The Material Handling Problem Solvers.

P.O. Box 7506 Paducah, KY 42002-7506Phone: (270) 442-1996 Fax: (270) 442-5214E-Mail: sales@pebco.com Web Address: www.pebco.com

BLADE IN CLOSED POSITION

BLADES IN OPEN POSITION

BLADES IN OPEN POSITION

BLADES IN CLOSED POSITION

BLADES IN CLOSED POSITION

BLADE IN CLOSED POSITION

BLADES IN OPEN POSITION

BLADES IN OPEN POSITION

BLADES IN CLOSED POSITION

BLADES IN CLOSED POSITION

BLADE IN CLOSED POSITION

BLADES IN OPEN POSITION

BLADES IN OPEN POSITION

BLADES IN CLOSED POSITION

BLADES IN CLOSED POSITION

The Mass Flow Feeder

Variable RateEach feeder will have a theoretical flow rate based upon the geometry of the hopper’s bulk material flow properties, the slope of the hopper measured from the vertical material weight and the corrected diameter of the hopper outlet. The actual flow rate will be calibrated during start-up of the system. Depending upon the material controlled, the Mass Flow Feeder will generally have a turn-down ratio of 10 to 1 (example – 7,000 tph to 700 tph). In the western United States one series of 60” Mass Flow Feeders will feed 3” x 0 coal between 8,000 tph and 300 tph.

New SilosPEBCO® Mass Flow Feeders have been installed on numerous new silos. With the tremendous damage associated with asymmetric flow and elimination of older silos, silo designers have begun to specify and insist upon PEBCO®’s double-bladed Mass Flow Feeders for new silos.

Old SilosDue to the dangers associated with catastrophic failure of some older silos caused by asymmetric flow, silo designers are beginning to recommend banding of the silos and installation of dual bladed, variable rate, high capacity, PEBCO® Mass Flow Feeders. PEBCO® engineers routinely work with silo designers and end users to provide budgetary figures in the resolution of these potential problems.

Low Energy ConsumptionPEBCO®’s 60” Mass Flow Feeder with an upward capacity of 25,000 tph utilizes a relatively small 15 hp electric motor, which is not constantly used and may power several feeders simultaneously. This may be compared with a typical 2,000 tph vibratory feeder which constantly requires a 25 hp electric motor. PEBCO® Mass Flow Feeders are a clear choice for low energy consumption.

Reduced Space Requirement

The High capacity dual bladed Mass Flow Feeder can generally be retrofitted into spaces previously utilized by vibratory feeders discharging at much lower rates.

High CapacityThe capacity of the PEBCO® Mass Flow Feeder is virtually limitless. Several existing applications feeding unit train loadouts are operating at 10,000 tph. However, the capacity of the PEBCO® Mass Flow Feeder is generally limited by the capability of the conveyor to carry material away from the Mass Flow Feeder.

Accuracy and ControlThe PEBCO® Mass Flow Feeder is designed to discharge through its centerpoint and to control a mass flow opening. Material flow rates can be controlled within ±1% of set rate for a single feeder or between two or more feeders. A single feeder will be equipped with a control panel with initiation and flow rate setting capabilities. To begin operation, personnel merely preset the amount of material to be fed and push a start button.

Used in Multiples (Blending)

The multiple Mass Flow Feeder is ideal for blending coal, crushed stone, taconite and a wide range of other bulk materials. It applies perfectly to situations where different materials must be fed to collection conveyors simultaneously. With a turndown ratio exceeding 10 to 1, very accurate blending between feed points is possible.

In the early 1980’s PEBCO® engineers were introduced to the numerous problems associated with silos. In fact, silos began to deteriorate rapidly and even failed catastrophically due to the problems associated with asymmetric funnel flow, funnel flow, and rat-holing. Many silos around the world have begun to delaminate due to these problems and silo experts are being consulted to develop a plan to correct the various flow problems.

Design, Construction and Operating Characteristics

PEBCO® engineers recognized the need to develop a Mass Flow Feeder to aid in the solution to the asymmetric flow problem discovered in many silos. Like other products in our full line of gates, valves, an material handling equipment, the PEBCO® double-bladed Mass Flow Feeder features extra heavy-duty standard construction with many adders and more exotic construction materials available to handle virtually all bulk materials.

The standard Mass Flow Feeder sizes are 24”, 36”, 48”, 54”, and 60” square. They are constructed of rigidly reinforced carbon steel with a type 304 stainless steel liner on the blade and inlet throat with 2B finish. Type 304 stainless steel with 2B finish and the proper angle with respect to the horizontal allows the material to mass flow through the feeder.

The PEBCO® dual bladed, high capacity, variable rate Mass Flow Feeder offers the flowing advantages:

The discharge opening is aligned longitudinally with the center line of the belt conveyor which produces an improved material profile on the belt.

The blades on the two-blade Mass Flow Feeder move through a smaller angle for a given opening size or rate of flow, thus allowing a lower discharge rate for the same opening. One of the functions controlling the discharge rate is the slope of the blades.

Since both blades move, the Mass Flow Feeder can attain larger flow rates before reaching the vertical blade position. The feeder reaches its maximum controllable discharge slightly before the blades reach the vertical position.

Due to its adjustable capabilities, the Mass Flow Feeder has application in facilities where several types of bulk materials of varying densities and properties are handled and where the flow rate must be controlled. The Mass Flow Feeder performs as a volumetric feed rate control device which can adjust to varying material flow properties. The Mass Flow Feeder has few moving parts, consumes minimal energy, and produces much lower noise levels when compared with either reciprocating or vibratory type feeders.

The PEBCO® Mass Flow Feeder and control scheme is protected by U.S. Patent # 4,580,698 and Foreign Patents.

The Mass Flow Feeder