TTD Tritan Drill from MAPAL Drastically Reduces Machining Times
The triple edge replaceable head drill TTD-Tritan from MAPAL has been tested in the petrochemical industry on heat exchangers and it is convincing right down the line when machining a tube plate. Many versions of heat exchangers are used in different industries. After all, they help to make generated heat usable for other processes.
In the case of recuperators, two liquid or gaseous media with different temperatures are pumped into separate circuits and the heat exchange takes place without mixing the media. Recuperators include bundle heat exchangers, which are usually made of metal and consist of a tube bundle that conducts a medium and an orifice baffle with a front tube plate through which a second medium flows. Depending on the size of the heat exchanger, the front tube plate has a large number of bores. To ensure that the medium does not escape at this component transition, high requirements are set at the bores with regard to position accuracy and dimensional accuracy.
Triple edge drill is the method of choice
On the TTD-Tritan, tool head and tool holders are joined by hirth serration. This connection is easy to operate and particularly stable, so the drill reaches the performance level of the solid carbide equivalent. In addition, it guarantees the best torque transmission with simultaneous high changing and radial run-out accuracy. The TTD-Tritan is optimally centered via its pronounced drill tip and ensures very good circularity. In addition, the cost-intensive carbide is limited to the tool head for the replaceable head system, which leads to low tool costs even with large diameters. The replaceable head system has a positive effect on stock, as the wear parts are mainly limited to the drill heads. The result is that capital tied up in stock is also reduced.
In one specific case, the customer needed each drill diameter version in several lengths to machine the different versions of tube plates. The complete MAPAL range makes it possible to provide all desired versions. In addition, smaller diameters are served with the solid carbide design.
Machining time reduced by 57 percent
The carbon steel tube plates for this customer are drilled using the TTD-Tritan. The bore diameter is 25.6 mm and the bore length is 63.5mm. Here the TTD-Tritan operates with a feed rate 59 percent higher than the double edge replaceable head drill from a competitor previously used. For the solid drilling operation described, the TTD-Tritan achieves a tool life of 53m while the drill previously used only achieved 28m. In addition to this tool life increase of 90 percent, the MAPAL tool performs the solid drilling operation in one machining step and only takes 29 minutes for the complete tube plate with 550 bores. In contrast, piloting was necessary in the previous machining process. The tube plate also had to be manually cleaned to remove the partly very long chips after piloting. Overall, the TTD-Tritan reduces the machining time by 57 percent whilst massively improving tool life.