Ball Shoulder Research Articles

Effect of Grinding Conditions on Clinker Grinding Efficiency: Ball Size, Mill Rotation Speed, and Feed Rate

The production of cement, an essential material in civil engineering, requires a substantial energy input, with a significant portion of this energy consumed during the grinding stage. This study addresses the gap in the literature concerning the collective impact of key parameters, including ball size, feed rate, and mill speed, on grinding efficiency. Nine spherical balls, ranging from 15–65 mm, were utilized in six distinct distributions, alongside varying feed rates and mill speeds. ANOVA, Taguchi, and regression analyses were employed to explore their influence on grinding efficiency and cement properties. The findings revealed that ball size variation significantly affects grinding performance, with smaller diameter balls yielding higher efficiency due to increased abrasion and fine formation. Conversely, elevating mill speed generally diminishes grinding efficiency, particularly at speeds approaching 90% of the critical speed, impacting ball shoulder and foot angles. Moreover, increasing the feed rate affects the grinding performance differently based on ball distribution, with finer distributions experiencing adverse effects. Signal-to-noise ratios facilitated determining the optimal control factor levels to minimize energy consumption. Quadratic regression models exhibited strong predictive capabilities for energy consumption in grinding. Ultimately, the optimal grinding performance was achieved with Bond-type ball distribution No. 6, considering ball size, mill speed, and feed-rate interactions, albeit with considerations regarding grinding time and energy efficiency.

Experimental investigation of friction stir welding with special spherical ball shoulder different probe tools and parameters for enhanced material properties of AA2219 aluminium alloy

This research investigates the impact of unique spherical ball shoulder enhancement tool pin configurations on the friction stir welding (FSW) of AA2219 aluminum alloy under various parameters. FSW was performed using three different pin shapes: square, hexagonal, and octagonal. Testing samples were prepared using an L9 orthogonal array layout with varying welding parameters. The material behavior in the three distinct weld zones was evaluated for each pin configuration. Results indicated superior microhardness values in the heat-affected zone (HAZ) and thermo-mechanically affected zone (TMAZ) compared to the weld nugget zone. Elemental composition analysis of the TMAZ revealed significant differences, highlighting the influence of thermal stress and material behavior due to the tool pin and shoulder configuration. The square-headed tool demonstrated improved tensile strength and microhardness. Optimal welding performance was achieved with a spindle speed of 1000 RPM, a travel speed of 25 mm/min, and a tilt angle of 3°. Variations in Cu content in the TMAZ and HAZ underscored localized modifications within the material structure, driven by the spherical ball spinning effects on the shoulder. Tensile tests showed that welds made with the square pin consistently exhibited higher tensile strength compared to those made with hexagonal and octagonal pins.

Effect of Spherical Ball Shoulder with Square Tool Pin on the Metallurgical and Mechanical Performance of Friction Stir Welded AA2219-T87 Alloy

Effect of Spherical Ball Shoulder with Square Tool Pin on the Metallurgical and Mechanical Performance of Friction Stir Welded AA2219-T87 Alloy

Subscapular and Pectoralis Major Sparing Deltopectoral Approach for Reverse Total Shoulder Arthroplasty.

In reverse ball shoulder replacement, surgery is usually performed using a deltopectoral approach or an anterosuperior transdeltoid approach. The deltopectoral approach is to incise the pectoralis major to upper 1/3 to 1/2, and subscapularis tendon should be removed at the lesser tuberosity of the humerus. This approach has the problem of breaking the shoulder deltoid instead of incising the rotator cuff. Therefore, we report a detailed procedure of reverse ball shoulder replacement using approach without incision of the pectoralis major muscle and subscapularis muscle.

Combined DEM and SPH simulation of ball milling

A deeper understanding of the milling operation of ball mills helps mineral processing engineers to control and optimize them, and therefore, reduce their consuming power. In this work, the milling operation of ball mills is investigated using two methods, i.e. DEM and combined DEM-SPH. First, a pilot scale ball mill with no lifter is simulated by both methods. Then another pilot scale ball mill with eight rectangle lifters is simulated again by both methods. The effects of lifters on ball shoulder and toe points as well as on creation of cascading and cataracting movements for balls are studied by both methods. At the present time, there is not enough measured data available for dense slurries interacting with the coarse particulates available in the public domain that can be used adequately to validate these types of predictions. The results obtained indicated that fluid slurry in the mill lowered the charge shoulder by about 28 cm and 25 cm in the no-lifter and eight-lifter cases, respectively. However, it raised the charge toe by about 36 cm and 6 cm in the no-lifter and eight-lifter cases, respectively.