With the improvement of national environmental protection standards and the comprehensive utilization of fly ash, it has become the current development trend for power plants to change hydraulic ash to dry ash. In recent years, silo pumps are mostly used for dry ash transportation. However, the current operating conditions of the use of silo pumps due to high air pressure, large power consumption, high maintenance costs, etc., both pollute the environment and waste resources, causing inconvenience to storage and transportation of coal ash. The LFB series material-sealed pump developed by our factory has the characteristics of low air pressure, simple operation, and small maintenance. It is widely used in power, cement, chemical and other industries. It is an ideal equipment for conveying various powdery materials.
Second, the existing problems of single silo pump and negative pressure conveying fly ash
1.High power consumption and severe wear
Because the warehouse pump uses 0.4Mpa-0.6Mpa high pressure air supply, the elbow pipe is severely worn. Wear-through welding repair, frequent replacement, especially the discharge valve, feed valve, exhaust valve wear seriously, often stuck, coupled with the three major pieces of pneumatic damage and high maintenance costs, workers rush to repair the pump body, high temperature, environment Harsh and labor-intensive.
Due to the automatic control of the material level and time of the warehouse pump, the wiring of the console is complicated and slightly problematic, involving multiple professionals from the three major departments of electrical, thermal engineering, ash removal and maintenance to the ash yard, delaying the maintenance time and bringing a lot of trouble to the management It is difficult to guarantee the normal production.
3. Extremely poor environment
Due to the above reasons, in order to ensure the operation, the frequency of emergency repairs is large, the equipment leaks ash everywhere, endangers the environment of the factory and the living environment of the surrounding people, and has a great impact on civilized production.
4. Affect comprehensive utilization of fly ash
In order to carry out the comprehensive utilization of fly ash, the company invested heavily in a fly ash production line. However, due to frequent damage to the conveying system, normal production of the wind separation equipment system could not be guaranteed, and the ash pipeline could not be sent out, which affected users' ash supply and damaged the corporate image. And benefits.
5. Affects the normal operation of the sedimentation tank
After the design of ash and slag separation and the damage of the warehouse pump, it had to be flushed with water to the sedimentation tank, which caused insufficient slag flushing water and tight water supply. Because of the small ash fineness, it was easy to cause blockage of the network management, and the valve and ash slag pump pipelines were scrapped , Causing serious losses of the entire slag flushing system.
6. Negative pressure conveying has less wear and tear, but after a few years of use, the air volume gradually decreases, resulting in the phenomenon of insufficient delivery.
Advantages of using a material-sealed pump
1. Equipment investment is small. One material-sealed pump can replace two warehouse pumps, reducing equipment investment.
2. The gas pressure of the material seal pump is 0.04Mpa-0.1Mpa, which reduces the gas supply pressure, saves air consumption, and reduces the motor power.
3. Reduced maintenance costs. After the system is installed, commissioned and put into operation once, it basically needs no operation, and there is almost no maintenance. The maintenance workers only need to check regularly.
4. Low pressure conveying, the equipment has good sealing performance, reliable operation, no pipe blocking phenomenon, and the environment has been improved.
Structure and working principle
The material sealing pump is composed of a diffusion chamber, a pump body, a movable air pipe, an actuator and the like. The low-pressure air enters the diffusion chamber through the air inlet pipe and the pump body. The high-speed air flows through the pump body to vaporize the material around the nozzle. The air flowing out of the nozzle into the diffusion chamber forms a local negative pressure between the nozzle and the diffusion chamber. The gasified material is sucked into the conveying pipe and is lifted to the discharge point by the high-speed airflow. Its structure The diagram is as follows:
V. Comparison of the cost of using a single-tank pump and a material-sealed pump
(According to 50MW unit as an example, the conveying length is 350m)
| project || Single Silo Pump || Sealed pump |
2 × 68,000 yuan
Annual power consumption
Consumables and pipeline costs
| Dust || Poor environment
|| good |
Significant energy saving effect
1. Annual cost savings (20m 3 air compressors, warehouse pumps are required, material sealing pumps need a Roots blower, power is 90KW, efficiency is 80%, annual work is 6000 hours, and electricity price is 0.28 yuan.)
Annual electricity cost of single tank pump
2 × 132 × 0.8 × 6000 × 0.28 = 350,000 yuan
Annual electricity cost of material seal pump
1 × 90 × 0.8 × 6000 × 0.28 = 12.1 million
Switching from single-tank pumps to material-sealed pumps saved 229,000 yuan in annual electricity costs.
2. Save operating costs 13 + 5-2 = 160,000 yuan.
3. Reduce equipment investment by 20- (6.8 × 2) = 64 thousand yuan
The above data shows that two sealed pumps can save more than 300,000 yuan each year, which not only reduces labor intensity, increases economic benefits, but also protects the working environment.
6. Main technical parameters of specifications and models
| model ||
Feeding tube diameter (mm)
Conveying capacity (m 3 / h)
Air demand (free) (m 3 / min)
Demand wind pressure (Kpa)
Motor power (Kw)
Conveying equivalent length (m)
| LFB75 || 108 || 1-3 || 3-9 || 40-98 || 3-15
|| 30-500 |
| LFB100 || 133 || 3-7 || 9-20 || 40-98 || 15-45 || 30-500 |
|| 159 || 7-13 || 20-36 || 40-98 || 45-75 || 30-500 |
| LFB200 || 219 || 13-18 || 36-50 || 40-98
|| 75-90 || 30-500 |
| LFB250 || 273 || 18-25 || 50-70 || 40-98 || 90-110 || 30-500 |
| LFB300 || 325 || 25-35 || 70-98 || 40-98 || 110-132 || 30-500 |
| LFB400 || 426 || 35-45
|| 98-130 || 40-98 || 132-220 || 30-500 |
Seven, installation operation and maintenance
The material seal pump is generally suitable to be installed at the bottom of the material warehouse. It must be fixed firmly and the inlet and outlet air pipes must be fixed. At the same time, ensure that the air pipe is on the horizontal line, and the joints should be sealed to ensure that there is no air leakage.
When a new pump is put into operation or the material to be conveyed is changed, a sufficient amount of lubricant should be added to the outer cavity of the movable air duct, and then the movable duct is adjusted by the actuator to change the distance between the nozzle and the nozzle. Select a more ideal location and write down the ruler's scale at the same time to start normal work. When the machine is stopped, the nozzle and the nozzle should be closed and the material in the pipeline should be completely sent before the air can be stopped.
The material sealing pump can work normally only when the material surface has a certain height. If the material level is lower than a certain value, the conveying capacity will be reduced.
If the pipeline is blocked due to sudden gas stoppage or other reasons, the nozzle and nozzle should be closed and blown until the pipeline is unobstructed.
The use of high-efficiency, low-consumption, sealed pumps in the thermoelectric industry to eliminate single-tank pumps is an inevitable result of technological development. It can be expected that in the near future, this technology will replace the warehouse pump and take the lead in the thermoelectric industry, raise the comprehensive utilization level of fly ash to a new height, and create more economic and social benefits for the enterprise.