Whitepapers

Abstract

Inefficiencies in batch mixing operations manifest themselves in a number of ways such as long cycle times, frequent reworks, defects or low product quality, difficulties in maintaining temperature, losses in raw material or finished product, and intensive clean-up, to name a few.

This white paper presents some strategies for improving commonly encountered batch mixing problems. Because mixing processes vary from one application to another – with different objectives, design configurations, rheologies, operating limitations, etc. – there are no fix-all solutions that will apply to every situation. A particular type of agitator or level of mixing intensity may be beneficial to one formulation but detrimental to another product. The ideas discussed in this paper are recommendations of Ross mixing experts based on the company's collective experience as a mixing equipment provider to the process industries for over 169 years. Mixer testing and simulation trials are encouraged to confirm the suitability of a specific mixing strategy.

Introduction

Mixing, like any other unit operation, should be viewed as an evolving technology. Many mixing processes in place today were designed decades ago, a time when process efficiency was not considered as important as it is in the current competitive market. Settling on a "norm" that takes time but works can put a business at risk of losing customers to competition that follow an updated and more profitable manufacturing process. The ability or failure to mix efficiently and economically can profoundly influence the growth or decline of a product line.

The good news is that improving the mixing operation does not necessarily have to involve huge costs or a complete process overhaul. Simple upgrades and practical techniques can bring better mixing performance within reach. The following discussion explores ways to improve a number of batch mixing practices. Some of these procedure