What Factors You Should Consider Fully When Selecting Vacuum Furnace for Your Application?

Want to invest in vacuum furnace for brazing? Or for vacuum heat treatment, vacuum sintering, annealing, thermal processing in your industrial application? All these are extremely important procedures and must be executed with the finest furnace.

If you start scouting for vacuum furnaces, then you will see that there are hordes of options available – including graphite crucible & wafer, tungsten crucible & wafer in laboratory vacuum furnace, as well as tungsten crucible & wafer, graphite crucible & wafer in benchtop furnace. With many options available to you, and with respect to your precise industrial application requirement, you need to search for the vacuum furnace keeping in mind all the factors like design, functionality and all.

What Considerations to Make When Shopping for Vacuum Furnace?

• Weight Capacity

You need to ensure what maximum load weight at a specific elevated operating temperature can be processed.

• Work Area

What load size can be processed is the consideration for determining the effective work area. This is important so you are able to buy a fit-size furnace hearth and not larger than that because it will increase operating costs.

• Temperature Consideration

 What your requirement is pertaining to high temperature furnaces operation? This is an important consideration. Most furnaces come with a capability to operate at 2400°F, while for higher requirements added temperature capability can also be availed.

 Temperature operating uniformity across the furnace range should be looked into, exploring all the options.

 Hot zone temperature uniformity pertaining to insulation and openings is also important to consider for ensuring right trimming and power input adjustment.

• Vacuum Performance

 For blower/mechanical pump furnace, ultimate vacuum is in range of 20 Microns Hg or more. For diffusion pumped, ultimate vacuum range is 10‐6 Torr.

 There should be approximate 10 minutes time period from pump-down to high-vacuum cross-over.

 For a diffusion pump furnace, the operating vacuum range is 10-5 Torr. While for other furnaces, it is in the range of 50-60 micron Hg.

 The furnace leak rate should strictly be less than 5 microns per hour, as this is an important consideration for clean furnace operation.

• Hot Zone Construction

 Acceptable insulation package has to be considered based on the industrial standards pertaining to thick 304 stainless steel structure and flaxshield. This is important to reduce moisture absorption and reduce the chances of oxidization and rusting.

 Heating elements have to be used properly resistance matched so that problems related to temperature uniformity do not arise. Each heating zone of a hot zone has to be properly provided with proper indicators.

 Work support rails should be heavy-duty graphite rails to reduce the chances of load contact reactions.

 Heating element insulators must be used in a way that these are protected from contaminating vapors.

• Vacuum System Components

 The mechanical pumps have to be of high quality and must provide for a large reservoir for efficient functioning during hot & humid days.

 A vacuum blower pump is also another important component that has to be considered with good research.

 The main vacuum valve has to be at the right angle.

 Apart from the above, ensure that the diffusion pump and vacuum roughing port are also given key consideration.

• Furnace Chamber Design

 The basic construction of the furnace design has to be well thought out. It must conform to the industry standards and codes and must be able to properly allow water circulation.

 The chamber door design must be like it allows for proper personnel safety during the autoclave movement. The door should be able to avoid seal failure and dirt collection.

• Electrical Equipment & Controls

 A centralized, easy-to-operate cabinet, conforming to the industry standard, is important to house the electrical controls.

 For proper control and monitoring of the furnace, a cabinet that houses a temperature controller, programmable controller, and other controllers and recorders for smooth operation is much-needed.

 Industry-standard Type ‘S’ and Type ‘K’ thermocouples are preferred for control & temperature and work monitoring.

• Power Supply

An advanced power supply with complete controls including the trim control has to be provided within the cabinet. It must be able to remove any possibility of power flow problem in the transformer.

• Gas Cooling System

 Both internal and external cooling systems have to be considered fully, so these are able to provide easy access to heat exchange, drive motor, eliminate drive motor shaft rotating seals.

 Gas nozzles have to be optimum in allowing for accelerated gas flow and ensure proper functioning throughout the hot zone & front door main section.

So, when you are looking for vacuum furnaces for your industrial application, are you considering these aspects? Make sure to look into each factor that makes up a furnace design and functionality, matching it up with your precise requirements before selecting the right one.