Measures for Energy Saving and Emission reduction in cement PlantDate: 2019-06-20 Views:
With the rapid development of national economy, China's building materials industry has also made great progress, not only the output has increased greatly, but also a number of backbone enterprises with the world advanced level have been trained. However, compared with the developed countries in the world, the overall level of our building materials industry is still relatively backward. Further strengthening the energy saving work is an important measure to carry out the scientific concept of development, implement the basic national policy of saving resources, and build an economical society. Cement plant is a large energy consumer but has great energy saving potential. How to make rational use of energy and improve energy efficiency? How to put an end to the waste of energy from the source and improve the economic benefits of enterprises? this These are the important problems faced by cement industry enterprises. At present, our company briefly expounds the energy saving scheme of cement factory, hoping to play the role of throwing bricks and attracting jade. Cement enterprise is recognized as a high energy consumption industry. In the current environment of energy saving and emission reduction, cement enterprises can start from the following aspects: rotary kiln transformation, waste heat residual pressure utilization, motor system energy saving, energy system optimization, dust removal system transformation and so on.
1. Kiln coal saving
(1) use high performance thermal insulation materials: kiln, cooler, preheater, hot air pipe and other equipment, in the new construction, maintenance project using high performance thermal insulation materials to reduce heat dissipation.
(2) Reasonable setting of process parameters: reasonable setting of process parameters in batching, kiln coal air consumption, preheater outlet temperature and other production links, reduce system air leakage, control exhaust system gas, material temperature, reduce total coal consumption
(3) strict management: the whole process of raw coal entering the plant to use is brought into the scientific management system. In metrology, sampling, quality inspection, password sampling, custody, use and other production links, formulate a reasonable system, standard management, responsibility to people.
2, waste heat power generation our company put into production in February 2012, there is no high temperature waste heat power generation project, but using pure low temperature waste heat power generation technology. The pure low temperature waste heat power generation project is designed in the new cement clinker production line, and the pure low temperature waste heat power generation project is arranged in the original cement clinker production line. 2500t / d cement clinker production line is equipped with 4.5 MW generator set, the actual unit power generation is above 36kWh/t, our company will start the low temperature waste heat power generation project in a period of time, actively respond to the national policy, and truly achieve energy saving and emission reduction. 3. Energy saving of motor system
(1) Transformer energy saving: reasonable determination of transformer capacity to make it run in the best state. Replace with a new type of energy saving S9 transformer to reduce iron loss when no load. The loss of magnetic flux leakage, the iron loss caused by excitation current and the loss caused by load current on the coil resistance of transformer (its size is proportional to the square of load current) it improves the design and manufacturing process of transformer under the main method of reducing no-load loss, and uses better quality iron core material (low loss silicon steel sheet) to reduce the no-load loss by more than 10% compared with S7 series. The load loss is reduced by more than 20%.
(2) reactive power compensation energy saving: reactive power supply, like active power supply, is an indispensable part to ensure power quality. Reactive power balance should be maintained in the power system, otherwise the voltage of the system will be reduced Low, equipment damage, power factor down. When serious, it will cause voltage collapse, system cracking, resulting in a large area of power outages. Therefore, it is of great significance to solve the problem of insufficient reactive power capacity, to install additional reactive power compensation equipment and to improve the power factor of the network, which is of great significance to the reduction of power loss and power saving and safe and reliable operation of the power grid. The main solutions adopted: the perfect capacitance local compensation mainly has the following three functions: capacity increase 15 ≤ 35%, power saving 4 ≤ 10%, protection equipment, improve efficiency.
(3) Speed energy saving: the power saving method of variable frequency speed regulation is to change the frequency of power consumption to adjust the speed of motor to meet the load requirements, so as to achieve To power saving effect. When the voltage and current do not change, the power saving is proportional to the electricity consumption, and the performance characteristic is that the equipment can start smoothly. It has the function of automatic torque compensation. The range of speed regulation is large, and the speed regulation ratio can generally reach 10:1 to 5 °1. Speed regulation smoothness is good. According to the load of the motor, the power saving rate can reach 20 ≤ 50%. Applicable equipment: centrifugal fan, fan that needs to be adjusted by small valve for a long time, such as grinding fan, cooling fan and so on. Roots fan, a Roots fan that needs to emit excess wind. Pump. Belt conveyor, in order to adapt to the load start motor selection is too large, the material layer thin belt conveyor and so on. high pressure or low-voltage centrifugal fan, over 200kW, the door opening is often less than 80%, and the power saving rate is 20%~40%, and the energy-saving transformation can be carried out. Roots blower, more than 37kW, emptying above 15%, power saving rate of 15%~40%can be modified.
(4) Energy-saving device:a series of patented products, such as reactive automatic compensation device and motor energy saving device, specially designed and manufactured to improve the utilization rate of electric energy according to the specific equipment and operation state.
