TL;DR — Direct answer: A detergent and household chemical plant needs clean dry air at 7 to 8 bar for mixing, filling and packing, with a pressure dew point of 3 degrees C and corrosion-resistant treatment so no oil, water or chemical vapour reaches product, filling heads or packing lines. Size on the coincident peak of mixing, filling and packing, commonly 6 to 13 cubic metres per minute for a mid-size plant, and use a variable speed drive because mixing and filling run in batches. QiAir, a Chinese screw compressor manufacturer and supplier, builds machines with corrosion-resistant air treatment for household chemical production.
Detergent and household chemical production runs on air in more places than most managers realise. Mixing vessels use compressed air for valve actuation and agitation control, spray-drying towers use it for atomisation and conveying, filling lines use it for dosing heads and cap torquing, and packing lines depend on dry air for labelling, cartoning and palletising. When the air falters, the whole line slows: a sticky valve leaves a batch half mixed, a damp air line clogs a filling head, and a labeller misfires on every tenth bottle. Chemical vapour and corrosive dust make it worse, because they attack pipework and valves from the inside and the outside at the same time. QiAir is a Chinese manufacturer and supplier of screw air compressors, and its machines are specified for exactly this kind of continuous, corrosive, multi-user duty.
The mistake buyers make most often is sizing from a catalogue table instead of from the plant itself. A mixer, a spray dryer, a filling line and a packing line rarely all peak at the same second, but two of them often do, and that coincident peak is what the compressor must cover without dropping below 6.5 bar at the farthest user. This guide walks through where the air goes in a detergent and household chemical plant, how to size for it, how to keep chemical vapour and moisture out of the system, and what to ask a China supplier before ordering.
Where Compressed Air Is Used in a Detergent and Chemical Plant
Start at mixing. Raw materials arrive, are weighed and blended, and each step has air users hiding in plain sight. Mixing vessels use compressed air for valve actuation, agitator control and blow-down between batches, and the mixing hall is dusty with detergent powder, so any air tool or cylinder there needs filtration that survives fine alkaline dust. A plant that maps every user, including the small ones, usually finds 15 to 25 percent more demand than the original estimate, and that gap is where pressure problems start.
Downstream, spray drying and filling are the most sensitive users. Spray-drying towers use air for atomisation, conveying and tower cleaning, and wet or oily air at the nozzle changes droplet size and product quality. Filling lines need steady air for dosing heads, cap torquing and level control, and a pressure dip can leave a bottle under-filled or a cap loose. Packing closes the loop: labellers, cartoners and palletisers all want dry air at a steady 7 bar, and a single damp pulse can spoil a label and send a carton back for rework.
- Mixing and blending: vessel valves, agitator control and blow-down in a dusty, alkaline hall.
- Spray drying and filling: atomisation, conveying, dosing heads and cap torquing where moisture affects product quality.
- Packing and palletising: labelling, cartoning and strapping tools that need dry air at stable pressure.
Sizing for the Real Peak in a Batch Chemical Plant
The practical way to size is to list every air user with its flow and duty cycle, then add up only the users that run together. In a mid-size detergent plant running 5 to 15 tonnes per hour, a realistic coincident peak is often 6 to 13 cubic metres per minute at 7 to 8 bar, and a 45 to 90 kW screw compressor covers it, with a variable speed drive trimming the part-load hours when mixing pauses between batches. If the plant plans a second filling line within two years, leave a 20 to 25 percent margin or a spare connection point now, because retrofitting a larger receiver and header later costs more than the extra capacity costs today.
Pressure matters as much as flow. Size the pipe so the drop from the compressor room to the farthest filling head is under 0.3 bar at peak flow, and verify it with a gauge at the far end during a full production run, not at the receiver. A 500 to 1000 litre receiver per 10 cubic metres per minute smooths the short spikes from valve actuation and filling heads, and a ring main beats a long dead-end run wherever the building layout allows it. Avoid the trap of buying a bigger compressor to fix a small pipe: it burns power every day and still leaves the far end short.
- Work at 7 to 8 bar for most detergent and chemical plants, and confirm the highest-pressure user before choosing a 10 bar machine.
- Use a variable speed drive when load varies by more than 30 percent across a shift, which it usually does in batch mixing.
