Vacuum distillation separates mixture components under reduced or high pressure. When vacuum distillation occurs at a lower boiling point, compounds are separated from higher boiling point compounds mixtures. In order to get the desired valuable products separated and recovered, vacuum distillation is necessary for several industries including:

  • Chemical manufacturing plants
  • Petrochemical
  • Pharmaceutical
  • Fine chemical manufacturing
  • Bulk chemical manufacturing
  • General industries 

Vacuum distillation operates to extract and capture light hydrocarbons that disassociate from crude oil and to avoid thermal degrading or discoloration of the product. Moreover, vacuum distillation lowers operating costs, averts breaking hydrocarbon chains due to excessive heat, reduces undesirable side reactions, and increases product recovery when maximum temperature constraints are applied. 

Atmospheric distillation happens when the product is heated and distilled under atmospheric conditions. In this process, lots of heating energy is required. It is important to not degrade the quality or properties of the product needing distilled. 

The vacuum distillation column is typically large, with column diameter up to 46 ft. (14 m), heights up to 164 ft. (50 m), and feed rates to approximately 160,000 barrels a day. 

Vacuum distillation columns must provide good vapor-liquid contact while maintaining a low-pressure increase from the top of the column to the bottom. Therefore, vacuum columns utilize distillation trays only when withdrawing products from the side of the column. Most of the columns use packing material for the vapor-liquid-contact because such packaging has a lower pressure drop than distillation trays. Packaging material can be structured sheet metal or randomly dumped packing like Raschig rings. 

The absolute pressure of 10 to 40 mmHg in the column is most often achieved by using multiple stages of steam jet ejectors, or a combination of steam ejectors and liquid ring vacuum pumps.

NASH Vectra Cutaway of Functional Elements



Vacuum is achieved by an all-steam jet system or a hybrid system that combines two vacuum technologies. The ejectors are more efficient with the addition of NASH liquid ring vacuum pumps and high vacuum capabilities resulting in a hybrid system.

The vectra vacuum pump series is the best single-stage liquid ring pump in the world. This vacuum pump series is used for differential pressure as it pulls vacuum and achieves up to 1551 mmHg discharge pressure.

NASH vacuum hybrid systems reduce greenhouse gas emissions and operating costs while improving system stability. Hybrid systems are innovatively designed to improve efficiency, increasing energy savings, and deliver reliable service.

Nash is recognized worldwide and is the only manufacturer to produce both liquid ring pumps and steam ejectors that go into a hybrid vacuum system.

NASH Hybrid System
NASH Hybrid System

NASH Liquid Ring Vacuum Pumps, Ejectors & Hybrid Systems

NASH hybrid systems are a combination utilizing steam jet air ejectors or vacuum boosters in the first stages and liquid ring vacuum pumps or dry screw pumps in the final stage and include inter-condensers.

Hybrid vacuum systems are used in new and existing installations to reduce operating costs and lower greenhouse gas emissions. Nash Application Engineers optimize vacuum systems to meet customer-specific application requirements.

Trusted Experts

Nash is a global leader of engineered vacuum solutions and produces premier quality products efficiently and economically. Backed by over 110 years of experience, NASH CERTIFIED™ experts provide aftermarket support with maintenance, service, parts, and repair. Service centers are globally located to protect your vacuum system investment and provide quality, reliable, and efficient solutions.