Rotary Dust Valves

'Floating Seal' Type HDFSFB - Sizes 300, 450 and 600mm

The type HDFSFB ‘Floating Seal’ valve is a variation upon the standard type HDFBCI valve. The HDFSFB is of fabricated construction allowing the plants to vary a number of the operating design parameters to suit specific applications. 

The body is of heavy duty construction enabling the valve to operate at elevated temperatures and handle abrasive dusts. 

The bolted side panel allows the rotor and floating seal to be withdrawn from the side of the unit for maintenance purposes.

The Type HDFSFB ‘Floating Seal’ dust valve may be supplied as a bare shaft unit (i.e. no drive) or complete with electrically driven gearmotor as a direct drive or chain drive unit.

FEATURES

  • Cast iron rotor and seal of controlled hardness.

  • Fabricated heavy duty carbon steel body.
     

  • Rotor and floating seal withdrawable from side of valve.
     

  • Eight vane rotor to provide air lock seal.
     

  • Designed to handle abrasive materials at temperatures up to 400°C.
     

  • Suitable for positive or negative pressure up to 5 kPa.
     

  • Operates well with any type of dry material. Not suited for use with sticky material or material that will pack.
     

  • Valve cannot be overloaded; each pocket of the rotor is filled as it passes below the spout opening and the excess is scraped into the next pocket.
     

  • Dust-tight seals and collars seal the points where the shaft passes through the body.
     

  • Shaft moves in self-aligning, sealed-in ball bearing pillow blocks mounted on outrigger brackets secured to machined pads of valve housing.
     

  • Top of ‘floating seal’ firmly packed in upper housing with non-asbestos packing rings held in place by a retainer plate.
     

  • Simple construction and maintenance.
     

  • Replacement rotor and seal means that machining of housing is not required as occurs when components of other types of rotary valve wear.
     

  • Valve driven by a suitable sized 415V, 3-phase, 50Hz, TEFC IP55 electric motor through a gearbox complete with couplings, sprockets, chains, guards etc, as required for the type of drive selected.
     

  • Gearbox fits standard motors.

 
OPTIONS

  • Nil-speed switch.
     

  • Electrical or mechanical variable speed drives where it is desired to use the valve as a ‘metering’ valve.
     

  • Client specified or higher power requirement motor / gearbox.
     

  • Crating for transport.
     

  • Shear pin in drive to protect drive train in case of jamming by foreign material or object where application is subject to this.
     

  • Stainless steel body.
     

VALVE CAPACITY

All dust valves capacities are rated in m3/hr. If this is not directly available, the capacity may be calculated from:

 

A)
  • Known dust load in kg/hr
  • Known dust bulk density in kg/m3.

To obtain capacity, divide dust load by bulk density.
e.g:  Dust Load    =  1800kg/hr
       Bulk Density =    600kg/m3

Capacity  = 1800 kg/hr =  3 m3/hr
                  600 kg/m3
 
B)
  • Known dust load in g/m3 *
  • Known dust flow in m3/hr *

To obtain capacity, multiply dust load and gas flow and divide by 1000 to give kg/hr.

Then proceed as in A) above.

e.g: Dust Load  =  12g/m3
       Gas Flow   =  150,000 m3/hr

Load = 20 x 30,000/1000 = 1800kg/hr

Then from A) above capacity  =  3m3/hr

Once the capacity in m3/hr is established, the appropriate size value and speed may be selected from the following table.
 
* Note: Both dust load and gas flow must be in the same terms, 
for example, g/Nm3 and Nm3/hr OR g/Am3 and Am3/hr. 


CAPACITY

In selecting a valve to suit the required capacity it is preferrable to select the lowest speed compatible with requirements. Capacities given are for typical speeds generally available, other speeds are available.

Valve capacity is a function of the dust flowability such as hopper valley angle, type of material, angle of repose etc, much of which is not known. The speed of the valve also determines rate of material fall into each pocket. Two capacity tables are given, one based on theoretical 100% full, the other based on an emperical figure of 65% full from previous experience.
 
 

 

VALVE CAPACITY

VALVE FLANGE SIZE

SPEED
R.P.M.

 300MM 450MM 600MM
100% FULL
m3/hr		 65% FULL
m3/hr		 100% FULL
m3/hr		 65% FULL
m3/hr		 100% FULL
m3/hr		 65% FULL
m3/hr
9 25.33 16.46 90.18 58.61 160.38 104.24
14 39.40 25.61 140.28 91.18 249.48 162.16
20 56.28 36.59 200.40 139.26 356.40 231.66
25 70.35 45.73 250.50 162.82 445.50 289.57

 

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