatures are high when the air supply volume is large, and low otherwise, with little variation. (3) Warehouse temperature is high (when strong airflow is present) or normal (when weak airflow is present), with relatively even distribution ； (4) Wind pressure is low, while CO2% in the gas flow in both upward and downward directions is high ； (5) High downstream emissions and excessive foam ； (6) The gasification layer is soft. Treatment: Adjustments are made based on factors such as the amount of ash falling, the temperatures in the top and bottom chambers, and the condition of the furnace rods, taking into account parameters like air pressure, CO2 percentage, and coal feeding time. (1) When both the top and bottom temperatures are high (top temperature above 250 degrees, bottom temperature above 300 degrees), the focus should be on reducing the upward airflow. 5—1. 5 cm or minus 1–2 blows (total number not less than 30) ； If the bottom temperature rises rapidly, the downward blowing can be reduced by 0. 5—1. 5 cm, or the rod-reducing machine should be operated at 20–60 revolutions per minute, to ensure that the gasification layer heats up gradually, in a concentrated manner, and at a lower position ； 　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　 (2) Top high and bottom low, subtract 0 from the upper blowing handwheel. 5—1. 5 cm, with the rod adding machine at 20–40 revolutions ； Top low bottom high, subtract 0 from the blower wheel. 5—1. 5 cm, rod-reducing machine: 20–40 revolutions ； (3) If both the top and bottom angles are low (less than 180 degrees), reduce the upper and lower blowing handwheels by 0 simultaneously. 5—1. 5 cm or add 1–2 numbers; use a rod feeder at 20–60 revolutions ； (4) After adjusting for one hour, take a gas sample for analysis and comparison before making further adjustments. B. Furnace rod machine factors. 1. The speed of the furnace rod machine is too high. 　Features: (1) The gasification layer moves downward, resulting in a shorter residence time inside the furnace; unburned carbon is discharged, which leads to high coke return ； 　　　　(2) When the clumps formed inside the furnace are pulled out, the unburned carbon at their upper part is discharged along with them, resulting in high coke return ； (3) Large amount of foam in downward emissions ； (4) As the bottom temperature rises, the bin temperature rises even faster. Treatment: (1) Reduce the rotation speed of the rod feeder by 20–100 revolutions to increase the residence time of the material inside the furnace ； (2) Adjust the steam amount appropriately to reduce scarring ； (3) Reduce ash content in a timely manner. 2. The speed adjustment range of the furnace rod machine is too large or too frequent. Features: (1) When the furnace is turned over, in order to reduce the temperature at the furnace top, the rod feeding mechanism is operated aggressively, resulting in local collapse and carbon inclusion ； (2) Stop the strip mill when the bottom temperature is excessively high, there is flow generation, or the downward emission zone contains a large amount of carbon ； (3) Focusing only on the top temperature, using a machine to raise the level by adding furnace rods and another machine to lower it by removing rods, with frequent adjustments, disrupts the normal downward movement of the material layer; as a result, the layer becomes disordered and coke formation increases. Treatment: (1) When turning the furnace, first reduce the air supply by 2–4 units, and then decide whether to perform a hard turn or a soft turn; adjust the steam supply and furnace control devices as appropriate ； (2) In principle, the furnace should be started along with the strip rolling machine, with adjusting the rotation speed as the main objective ； (3) Consider the relationship between temperature and the gasification layer comprehensively, with stabilizing the gasification layer as the primary goal, rather than merely achieving a specific temperature threshold. Fully considering, the main function of the grate controller is to regulate the residence time of materials inside the furnace, in order to burn the coal thoroughly; without taking into account the total amount of steam used or the ratio of air supply from above and below, using this controller blindly to control the furnace temperature can easily lead to high levels of coking. C. Boiler hanging factor (relatively severe). Features: (1) The steam generator cannot enhance gas production; when blowing air is applied, the top temperature rises rapidly and it is easy to cause overpressure (the number of blows is less than 38) ； (2) During light-load production, the top temperature is high, while the bottom temperature is normal or high ； (3) The ash discharge is unstable, with periods of good performance and periods of poor performance ； (4) High wind pressure ； (5) The carbon addition interval is long (greater than 50 minutes). Treatment: There are mainly two reasons for the furnace to stop working (ignoring the jacket height). First, the vaporization layer rises above the jacket, causing \"peripheral hanging\"” ； Second, due to prolonged local blowing or the formation of a wind tunnel, the charcoal burns above the jacket, accumulating more and more and resulting in a \"lopsided accumulation\". To deal with a furnace that has stopped working, it is generally done by first reducing the carbon layer and then manually creating scars. If the furnace damage is severe and it’s not possible to repair it from the outside, the only option is to shut down the furnace and fix the damage. (The variability in performance when ashing is applied is mainly caused by uneven deposition.) D. Factors leading to the formation of large scars (dead scars). Features: (1) The lower ash layer has poor fluidity, high partial coking, and a large amount of green carbon; previously, angular black spots were often present ； (2) The bottom temperature is high or normal; there is a large temperature difference within the tank, with fluctuations from left to right ； (3) The current of the furnace rod machine occasionally rises to high levels ； (4) Oxygen content is sometimes high and sometimes normal ； (5) There are areas where it is difficult to probe deeply during inspection. Treatment: (1) Operate at light load, maintain a