Application of Environment-friendly Concrete Mixing Plant

Wuhan Hongji Construction Materials Co., Ltd. is a relatively large concrete manufacture in Wuhan, since its entrance into the industry in 2004. In 2014, in order to respond to the call of green production, Wuhan Hongji re-planed to adjust the development idea, introduce two fully environment-friendly concrete production lines to replace all the originals, and fitted in the construction of new economical city. The new station has produced 100 thousand cubic meters concrete since its establishment at the end of 2014.

Equipment Description

According to the definition of environmental friendly concrete station of NFLG: reasonable utilization of site, environmental friendly equipment, production energy saving and noise reducing, and intelligent system control. In combination of the production demand and actual onsite condition of Hongji, NFLG will offer Hongji the 2hzs270 double station with a powder tank top-mounted structure as its planning design, which is equipped with 4.5 cubic meters crusher with large volume and all-around dust removal and noise elimination system, as well as a closed large stockyard in the limited site (no loader), which adopt full-automatic feeding system suiting with wet concrete recycling system to treat the waste water and slug produced in the production process of concrete, to realize circular using of resource, application of intelligent control system and ERP production management & control system, thus improving the production management efficiency and achieving the professional and environmental protection of concrete production.

Energy-saving Production, Full-automatic Control of Feeding System and Reasonable Utilization of Environment Protection Technology

In production process, material feeding system of sand aggregate and powder materials is the key energy consumption spot in the whole production. The manner of reasonable planning & design will directly affect the production cost.

Full-automatic material feeding stockyard is one of the highlights of Hongji, which is enclosed completely with reasonable distributed and separated bins. Material separating and feeding of full-automatic feeding system is delivered with belt completely. After material delivery of trucks, the sands of various specifications will be delivered with feeding belt conveyor and separating belt conveyor to designated bins to save the feeding procedures of the loader, which greatly reduces labor and production costs, to avoid noise and dust pollution of feeding by loader. Meanwhile, the delivery amount of belt conveying is larger with about 1/3 higher than the original feeding speed, which can fully satisfy the continuous aggregates supply of large volume production lines, to enhance the production efficiency of the entire station. Considering comprehensively on aspect of cost, production of each cubic meter concrete can save RMB 0.5 loader cost. Calculating by an annual output of RMB 1 million concrete, it can save RMB 500,000 Yuan of production cost.

Besides, the cement powder material delivery adopts air chute which is the pneumatic transport equipment that takes advantage of compressed air to make the cement to flow along the chute in a fluidized state; it utilizes the air driving force as the major driving force source of conveying to greatly reduce the energy consumption in the utilization process by saving about RMB 50 thousand each year. It avoids the motor operation in the spiral delivery process without any noise, and it is easy for maintenance, and save the power consumption and maintenance cost.

Energy-saving Production, Full-automatic Control of Feeding System and Reasonable Utilization of Environmental Protection Technology

In production process, the feeding system of sand aggregate and powder materials is the major energy consumption spot in the whole production process. The manner of reasonable planning & design will directly affect the production cost.

The full-automatic feeding stockyard is a major highlight of Hongji with reasonable distribution of bins and a reasonable separation manner. The full-automatic feeding system realizes complete belt delivery for materials separation and feeding. After materials' entrance by trucks, the sands of various specifications will be delivered with feeding belt conveyor and separating belt conveyor to designated bins, which completely save the feeding procedures by loaders, to greatly reduce labor and production costs and avoid noise and powder pollution incurred by feeding of loaders. Meanwhile, the delivery amount of belt conveyor is larger, which can improve about 1/3 of the feeding speed and satisfy the aggregate supply of continuous production of the two massive volume production lines to enhance the production efficiency of the whole station. Considering on aspect of cost, each cubic meter concrete produced can save about RMB 0.5 loader cost. Calculating according to an annual output of 1 million cubic meter concrete, it can save a production cost of RMB 0.5 million.

