INTRODUCTION TO NIKKO ASPHALT MIXING PLANTS

A BRIEF INTRODUCTION TO THE NIKKO ASPHALT MIXING PLANT BRAND

Nikko is recognized as a leading asphalt mixing plant manufacturer in Japan and Southeast Asia, with a 100-year history of operation. Its asphalt mixing plants have been widely used to produce asphalt mixtures for over 90% of airports and highways in Japan. The company boasts the highest sales of used equipment in Southeast Asia.

Established in 1919, Nikko has a 98-year history and is Japan's oldest asphalt mixing plant manufacturer. In 1958, it successfully developed Japan's first asphalt mixing plant, and in 1980, it produced Japan's first thermal asphalt recycling equipment.

With 60 years of valuable experience and technical expertise in research and production, Nikko currently holds over 85% of the market share in Japan. Its plants are used in over 95% of highway construction projects, and over 3,000 asphalt mixing plants have been exported to more than 50 countries worldwide.

Nikko began exporting its products in the 1970s. Due to their superior quality and technology, these products have been well-received by international customers. To better serve customer needs and enhance design and manufacturing capabilities, Nikko established its first overseas production facility in Shanghai, China, in 2008, named Shanghai Construction Machinery Co., Ltd.

Nikko continuously improves its equipment and enhances customer experience. To date, Nikko has supplied 300 asphalt mixing plants to customers in China and abroad, with its Shanghai facility becoming a major overseas production branch.

NIKKO'S MAIN PRODUCT LINES

1. ASPHALT MIXING PLANTS

CBD Series 60 / 80 / 100 / 120

View product specifications: HERE

The Nikko CBD series is exclusively designed to meet the demands of overseas users. Inheriting the features of the NBD series, all units can fit into 40 HQ containers for easy transportation and cost reduction. Relocation of the plant is made possible by the specially designed steel anchor base and hauling attachments. Installation time is also significantly reduced.

NBD Series 120 / 160 / 240

View product specifications: HERE

The Nikko NBD series integrates all of Nikko's technologies and technical expertise, improving efficiency and simplifying maintenance. The NBD series features fully automated asphalt mixing plants capable of producing high-quality asphalt mixtures with stable performance and low dust, noise, and nitrogen oxide emissions. The compact plant design allows for easy installation and dismantling, resulting in shorter transportation times.

2. RECYCLING SYSTEM

Modular Type - NRK Series

- RAP (Reclaimed Asphalt Pavement) is directly fed into the asphalt mixer.

- Suitable for areas with small amounts of RAP.

- No heating and drying equipment required.

- Can be retrofitted to existing asphalt mixing plants.

Counterflow Drum Mixer Type

- Reduced adhesion to the R dryer.

- Maintains mixing ability even at the start of adhesion.

- No extra space required ⇒ Recycling dryer is placed on top.

- Simple and easy maintenance.

- Reduced installation time ⇒ No transfer conveyor required.

- High efficiency ⇒ Direct heating and mixing blade recovery

Exhaust Gas Treatment System

Choosing the right exhaust gas treatment system mainly depends on the plant size, the location of the treatment station, and the surrounding environment.

- The most common system is used in conjunction with the dust removal equipment of the hot mix asphalt plant.

- Exhaust gas is drawn into the bag filter by a recycling suction fan.

- Simple structure

Deodorizing system

Exhaust Gas Treatment System

- Choosing the right exhaust gas treatment system mainly depends on the plant size, the location of the treatment station, and the surrounding environment.

- The most common system is used in conjunction with the dust removal equipment of the hot mix asphalt plant.

- Exhaust gas is drawn into the bag filter by a recycling suction fan.

- Simple structure.

Deodorizing system:

- Odorous components (mainly hydrocarbons) in the exhaust gas are decomposed into carbon dioxide and water by direct combustion.

- Dual Combustion Chamber Type:

+ The odorous gas collected by the suction fan is heated by an independent combustion chamber.

+ The exhaust gas then passes through a heat exchanger to recover energy.

+ Suitable for plants with long and continuous operating hours.

ADVANTAGES OF NIKKO ASPHALT MIXING PLANTS

1. SUPERIOR PRODUCTS

Overseas construction projects often face challenges like inconsistent raw material quality, high-intensity work, and tight deadlines. Nikko's uniquely designed drying, screening, and mixing system addresses these challenges. The production line design incorporates surplus capacity. Compared to European products designed for 3% aggregate moisture content, NIKKO's asphalt mixing plants adhere to a 5% standard.

