Centrifugal Blowers for Lime, Gypsum, Brick and Building Materials

Lime, gypsum, brick, and similar building-materials plants share a common pattern with cement: kiln or calciner combustion air, hot recirculation inside the process, drying, pneumatic conveying of fine powder, and dust collection at material handling points. The largest kiln draught fans in these plants are outside our range, in the same way they are in cement, but the surrounding duties, which are numerous, are centrifugal blower territory.

Where Blowers Fit

Duty	Typical pressure	Notes
Kiln and calciner combustion air	High	Lime kilns, gypsum calciners
Kiln and calciner recirculation	High	Hot gas within our temperature range
Powder conveying (air slides, dilute phase)	Low to the start of very high	Lime, gypsum, and cement additives
Dryer process air	High	Aggregate, gypsum, and brick material drying
Dust collection at transfer points	High	Crushers, screens, silos, packing
Motor and control room cooling	Low to medium	Standard cooling duty
Large kiln draught fans	Very high flow	Outside our range

Combustion Air for Lime Kilns and Gypsum Calciners

Lime kilns and gypsum calciners need stable combustion air across their firing range, sized the same way as any combustion duty: from the fuel input, with excess air, converted to actual volume at the operating temperature and site altitude. See combustion air.

Hot Recirculation and Process Gas

Where a blower handles the hot process gas directly, rather than ambient combustion air, our high-temperature range applies: furnaces up to 800 °C, kilns up to 650 °C, and ovens up to 500 °C. The same physics as any hot-gas duty applies: the gas is less dense, so the blower develops less pressure, and the same mass flow occupies more volume, so the system needs more pressure at the same time. See furnaces, kilns and ovens and gas temperature, altitude and density correction.

Powder Conveying: Lime and Gypsum

Fine lime and gypsum powders are often moved on air slides or conveyed pneumatically over short distances, much as in cement. Air-slide blowers are small, numerous, and run continuously, needing dry, clean, steady low-pressure air, and dilute-phase conveying within our pressure range handles many short, light-loading duties. Longer or denser conveying moves beyond our range. See low-pressure pneumatic conveying and air slides.

Drying Aggregate, Gypsum, and Brick Material

Aggregate dryers, gypsum board process dryers, and brick drying kilns need process air sized from the water to evaporate and the operating temperature.

Worked example. A brick dryer must evaporate 800 kg/h of water at 90 °C, with the air picking up 0.025 kg of moisture per kg of dry air. Air mass flow is 800 ÷ 0.025 = 32,000 kg/h, about 8.89 kg/s. At 90 °C, air density is about 0.972 kg/m³, so the volume flow is about 9.14 m³/s, or 32,900 m³/h. See industrial drying and process air.

Dust Collection Throughout the Plant

Crushers, screens, silo tops, and packing lines all generate dust, and most of these collectors are modest, clean-side, backward-curved blower duties, similar in scale to a cement plant’s nuisance dust collection. See dust collection system design.

Where 800 HP Ends

The main kiln draught fan on a large lime kiln, and similar large process fans on gypsum calciners and brick tunnel kilns, move far more air, often at high temperature and against significant resistance, than our 800 HP range covers. As with cement, we are clear about this boundary rather than force an undersized selection onto a duty that needs a bigger, specialist machine.

Dust Alkalinity and Abrasion

Lime dust is alkaline and, when damp, can attack coatings and equipment, and gypsum and aggregate dust are abrasive. Choose materials and coatings for the environment, and plan cleaning access, since deposits unbalance wheels before wear becomes visible. See maintaining industrial blowers.

Standardising Across Similar Plants

A group of plants producing lime, gypsum, or brick often repeats the same set of duties: kiln combustion air, a handful of dryers, and dust collection at similar transfer points. Standardising on a small number of blower models across these plants reduces the spares inventory, speeds up fault-finding because technicians see familiar equipment at every site, and simplifies procurement when a new plant is commissioned. Before specifying a new duty, check whether an existing model already used at another site in the group covers it.

Where Our Range Fits

NextAir Systems manufactures centrifugal blowers up to 800 HP (about 597 kW) and up to 500 mm WC (about 4.9 kPa) static pressure, with backward-curved and forward-curved wheels and high-temperature designs. That covers kiln and calciner combustion air, hot recirculation within our temperature range, powder conveying, drying, and dust collection. Large kiln draught fans at very high flow are outside our range.

What to Specify

1. Duty: combustion air, recirculation, conveying, drying, or dust collection.
2. Gas or air temperature and whether hot gas is handled directly.
3. Airflow and resistance, at clean and worst-case conditions.
4. Powder type, moisture content, and conveying distance.
5. Control approach and noise limits.

Verifying Combustion Air After Commissioning

Once a kiln or calciner blower is commissioned, verify it delivers what the burner needs, not just what the calculation predicted. Measure actual airflow against the blower curve at the commissioned speed, check the excess-air ratio against the fuel flow using flue-gas analysis, and record baseline vibration and motor current. Repeat the check after any change to the fuel, the burner, or the kiln refractory, since all three can shift the resistance the blower has to overcome. See blower curves, system curves and operating point drift.

Get a Blower Selection for Your Plant

Send your duty, gas temperature, and airflow, and we’ll size the blower and confirm the range. Contact us for a free quote.

Frequently Asked Questions