Effective cooling and lubrication are essential for achieving high-quality surface finishes and maintaining precision in grinding operations. Coolant nozzles, often overlooked, play a crucial role in the process. Dr. John A. Webster has long emphasized the importance of coolant in ensuring consistent performance and durability, especially when it comes to micro-precision work.
Coolant nozzles spray coolant continuously during grinding, helping to control temperature in the grinding zone and keeping the wheel clean by washing away debris into the filtration system. While plastic modular nozzles perform well at low pressures (around 2 atmospheres), they can become misaligned under higher pressure conditions, which are common in advanced grinding setups. Proper positioning is key—nozzles must be placed close to the grinding area for optimal effectiveness.
Rigid metal tubes, such as copper, are more durable but can introduce air into the coolant stream if not precisely aligned. Frequent bending to adjust alignment may eventually lead to breakage, making them less ideal for dynamic grinding environments.
Cluster jet nozzles are highly effective
For over two decades, cluster jet nozzles have proven to be far more efficient than traditional plastic nozzles, especially in high-speed grinding applications where most of the heat is transferred to the workpiece rather than the chip. When grinding wheels operate at or above 6000 SFPM (about 30 m/s), an air boundary layer forms on the wheel surface, preventing low-pressure coolant from reaching the contact area. Cluster jets deliver higher impact energy, breaking through this boundary layer, cleaning the wheel, and enabling better coolant transfer to the grinding zone.
This dual high pressure slotted nozzle system has proven to be suitable for ANCA TX7 grinding machines. The round mouth is aligned with the angle of the grinding wheel, and the flat mouth is aligned with the outer diameter of the grinding wheel. The two outer grinding wheels are lubricated by a rotary nozzle on the ring manifold.
Cluster jet nozzles for medical and aerospace applications
A medical device manufacturer using the ANCA TX7 has reported significant improvements after switching to cluster jet nozzles. The grinding wheel angles remain consistent, with wear occurring only five times as often. Burrs and burns on tough stainless steel parts have been eliminated, thanks to better coolant delivery. Nozzle damage is reduced, alignment is easier, and productivity has increased by 40%.
In the grinding industry, a well-designed cooling system typically requires 1.5 to 2 GPM per spindle (5.5–7.5 L/min). For example, a 5HP spindle may need 7 to 10 GPM (26.5–38 L/min). An aerospace company producing turbine blades found that increasing nozzle aperture sizes over time helped reduce grinding burns. However, by optimizing their system, they managed to operate just five nozzles across 10 machines efficiently.
Each machine was equipped with eight 10 mm open tubes for cooling two grinding wheels on a single spindle. After replacing the original nozzles with five 4.5 mm circular cluster jet nozzles, the dressing interval doubled, surface quality improved, grinding power dropped by 40%, flow rate decreased by 66%, and burn issues were completely resolved. This allowed all 10 machines to run smoothly within a centralized system.
The TX7 coolant splitter closes the slotted nozzle system with matching grinding wheel angle
Aluminum Non-Standard Fasteners
Taizhou TS HARDWARE Co., Ltd , https://www.shuwengroup.com