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NGC’s Standard Gearbox “Rejuvenates” Large Blast Furnaces

Publish Date: 2020-06-15

In China’s manufacturing industry, many enterprises are facing problems of high investment, high consumption and low efficiency. Especially for steel companies, with the promulgation and implementation of new national environmental protection regulations and policies, it is a legal duty to ensure that all industrial polluters comply with discharge standards. Ultra-low emissions have become the new trend. As a well-known enterprise in the stainless steel industry, TISCO Group has taken the lead to face up to the challenges and pioneer new technological innovations, thus accelerating the high-quality transformation and development of the enterprise.

In order to further save energy, reduce emissions, and optimize resources, TISCO Group proposed an upgrade plan for the No. 5 Blast Furnace at their ironworks. This blast furnace is one of the largest blast furnaces independently designed and constructed in China. It was built and put into production in October 2006, with a capacity of 4,350 cubic meters. It has been in operation for nearly 14 years, and is now facing the issues of low overall energy efficiency, requiring further upgrades to the feeding and slag processing systems.

Joining hands to promote technological progress in the industry

As a strategic partner of TISCO Group for more than 20 years, NGC has been involved in numerous technical discussions and on-site surveys during the upgrading process, in particular in terms of the operating environment. Aimed at the main belt conveyor and grain slag conveying system for blast furnace feeding and transportation, NGC proposed its MHB-series standard gearboxes, which now feature a number of improved technical upgrades.

This range of standard gearboxes is tailor-made for the material handling industry. Since its introduction, the product has been widely used in the feeding systems of blast furnaces in major steel enterprises such as Baosteel Zhanjiang Iron & Steel Co., Ltd., Desheng Steel Co., Ltd., Hebei Zongheng Fengnan Steel Co., Ltd., and Huaxi Special Steel Co., Ltd.

Image source: www.tisco.com.cn

For this project, a total of 2 MH3S180 reducers were used in the main belt conveyor for blast furnace feeding and transportation. The conveyor’s capacity Q=3000t/h and its bandwidth B=1600mm. There are 9 more reducers used in the grain slag conveying system. This batch of products has been recently put into operation.

Innovation to solve the problem of “old to new conversion”

The main belt of the blast furnace is used to supply raw materials during ironmaking. It is the “throat” of the direct material delivery system within the blast furnace, so the key components of the conveyor system and the reducer should all have high reliability. Since in this blast furnace upgrade project, the feeding system, the slag processing system, and the executive standards, raw materials, design, and manufacturing requirements of the original reducer cannot meet the current requirements, NGC came up with a creative solution without changing the original installation size.

Taking into account the highly dusty environment of the conveyor system, NGC optimized the design of the sealing structure on the reducer to further improve dust-proofing and anti-leakage performance. The product makes use of unique modification technology to ensure higher power density, better noise reduction and higher mechanical efficiency. The performance indicators of the product greatly exceed the expectations of the clients.

New solutions come with new products

When the TISCO Group’s No. 5 blast furnace was put into operation in 2006, the grain slag conveying system used ZY/DY series reducers (executive standard: JB/T 8853-2001). The design standards of this series of products are now outdated however, and the technology considered basic. The input shaft is prone to bend or break down. The hardness of the journal is low, and it is easy for the product to become worn out and leak oil. The mechanical efficiency is particularly low, which cannot meet today’s needs for energy saving and consumption reduction as required by the equipment upgrade and transformation project.

NGC gave up the original plan to produce ZY/DY series products based on the original standards, and replaced them with MHB-series standard gearboxes instead. The energy consumption performance and reliability of the product is greatly improved, and various hidden dangers such as bending and deformation, breakage, and oil leakage of the journal can now be avoided.

This alternative solution does not change the anchor installation dimensions of the original motor and reducer. It creatively provides a seamless connection between the new reducer, the original motor and the belt roller by adding a joint base, which has greatly shortened the transformation period and reduced the cost of the drive system. Years of experience in the promotion and application of technical solutions for MHB-series standard gearboxes replacing traditional ZY/DY series reducers in various industries has now brought a brand new solution to clients who had been deeply unsatisfied with the quality of the traditional reducers.

The successful delivery and implementation of the project provided a demonstration for the industry to improve the overall supply chain for key parts.

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