For example, the Nikko 240 plant has a standard output of ≥240 t/h and a maximum output of 280 t/h, surpassing other 240 t/h plants. You can view detailed specifications of the 240 t/h plant HERE.

2. LOW FUEL CONSUMPTION AND ENVIRONMENTAL PROTECTION

Fuel consumption and emissions are crucial in asphalt mixing plants. Using high-efficiency combustion systems and clean energy sources reduces fuel consumption and pollution. Japan leads in energy efficiency, and Nikko incorporates this into its designs, prioritizing high efficiency, fuel economy, and environmental protection.

Unlike other manufacturers using generic combustion chambers, Nikko's third-generation chamber is specifically designed for asphalt mixing plants. It uses a unique low-air ratio technique, ensuring complete fuel combustion. By reducing excessive airflow, it controls emissions. The 240 t/h plant from XX has an air volume of only 1195 m3/min, a 10% - 35% reduction compared to others.

Reducing excess air minimizes heat loss, enhancing the drying drum's thermal efficiency. This results in a 5% - 20% average fuel consumption reduction. Additionally, Nikko's drying drum features a unique arrangement of lifting flights, causing different movements of aggregates at various positions.

Aggregates form a film layer farther from the flame, while those closer envelop it, preventing heat loss. Combined with the low-air ratio burner, this achieves 90% thermal efficiency.

Under standard working conditions, fuel consumption per ton of material is below 5.5 kg, compared to 7 kg/ton for others. This saves at least $90,000 in fuel costs for every 200,000 tons of material produced (Mazut oil = $0.3/kg).

Furthermore, Nikko exclusively uses electric heating for asphalt tanks, eliminating heat transfer oil and fuel consumption. This reduces daily operating costs by 70% while being pollution-free, emission-free, noise-free, and environmentally friendly.

3. HIGH STABILITY, LOW FAILURE RATE

Nikko has nearly 60 years of experience in designing and manufacturing asphalt mixing plants. With mature mechanical design, key components from renowned brands, and strict adherence to a 30-year lifespan requirement, Nikko plants lead the industry.

Unlike others who outsource electrical control systems, Nikko established a subsidiary in the 1970s specializing in designing and manufacturing these systems for mixing plants. This self-sufficiency ensures maximum completeness and stability of the production line.

MAIN FEATURES AND TECHNOLOGIES OF NIKKO ASPHALT MIXING PLANTS

1. BASIC TECHNOLOGY

Aggregate Drying System.

A. NTB Low Air Ratio Oil/Gas Dual Fuel Burner

Low air ratio combustion, reducing the air ratio from 1.7 to 1.2, decreases air supply volume, dust, and CO2 emissions. The 240 model uses a 90 kW suction fan with a compact bag filter, saving energy and protecting the environment.

- More thorough atomization of air and mazut oil, with lower oil pressure (30 kg/cm2 → 10 kg/cm2), reduces wear on the oil pump.

- Under standard working conditions, fuel consumption is below 5.5 l/t.

- Effectively reduces noise by 10 dB(A).

- Integrated combustion chamber and blower for convenient maintenance.

- Simple operation, stable performance, and high reliability.

- Dual fuel (oil/gas) capability with push-button switching.

B. High-Efficiency Drying Drum

- Basket-type lifting flights, with a unique arrangement, allow the aggregates to form a film that envelops the flame, preventing heat loss and achieving a thermal efficiency of nearly 90%.

- The drying drum utilizes special steel from steelmaking ladles, with a thickness of up to 16mm. The inner steel plates use wear-resistant steel with a thickness of up to 12mm, which is 16Mn alloy steel.

- The operating track chain provides stable movement, low noise, and long service life.

- The front section of the drying drum has a surface temperature of only about 150°C - 180°C, eliminating the need for surface heat preservation. This reduces cooldown time by half at the end of each production day, significantly saving operating costs in the long run.

- A dust collector, exclusively developed by Nikko, is installed above the drying drum.

- Reduces footprint by 30%.

- Utilizes the drying drum's heat dissipation to prevent dust adhesion.

- The bag filter dust collector placed above the drying drum acts as a rain cover, extending the drum's service life.

- Two-in-one gravity dust removal and bag filter dust removal shorten the chimney length and reduce the heat dissipation area by 30%.

- Employs high-pressure pulse cleaning with Dupont NOMEX fiber bags for low wear, long life, and efficient dust removal.

- Collected dust can be reused or disposed of.

- High-pressure pulse cleaning of the bag filter.

