Customized Case

In the face of increasingly fierce competition in the machinery manufacturing industry, Lijia customers, as an enterprise focusing on the production of high-end mechanical parts, have been committed to improving product performance and quality to meet the market demand for high-performance parts. However, when the traditional spraying technology copes with the coating needs of parts under some special working conditions, it gradually exposes deficiencies, such as low coating bonding strength, insufficient hardness, high porosity and other problems, which seriously affects the service life and performance of parts. In order to break through this dilemma, Lijia customers actively sought advanced spraying solutions, and finally chose the HV-8000 full closed-loop supersonic flame spraying system of Zhengzhou Lijia Thermal Spraying Machinery Co., Ltd. after many investigations and comparisons.

Ⅰ. Project background

The mechanical parts produced by Lijia customers are widely used in aerospace, automobile manufacturing, petrochemical and other fields, and these parts are faced with harsh working environments such as high temperature, high pressure, wear and corrosion during use. Taking aero engine blades as an example, they need to have extremely high temperature resistance, wear resistance and oxidation resistance under the scouring of high-temperature gas. The piston rings and valves of automobile engines have extremely high requirements for the hardness and anti-friction properties of the coating under frequent friction and high temperature environments. Previously, the spraying equipment used by Lijia's customers could not meet the strict requirements of coating performance under these complex working conditions, resulting in an increase in the rate of product defects, an increase in production costs, and an impact on market competitiveness.

Ⅱ.The solution

The HV-8000 full closed-loop supersonic flame spraying system provided by Zhengzhou Lijia for Lijia customers is a set of solutions that integrate advanced technology and high-quality equipment. The core equipment of the system includes HV-80S kerosene supersonic flame spray gun, HV-8000 supersonic flame spraying control cabinet, D-3000 powder feeder, KM-80 oil pump storage system, DX-30AD chiller, etc., and is also equipped with auxiliary equipment such as soundproof spraying room, sandblasting room, 6+1 axis robot, horizontal turntable, as well as pulse ventilation dust removal system, air compressor system, sandblasting system, air supply system and centralized control system, forming a complete spraying production line.

（1） Advantages of core equipment

1. HV-80S kerosene supersonic flame spray gun: The main body of the spray gun is made of imported chromium zirconium copper material, which has high strength, high hardness, good electrical and thermal conductivity, and has better performance after special treatment. Its combustion chamber pressure can reach 10Bar/150psi, flame flow rate is greater than 2000m/s, powder particle velocity is 500 - 1100m/s, and the unique dual-channel waterway design ensures sufficient cooling for 24-hour continuous work. The patented kerosene physicochemical nozzle and combustion chamber design ensure that the combustion is completely free of carbon deposits, and the flame flow rate is stable and the injection force is strong.

2. HV-8000 supersonic flame spraying control cabinet: As the control core of the system, it adopts a full closed-loop control system, and digitally manages all process gases and powder carrier gases through advanced mass flow meters to ensure the high precision and repeatability of the spraying process. Equipped with a high-performance PLC and a 12-inch touch screen, it can store 8,000 spraying formulas, which is easy to operate, and can monitor and record the entire spraying process in real time. With perfect safety interlock and alarm functions, all peripheral equipment can be controlled and monitored to ensure the safety of equipment and personnel.

3. D-3000 powder feeder: It adopts the high-precision powder feeding mechanism output of the metering plate, which is more uniform and more accurate than the scraper, spiral and vibration powder feeding methods. The unique blowing and cleaning structure can effectively prevent the powder from clogging, and can realize the downward flipping of the powder barrel mouth, and complete the powder pouring and cleaning work in 3 seconds. Low-flow nitrogen or argon is used as powder feeding gas to save gas, and the powder feeding accuracy can reach ±1%.

4. KM-80 oil pump storage system: using South Korean imported motor and Taiwan constant pressure oil pump, stable and reliable operation, can provide stable kerosene pressure and flow for the spray gun, ensure that kerosene enters the spray gun under stable oil pressure, form a stable atomization environment, and ensure that the pressure in the combustion chamber is constant.

5. DX-30AD chiller: specially designed for thermal spraying system, using international advanced fully enclosed scroll compressor, motor and compression chamber integration, no shaft seal leakage problem. Equipped with high-efficiency heat exchange copper tubes, high heat exchange efficiency, temperature control accuracy up to ±1°C, perfect protection system and fault reminder function, stable operation and low maintenance cost.