Besides, cement powder material delivery adopts air chute which is the pneumatic transport equipment that takes advantage of compressed air to make the cement downward along the chute in a fluidized state; it utilizes the air force as the main force source for conveying which can greatly reduce energy consumption in the utilization process, saving about RMB 50 thousand of utilization cost. It avoids the motor operation in the spiral delivery process with advantages of noise free, easy maintenance, lower power consumption and repair cost.

| System Status | Operation Power | Work Duration | Power Consumption of Each Disc | Daily Power Consumption | Annual Power Consumption | | Spiral | 52KW | 40s | 0.57KW-H | 285KW-H | 85500KW-H | | Air Chute | 15KW | 36s | 0.15KW-H | 75KW-H | 22500KW-H | | Annual energy saved 85500-22500=63000KW-H. About RMB 50 thousand / year |

Powder Control and Waste Material Recycling! High Standard Environmental Protection Measure to Coordinate with Environment

For environment protection measures, NFLG controls each dust raising spot in the production process by equipping high performance pulse dust removing system from warehouse belt conveyor, horizontal and inclined belt connecting part, to the transitional bin of main building, instead of simply enclosing and covering, to avoid the dust raising phenomenon in the production process.

In the mixing plant, NFLG eliminates the dust raising in the main building from the source by adopting positive pulse dust remover to eliminate dust for crusher, transitional bin, and powder, etc., which is different from other manufactures who simply rely on adopting enclosing and isolating dust which may easily incur dust leakage and is a temporary relief.

Automatic Feeding Material of Fully Enclosed Stockyard

Completely Enclosed Belt to Avoid Raised Dust

It is well known that the dust raising problem on top of powder tank of ordinary mixing plant is very serious, which is widely criticized. NFLG adopts tank top pulse dust remover with high pressure blowback + pulse-type continuous dust removal. Remove dust by fans actively, and balance the internal air pressure. The eliminating efficiency is high, and it can not be blocked easily. It is very easy for workers to maintain, and completely avoid the previous leakage and splashing of devices. Meanwhile, the level meter on top of the powder bin is equipped with automatic alarming device which will give alarm in case that the dusting of powder bin reaches the setting level. It is very sensitive and can avoid powder dusting overfilling effectively.

The waste water and slug in the mixing plant shall be collected and the slurry shall be recycled through wet concrete recycling system after separation. It will be recycled completely for the second utilization of main building after settlement in the sedimentation pool, which realizes 100% circulating adoption, instead of discharging any sewage, and saves water and cost at the same time.

No Leakage, No Splashing During Materials Discharging of Gate Valve Discharge Hopper

Wet Concrete Recycling Device to Collect Waste Water

High Mixing Efficiency and Accurate Measurement. Control Each Process of Production Accurately to Ensure Concrete Quality and Reduce Production Cost

On aspect of mixing technology, NFLG has a great advantage. The double spiral mixer is designed with spiral blade to form spiral circulating flow by mixing arm and continuous spiral blades to crush and mix the aggregate at the high speed, and speed up the integrate circulating and flow of mixed materials in the mixer with strong shear effect to the concrete of better evenness and short mixing duration, which can produce high quality concrete rapidly.

The safety of product quality relates to the life of enterprise. The proportion ratio of mixing plant and the accuracy of measurement directly affect the quality of concrete. The measuring system with high accuracy of NFLG can measure the cement, powder material, additions, and sands without any difference, and effectively ensure concrete quality and safety.

For Wuhan Hongji, the application of ERP production & operation professional management system of NFLG is an upgrade of information and data, which realizes standardized management on aspects of sales, production, operation, data statistics, decision analysis, and information communication, etc., and the real-time delivery, and remote share of production data among multiple machine sets, for a centralized management of company, so as to realize the information intellectualization of mixing plant.

Humanized Layout. Equipment Layout Based on Human to Improve the Work Comfort Level of Employees

Ordinary mixing plants set control rooms on the main building with excessive noise and vibration and poor working environment of employees. Considering the improvement of comfort level for the employees in the production process, NFLG set the control center of Hongji Mixing plant in a place far away from the mixing building, which carry out remote control by electrical control, to keep away from noise and make it easier for integrate management of system dispatching and production operation.

Powder Material Air Chute

Twin spiral mixer

The main panel control room with large display can display the operation condition of production, dispatching, and devices real time. Employee can learn about the dynamic status of mixing plant as plain as print, and dispatch at ease by seating in the operation room, which can reduce the labor strength of employee. Electrical control system can display real-time failure alarm, real-time mechanical failure warning, and in-time repair, to guarantee the production.

Clean and Comfortable Equipment Control Room

A Clear View on Display of Main Panel

The environment-friendly commercial concrete device of NFLG achieves the highly appreciation from Wuhan Hongji by its stable integrate performance, good energy conservation and environment protection effect, specific software system, and the economic operation cost.