Abstract: The centralized lubrication of dry oil in sintering machines has long used a single or double line outflow lubrication method. This lubrication method is difficult to judge whether the oil supply point is supplied with oil and whether the oil amount is appropriate. At the same time, due to the insufficient performance of the lubricating grease used, it is easy to accelerate the wear of the equipment due to oil loss. This article focuses on the application of ZDRH-2000 intelligent centralized lubrication system and YP7035 sintering machine specific sealing grease on the 105m2 sintering machine of Chongqing Iron and Steel.  
Keywords: lubrication system, intelligent sealing, lubricating grease

1. Condition of the original lubrication system of the sintering machine
Each of the two 105m2 sintering machines in the Chongqing Iron and Steel Sintering Plant has over 90 lubrication points. The head and tail of the machines are lubricated with manual dual line centralized lubrication, while the slide is lubricated with an electric dual line centralized lubrication system. The lubrication points are powered by manual and electric dry oil pumps, and are supplied with oil through a dual line distributor. Due to the limitations of the principle and structure of the dual line centralized lubrication system, the following problems often occur during use:
1.1 The lubricating grease pumped by the pump is directly sent to each distributor, pushing the piston to supply oil to the lubrication point. But lubrication points that are close to the pump, have low back pressure, and low resistance are the first to receive oil supply. If one or several of them are blocked, it is not easy to detect.  
1.2 Whether the distributor is supplying oil can only be determined by observing whether the motion indicator on the distributor is working, which is very inconvenient to check.  
The amount of grease given to the lubrication point is affected by factors such as pipeline distance, back pressure, and resistance. If the amount of grease given does not match the predetermined amount, it is easy to have too much or too little or even interruption.  
1.4 Fault points are difficult to detect (such as high resistance in the distributor and blocked lubrication points), which can easily cause equipment damage due to oil loss at the lubrication points.  
1.5 Manual pump refueling is difficult, increasing the labor intensity of workers, and due to its poor reliability, it is not suitable for modern production needs.  
Before the system renovation, we had modified the lubricating grease of the sintering machine, and its performance was much higher than that of composite aluminum based grease. However, due to many problems in the system, the grease could not be pumped to each lubrication point, resulting in poor lubrication effect of good grease.  
Due to the above reasons, the operation of the slide and bearings without lubricating grease exacerbates equipment wear, resulting in increased clearance and severe air leakage of the slide, greatly shortening the maintenance cycle, increasing maintenance workload, and significantly increasing maintenance costs. Although the sintering plant has conducted multiple inspections on the lubrication system, the problem has not been fundamentally resolved due to inherent defects in the lubrication system that cannot be overcome. In 2002, the company introduced the patented product ZDRH-2000 intelligent multi-point centralized lubrication system developed by Beijing MCC Huarun Technology Development Co., Ltd., replacing traditional lubrication systems. This lubrication system combines microcomputer technology with programmable control, bringing equipment lubrication into a new field of intelligence.  
2. Introduction to ZDRH-2000 Intelligent Centralized Lubrication System
2.1 The ZDRH-2000 intelligent centralized lubrication system is a new generation of lubrication developed and researched by Beijing MCC Huarun Technology Development Co., Ltd. It is the first of its kind both domestically and internationally. This system can select different oils and fats according to the different conditions of the equipment site environment, and can adapt to various lubrication requirements of single or multiple devices.  








ZDRH-2000 Intelligent Centralized Lubrication System
2.2 Technical characteristics of ZDRH-2000 intelligent centralized lubrication system:
2.2.1 Use PLC programming controller to achieve remote control of lubrication points;  
2.2.2 Implement network connection and real-time monitoring of microcomputer communication;  
2.2.3 Microcomputer controlled quantitative and timed fuel supply, and the ability to adjust fuel supply parameters at any time;  
2.2.4 Use pressure sensors to monitor system pressure in real-time;  
2.2.5 Advanced high-pressure high flow oil pump, stable and reliable;  
2.2.6 Advanced flow sensors monitor the real-time operating status of lubrication points, making system maintenance convenient;  
In summary, the technical characteristics of the ZDRH-2000 intelligent centralized lubrication system can successfully solve the disadvantages of insufficient or excessive oil supply to lubrication points and inconvenient maintenance in equipment lubrication.  
3. Design of lubrication system for sintering machine
3.1 The lubrication of the slide of the sintering machine not only requires high requirements in the selection of the oil supply pump, circulation mode, and automation level, but also plays an extremely important role in the selection of lubricants and the design of lubrication systems. Otherwise, an oil film cannot be formed between the trolley sealing plate and the bellows sliding plate, which not only fails to provide lubrication, but also damages the seal, causing the sliding plate to wear out and leak air.  
3.2 On site design:
3.2.1 Separating the gas station from the control system is beneficial for their smooth operation in a favorable environment;  
3.2.2 The oil supply method has been changed from simultaneously supplying oil to each point to sequentially supplying oil to only one point at a time, which is centrally controlled by a PC;  
3.2.3 The pipeline design adopts a multi-point distribution of single main oil pipes for each sintering machine, with one electric lubricating oil pump in use and one backup, simplifying the pipeline layout. In addition to the lubrication points of the elastic slide, each sintering machine also incorporates the lubrication of bearings for the round rollers of the machine head, the nine roll material feeder, the transmission device of the machine head, the bearings of the single roll crusher at the tail, the tail swing frame, and the hot mineral vibrating screen into the system for centralized control.  
4. Re select sintering machine lubricant
4.1 Change the 1 # composite aluminum based grease used in the original lubrication system to YP7035 sintering machine slide special sealing grease (hereinafter referred to as YP7035 grease) produced by Chongqing Yiping Lubricating Oil Branch of Sinopec Corporation. The technical parameters of this grease and the composite aluminum based grease are compared as follows:
Test standard for YP7035 composite aluminum based grease project
Micro cone penetration/10-1mm 8183GB/T269
Drip point/℃ 267311 GB/T4929
45 # Steel Corrosion Qualified SH/T0331
Evaporation (180 ℃),% 5.42.1SH/T7325
Similar viscosity (-10 ℃, 10s-1)/pa · s587199SH/T0048
Water resistance (38 ℃),% 4.81.3SH/T0919
150 ℃ dynamic sealing test ※/h3.5>; 10 One Ping Research Institute Method
Four ball test (1500r · min-1, room temperature)
d(294N,30min)/mm0.540.35SH/T0204
PB/N319931GB/T3142 
PD/N11271960GB/T3142 