（2） Peripherals

1. Soundproof spraying room and sandblasting room: The soundproof spraying room adopts a multi-layer soundproof structure, which can reduce the noise from 130 decibels indoors to less than 80 decibels at 1 meter outdoors, effectively protecting the hearing of operators. The sandblasting room can effectively isolate the noise and dust generated by the sandblasting operation, providing a safe and comfortable working environment for the operator.

2. 6+1 axis robot and horizontal turntable: imported ABB six-axis robot is selected, with high programming and control accuracy, which can realize spraying coverage and spraying distance adjustment at various angles, and improve spraying efficiency and quality. The horizontal turntable is specially designed for thermal spraying of shafts and roller parts, and adopts frequency conversion control, which can adjust the speed according to the diameter of the workpiece and the process requirements to ensure uniform coating thickness.

3. Pulse ventilation dust removal system: The ventilation volume is calculated according to the volume of the soundproof room, and the longitudinal ventilation method is adopted, equipped with an efficient pulse bag dust collector, with a filtration accuracy of 5μm and a dust removal efficiency of up to 99.99%, which can effectively purify the dust generated in the spraying process and protect the environment.

Ⅲ. Project implementation

During the implementation of the project, Zhengzhou Lijia worked closely with Lijia's customers to ensure the smooth progress of the project. Lijia sent a professional technical team to the factory of Lijia customers to install, debug and train the equipment. During the installation process, the technicians operate in strict accordance with the operation specifications to ensure the quality of equipment installation. In the commissioning stage, the performance indicators of the equipment were comprehensively tested and optimized to achieve the best operating state. At the same time, it provides systematic training for the operators and maintenance personnel of Lijia customers, including equipment operation, system maintenance, special operation, etc., to ensure that they can be proficient in the use and maintenance skills of the equipment.

Ⅳ  The results of the project

(1) The coating performance has been significantly improved

After adopting the HV-8000 full closed-loop supersonic flame spraying system, the coating performance of the mechanical parts produced by Lijia's customers has been significantly improved. Taking aero engine blades as an example, the bonding strength of the coating is increased from the original 50MPa to 90MPa, the porosity is reduced from 3% to less than 1%, and the coating hardness is increased from HV1000 to HV1450, which effectively improves the high temperature resistance, wear resistance and oxidation resistance of the blade, and prolongs the service life of the blade. After spraying the piston rings and valves of the automobile engine, the wear rate is reduced by 50%, and the power transmission efficiency is increased by 10%, which improves the performance and reliability of the automobile engine.

(2) The production efficiency has been greatly improved

The system has a high degree of automation, and the 6+1 axis robot and horizontal turntable work together to realize the automatic spraying of parts, reduce manual operation, and improve the spraying efficiency. Compared with traditional spraying equipment, the production efficiency has been increased by more than 30%, which effectively shortens the production cycle and improves the market response speed of the enterprise.

(3) Cost reduction

The improvement of coating performance reduces the defective rate of products and reduces production costs. The increase in production efficiency increases the company's capacity and dilutes fixed costs. At the same time, the energy-saving design and efficient operation of the system reduce energy consumption and further reduce the operating costs of enterprises.

(4) Customer satisfaction improvement

After the product quality and performance of our customers have been significantly improved, they have gained higher recognition in the market and customer satisfaction has been greatly improved. The company's market share continues to expand, the number of orders continues to grow, and the brand influence has been further enhanced.

Ⅴ. Project summary

Zhengzhou Lijia's HV-8000 full closed-loop supersonic flame spraying system has achieved remarkable results in the application of Lijia's customers, which not only solves the problems of the enterprise in coating technology, improves product performance and quality, but also improves production efficiency, reduces costs, and enhances the market competitiveness of the enterprise. The successful implementation of this project fully demonstrates the technical strength and professional ability of Zhengzhou Lijia in the field of thermal spraying, and provides valuable experience for other enterprises in the application of thermal spraying technology. In the future, Zhengzhou Lijia will continue to uphold the concept of innovation, professionalism and efficiency, provide customers with more advanced thermal spraying solutions, and help enterprises continue to move forward in the field of high-end manufacturing.