higher steam supply, reduce ash accumulation as appropriate, and wait until the large scars shrink or break before removing them ； (2) Eliminate furnace scars. E. Equipment factors. Category: (1) Damage to one side of the baffle, resulting in uneven descent of the material layer and incomplete combustion of carbon on one side ； (2) If there is significant damage or loss of the slag strips, large slag clumps can easily form and block the slag discharge outlet, thereby interfering with the normal flow of materials and causing uneven cooking ； (3) The slag discharge port is positioned too high, and the ash plow is too long, resulting in excessive slag discharge capacity; this can easily damage the slag layer and lead to increased coking ； (4) The grate has poor slag breaking capacity, leading to the formation of large slag masses and scabs; when these masses crack or the scabs break away, carbon can be carried back, resulting in high coking degree ； (5) High resistance in the central ring area (coke feeder-equipped gasifier); weak gasification intensity, resulting in incomplete carbon combustion and high levels thereof ； Alternatively, excessive air flow in the outer ring area (this is more evident when the carbon particles are uneven) leads to a rapid rise in apparent temperature; this makes it difficult to ensure that all the carbon in the central ring area is burned completely, resulting in high coking ； (6) Internal leakage in the air blower, upward and downward gas valves, and steam valves causes an imbalance between air and steam, resulting in poor gasification conditions and high coke formation. (7) If the distributor of the coke feeder is too long, the material layer becomes thin; this makes it easy for coke to form at the top of the furnace when gas production is increased. Additionally, if the machine used to add furnace bars operates too quickly, it damages the gasification layer, leading to high coke formation. Treatment: (1) If one side of the baffle is damaged, take immediate measures to reduce ash accumulation or repair it ； (2) The issue with the broken slag strips can only be resolved by shutting down the furnace at an appropriate time for repairs ； (3) The slag discharge port and ash plow issues require redesign and installation ； (4) Poor slag breaking capacity of the furnace grates; replace them in a timely manner ； (5) For the issue of air distribution through the grate, a dedicated grate must be considered ； (6) Valve issues were repaired immediately ； (7) The issue of the excessive length of the feeder in the coke feeder unit can be resolved by redesigning and reinstalling it. F. Material issues. Category: (1) The coal particles are relatively small, resulting in a thin gasification layer; this makes coking likely to occur during enhanced gas production, leading to high coke formation ； (2) Coal has a high ash melting point and low ash content (poor slag-forming properties); if the furnace has a strong slag discharge capacity, it is easy for the slag layer to be damaged, resulting in high coking ； (3) The coal particle size range is wide; the smaller coal particles have already burned out, while the larger ones do not burn completely, resulting in high coking ； (4) The proportion of carbon used in blending is inappropriate: an excessive amount of low-melting-point carbon leads to a high main temperature, while the high-melting-point carbon fails to burn completely or forms carbon slag, resulting in increased coking ； (5) Uneven carbon distribution: in some bins, the content of carbon-rich gangue is high, which causes the normal gasification layer to sinter and leads to deteriorated furnace conditions as well as increased coking ； (6) Large fluctuations in the temperature and pressure of the steam entering the furnace disrupt the thermal balance within it; if not handled properly, the furnace conditions deteriorate, leading to increased coking (for example, when the steam contains water, its temperature is above 220 degrees, or there are frequent shutdowns). Treatment: (1) Carbon with a relatively small particle size can be burned alone or in combination with other materials; when burned alone, a short combustion cycle and moderate to low load levels are used, while when mixed with other materials, its proportion should not exceed one-third, and it is not advisable to mix it with larger particles of carbon ； (2) Appropriately reduce the furnace’s slag discharge capacity (by lowering the height of the slag discharge opening, reducing the distance between the grates and the slag breaking bars, using short ash plows, etc.) ； (3) Wide particle size range enables grading and furnace-based combustion ； (4) Adjust the carbon ratio so that the proportion of high-melting-point carbon increases, becoming the primary carbon component, while low-melting-point carbon serves to assist combustion and form the structural framework ； (5) Uneven carbon incorporation: pay attention to adjusting the amount of steam used, and strengthen management at the same time ； (6) Coordinate the external steam temperature to maintain stability, strengthen inspections and regular drainage; when the boiler is shut down, adjust the pressure in the main steam pipeline appropriately (by 0 for each boiler). 05—0. 08 kilograms is used as a reference). G. Other factors. Factors such as strong winds, disruptions in the operation of microcomputers or prolonged windy conditions, malfunctioning temperature indicators, unclear handovers between shifts, incorrect judgments and operations, and lax management oversight can all affect the furnace operation in various ways and to varying degrees, thereby leading to high levels of coke reformation. No further details are provided here. In short, the level of backfocusing is an important factor in measuring the gas production efficiency of a gas generator. It has many influencing factors, a complex process, and is difficult to control. Only by taking various factors into account, making accurate judgments, and making timely adjustments can it be done well. Appendix: 1. Classification of ash and slag. Category (Good): Backfocusing rate less than or equal to 15% ； Category II (poor): Defocus rate 15–25% ； Category 3 (unqualified): 25–35% ； Category 4 (undergrowing): Refocusing rate greater than 35%.

