Safety Process in Mixing Processes

In every good company, the safety process is always the high priority. Any process we transfer to the next step for the facility requires that we are able to control the process, regardless of any surprises, so that we don’t generate dangerous or hazardous situations for the company. So, what happens if the temperature is going up? What happens if the concentration was tight? What happens if we close this valve or open another valve? All of these studies, which are normally called hazardous studies, we must do, because we are protecting the life of every operator, of everyone involved in manufacturing in the chemical industry. These studies are part of every company’s policy, and every good company will always explain that the safety process is critical.

Now, if we are asked about how to develop a safety process and what happens if the mixing is not working well, we need to give an answer to the company. But what is the point? The main reason for the aviation we can have is that mixing is the unit operation that generates the environment in which the materials will interact. So, when we talk about mixing and safety process, we are really talking about the hard part of the knowledge of the process. We will need to be able to explain and show what to do when we are working in extreme conditions of stopping mixing after this turn and turning the mixing on again in that turn. We need to be sure that the process of restarting will be safe.

Process / Unit OperationProblem and Key Mixing Parameters
1.   Basic mixing information  Main mixing characteristics
   Flow dynamics
   Vortex formation
   Turbulence, shear rates and stresses
2.    Blending (distribution of a solute)  Mixing time
   Simulation of blending
3.    Liquid-solid mixing: 
3.1. Suspension  Checking “non-settling” conditions
   Distribution of solid phase
3.2. Dissolution of solid  Completeness  of dissolution
   Simulation of a dissolution process
   Mass transfer
3.3.  Leaching (liquid-solid extraction)        Collisions of particles
   Mass transfer
   Distribution of solid phase
3.4. Crystallization  Uniformity of mother solution
   Mixing parameters affecting nucleation and  
   growth of crystals
3.5. Heterogeneous liquid- solid reaction   Mass transfer characteristics
4.    Liquid-liquid mixing: 
4.1. Emulsification  Completeness of emulsification
   Drop size distribution
   Mixing parameters affecting emulsification
4.2. Liquid extraction and heterogeneous liquid- liquid reaction    Mass transfer characteristics
   Mixing parameters affecting liquid extraction and reaction
5. Single phase chemical reaction . Batch, Semi-batch and Continuous flow reactorsLocal concentration of reactants
 Non-uniformity of mixing in reactor
 Selectivity of reaction
 Dynamic characteristics
 Approach to “perfect mixing”
6.    Mechanical reliabilityStresses in dangerous cross-section   
 Shaft vibration
7.   Temperature-dependent reaction. Batch, Semi-batch and Continuous flow reactorsA comprehensive set of heat transfer     characteristics Simulation of thermal regimes
8.   Thermal safetyAnalysis of runaway process
 Prediction of media overheating/overcooling




We might have situations where not enough material accumulates to generate a fast reaction, or our mixing is enough that we will not generate a mechanical function of the reactor. We might have vibration, bending of the shaft, simple solid state in the bottom, or two liquid phases that are not miscible. So, when we mix, we generate the multiplication that can be separated or not. All of these kinds of typical situations are directly related to the intensity of mixing, whatever we are able to get. What happens if the mixing does not operate well? We stop it or we don’t control it, which results in high velocities or vibration and more. The capability to understand the deviation from the normal operation is important, and the capability to show it during the activities is critical.

So, if we have a tool that is able to notify us about solid deposition in the bottom; floating in the top of the level medium; partial non-emulsification; heat release and temperature going up to the limits of the process; vibration shaft or bending shaft; or runaway reaction, we will be able to control all of these extreme conditions because we have been notified. The tool was designed so that when we have extreme conditions in the solution of the mixing calculations, we get not only numbers but also the limits of operations. These notifications will protect a good mixing process and generate a good mixing practice. These notifications are the best and we have a table discussing them on our website.

VisiMix Video

The Influence of Mixing in the Process
New methodology using VisiMix software for the purpose of checking the influence of mixing in the processes.

VisiMix Demo Operation
Learning how to input data into the VisiMix software and get results the will help us understand the influence of mixing in our processes.

Lab Experiments
Learning how to set up the relevant experiments at the lab scale, to develop the processes from an engineering point of view.