Push type automatic plugging and anti blocking device

Push type automatic plugging and anti blocking device

1、 Working principle
According to the actual conditions such as medium, pipe diameter, conveying distance, and geometric layout of ash conveying pipelines, design and install automatic plugging devices at intervals. The inlet of the bin pump adopts a pressure reducing valve, which maintains a constant pressure lower than the gas source pressure inside the bin pump during transportation. The design of the pressure depends on the total gas source pressure and the required transportation volume. A high pressure results in a faster ash discharge speed and improved transportation efficiency. At the outlet of the warehouse pump, there is full pipe transportation. When the medium is transported to a certain distance, there will be a pressure rise phenomenon inside the pipe. At this time, the automatic plugging device installed on the pipeline will automatically detect the pressure inside the ash conveying pipe. When the pressure inside the pipeline reaches the opening pressure of the automatic plugging device, the valve will automatically open to supply air into the pipeline. The medium inside the pipeline will be disturbed by the intake air and will automatically loosen. The pipe blockage phenomenon at this point will be eliminated, the valve will automatically close, and the medium inside the pipeline will continue to move forward.

2、 Characteristics of the new embolic delivery system

1. Do not block the pipe! The conveying system can adapt to any powder material, and after installing an automatic plug valve, the system will never experience pipe blockage, and its reliability is very high. Even if the system is artificially blocked, it is almost impossible.

2. Long distance! The ideal long-distance transportation can be achieved, theoretically, it is possible to deliver as far as you want. Currently, among many successful cases of transportation equipment manufacturers at home and abroad, the only one that can achieve true long-distance (such as over 2000 meters) and stable operation is the new embolization transportation system. When the conveying distance exceeds 800 meters, conventional conveying systems must be adjusted through reasonable gas distribution, control, etc. At this time, only the ash to gas ratio of the system can be reduced; When the conveying distance exceeds 1200 meters, conventional conveying systems must add pipeline boosters to carry out secondary fluidization of materials in the pipeline, prevent gas ash stratification, further reduce the ash to gas ratio, increase system flow rate, and increase pipeline wear;

3. Low energy consumption! The conventional conveying system is divided into four processes: feeding, pressurized fluidization, conveying, and pipeline blowing; The new embolization delivery system only has three processes, feeding and pressurized delivery, omitting pipeline blowing; The process of pipeline blowing has the following characteristics: high flow rate, low ash to air ratio, and waste of a large amount of compressed air. The new embolic conveying system can achieve full pipe conveying of all materials with low flow rate. When there is no ash in the bin pump, the conveying can be stopped. The materials in the pipeline will not affect the next process of conveying and will not block the pipe.

4. Small wear and tear! The new embolic delivery system has a low delivery flow rate due to its full tube delivery, and the flow rate is proportional to wear, resulting in much lower wear on pipeline bends and other components compared to conventional delivery systems. The average conveying flow rate shall not exceed 5m/s, and the ash storage end shall not exceed 8m/s

5. High efficiency! The conveying capacity of the same ash conveying pipe diameter is more than twice that of the conventional conveying system. With the same system configuration, the use of the new plug conveying system can increase the conveying capacity by more than twice.

6. High proportion! The new embolization delivery system has a wide adaptability, and almost all powdered materials can be delivered without clogging the tube.

7. Simplified configuration! The system configuration is quite simple, without tedious control or complicated air distribution. The bin pump only has one main intake point. All warehouse pumps do not require fluidization, primary gas, or secondary gas, reducing the number of system failure points and control points.

3、 Common causes of pipe blockage

1. Compressed air with water content blocking the pipe

The major ash blockage problem encountered during the system is due to the cold winter weather. When compressed air enters the pipeline for cooling, it condenses into liquid water. This liquid water, along with the compressed air, enters the conveying pipeline and causes the material to bond, increasing conveying resistance and reducing conveying speed, resulting in pipe blockage. Cold weather can also cause ice blockage at the throttle orifice of the trachea, preventing the air source from entering the delivery pipeline normally and reducing the intake of compressed air, resulting in pipe blockage.

In response to the above issues, we have installed insulation on the compressed air pipeline and also installed a gas water separator on the compressed air pipeline. By increasing the temperature of the compressed air and reducing the content of condensed water, we have not yet solved the problem of pipe blockage caused by water content in the compressed air.

