Furnace Recirculation Fans for Ferrous and Non-Ferrous Metal Production
Familiar with both Ferrous and Non-Ferrous metal production applications, Robinson Fans provides custom-engineered solutions to the metal industry to meet existing and emerging high temperature process fan requirements. Robinson’s experienced and knowledgeable technical team is able to recommend solutions that meet the specifications of any installation.
We have worked with hundreds of aluminum, steel, and other types of metal production facilities to minimize downtime, and maximize the efficiency of the facility’s air moving equipment.
Aluminum Case History
This aluminum company had been experiencing vibration instability on their ingot preheat furnace recirculation fans. Robinson field technicians were called in to determine the cause and recommend solutions. A series of vibration measurements were made with the fans running under normal operating conditions.
Robinson determined the cause of the instability was vibration interaction (‘beating”) between adjacent fans operating at almost identical speeds within each furnace.
Each furnace had three identical recirculation fans. The center fan’s speed was reduced which broke up the beat pattern and stabilized the operation.
Steel Industry Case History
The 94” Baghouse induced draft fan housing was worn extensively to the point that the side walls collapsed under pressure, allowing one of the inlet cones to be forced into the fan wheel. This resulted in the total failure of the unit.
All new components were purchased from Robinson Fans and shipped to the job site. The customer contacted Robinson Service. We dispatched a crew and immediately began the removal of all of the old equipment. After removal, the site was prepared for the installation of the new fan housing, wheel and dampers. The new unit was completely reassembled and brought back to “online” status.
The customer was able to achieve all aspects of the repairs he needed including demolition, installation, grouting of the housing, bearing assembly, precision alignment and balancing of the fan after start-up. All of this was accomplished with one well-placed phone call to the company who offers “one-source responsibility.” Call us and get the kind of service you deserve.
Steel Industry Case History 2
The company’s booster fan carries a high volume of abrasive particulate in the gas stream. Because this is a large, single width, single inlet fan, the velocity of the particulate erodes the casing cut-off point and its surrounding scroll area.
Robinson designed, manufactured and installed a new pie-shaped cut-off area that can be easily changed out with a spare. This cut-off is a small area in the scroll that is separate from the removable pie that enables the rotor to be removed.
Due to this extra removable part in the housing, the customer now can change this piece in a one-day planned outage. The worn part can therefore be repaired at a reasonable price to become his spare.
Steel Industry Case History 3
This steel company had been experiencing severe vibration and cracking of the casing on their coke oven battery scrubber booster fans supplied by a competitor when operated at reduced flow conditions. Robinson field service technicians were called in to investigate. Measurements of vibration and pressure pulsation versus frequency revealed a rotating stall condition. This is an aerodynamic instability that can occur with certain fan/damper combinations at reduced flow.
A variable speed controller was installed which allowed regulation of the flow rate by fan speed, so the damper could remain fully open.
The fan now operates smoothly at all process flow rates, plus the energy savings of this method of control is estimated to be $200,000 annually.
Steel Industry Case History 4
Our customer lost his Boiler House l.D. Fan due to faulty roller bearings, resulting in an overheated and bent shaft. Since this fan was installed, there had been new equipment placed around it in a fashion which would have made removing the wheel through the original removal housing section very difficult and time consuming.
Robinson Service personnel arrived and examined the situation. Our project manager decided to make a new removable section and come out through the back side. This way, only a couple of pieces of ductwork had to be removed. New flanges were added to this section and bolted together for future use. Once out, the damaged wheel was loaded on a waiting truck and taken to Robinson Fans, where a new replacement shaft had already been made, while the field crew was working to remove the original wheel and shaft assembly from the fan. The new shaft was installed into the wheel and the assembly was trucked back to the plant for the field crew to install.
The fan wheel was put back into the housing and put back into operation. After a “touch up” balance was made, this unit was back into full swing with no further complications. All of this was achieved in four (4) days. Our customer originally expected it to take that long just to take the fan wheel out. It has been running for well over a year, trouble-free.