Case Study: Preheat Oven for Tank Transmission Casing KHF-27

Equipment specialists at a manufacturer of army tanks contacted us seeking an industrial batch oven that could postheat a large transmission casing made of aluminum. The process involved a series of plugs that were to be welded to the casing, and the process specifications required that the weld zones reach 350F. Some cleaning was to be done after the weld, and then the part was to be warmed in a batch oven at 280F-300F for 2 hours. The part was then cooled down at a rate not to exceed 50F per hour to prevent cracking. The client also wanted a quick way to slide the large casing in and out of the oven for ease of handling and to make sure the temperature requirements for the part were maintained. The oven had to be front-loading so a conveyor could be lined up right to the front of the oven.

For this particular application we designed a custom industrial preheating oven from scratch and called it the KHF-27. This is a solid unit. It had to be front-loading, and because of the size of the preheat oven, KEEN engineers designed wide-opening double doors to allow for the easy loading and unloading of the part. The oven doors were outfitted with with heavy duty bar locks and grab handles with a cam lock to securely and quickly close the doors while preheating was underway. As a standard procedure for most of our industrial ovens, the doors on the KHF-27 oven were installed with cold-rolled steel butt hinges that were tack welded to ensure solid door usage for many years.

As for shelving, the equipment specialists had a special request for the KHF-27 preheat oven. They wanted KEEN to design a way for the part to slide in and out of the oven quickly in order to keep the process moving along. They requested a roller table, but our engineers suggested a ball transfer plate. The bottom of the preheat oven was outfitted with 25 1" transfer balls with steel housings and flange mounts. This enabled the part to slide in and out easily, but also to allowed the operators to rotate the part inside the oven if needed.

The KHF-27 preheat oven is insulated all around, including the doors to ensure containment of heat and rapid preheating. The KHF-27 preheating oven rests on tack welded forklift slots to enable free movement of the oven around the workplace and to different workstations.

This custom oven is useful for a variety of purposes, not just for transmission casings. The temperature range can be modified for any application. A programmable digital controller was installed for this oven so the temperature reading would remain very accurate, and so the oven could be ramped down for the required cool down specifications.