AC series air purge cleaners solve the problem of returning material blanking of raw material mill conveyors in cement plants| Wuhan Junwei Application Cases
In the entire process of new dry process cement production, raw meal powder transportation is the core link connecting the raw meal mill and the preheater, which directly determines the continuous and stable operation of the entire production line. The raw meal powder has the characteristics of high fineness, strong viscosity, and easy moisture absorption. Especially under the high humidity and high dust conditions of the raw meal mill workshop, it is easy to adhere to the rubber surface texture of the conveyor belt. Traditional contact cleaners are difficult to completely remove, resulting in the conveyor belt carrying materials back and dropping materials along the way, which has become a long-standing common problem in the cement industry.
The raw material conveying systems of most domestic cement plants face multiple problems caused by return blanking: the dust concentration at the on-site post exceeds the standard, and the pressure on environmental protection compliance is high; the blanking powder enters the return journeyidler, redirecting the roller, resulting in frequent damage to bearings and accelerated wear of equipment; daily special personnel need to be arranged to clean the ground area materials continuously, and the workload of operation and maintenance personnel is saturated; the ground area materials can also easily cause safety hazards such as personnel slips and equipment jams, which seriously restricts the realization of the cement plant's safety production and cost reduction and efficiency increase goals.
2. Project overview and core issues of the original system
This transformation project is a large-scale domestic new dry-process cement enterprise with a daily output of 5000 tons. The core conveying equipment of its raw meal mill workshop isB1800 belt conveyor, the core operating parameters are as follows:
Belt width: B1800 mm
Belt speed: 2.0m/s
Design conveying capacity: 1200 t/h
Material transported: raw meal powder (80 μ m square hole sieve residue ≤ 10%, moisture content 8%-12%)
Operation mode: Continuous operation 24 hours a day for 365 days
Before the transformation, the conveyor was only equipped with a first-stage polyurethane contact cleaner at the head discharge roller. Under the working conditions where raw meal powder was highly viscous and easy to adhere, the cleaning effect was extremely poor, and four core problems were exposed during operation:
Heavy material loading on the return journey, and frequent material dropping along the way
A large amount of raw material powder is embedded in the rubber surface texture of the conveyor belt, which cannot be completely removed by the first-level cleaner. During the return journey of the conveyor belt, due to the vibration of the idler, the powder continues to spill along the way. After on-site calculations, the material falling per hour can reach 150 kg, and the material falling in a single day exceeds 3.6 tons, which not only causes serious material waste, but also brings great pressure to on-site management.
Serious dust pollution and great pressure on environmental protection compliance
The scattered raw material powder causes secondary dust in the workshop. The dust concentration at the on-site post has been maintained at 26.8 mg/m ³ for a long time, far exceeding the limit specified in the "Cement Industry Air Pollutants Emission Standards". It has been required to rectify many times during environmental protection inspections., environmental protection compliance pressure is extremely high.
Equipment wear is accelerating, and operation and maintenance costs remain high
The unremoved raw meal powder enters the idler along with the return belt and is redirected to the inside of the drum, resulting in frequent seizure and damage of the idler bearings and rapid wear of the drum rubber coating. Before the renovation, the conveyor needed to replace more than 20 groups of damaged return rollers every month. The average service life of the rollers was only 6 months. The covering rubber of the conveyor belt was wearing extremely fast, and the overall service life was less than 2 years. The annual replacement of parts and equipment maintenance costs remain high.
Heavy operation and maintenance workload and prominent safety hazards
The workshop needs to specially arrange two operation and maintenance workers to clean up the ground area continuously for each shift, which takes up more than 60% of the work energy of the operation and maintenance team; the accumulation of raw material powder on the ground can easily cause people to slip and fall, and the scattered powder material is stuck. Staggering rollers can also easily cause equipment failures such as belt deviation and tearing, posing serious production safety hazards.
The cement factory has tried many times to replace contact cleaners made of different materials, but failed to solve the problem of incomplete cleaning caused by fine raw materials and strong viscosity. In the end, it chose to cooperate with Wuhan Junwei to adopt a customized AC series air purge cleaner solution to comprehensively upgrade the conveyor cleaning system.
3. Customized solutions: Application of AC series air purge cleaners
In response to the working conditions and core pain points of the raw meal mill workshop of the cement plant, Wuhan Junwei technical team conducted in-depth site surveys many times and customized theAC series air purge cleanerThe core secondary cleaning closed-loop solution perfectly meets the operating needs of the B1800 bandwidth conveyor and solves the root cause of the industry problem of carrying materials back and dropping materials along the way.
The AC series air purge cleaner selected this time is a non-contact cleaning equipment specially developed by Wuhan Junwei for the transportation of fine powder and viscous materials. It has been specially optimized for the characteristics of cement raw meal powder, and its core technical advantages and transformation plan is as follows:
Matrix adjustable air nozzle, full coverage and no dead angle blowing
For the B1800 mm bandwidth, 22 groups of matrix-type adjustable stainless steel air nozzles have been customized. They adopt a low pressure and large air volume design. They can use the existing 0.3 - 0.5MPa compressed air system in the cement plant to form a uniform and fully covered purging air curtain. It can penetrate into the texture of the rubber surface of the conveyor belt and completely remove the attached fine raw meal powder, and the cleaning efficiency can reach more than 99%. At the same time, the angle of the wind corner and wind pressure can be flexibly adjusted according to the material humidity and belt speed, adapting to the fluctuations and changes in different working conditions in the raw meal mill workshop, and always maintaining the best cleaning effect.