- Check pressure at the farthest user under full load, and log it weekly so a slow leak or filter clog shows up early.
Chemical Vapour, Corrosion and Dry Air
Detergent dust is fine, alkaline and corrosive, and chemical vapour finds every gap in a compressor room, so intake placement is a design decision, not an afterthought. Put the compressor intake on the clean side of the building, away from the mixing hall and the spray-drying tower, and duct it if necessary so the machine breathes relatively clean air. A standard intake filter clogs fast in a chemical plant; check it weekly, keep a spare on the shelf, and watch the pressure drop across it, because a choked intake raises discharge temperature and power draw at the same time.
Treatment is three stages in series, and skipping one always shows up later. A pre-filter catches bulk dust and water, a refrigerated dryer brings the pressure dew point to around 3 degrees C, and a coalescing filter removes oil aerosol before air reaches spray nozzles, filling heads and packing lines. Use corrosion-resistant pipework, stainless fittings and coated receivers in the production area, and inspect them quarterly for the white and green corrosion that alkaline dust and chemical vapour leave behind. Drain condensate automatically with a zero-loss drain, and never let a manual drain become a daily chore that someone forgets on a busy shift.
- Keep compressor intake away from mixing dust and chemical vapour, check the intake filter weekly and keep a spare in stock.
- Fit pre-filter, refrigerated dryer and coalescing filter in series, with corrosion-resistant pipework in the production area.
- Use automatic zero-loss drains, slope air lines to drain legs, and inspect pipework quarterly for chemical corrosion.
Buying from China: Sizing Sheet for a Detergent and Chemical Plant Compressor
QiAir is a Chinese manufacturer and supplier of screw air compressors, and a detergent order should start with a sizing sheet rather than a model name. Send the supplier your coincident-peak flow at 7 to 8 bar, your highest-pressure user, the dust and vapour level and ambient temperature in the compressor room, and the distance to the farthest air user. Ask for a fixed-speed and a variable-speed quotation side by side, with the part-load power curve for each, so you can compare energy cost over a year rather than purchase price on one day. Confirm the receiver size, dryer type and filter grades in writing, and confirm which spares ship with the machine.
Before the machine leaves the factory, agree on the acceptance checks: a full-load run at rated pressure, a dew point reading at the dryer outlet, and a pressure reading at a simulated far-end load. On arrival, install on a level plinth with clear airflow around the cooler, connect the drains before the first run, and run a pressure survey at the farthest filling head during the first full production week. Keep a simple log of pressure, temperature and filter changes, and it will tell you months ahead when a service is due.
- Send the supplier coincident peak flow, highest-pressure user, ambient conditions and farthest-user distance.
- Compare fixed and variable speed on annual energy cost, and confirm receiver, dryer and filter grades in writing.
- Accept on a full-load test plus dew point and far-end pressure readings, then survey pressure again in week one.
Frequently asked questions
What size screw compressor does a detergent plant need?
A mid-size detergent plant running 5 to 15 tonnes per hour usually needs 6 to 13 cubic metres per minute at 7 to 8 bar, which is roughly a 45 to 90 kW screw compressor. Size on the coincident peak of mixing, spray drying and filling, add a 500 to 1000 litre receiver per 10 cubic metres per minute, and verify pressure at the farthest filling head under full load.
Why does chemical vapour damage a compressed air system?
Alkaline dust and chemical vapour corrode pipework, valves and receivers from the inside and the outside, and moisture carries that corrosion into filling heads and packing equipment. Use corrosion-resistant pipework and stainless fittings, site the compressor intake away from the mixing hall, and inspect pipework quarterly for corrosion.
How do I keep dust out of the compressor in a detergent plant?
Put the intake on the clean side of the building away from mixing and spray drying, duct it if needed, check the intake filter weekly and keep a spare. Fit automatic zero-loss drains, slope pipework to drain legs, and log pressure drop across filters so a clog shows up before it raises power draw.
Related reading
- Single-Stage vs Two-Stage Screw Compressors: Which One a China Manufacturer Recommends
- Buying Screw Compressors from China: A Ranking Checklist for Choosing a Supplier
QiAir is a Chinese manufacturer and supplier of screw air compressors. If you are sourcing a screw compressor from China — for a factory, a food plant, a construction site or a new production line — contact QiAir for a sized quotation, documented performance data and export support.