Intelligent Dry Vacuum pumps are High Performing and Cost-Effective

The two most significant challenges being faced by the global heat-treatment industry at the moment are energy efficiency and environmental sustainability. Two of the most crucial areas currently threatening the global heat-treatment industry are the need to increase energy efficiency and decrease environmental impact.These problems are compounded when vacuum furnaces need to be more reliable and productive. This is done to reduce installation and operating expenses, as well as to make technological advances to meet market demands for improved functionality and performance.

Vacuum pumping technology has advanced significantly over the years to provide system builders and users with vacuum pumps that meet their needs. These pumps are not only reliable and efficient, but they also make it easier to integrate with furnace control systems and save significant energy.This is particularly evident with the most recent intelligence installed in industrial dry vacuum pumps like the ESPH series. These pumps are equipped with integrated controllers which can perform basic control functions, such as. Pressure control. These can be integrated seamlessly into the vacuum furnace control system using a variety of hard-wired and digital methods. This allows for complete flexibility in installation for all types of vacuum metallurgical apparatus.These dry pumping systems can be extremely quiet and efficient. These systems are compact in size and provide excellent vacuum pumping performance. The significant design features allow for extended service intervals, sometimes up to 5 years, between each service. The pumps are equipped with an intelligent control system onboard that protects the pumping mechanism from adverse process conditions. It has intelligent start-up, warm-up and shut-down sequences and can also perform automated self-cleaning when needed.

Applications and Parameters:

In metallurgy, vacuum is essential in order to avoid hot-metal reaction with atmospheric gasses or moisture. To ensure homogeneity in liquid metals, vacuum is required to degas them, to remove light metal impurities at higher vapor pressures, to evacuate the molds before filling, to prevent trapped gas pockets and to control reactive gas environments.The following areas are the key to understanding metallurgical processes that require vacuum:1). Preparation, purification, and alloying- vacuum induction melting, vacuum degassing and vacuum arc refining

1. Shape forming: precision investment casting, metal injection mold and powdered metal sintering
2. Reactive heat treatment: Carburizing, Nitriding and other surface-coating/modification techniques
3. Nonreactive heat treatment: Annealing, tempering, and quenching operations
4. Clean assembly processes: vacuum brazing furnaces and electron beam welding

All of these processes share a common characteristic, High vacuum pumping performance is required. The combination of primary vacuum pumps which can exhaust directly to the atmosphere and secondary vacuum pumps (typically mechanical boosts) is how this is accomplished. Although secondary pumps can produce higher vacuum levels for cleaning, purification, and casting, they must be backed up by primary vacuum pumps.Combinations of primary vacuum pumps and mechanical boosters are used in a typical vacuum metallurgy system. They quickly reduce the furnace pressure to a minimum of 0.1 bar.

Other secondary vacuum pumps, such as oil diffusion pumps, can be used to provide deeper vacuum for processes that require it. They remove the residual atmospheric gas from the chamber interior surfaces and the outgassing load. This creates the deep vacuum levels of 10-3 to 10-4 mbar (or lower) typically required to purify and cast operations.

The furnace designer must meet certain requirements when selecting the right vacuum-pump type:

A). Pumping power: This refers to volumetric pumping speed. It must be sufficient to pump the chamber down to the required vacuum within the timeframe. The low pressure is maintained against the expected process gas loads. It should also have enough reserve performance to allow for unexpected gas loads, such as minor leaks)

B). Utility consumption: Power, Cooling Water and purge gas consumption should be reduced.

C). Reliability: The pump must be reliable and require minimal maintenance.

D). Survivability: The pumping device should be capable of handling the abrasive particles and other materials that may come from the metallurgical process.

E). User convenience: Small size, low noise, and easy installation and operation are all desirable characteristics.

Reduce Operating Costs

Figure. 1 Figure. 2

Over the years, the traditional oil-sealed primary vacuum pumps (also called "wet" and "rotary vane") have gradually been replaced by "Dry Vacuum pumping technology in many metallurgical processes. Older oil-sealed vacuum pump models have higher operating costs and need more frequent maintenance. These older oil-sealed vacuum pumps are more costly and require more labor than modern dry vacuum pumps. "Figure-1" shows a typical cost-of ownership comparison between a rotary oil lubricated vane vacuum pump and an equivalent Dry Screws Vacuum Pump. This calculation is based upon power consumption, water consumption, and typical service costs in a metallic application.

"Figure-2" shows a typical cut section of a Dry Screw Vacuum Pump which is well-suited to the metallurgy sector. It features a number of innovative features that offer the best-in class pumping performance as well as low noise generation and energy consumption. All this, in a small package.These dry screw pumps use 60% less energy at maximum pressure than comparable oil-sealed wet-pump power consumption. This compact pump is characterized by a unique screw-rotor design which provides quiet operation, high pumping speed and deep vacuum capability. It is also equipped with an advanced pump temperature-management system that maximizes pump performance and life of the seals, bearings and motor.

Use of a non oxidizing and non hydrocarbon-free, recyclable gearbox oil allows for service intervals of up to five years. This makes it virtually maintenance-free. The ESPH DSP has a high-efficiency water-cooled design with an integrated inverter drive system. This allows for lower power consumption.Its small size and integrated intelligence make it simple to install and use. The pump can be moved by being wheeled or forklifted into position. It is then attached to the vacuum furnace with the connectors provided and connected to its utility services. The pump can be started immediately after the button has been pushed. This invention gave rise to the term "plug-and-pump" which reflects the speed at which installation can be done.

Dhruv Malhotra is the director and expert author of the Dry Vacuum Pump website, and the website having lot of information about all dry screw vacuum pumps, roots vacuum pumps, rotary vane vacuum pumps, oil syst vacuum systems.