Closed-loop residual material recycling structure, no secondary pollution and material waste
The equipment is equipped with a fully enclosed recovery hopper, which is seamlessly connected with the head discharge chute. All the purged raw material powder re-enters the conveying system through the recovery hopper, achieving 100% material recovery, which not only eliminates secondary dust during the purging process, but also avoids material waste and fully meets the requirements of green production in cement plants.
Non-contact design, zero damage and extended equipment life
By adopting the principle of non-contact purging, there is no physical contact between the equipment and the conveyor belt during the cleaning process, which completely avoids the problem of wear and scratching of the rubber surface of the belt by traditional contact cleaners, and greatly extends the service life of the conveyor belt; at the same time, there is no wearing parts, and there is no need to frequently replace the cleaning blade, which is suitable for the 24-hour continuous operation of the cement plant.
All-stainless steel wear-resistant structure, maintenance-free for harsh working conditions
The main body and core components of the equipment are made of 304 stainless steel, which is wear-resistant, corrosion-resistant and anti-fouling. It can be perfectly adapted to the harsh working conditions of high humidity and high dust in the raw meal mill workshop. Only routine inspections are needed daily and no special maintenance is needed., greatly reducing the workload of operation and maintenance personnel.
Safety interlock design adapts to intelligent management and control of production lines
The equipment is equipped with pressure detection and loss of pressure alarm modules, which can be interlocked with the conveyor control system. The equipment automatically turns on when the conveyor starts and automatically turns off when the conveyor stops. At the same time, when the wind pressure is abnormal, an alarm signal can be issued in real time, without manual duty, which is perfect for the intelligent production management and control needs of cement plants.
In terms of installation layout, the AC series air purge cleaner is installed below the head discharge roller and behind the primary polyurethane cleaner, and forms a combined cleaning system of "rough sweep + fine sweep" with the primary cleaner: the primary cleaner removes large pieces of material, and the AC series air purge cleaners thoroughly remove residual fine raw material powder, forming a double guarantee and completely solving the problem of material carrying on the return journey.
4. Application effect and data verification after transformation
After the renovation of the project was completed, after 6 months of continuous operation testing, the equipment operated stably, and all indicators far exceeded customer expectations, completely solving the return blanking problem that had plagued the cement plant for a long time. The core renovation effects are as follows:
The cleaning effect is completely up to standard, with zero blanking and zero loading
The cleanliness of the working surface of the conveyor belt has been improved by 99%, the phenomenon of carrying materials on the return journey has been completely eliminated, and the conveyor has achieved sporadic material dropping along the way, which has completely solved the core pain point of raw material powder sticking to the belt. More than 1200 tons of raw material powder can be recycled every year, directly reducing material losses exceed 300,000 yuan.
Dust control meets standards, environmental protection compliance zero risks
The dust concentration in the raw meal mill workshop has steadily dropped from 26.8mg/m³ before the renovation to within 3.2mg/m ³, far below the limit of the national environmental protection standard. The problem of secondary dust dust has been completely solved and the special acceptance of the environmental protection department has been successfully passed., eliminating environmental protection compliance risks.
Equipment wear is greatly reduced and service life is significantly improved
The average service life of the return idler has been increased from 6 months before the transformation to more than 36 months, reducing the cost of idler replacement by more than 80,000 yuan every year; the wear rate of the covering rubber of the conveyor belt has been reduced by 65%, and the overall service life has been reduced from the original 24 months. Increase from months to more than 50 months, a single replacement of the conveyor belt can save procurement costs by more than 400,000 yuan.
Operation and maintenance costs are greatly reduced, eliminating potential safety hazards
The work arrangement of specially assigned personnel to clean up the land area and materials has been completely cancelled, the workload of operation and maintenance personnel has been reduced by more than 90%, and the annual labor costs and operation and maintenance costs have been comprehensively reduced by more than 75%. There is no accumulation of materials on the ground and no equipment jams, which has completely eliminated the safety hazards of personnel slips and equipment failures, and the on-site management level of the workshop has been greatly improved.
The relevant person in charge of the cement factory said: "Wuhan Junwei's AC series air purge cleaners have completely solved the blanking problem of our raw meal mill workshop for more than ten years. They not only help us achieve environmental protection standards, but also effectively reduce the operation and maintenance costs, improve the operation stability of the production line, and are a good product that truly suits the working conditions of the cement industry."
5. Conclusion
The core problem of back-trip blanking and sticky tape cleaning for raw meal powder transportation in the cement industry is that traditional contact cleaners cannot adapt to the working conditions of fine powder and sticky materials. Wuhan Junwei AC series air purge cleaners, relying on the core advantages of non-contact efficient purging, closed-loop material recovery, and maintenance-free long life, perfectly solve this industry pain point in the cement industry and clean the cement plant's conveying system. Intelligent transformation provides a reliable solution.
As a one-stop service provider focusing on bulk material transportation systems, Wuhan Junwei has been deeply involved in core industries such as cement, mining, steel, and electric power for more than ten years. It has always focused on customer working conditions and continues to develop transportation supporting equipment suitable for different scenarios. and solutions. In the future, Wuhan Junwei will continue to deepen innovation in bulk material transportation technology to help more industrial enterprises achieve the multiple goals of production safety, environmental protection compliance, and cost reduction and efficiency improvement.
