Auto-cleaning ESP systems introduce water into the kitchen exhaust environment, creating water management requirements that must be correctly designed. From drainage to grease trap integration to environmental discharge compliance, this guide covers the water management aspects of modern kitchen purification.
| Parameter | Specification |
|---|---|
| Wash Water Volume | 30-60 L per auto-clean cycle per module; 1-2 cycles per day typical |
| Water Quality Requirements | Clean water supply, 2-4 bar pressure; detergent is food-grade alkaline (biodegradable) |
| Drainage Requirements | 50mm gravity drain connection; connection to grease trap required upstream |
| FOG (Fats, Oil, Grease) Compliance | Wash water routed through grease interceptor before sanitary sewer discharge; meets local FOG limits |
| Recycling Option | Filtered and UV-treated wash water can be reused for 3-5 cycles; 70% water reduction |
Application Scenarios
- Shopping mall multi-module drainage design: A Bangkok mall with 12 auto-cleaning ESP modules designed a centralized drainage system. Each module drains via 50mm PVC to a common 100mm collector pipe, which flows through a 500L in-line grease trap before connecting to the mall’s sanitary sewer. The grease trap is serviced monthly by the mall’s waste contractor. The system has operated for 3 years with zero drainage blockages or FOG compliance issues.
- Water recycling implementation (Dubai hotel): A luxury hotel in water-scarce Dubai implemented wash water recycling for its 8 auto-cleaning ESP modules. The wash water passes through a settling tank (grease skimming), sand filter, activated carbon filter, and UV sterilizer before returning to the clean water tank. The system reduced fresh water consumption by 65%. The recycling system paid for itself in 14 months at Dubai’s commercial water rates.
- Grease trap integration failure and fix: A restaurant connected ESP wash water directly to the sanitary sewer, bypassing the grease trap. Within 3 months, the municipal sewer authority detected elevated FOG at the restaurant’s connection point and issued a notice of violation. The fix was straightforward — routing wash water through the existing grease trap — but the remediation cost (emergency plumbing, penalty, re-inspection fee) was $4,500. The lesson: always route wash water through the grease trap.
- Environmental discharge permit (California): A large central kitchen in California required an industrial wastewater discharge permit for ESP wash water. The permit application included: wash water volume estimates, detergent SDS (Safety Data Sheet) showing biodegradability, grease trap design calculations, and a sampling and monitoring plan. The permit was issued with quarterly FOG monitoring requirements. The first year of monitoring showed FOG consistently 60% below the permit limit.