Note: ※ The vacuum degree shall not be less than 0.92Kpa
From the performance comparison in the table, it can be seen that the main characteristics of YP7035 grease used on the sintering machine slide are:
4.1.1 Drop point up to 311 ℃, nearly 50 ℃ higher than composite aluminum based grease; At 180 ℃, the evaporation rate is only about one-third of that of the composite aluminum based grease, and its excellent high-temperature performance ensures its use under high temperature conditions;  
4.1.2 The maximum non jamming load PB and sintering load PD of the grease are higher than those of the composite aluminum based grease, while the wear marks are lower than those of the composite aluminum based grease, indicating that the grease has excellent lubrication and anti-wear performance, which is conducive to protecting the sintering machine slide and extending its service life;  
4.1.3 The low-temperature similar viscosity of the grease is lower than that of the composite aluminum based grease, indicating that the grease has better pumping performance and is conducive to multi-point centralized lubrication of the sintering machine;  
4.1.4 Due to the use of special polyurea as a thickener, this type of double urea grease has the characteristic of small viscosity change at high temperatures, which is beneficial for the sealing of the slide. The oxidation stability of double urea grease is better than soap based grease, and it will not affect the transportation in the pipeline due to coking.  
5. The Effect of ZDRH-2000 Intelligent Centralized Lubrication System after Its Operation
5.1 The main body of the sintering machine has truly achieved the five fixed lubrication;  
5.1.1 Thanks to the monitoring system, it is ensured that refueling workers can replenish oil and grease to the system fuel tank in a timely manner;  
5.1.2 Due to the excellent pumpability of YP7035 grease, every lubrication point is well lubricated;  
5.1.3 Due to the adjustability of PC, on-site operators can make local adjustments through PC according to the lubrication situation of each point, ensuring sufficient lubrication of each lubrication point;  
5.1.4 Due to the use of an electric fuel pump to refuel the main oil pump, the cleanliness of the lubricating grease is ensured;  
5.1.5 Due to the application of PC control, the cycle and continuity of oil supply are ensured, ensuring the lubrication effect of the equipment.  
5.2 The service life of the bearings and sliding plates of the sintering machine has been extended. The service life of the elastic slide has been extended from 10 months to an average of 24 months, and the service life of the fixed slide has been extended from 20 months to an average of 48 months, reducing spare parts consumption and minimizing equipment maintenance and repair work..  
5.3 The air leakage rate of the sintering machine is reduced. The sintering machine has decreased from 55.6% to 44.7%; The 2 # sintering machine has decreased from 53.8% to 48.5%, with an average reduction of 8% in air leakage rate and an increase in sintering machine utilization rate of 0.064t/m2. h. The annual average operating rate is 91.52%. The main exhaust fan rotor mud hanging period has been extended by more than 6 months, and the negative pressure and exhaust gas temperature have also been increased, improving sintering conditions. The physical and chemical properties of sintered ore have been improved, and the output has been correspondingly increased.  
5.4 Reduced the load on the host, and the current of the sintering machine drive motor decreased from 30-32 (A) to 18-20 (A), with an average reduction of 12 (A), saving energy.  
6. Issues to be noted during the operation of intelligent centralized lubrication system
6.1 The circulation and oil supply time of the slide and equipment bearings should be different, that is:
Oil supply time for equipment parts (seconds) Cycle time (minutes)
Sintering machine slide 330
Other equipment bearings 1120

Operators can adjust the program according to the needs of the on-site equipment, with oil supply time as the main focus and circulation time as a supplement, which can ensure equipment lubrication without causing oil waste;  
During the initial stage of equipment operation, attention should be paid to the adjustment and processing of individual components such as electromagnetic oil feeders and flow sensors to ensure the normal operation of the equipment.  
7. Conclusion
Since its launch on the market, the 7.1ZDRH-2000 intelligent centralized lubrication system has attracted more and more attention from steel enterprises. It has been widely used in the renovation of lubrication systems for equipment in the steel industry, such as blast furnaces, sintering machines, rolling mills, double-sided cutters, etc., and has achieved significant results. At present, our company is using this technology to retrofit the large package bearings and vibration dry oil lubrication system of the 1 # and 2 # continuous casting machines in the steel plant; The sintering plant is also preparing to renovate the 120M2 cooling machine's dry oil lubrication system. Practice has proven that advanced technologies such as intelligent centralized lubrication, network connection, and real-time monitoring have brought a new revolution to the modern lubrication field and are worthy of vigorous promotion and application.  
The YP7035 sintering machine slide special sealing grease (referred to as YP7035 grease) produced by Chongqing Yiping Lubricating Oil Branch has good lubrication, sealing and pumping performance under high temperature conditions, and can meet the requirements for centralized lubrication of long pipelines, including bearings of sintering machine main equipment and other ancillary equipment.  
7.3 Practice has proven that the organic combination of a good lubrication system and reasonable lubrication materials can better meet the lubrication needs of equipment and ensure its normal operation.