Main Tower System

A. Modular Design

The main tower uses a compact modular design, allowing the vibrating screen, weighing hopper, and mixing unit to be easily transported by road, making installation and dismantling more convenient.

- The screening, weighing, mixing, and discharging units of the main tower are designed with surplus capacity, ensuring mixture quality and enhancing production capacity, highlighting the superiority of Nikko's production line - prioritizing productivity.

- Under standard working conditions, the 240 asphalt mixing plant achieves an output of ≥240 t/h, with a maximum output of 280 t/h, exceeding the output of some 320 models from other manufacturers.

B. Electromechanical Vibrating Screen

Vibration is generated by an electric motor, reducing maintenance and extending service life.

- The vibrating unit and related components are imported directly from Germany.

- The front chute is designed to be fully mobile, allowing for easy and convenient screen replacement.

C. Twin-Shaft Mixer

Developed in collaboration with Tokushima University, this is the world's only asphalt mixer with mixing blades arranged on two shafts for fast and multi-dimensional mixing.

- Unique twin-shaft design reduces mixing time by over 30% compared to other mixers.

- The 240 model utilizes two 45 kW electric motors for fast and powerful mixing, ensuring ample capacity.

- An electric heater is installed at the bottom of the mixer to prevent the mixing tank from cooling down during startup and to avoid asphalt adhesion. This also offers higher safety compared to oil-based heating systems.

- A large sliding gate at the bottom allows for quick discharge, increasing production efficiency.

D. High-Precision Weighing Hopper

- Uses imported high-performance force sensors with an accuracy of 1/2000.

- The weighing hopper gate is rationally designed to prevent blockage.

- Features a weighing hopper protection device that allows for easy or automatic manual adjustment in case of malfunctions.

- Utilizes Zeus control software for fast signal transmission and processing, with automatic deviation compensation capabilities.

- Three weighing units with a total of 9 sensors ensure accurate measurement.

+ Aggregates < ±0.5%

+ Asphalt < ±0.2%

+ Filler < ±0.3%

- User-friendly design with a dedicated weighing platform eliminates the need to place 2-3 ton weights on the tower. Calibration can be performed directly under the tower, making it convenient and effortless.

E. Unique Material Feeding Method

- Aggregates are fed into the left and right sides of the main mixer, following the direction of rotation. This reduces the load on the mixing blades, increasing mixing speed and efficiency.

- Asphalt, through a booster pump and piping, is sprayed evenly into the main mixer, immediately coating the aggregates. This enhances mixing speed and ensures asphalt concrete homogeneity.

F. Hot Material Elevator

- Upper and lower head sprockets are imported as complete units, offering high wear resistance and long service life.

- The trough-shaped conveyor belt is imported as a complete unit, providing heat resistance, wear resistance, and easy replacement without deformation.

- The material inlet at the chute is equipped with a wear-resistant liner, reducing maintenance.

Control System

Hardware:

- Industrial computer (PC/AT compatible) with Windows Embedded and dedicated operating system ensures stability and reliability in harsh working environments.

- Two 19-inch LCD displays provide clear visuals, reducing eye strain during prolonged use.

Software:

- Building upon the strengths of Next-J, it offers enhanced functionality, more intuitive operation, and higher system reliability. Displays all valve operation buttons, allowing control of all machine valves and the entire system through mouse clicks.

- The display shows 16 types of electrical flow variations (up to 32 types can be displayed). Visually displays over 16 types of electrical flow variations under normal, abnormal, and limit conditions.

Massive Data Processing Capability:

- Real-time storage of operational data, including 1000 types of ratios.

- Multiple quantitative adjustment functions.

- Allows free classification changes during weighing and automatic compensation during automatic weighing.

2. ELECTRIC ASPHALT TANK HEATING TECHNOLOGY

Electrically heated asphalt tanks are a new type of safe, high-efficiency, and energy-saving tank used for storing, heating, and maintaining the temperature of asphalt. They are favored by overseas customers for their high performance, energy-saving, and environmentally friendly features, with over 200 units sold to international clients. Employing a vertical cylindrical structure with external insulation to prevent heat loss, these tanks are equipped with electric heating elements at the bottom for safe and uniform asphalt heating. Key features include:

High Efficiency

Currently, conventional asphalt tanks use heat transfer oil for heating. This requires a heat transfer oil furnace system, where the furnace first heats the oil, which then indirectly transfers heat to the asphalt through circulation. Electrically heated tanks utilize electric heating elements directly.