(5)Line loss reduction and energy saving:the most economical transmission line diameter shall be selected according to the load current. Replacement is unsafe, not economical, . Insulation aging line. Aluminum cores, in particular, generally have to be replaced if they have been in use for more than 8 years. Clean the wire contact surface. Replace the bad controller in the line.
(6) Energy saving of phase feeder: it is mainly used for high power three-phase wound asynchronous motor, which is connected to the rotor loop of the motor to improve and reduce the unit energy consumption of the product. The main benefits are as follows: the power factor is increased to more than 0.95. After phase introduction, the stator current is reduced by 10% ≤ 20%, the line loss is reduced, and the copper loss is 20 ≤ 30% to save active power. The temperature rise of the motor is significantly reduced, the overload capacity and efficiency are greatly improved, and the life of the motor is prolonged. Adopt intelligent technology Operation, automatic phase advance and phase removal, automatic fault protection to ensure long-term safe operation. The structure is contactless, so it is not afraid of dust and wear (static phase feeder).
4. Process and equipment improvement (1) ordinary cement mill is transformed into high fine grinding: ordinary cement mill produces cement with thick particles and low roundness of particle morphology, which reduces the output of the mill and is not conducive to environmental protection. Ordinary cement is transformed into high fine grinding, and the effect of improving particle size of cement products is good, increasing yield and saving energy are more remarkable. And the operation is more stable, reliable, more in line with the national conditions of our country. It has several advantages:
1 )when the strength of cement is kept unchanged, The yield of cement mill can be increased by 25%, the minimum yield can be guaranteed by 20%, and the power saving can be saved by 17-25%.
(2) increasing the grade of cement to ensure the stability of cement quality.
(3) the total output of cement can be increased by about 5% by adding multiple admixtures to increase the total output of cement, and the benefit is very remarkable.
(2) improving the grade of clinker: using ultra-fine grinding technology, the ordinary grinding is transformed into ultra-fine grinding, the production of ultra-fine powder, the addition of cement to increase the content of mixed materials, or direct sale as commodities. Increasing the grade of clinker can increase the content of mixture, so as to reduce the comprehensive coal consumption of cement. If press 32.5 cement flat When 40% mixture is added, 42.5 cement is added with 20% mixture on average, and 42.5 cement is 50% each, the comprehensive coal consumption of cement can be reduced by about 30%, and the unit cement coal consumption can be reduced by 46.5 kg / ton cement. According to the conversion of 1 million tons of clinker to the corresponding cement meter, the raw coal can be saved 46500 tons and the economic value can be nearly 30 million yuan.
(3) Comprehensive retrofit of preheater technical engineering: the kiln seal adopts simple graphite block and fish phosphorus sheet type structure, and the air leakage rate is controlled below 1%. Improve the coal combustion condition of preheater and find the suitable coal injection point. Improve communication Wind to prevent preheater from collapse and clogging of crust. Strengthen the dispersion and heat exchange of preheater materials. Use advanced inner cylinder structure and material to prolong the service cycle. High quality refractories are used in coal injection pipes and rotary kilns.
(4) all kinds of crusher optimization technical transformation engineering: under the condition that the grinding equipment has no feed particles, for all kinds of horizontal and vertical crushers, such as vertical shaft breaking, hammering, counterattack breaking, etc., improving the structure of rotor, hammer, liner and castor plate, selecting high quality wear-resistant materials, optimizing performance, improving crushing ability of crusher, increasing output and realizing "more breaking and less grinding" production mode. After the crusher has been reformed, the discharge particle size can be obtained. According to the demand, the grain size is less than 3 mm, most of which are powdered, and the grain size of the grinding material is small, and the mill can greatly increase the yield by more than 20%.
(5) the optimization technical transformation project of dust removal equipment: strengthen the optimization technical transformation of dust removal equipment, and the organized emission point reaches the national standard. Strengthen the awareness of cleaner production and improve the working standards. The new project considers the use of large cloth bag dust cleaners to improve emission standards. Strengthen the management and improve the maintenance level, that is, the electric dust collector should meet the technical requirements in the electric field, pole plate and vibration beating, and the bag dust collector should gradually select new equipment to achieve the cleaners. Production requirements.
(6) Prevent oil leakage: make equipment sealing work, and prevent oil leakage. And the oil recovery equipment is used to reduce the environmental pollution.
(7) Save water: strengthen the management and carry out appropriate transformation, and put an end to the long running water for the equipment cooling water.
(8) Reduce the ineffective operation of the electric equipment: improve the operation rate and reliability of the equipment, and reduce the idle running time of the equipment when the production line is started. Use power-saving lighting fixtures, office lighting, and personnel to leave in time.