Case study · Revamp

Revamping a rotary hearth furnace that kept failing

A bearing manufacturer's rotary hearth furnace kept losing element connections and hood insulation. We redesigned the elements and their cold zone, and relined the hood with high-temperature ceramic board.

Furnace:: Rotary hearth furnace

Results

What the project delivered.

Charge weight: 300 kg
Rated power: 180 kW
Operating temperature: 850 °C
Heating zones: 2 pre-heating, 2 soaking: 4

The heating elements' cold zone was modified so the electrical connections stop failing and are easier to maintain, and the elements themselves were redesigned for a longer life.

The hood's ceramic blanket, which kept failing, was replaced with a high-temperature ceramic board lining. Ordered in February 2024, the furnace was installed and commissioned in July 2024.

Overview

The project.

Case study · Revamp

What we did

The furnace had a pattern of repeat failures: the electrical connections in the heating elements' cold zone kept failing and were hard to maintain, the elements weren't lasting, and the ceramic blanket lining the top hood kept breaking down.

Rather than replace the same parts again, we changed the design at each point: a modified cold zone for the connections, redesigned elements built for a longer life, and a high-temperature ceramic board lining in place of the blanket. The new elements were engineered to work with the furnace's existing control panel, so the panel stayed as it was.

CustomerBearing manufacturer
EquipmentRotary hearth furnace
Charge weight300 kg
Rated power180 kW
Operating temperature850 °C
Heating zonesPre-heating zones 1 and 2, soaking zones 1 and 2
ScopeHeating elements, element connections and hood insulation
Heating elementsRedesigned, with a modified cold zone
Hood insulationHigh-temperature ceramic board, replacing ceramic blanket
Control panelExisting panel retained; new elements engineered to work with it
Ordered / commissionedFebruary 2024 / July 2024

Scope of work

How it was done.

01
The furnace and its hood
The rotary hearth furnace in production, and its top hood lifted off to reach the heating elements and the insulation.
Furnace
Hood lifted
02
Failing insulation removed
The ceramic blanket lining the hood had broken down. It was stripped back to the shell, ready for the new lining.
Before
Stripped
03
Ceramic board lining
The hood was relined with high-temperature ceramic board instead of blanket, to stop the repeated lining failures.
Board lining
Completed
04
Cold zone modified
The heater mounting base was modified, changing the cold zone where the element connections had kept failing, and making them easier to maintain.
Mounting base
Modification
05
Redesigned elements installed
The redesigned heating elements were installed and wired to the furnace's existing control panel, which they were engineered to work with, and the furnace was commissioned in July 2024.
Installed
After