Power Supplies
Furnace Power Supply System
One of the best opportunities for custom power supplies is power regulating equipment for the refractory and glass melting industries. Actually, we got our first big break in providing power supplies with a manufacturer of ceramic fiber and we have been supplying similar systems to date. The purpose of this write up is to familiarize you where they are applied and a "Nuts & Bolts" description of what they entail.
General Requirement
A system consists of Solid State Controls, Transformer and Tap Changing Equipment, related instrumentation and annunciation to service a 800 to 1500 kva three phase submerged electrode furnace. Composition of the melting mixture is alumina and silica which melts at 3600°F to 3800°F, glass melts at 2800°F to 3200°F.
The purpose of this power supply and regulating equipment is to provide a uniform and symmetrical melt and to have the capability of maintaining this melt through a given production run, typically for 60 to 90 days. Instrumentation should provide accurate information while equipment is in use regardless of the conducting angle of the SCR power device.
The heart of the control scheme is the SCR and Gate Module which control the input voltage and vary it over preset values, typically through a potentiometer. To optimize the power factor, a multi-tap transformer is used, typically having a 2 to 1 voltage range (see simplified elementary schematic).
Examples of industries requiring a furnace power Supply system as described are as follows:
- Owens-Illinois, Inc.
Anchor Hocking Corp.- Container Glass Manufacturing
- AP Green
Thermal Ceramics
Unifrax- Ceramic Fiber Manufacturing
- Rock Wool Manufacturing
Tenmat, Inc.
- Mineral Wools
- Owens Corning
Johns Manville Engineered Products Div.
PPG Industries
- Fiberglass
Sales Opportunities These systems are efficient, take up less space and high in performance and of course field proven. Opportunities are both in new systems ranging in price of $150,000 and up and retrofit/upgrades costing $50,000 or more. Also, there are a number of value added benefits that come into play such as:
- Reduction of Power
- Improvement in the Process
- Increase in Production
- Longer Campaign Between Start-up and Shut-down
- Lower Maintenance Costs
When you factor in all these benefits, the payback for the cost of this type of upgrade can be in 18 to 24 months.
Why Homewood?
Homewood, through its affiliates, has been an active supplier of custom power supplies for the refractory industry for over 20 years. In addition to designing and building, we provide system start-up and check-out on the systems we sell. Some of these systems are still operating after 20 years. On some occasions we have provided upgrades offering the latest generation of controls without a major change-out of expensive equipment. As you know, few manufacturers will bother upgrading without completely replacing the system. We have some 30 systems throughout the world ranging from 225 kva to 4000 kva, many of which are still being supported.
Control Products
Genuine Westinghouse Products That Extend The Life Of Your Existing Equipment
For over a century, Westinghouse designed and built excellent industrial and power distribution equipment. The vast amounts of equipment still in operation today are a testament to the reliability and durability of the products.
Homewood is proud to continue the Westinghouse tradition by providing genuine Westinghouse products. Extend the life of your equipment without expensive change out costs, environmental concerns and re-training of personnel. With Homewood, you have options. Proven, reliable technology designed to provide service for a lifetime.
Control Products
Switches
Westinghouse- Master Switches
- Knife Switches
- Limit Switches
- Proximity
- Planner
- Precision
Push Buttons &
Panel Board
Westinghouse- Pushbuttons
- Selector Switches
- Indicating Lights
- Contact Blocks
Aftermarket Contact Kits
Westinghouse & Other Manufacturers- AC Aftermarket Parts
- DC Aftermarket Parts
Miscellaneous
Westinghouse- Contactors
- Motor Starters
- Interlocks
- Linestarters
- ManualRheostats
- Relays
- Timetactors
- Filter Paper
- Grid Resistors