A Look Inside the Furnace: Installing a New Hot Zone

Ipsen hot zone installation

In a previous post in this series, we examined the steps for removing an old hot zone from your furnace. In this post, we will complete the process by discussing the key steps for properly installing a new hot zone.

Note: Just as in the removal process, these steps are specific to certain types of furnaces, such as the Ipsen TurboTreater®, TITAN® and standard horizontal models. Regardless of your hot zone and furnace model, we recommend consulting your furnace’s manual or service expert before beginning the installation process.

As a reminder, after you’ve removed the hot zone, this is an ideal time to clean the inner chamber wall and replace the ductor seal gland and work thermocouple jack panel assembly. Then you are ready to install the new hot zone. Overall, the process is similar, but there are a few differences as outlined below.

1. Roughly fit and level the load support hearth system and install the hearth posts.

Expert Tip: Getting as close as you can to level during this step will make it much easier to fine-tune and finish leveling the hearth system during the installation process.

  • Install all of the hearth posts into their original locations, as noted prior to removing the old hot zone, and determine which one is the highest post.
    • Compare the new hearth height with the original height. The height you want will vary depending on the design of the loader, which must be able to lift the maximum load well above and clear of the hearth.
      • Shim all other posts to within .015” of the highest post.
      • Rounding the shims close to the size of hearth-post sockets is preferred.
  • Remove the hearth, but leave the shims in the sockets.
2. Install the hot zone.
  • Insert the hot zone into the furnace and lower it so the bulk of the weight is still supported by the 10,000-pound forklift.
    • It is beneficial to have a forklift with left-to-right shifting capabilities in order to assist with positioning the new hot zone during installation.
  • Position the hot zone so the power feedthrough holes, thermocouple (TC) holes and hearth post holes all line up as close as possible.
  • Lower the hot zone so all of the wheels and its full weight are on the support rails.

Expert Tip: If not all the hot zone wheels touch the support rails, shim the wheels until the hot zone rests stable on the rails.

  • For bolted-seal hot zones, push the hot zone back into the furnace until all the studs on the back of the hot zone penetrate the cooling system flange (inspect through the open motor housing). For slip-seal, simply push the hot zone back into the furnace.
  • Check all of the TC penetrations again for proper alignment.

Expert Tip: TC holes should be lined up in such a manner that a dowel rod (similar in size to the thermocouples) can run through from the outside of the furnace to the inside of the hot zone without touching anything on the sides.

  • Align the hearth-post holes and power feedthrough holes following the same process as the TC holes. Fine-tune the alignment by adding or subtracting shims under the hot zone wheels.
3. Install the load support hearth system.
4. Install the power feedthrough assemblies (but do not connect them yet), and lightly coat the silicone/buna o-rings using a vacuum-rated grease.
5. Install the control and overtemperature TCs.
6. If you have a slip-seal hot zone, skip to step 7. If you have a bolted-seal, follow these steps:
  • Install lock nuts and washers onto the bolts protruding out of the cooling system flange.
    • Use a long extension (48”) to reach the transition plate. The nuts should be approximately even with the fan blade surface and can be seen by looking through the back of the motor housing.

Expert Tip: Be sure to account for all nuts and washers. Loose parts that are lying near the fan when it starts could cause severe damage to the cooling coils.

7. Connect the power feedthrough assemblies.
  • It is recommended that new moly hardware be used when installing the hot zone. New nuts and rods are typically included with a new hot zone.

Expert Tip: Moly nuts should be tightened with two 6″ open-end wrenches. Care should be taken to not overtighten moly nuts as they will crack and/or break.

8. Install the head pack.
  • Position the wire-locking pins into the sockets on the door in their original position.
  • Place the hex nuts to the depth noted prior to removing the original head pack.
  • Use an overhead crane to support the head pack as you position it onto the wire-locking pins and secure it according to the hot zone assembly drawing.
  • Once installed, check the door gap between the head pack and the hot zone. The gap should be the same depth as noted previously during the removal process. Make adjustments as necessary and use the assembly drawing for reference.

Once you have finished these steps, the hot zone should be completely installed. However, the heating elements will still need to be installed. It is important to note that the process for installing heating elements can vary from furnace to furnace, depending on the type of heating elements used.

To receive additional information, assistance with the installation of a new hot zone or heating elements and/or a quote for a new hot zone installation, contact Ipsen Customer Service at 1-844-GO-IPSEN (Toll Free: 1-844-464-7736; International: +1-815-332-2530).