Engineering Specifications

The Comminutor is a motor driven comminuting mechanism that reduces the organic solids in sewage to 1/4" size or smaller that will pass through 1/4" slots in the rotating sewage drum. The comminutor is designed to pass maximum flows of 175-850 gallons per minute. The outer shell of the comminutor, the inlet trough and the vertical revolving sewage drum is cast of the finest grade aluminum for protection against corrosion and for overall weight reduction.

comminutors group bkg 3

The comminutor consists of a housing, inlet trough, right-angle gear-motor, drive shaft, double-sealed and shielded bearings, revolving sewage drum with four (4) rotating cutter bars, and one stationary cutter comb. The cutter bars and cutter comb are made of A2 chromecarbon tool steel.

The cutter bars are mounted at 90 degree intervals on the drum. The entire drum assembly revolves as a single integral unit. The teeth on the cutter bars pass through the stationary comb as the drum revolves, creating a cutting and shearing action between the ends of the comb and the top surface of the cutter bars which are recessed into the drum.

The drive unit is a right-angle gear-motor integral type with reduction type worm gearing. This unit is designed and applied in complete accordance with applicable practices of the American Gear Manufacturers Association. The worm gear materials shall comply with all mechanical ratings allowed by the AGMA Rating Standard. The motor size is 1/2 hp for operation on all volt, phase and cycle service. All equipment is designed for outdoor service.

The flow-through of the comminutor is as follows: the sewage enters the comminutor through an open-top inlet trough, passes through the 1/4" slots in the revolving sewage drum, and discharges out the bottom of the comminutor. In the event of prolonged power outages and subsequent plugging of the drum, sewage can overflow the open-top inlet trough into the flow chamber, thereby preventing plugging of the inlet line.

control panel inside

Automatic Reversing (Type "C")
The control circuitry for this unit includes all necessary electrical and electronic control equipment to automatically reverse the cutting drum of the comminutor in a jam situation, and restart it in forward position. The unit will continue this mode until it either unclogs itself or until the overload protection device in the motor stops the above sequence. The controls are mounted in a JIC enclosure. (Add "-C" to model number when the automatic reversing electrical control panel is required. Example: PH-5-C.)


Shaft Extension
Automatic Reversing Control Panel
Explosion Proof Motor
Pressure Relief Valve

Dynatec Machine Inc. 2015