Specialised Services.
We Design Custom Mixing Equipment
Including chemical reactors, to meet your complex liquid/liquid, liquid / solid and non-standard mixing needs (gas / liquid, different viscosities and densities, and other difficult cases). This service may include:
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Defining the technical characteristics of the mixing equipment based on the process requirements and constraints, using existing mixing vessels or new ones.
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Optimization of mixing related process parameters, such as mass transfer, phase separation quality, dissolution efficiency, homogeneity of suspension etc.
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Simulation of the mixing process using our proprietary software
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Guaranteed scale up services
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Analysis of mechanical loads on shaft, impeller and baffles during mixing
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Supply of data sheets for bid and detailed design drawings for build
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Supply and installation of custom mixing equipment
Our Specialized Consulting Services
Service Offerings include troubleshooting and problem solving for existing mixing systems or new mixing system designs, to improve performance and to solve recalcitrant problems, such as:
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Reducing entrainment (carry-over) in both streams after liquid/liquid separation (all types of separation equipment).
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Resolving inadequate mass transfer
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Achieving faster approach to equilibrium
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A need to increase throughput of existing equipment with no reduction in performance
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Continuous phase instability and inversions
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Modification of drop size distribution
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Slow or incomplete separation in gravity settlers, hydrocyclones or other separation equipment
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Partial or slow dissolution of solids
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Incomplete suspension formation.
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Dispergation problems with gas in liquid
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Undesired accumulation of precipitation
We also solve non-standard mixing problems such as:
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Mixing liquids with different densities and viscosities (dilution of bitumen to Dilbit, reactions with concentrated sulfuric acid etc.)
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Non-standard geometry of mixers
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Special requirements, like enhancing or preventing ingestion of air, or complex chemical reactions.
Case Studies
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Case Study: Corrosion Mystery
A petrochemical plant suffered an unusual corrosion attack in a mixing vessel in which an alkali stream is neutralized with a concentrated sulfuric acid. There was severe localized corrosion in one central part of the tank, etching a deep horizontal strip (10 cm wide). By mathematical analysis of the mixing equipment, we were able to prove that the reaction was confined to a narrow zone between two layers, creating an intermediate layer which was subject to continuous violent changes in pH and temperature. So the corrosion was caused by separation of the dense acid from the rest of the liquid, due to inadequate mixing, which led to extreme chemical stress in the tank wall, even though the tank material was supposed to be fully resistant to the liquids involved. Replacing the mixer internals with our custom design resolved the problem.
Case Study: Eternal Suspension
An engineering company approached us to design a mixing tank to keep particles suspended in a liquid continuously for an extremely long time without shutdown. Client specified that rotating impellers of any kind will not used, due to safety constraints. Mathematical analysis (using the physical properties of the liquid and the particles and our proprietary tools) determined that air injection through appropriate nozzles with carefully designed spacing could maintain the suspension with a margin of safety, and multiple external compressors (one duty and at least one standby) provided a reliable solution with no single point of failure, and which allowed maintenance without shutdown for the lifetime of the tank materials.
Case Study: Increasing throughput in Hydrometallurgy
As the quality of the ore often decreases over time in many mines, existing hydrometallurgy plants often struggle to maintain output, but they can’t justify costly expansions. Initially, the plant operators attempted to compensate by increasing the flowrates and the mixing intensity at the expense of the phase separation. Thus a large quantity of expensive extractant is lost, and degradation products of the extractant cause further separation problems. Moreover, entrainment of organics in the aqueous phase endangered the product quality in the electrowinning stage, which cannot be tolerated. By retrofitting our proprietary mixing system in the existing mixer tanks, the entrainment was reduced by more than a factor of 2, which allowed safe increasing of the throughput by 25% without compromising separation quality.
Case Study: Precipitation in mixer requiring frequent maintenance
A white acid plant with many extraction and washing stages suffered from maintenance induced shutdowns due to the accumulation of precipitated solids (mostly gypsum) in the mixers. Our proprietary split-pump reactor design reduced the precipitation accumulation dramatically (the precipitate was in fact shifted to the settler where it can be removed easily during scheduled maintenance).
Case Study: Preventing oxidation during mixing
A food ingredient manufacturing plant had complaints from customers that their product was a different color than their competitors. Our mixing analysis revealed that nitrogen ingestion from the surface was occurring. The trace amount of oxygen in the nitrogen blanket was causing oxidation under mixing conditions. Without having to completely seal the tank and without using extra-pure blanketing gas, our redesign of the mixing internals prevented the gas ingestion and the product color became acceptable (white as snow).
Case Study: Low mass transfer efficiency in solvent extraction (SX)
Mass transfer isn’t a common problem in most SX plants. Typical values are around 95-99.5% of equilibrium. However, this customer’s plant exhibited only 65-75% efficiency consistently. The mixing intensity cannot be increased, since the motors are already at the highest allowed speed. Our analysis has shown that the phases are separated inside the mixer, and there is a large quantity of the heavy phase (around 80% of the operating volume). This volume doesn’t participate in mass transfer, and technically is a dead zone. Installing our proprietary mixing system allowed usage of the whole volume of the equipment, and the mass transfer became 98.9%. Moreover, removal of a large volume of aqueous reduced the load on the pumps, which allowed more precise and flexible flow control.
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