Money Maker for Foundries
The recuperator has been the workhorse in energy recovery for decades. With the recuperator, the cupola furnace is able to "recycle" a great portion of its otherwise wasted energy that goes through your stack. Next to the savings that this implies, the operation of the cupola is improved and smoothened.
Waste heat from the cupola can be used to heat up blast air for the furnace. This recovered heat may also be used at other locations of a plant for heating. The achievable air temperature in exhaust systems is limited by the properties of the flue gas and the material properties of the heat exchanger.
It can mean reducing CO2 discharge plant wide, due to the fact that with the same amount of energy, a much lower amount of CO2 is generated. Together with the much lower CO2 footprint of the overall cupola operation, this system prepares you for the upcoming environmental challenges for foundry operations.
Wuerz Recuperator Tower
Flow through the recuperator is from top to bottom through "cross flow" recuperator tubes. The dirty gas is on the outside of the tubes and the clean air flows through the inside of the tubes. Each replaceable bundle consists of lyre shaped tubes that are welded to floating tube sheets on either end. Tube materials vary from top to bottom, depending on temperature profiles.
The blast blower will force ambient air through the tube bundles, traversing from the bottom bundle in an upward direction. The recuperator will pre-heat the combustion air (i.e., “hot blast air”) to a temperature of 1,000 to 1,150°F. The hot blast air will be conveyed to the cupola wind box via the hot blast duct.
Following is a list of advantages of Cupola Hot Blast:
Increase in overall cupola efficiency
Reduced coke consumption (reduction of 12% to 18% overall coke rate)
Increased iron spout temperature
Improved carbon pickup and silicon recovery
Improved productivity (increase of 10% to 15% in maximum melt rate)
Improved chemistry control and metallurgical stability over the course of a melt campaign as a result of stable temperatures
Continuous Steel Shot Cleaning System
A continuous, online automated shot cleaning system is utilized to prevent tube fouling in the recuperator and gas cooling heat exchanger. The shot cleaning system is fully automated and eliminates the expense associated with weekly, manual, labor intensive cleaning that is commonly required on heat exchangers. This allows for steady performance over long operating campaigns.
Exchange of Bundles
Even though recuperator bundles last a very long time (generally 10-15 years), they eventally need to be exchanged. Therefore, the design of the tower and recuperator bundle are such that each bundle can be removed without disassembly of the housing, in a reasonably short time and with contained efforts.