Compared to traditional heat transfer oil heating, electric heating in asphalt tanks directly converts electrical energy into heat, resulting in higher efficiency. Traditional oil furnaces typically have an efficiency of 80% - 85%, while electrically heated tanks experience almost no heat loss.

No Emissions

Electrically heated tanks use electricity as an energy source, converting electrical energy into heat through heating elements. This eliminates the need for fuel combustion, saving on operating costs and producing no pollution, emissions, or noise, thereby protecting the surrounding environment.

For example, a 1 million kcal/h heat transfer oil furnace produces approximately 1500 Nm3/h of exhaust gas with a temperature of 200 - 350 degrees Celsius (representing heat loss).

When burning diesel fuel, the sulfur oxide content in the exhaust gas is approximately 370 mg/m3, and the nitrogen oxide content is about 150 mg/m3. When using mazut oil, sulfur oxide is around 2100 mg/m3, and nitrogen oxide is about 250 mg/m3. In contrast, electrically heated tanks do not emit any harmful exhaust gases during operation.

This eliminates emissions and noise in populated areas, promoting a greener and healthier environment.

Cost-Effective Operation

A. Daily Electricity Consumption of the Electric Heating System (kWh/day)

Dịch sang tiếng Anh:

Electric Heating (Electricity Price: $0.17/kWh)

1,698 kWh/day x 100 days/year x $0.17/kWh = $28,866/year

Oil Heating (Diesel Fuel Consumption per Day)

150 L/day * 5 units + 240 L/day = 990 L/day

990 L/day x 100 days/year x $0.9/L = $89,100/year

A - B

Annual operating cost savings: $89,100 - $28,866 = $60,234/year

After testing at various construction sites, the electricity consumption per ton of oil is calculated to be 1.17 kWh/t. Furthermore, the electrically heated tank utilizes a nighttime heating method for daytime use, avoiding peak electricity hours. This stabilizes the power grid and saves on electricity costs.

3. THERMAL RECYCLING TECHNOLOGY

With the development of highways, older asphalt pavements have entered a period of major maintenance, and the recycling of large quantities of reclaimed asphalt pavement (RAP) has attracted widespread attention. Asphalt recycling saves significant amounts of asphalt and aggregates, reduces investment costs, facilitates waste disposal, conserves energy, protects the environment, and brings substantial economic and social benefits.

Using thermal recycling technology effectively reuses old materials, reduces the use of new materials, and plays a crucial role in alleviating pressure on asphalt resources. Japan, with its early adoption of highway construction, possesses mature research in pavement maintenance and recycling equipment.

Since the late 1970s, Nikko has been researching recycling equipment. In Japan, almost all asphalt mixing plants are equipped with NIKKO's recycling equipment, with nearly 600 sets in operation. Nikko's unique approach to thermal recycling and exhaust gas treatment leads the industry globally. Key features include:

Heating Temperature ≥ 160°C

Heating temperature plays a crucial role in recycling. Insufficient temperatures primarily affect the bonding between old and new materials, and higher temperatures are required for new materials. Moreover, inadequate recycling temperatures increase adhesion within the drying drum, requiring more frequent cleaning.

Nikko's recycling equipment easily achieves temperatures above 160°C with precise temperature control (equipment from other manufacturers only reaches 100-120°C). This avoids low temperatures that affect mixture quality and excessively high temperatures that can cause asphalt aging or fires.

Energy Saving

Exhaust gas from the drying drum is blown back into the V-shaped drying drum by the R ventilation fan. This regulates combustion temperature and reduces asphalt smoke, saving over 20% on fuel consumption. This is also a patented technology exclusive to Nikko.

Effective Anti-Adhesion Technology

The specially designed mixing blades inside the drying drum shorten the adhesion process, reducing cleaning requirements (no cleaning needed for a year) and preventing spontaneous combustion.

Large-Capacity Temporary Storage for Recycled Material

Frequent opening and closing of the thermal recycling equipment can lead to aggregate adhesion, affecting the operation of the entire system. To address this, the capacity of the temporary storage bin for recycled material has been increased from 15 tons to 35 tons, better accommodating daily production needs.

IV. MAIN COMPONENTS: MANUFACTURERS AND ORIGINS

1. Aggregate Cold Feed Bins

2. Conveyor belt

3. Drying Drum

4. Burner Unit

5. Dust removal bag

6. Hot Material and Filler Elevator

7. Mixing Tower

8. Components of the Control System (ZEUS)

9. Filler Supply Equipment

10. Asphalt Supply Equipment

Note: The above components may be subject to change due to design and technical modifications. We apologize for any inconvenience caused by such changes without prior notice.