I. Core Vulnerable Parts

- Vacuum pump oil, vacuum pump filter element

- Mechanical seal of circulation pump

- Wearing parts of feed pump / discharge pump (impeller, seal)

- Liquid level gauge, temperature sensor, pressure transmitter

- Pipeline gaskets, flange gaskets

- Filter element (bag type / PP melt-blown)

- Defoaming nozzles, distributor nozzles

- Condenser cleaning balls, demister packing

- Activated carbon (for tail gas treatment, also regarded as consumables)

II. Replacement Frequency (Under Conventional Cutting Fluid / Cleaning Wastewater Conditions)

- Vacuum pump oil: replaced every 1–2 months

- Vacuum pump filter element: every 2–3 months

- Mechanical seal: every 3–6 months

- Filter element: every 7–15 days (depending on suspended solids content)

- Temperature / pressure / liquid level sensors: every 6–12 months

- Sealing gaskets: every 3–6 months

- Activated carbon: every 1–3 months

- Pump impellers, bearings: every 6–12 months

III. Approximate Annual Maintenance Cost

For small low-temperature evaporators (1 ton/day ~ 3 tons/day):

- Vulnerable parts + consumables + chemicals

  Approximately 3,000–8,000 RMB per year

- Including labor, cleaning, overhaul and all vulnerable parts

  Generally sufficient at 5,000–12,000 RMB per year

For medium-sized equipment (5–10 tons/day):

- Total annual cost of vulnerable parts: approximately 8,000–15,000 RMB

- Overall maintenance cost: 15,000–30,000 RMB per year

IV. Key Factors Affecting Costs

- High slag content and strong corrosiveness in wastewater → rapid damage to mechanical seals, pumps and sensors

- High salinity and easy scaling → frequent cleaning, heavy wear of gaskets and seals

- Continuous 24-hour operation → 30%–50% higher wear than intermittent operation

- Consumption of tail gas activated carbon depends on odor intensity

V. One-Sentence Summary

The main vulnerable parts include pump seals, vacuum pump oil, filter elements, sensors, gaskets and activated carbon. The annual maintenance cost is several thousand to over ten thousand RMB for small equipment, and ten to thirty thousand RMB for medium-sized equipment, which is generally not high.