PMCA Rotary Feeder

A high-capacity rotary feeder for introducing cement raw materials, principally quarried limestone, into a vertical roller mill (VRM) or other type of raw mill. Designed for throughputs from 150 to 1000 tons per hour, the PMCA feeders are built to operate for a 24-month cycle between rebuilds.

Unplanned outages are virtually eliminated and the tight internal clearances lower energy costs in the milling operation.

PMCA Rotary Feeder

Key Advantages

  • Very little unplanned downtime to disrupt operating plans or production targets; a PMCA-60 recently had >99.8% uptime over a two-year operating cycle.
  • Two-year operating cycle between rebuilds should be expected, reduces costs and allows for feeder removal only every other year in the annual outage.
  • Install it, start it up, and run it – the PMCA requires only periodic maintenance and none of the adjustments or parts replacements that are common on other raw material feeders.
  • Separator horsepower and power consumption are expensive and false air intrusion drives up costs; the tight tolerances in a PMCA reduce false air by thousands of CFM compared to other feeders.
  • Lower false air reduces turbulence in the mill which leads to more uniform grinding and consistent particle size.
  • Compact design makes the PMCA a “universal replacement” for feeders from others – minimizing installation complexity and cost.

Problems Solved

Raw mill outages are disruptive to achieving operating plans and a prolonged outage can shut down the plant’s entire output; a reliable raw material feeder is critical to keeping the mill operating.

PMCA feeders can normally be rebuilt after a two-year service cycle which can substantially reduce total cost of ownership over a multi-year horizon compared to an annual rebuild or an annual new feeder purchase.

PMCA rotary feeder vanes

How Does It Work?

Depending on the feeder size, 1” or 1-1/2” thick Tri-Braze abrasion-resistant steel used to construct the barrel resulting in exceptional durability and making rebuilding possible.

Six-pocket rotor with rounded rotor pockets to minimize possible build-up of wet or sticky raw materials.

Rotor constructed of 1” thick Tri-Braze abrasion-resistant steel for durability.

Rotor body and main drive shaft are joined with taper-locks and Ringfeder shaft clamps for positive rotor location and to allow the replacement of one or the other independently.
Housings and rotors precision-machined for a clearance of 0.045” to 0.075” per side – depending on the size of the feeder.

Standard equipment includes MSHA/OSHA-compliant shaft guards, an Allen-Bradley zero speed sensor, and a split-ring shaft packing gland for easy service.

Oversize drive shaft and heavy-duty Dodge FCE piloted flange bearings
Nord Clincher or MaxxDrive (depending on feeder size) shaft-mounted gear-motor drive packages including integrated Tsubaki torque-limiter clutches.

Options and Upgrades Available

Option Benefit
TransitionsTransitions available for replacing Loesche, FLS, Pfeiffer, Polysius feeders and triple-gates.
Two ConfigurationsOrder with endbell ports and an open-core rotor for running hot air inside the rotor to reduce sticky material build-up in rotor pockets.

Technical Specifications

Material TypesCement raw materials, principally quarried limestone that has been through a primary crusher and possibly a secondary crusher.
Rotor pockets designed for max rock size of approximately 6” on a PMCA-35 to approximately 15-18” on a PMCA-72.
Moisture content up to 20% including a limited amount of free water if raw materials have been stored outdoors.
Temperature RatingsCement raw materials are normally at ambient temperature.
PMCA feeders can be configured to accommodate elevated temperature raw materials when necessary.
Power Requirements Drive motors powered by
230/460V 3Ph 60Hz
575V 3Ph 60Hz
Other voltages and frequencies available
Zero speed sensors operate at control voltage
VFD’s operate single-phase up to system voltage

Let our applications specialists help you with your extreme-duty bulk material handling needs.