Process / Product quality benefits
- Uniform dispersion of calcium hydroxide into liquid base
- Stable milk of lime concentration and suspension consistency
- Reduced agglomeration and settling
- Batch time reduced by 50%
- Improved process repeatability
Previously unsuccessful methods
The original batch mixing approach created multiple operational and safety concerns:
- Manual pouring of fine calcium hydroxide powder increased dust generation
- Elevated loading positions exposed operators to inhalation risk
- Slow wetting and agglomeration reduced mixing efficiency
- Long batch cycle times limited production capacity
- Repetitive heavy lifting increased fatigue and injury risk
These issues highlighted the limitations of top-entry powder addition for milk of lime production.
Fristam’s solution
Fristam supplied a Powder Mixer, an inline mixing system with enclosed induction funnel designed for safe, enclosed powder induction and rapid suspension formation. The system uses a self-priming FZX Liquid Ring Pump to generate vacuum suction, drawing calcium hydroxide powder directly into the liquid stream in a controlled manner.
The Powder Mixer’s floor-level and waist height table eliminated the need to pour powder into open tanks from height, significantly reducing dust release into the working environment. When integrated with a bulk bag unloading system, the process became fully contained — improving both operator safety and housekeeping conditions.
High-shear mixing elements ensured fast wet-out and uniform dispersion, producing a consistent milk of lime suspension in a single continuous process.
Process set-up
1. Floor-level installation
The Powder Mixer was installed beside the existing batch tank, enabling safe powder loading at ground level.
2. Controlled powder induction
Calcium hydroxide was fed from a bulk bag unloading system into the Powder Mixer funnel. Vacuum generated by the FZX pump pulled the powder directly into the liquid stream, minimizing airborne dust.
3. Inline high-shear mixing
As product passed through the Powder Mixer’s rotor-stator mixing section, calcium hydroxide particles were fully wetted and dispersed before returning to the tank.
4. Production monitoring
Operators monitored suspension quality, induction stability, and batch cycle times to confirm performance improvements.
A successful outcome with the Fristam Powder Mixer
The Powder Mixer delivered immediate and measurable improvements to milk of lime production:
- Mixing time was reduced by approximately 50%, from 14 minutes to 7 minutes per 600 lb (272 kg) batch, effectively doubling throughput.
- Uniform milk of lime suspension quality was achieved through controlled inline dispersion.
- Operator safety improved significantly by eliminating ladder access, heavy lifting, and direct exposure to airborne calcium hydroxide dust.
- Contained powder induction reduced housekeeping requirements, keeping surrounding production areas cleaner.
- Bulk feeding automation reduced manual intervention, freeing operators for other production tasks.
The processor continues to benefit from faster, safer milk of lime production with improved repeatability and reduced operational risk.
Sustainability benefits
- Reduced energy consumption through shorter mixing cycles
- Lower raw material waste from improved powder utilization
- Cleaner working environment reduces cleaning water and chemical usage
Financial benefits
- Increased effective production capacity
- Reduced labor input per batch
- Lower downtime linked to manual handling and rework
- Reduced indirect costs related to workplace safety incidents
Other benefits
- Floor-level ergonomic operation improves health and safety compliance
- Compact inline installation fits existing plant layouts
- Reduced operator fatigue and dust exposure
- Reliable long-term performance