The basis for judging the operating condition of a gas generation furnace comes from various conditions that affect its operation, or from external characteristics that reflect its operating condition. The standard is high gas production and low coking – more intake leads to better results. Based on this, the criteria used for assessing furnace conditions are classified into primary and secondary criteria as follows: A. Primary criteria: 1. Ash and slag, as they represent the ultimate outcome of the entire process of material movement in the gas generation furnace. Information regarding changes in furnace conditions can be obtained intuitively through aspects such as the amount of ash and slag (quantity and distribution), the slag formation status (slag formation rate, size of slag particles, as well as their color and shape), and the coking back phenomenon (rate of coking back, ratio of raw to cooked carbon, and its form of existence). These provide important data for tracking changes in furnace conditions. It plays an irreplaceable role, especially in the reaction prior to the gasification layer, the current conditions, and the prediction thereafter; it is a direct manifestation of \"achieving an optimal state\" as defined in the standards, and this is the main reason why it is designated as \"first\". (Attached: ash data) 2. Top and bottom temperatures: When the furnace operation is normal, the top and bottom temperatures can reflect the condition of the gasification zone; these are commonly referred to as \"actual temperatures\". When the furnace conditions are poor, such as sticking, localized blowing over, collapse, or an excessive amount of steam, only partial information can be obtained. In production, it is common to encounter situations where the temperature is normal yet the furnace still blows over or coke formation increases. Therefore, based on the criterion of \"proper operation,\" the top and bottom temperatures are necessary but not sufficient conditions; hence they are regarded as the \"second\" key factors. (Attached indicators) 3. Ash bin temperature: The level and variation of the ash bin temperature reflect the speed and uniformity of the downward movement of the ash layer (or the entire material layer). Generally, a steady rise and fall in the temperatures of the two bins indicates a steady movement of the gasification layer; a sudden increase suggests localized accumulation of red slag or red carbon (it is normal for ash to accumulate under red slag, but high coking occurs when ash accumulates under red carbon). A difference in temperatures between the two sides indicates that the gasification layer is offset to one side, often accompanied by high temperatures at both the top and bottom of the furnace. If one side has a lower temperature while the other remains normal, it indicates uneven ash deposition or the effect of artificial water addition. The temperature of the ash bin is primarily controlled by the speed of the furnace bars, and it is important for predicting the condition of ash deposition; hence it is considered the third key factor. (Attached indicators) 4. Rotational speed of the grate machine: The grate machine not only controls the ability of the grate to break and discharge slag as well as the uniform distribution of the gasification layer, but it also plays a decisive role in the movement speed of the material layer; it is an important condition for achieving efficient feeding and good material extraction. Its main function is to control the residence time of materials in the furnace based on different coal qualities and load levels, thereby ensuring stable operation of each material layer and a low coking rate; in practical operations, it is often used as the primary method for controlling the top and bottom temperatures. (Appended indicators) Supplementary basis for B: 1. Gas composition – generally, carbon dioxide from the blowing air and the upward and downward flowing air is sufficient. Perform a full analysis if necessary. 2. Material changes, including variations and trends in the pressure, temperature, and flow rate of the two types of air as well as steam under different carbon types and during co-firing (or back-firing of coke). (Attached data) 3. Percentage adjustment, including blowing speed and the percentages for upper and lower blowing. (Appended data) 4. Emissions from large and small dust collectors, emission amounts, distribution of coal powder, lump coal, and slag lumps, etc. The large dust collector having carbon is caused by furnace turning, while that having slag is caused by the blowing hole. A small amount of carbon in the dust collector is caused by the excessive downward movement of the gasification layer, while a large amount of carbon is due to a thin gasification layer and its downward movement, or damage to the grate. 5. Equipment-related factors, including the service life of the grate assembly, damage to flow control plates and slag breaking strips, idling of the grate mechanism, internal leakage in valves, incorrect operation of microcomputers, or malfunctioning instrument readings. 6. Others, including trends in the steam outlet temperature of the jacket, nitrogen addition for adjustment, and composition adjustment in subsequent stages. In short, assessing the furnace condition is a complex process that involves gathering information from various sources, gradually forming a conceptual understanding, and ultimately reaching a comprehensive judgment. It requires a strong sense of responsibility, extensive practical experience, and scientific analytical skills in order to identify the main issues, address them, and reduce or avoid misjudgments and improper operations.