2. Blockage caused by gray matter changes
During operation, boilers often use coal that deviates significantly from the original design, resulting in significant changes in ash characteristics, ash content, and ash content, which is also a major cause of severe pipe blockage.

3. Reasons for outdated equipment in the original system
Due to frequent malfunctions caused by changes in coal combustion conditions, ash plugs cannot be formed due to coarse ash and poor flowability. Ash can only be laid flat at the bottom of the ash pipe, and compressed air and ash are separated, making it impossible to bring the ash into the ash silo. When the ash settles and the pipeline becomes full, pipe blockage will occur. Neither of the above situations can ensure the normal operation of the system by adjusting the ash to air ratio, so the system can only be modified.

4、 Disadvantages of traditional conveying
1. Dilute phase pneumatic conveying: The gas source for this conveying method is usually a Roots blower. Due to the relatively small solid to gas ratio, conveying the same amount of material consumes more gas. In addition, the wind speed in the dilute phase conveying duct is usually above 20m/s, causing significant material wear and generating more dust.
2. Dense phase pneumatic conveying: This conveying method is usually plug flow pneumatic conveying. The powder material no longer disperses in the conveying pipe, but forms a material plug, which moves forward by relying on the static pressure difference at both ends of the material plug. It has the characteristics of low speed, dense phase, and low power index. Its advantage is that it can transport more materials with less air volume, that is, a high solid gas ratio, and low conveying gas speed, resulting in less material wear and low crushing rate.
3. Conventional conveying mode: Traditional ash removal systems usually add all the conveying gas to the bin pump (except for double tube systems), so that the material forms a fluidized ash gas mixture in the bin pump and generates sufficient dynamic pressure to overcome pipeline resistance to achieve conveying. This type of system is currently a widely used transportation method in the industry. The system has the advantages of low investment, stable operation, and wear and tear within a reasonable range. However, the disadvantage of this system is that it cannot be used for long-distance transportation. After the transportation distance exceeds 500m, it often causes material layering and settling in the pipeline, resulting in pipe blockage. Especially for the ash transportation pipeline, the on-site layout is complex, with many bends. In addition, when the coal combustion changes, the ash transportation system is likely to be unable to operate normally, causing the main equipment to be forced to shut down and resulting in serious consequences.
4. Double tube conveying system: In order to solve the problem of long-distance conveying, the double tube conveying technology produced by German company Molo was introduced in the late 1980s, which to some extent solved the problem of long-distance conveying. However, the double tube conveying technology has certain requirements for materials, and materials with high density or large particles have serious wear on the double tube, and the investment in double tube maintenance or replacement is relatively large. Therefore, the double tube technology has only been partially applied in some large power generation companies and has not been widely promoted in the domestic conveying industry. The double casing transportation method has certain improvements compared to conventional transportation methods, but there are also some defects that the system cannot overcome, such as high system investment, difficulty in repairing after the casing falls off, and difficulty in clearing blockages after blockage. But its major drawback still cannot solve the problem of long-distance transportation. Nowadays, when the engineering transportation distance exceeds 1200m, there is a serious problem of excessive gas consumption, decreased transportation capacity, and easy occurrence of pipe blockage. After pipe blockage, it cannot be cleared for a long time.

5、 Advantages of Progressive Automatic Hydration Device
1. Ensure long-term stable operation of the system without any blockage.
2. Ensure full pipe conveying to exceed the original system's conveying capacity by 50-70%.
3. Significantly reduce system wear and tear, and double the service life of conveying system pipelines and valve groups.
4. The system does not require a blowing process, greatly improving the ash conveying efficiency of the system.
5. After use, the air flow rate should not be less than 40-50%, ensuring that more than half of the ash conveying air compressors in this furnace are shut down.
6. Not strict on the conveying distance.
7. The system has a wide adaptability to materials and can transport materials with high density and large particles
8. Cancel the original fluidized gas and secondary air supply system.
9. Implement a disruptive replacement of the original system.

6、 Special purpose
1. Coal economizer ash conveying
2. Dust collector ash conveying
3. Transportation of other high concentration materials

7、 Engineering case

8、 Summary of Situation