If a detergent site has a spray drying tower, that tower is the most significant process safety asset on the site. Spray drying combines a fine organic powder, elevated temperature and a large enclosed volume, and tower fires and explosions are a well-documented feature of this industry. Everything else on a detergents site, and there is plenty of it, is engineered around that fact.

Projex Solutions provides engineering design, process safety studies and project delivery for detergent, soap and household chemical manufacturers, covering powder, liquid and tablet formats.

What makes this work different

Spray drying towers carry a serious dust and fire hazard. Deposits on internal surfaces self-heat, and the combination of hot surfaces, fine powder and confined volume creates conditions for fire and secondary explosion. Basis of safety, cleaning regime, temperature monitoring and explosion protection have to be designed together.

Surfactant handling is a materials and viscosity problem. Concentrated surfactants are viscous, temperature-sensitive and often corrosive, which constrains pumping, heating, line sizing and material selection.

Corrosive service is routine. Caustic, acids, bleach and hypochlorite bring materials compatibility, containment and emergency response requirements, and incompatible chemical segregation is a design obligation rather than a housekeeping one.

Aerosols and flammable propellants appear in air care and cleaning products, bringing DSEAR and filling hall design into scope.

Powder handling continues beyond the tower. Post-tower dosing, agglomeration, blending and packing all carry dust explosion risk.

Product regulation. Assimilated Regulation (EC) No 648/2004 governs detergents, with obligations that the plant has to support on traceability and formulation control.

Where we help

  • Spray drying tower safety review, covering basis of safety, deposit control, temperature monitoring and explosion protection
  • Dust explosion protection design across the powder train, covering venting, suppression and isolation
  • DSEAR assessment and hazardous area classification for dust and flammable service
  • Surfactant handling design, including heating, pumping and materials selection
  • Corrosive service design, containment, bunding and incompatible segregation
  • Aerosol filling area design, covering ventilation, detection and separation
  • HAZOP facilitation, LOPA and SIL determination to BS EN 61511
  • Feasibility, FEED, detailed design and EPCM delivery under ISO 9001:2015

Typical reasons clients get in touch

  • A spray drying tower needs a process safety review or explosion protection upgrade
  • Dust explosion protection across the powder train has never been formally assessed
  • Corrosive storage and segregation has been raised by a regulator or insurer
  • Surfactant handling is limiting throughput or causing quality variability
  • An aerosol line is being introduced or relocated
  • Capacity has to increase across powder or liquid formats

Related

Part of our work across the FMCG sector and the chemical sector. See also personal care and cosmetics manufacturing.

Standards and regulations we work to

  • Assimilated Regulation (EC) No 648/2004 on detergents
  • DSEAR 2002, with ACOP L138 (second edition, 2013)
  • BS EN 60079-10-2 for combustible dust area classification, and BS EN IEC 60079-10-1:2021 for vapour
  • BS EN 61511-1:2017+A1:2017 for safety instrumented systems
  • COSHH 2002, with ACOP L5 (sixth edition, 2013)
  • COMAH 2015, where thresholds are crossed
  • PSSR 2000, with guidance L122 (2014)
  • Environmental Permitting (England and Wales) Regulations 2016 (as amended)
  • CDM 2015 and ISO 9001:2015

Frequently asked questions

How serious is the risk from a spray drying tower?
Serious enough that it should be the starting point for any process safety review on a detergent site. Fine organic powder, elevated temperature and a large confined volume combine with deposits that can self-heat. Tower fires are a documented feature of this industry, and the basis of safety, cleaning regime, temperature monitoring and explosion protection have to be designed as one system.

Our tower has run for years without incident. Is that reassurance?
Not on its own. Deposit accumulation is progressive and self-heating is time-dependent, so an absence of incidents reflects the current cleaning regime as much as the design. A change in formulation, throughput or inlet temperature can alter that balance.

We store caustic and hypochlorite. What should we be checking?
Segregation and containment first. Incompatible chemical separation is a design obligation, and containment needs to be sized for a credible release rather than a routine spill. Materials compatibility across the transfer system is the second thing we would look at.

Can surfactant handling be improved?
Often. Viscosity and temperature sensitivity mean line sizing, trace heating and pump selection have a disproportionate effect on both throughput and product consistency.

Can tower cleaning frequency be reduced safely?
Only on evidence. Deposit accumulation rate depends on formulation, throughput and inlet temperature, so any change to the cleaning interval needs to be justified against those rather than against operational convenience.

Do you design bunding and containment?
Yes, including sizing for credible release rather than routine spill, materials compatibility, and segregation of incompatible chemicals within a shared containment area.

Our powder train has grown piecemeal. Where do you start?
With a single assessment across the whole train rather than equipment by equipment. Explosion protection only works as a system, and isolation between connected vessels is what prevents an event in one item propagating through the rest.

Talk to us about your plant. Request a call