Loss-in-weight GRAVIMETRIC feeders

Doseur pondéral à perte de poids
Logo de la marque Hasler

Function :
The feeders work using the principle of controlled Loss-In-Weight.
The hopper with its extraction device (screw) is installed on a weighing system giving continuously to the controller the measure of weight.
The loss of weight by time unit (measuring sampling time) represents the actual proportioning flow rate.

Regulation :
The controller compares the actual measured flow to the setpoint and calculates the drive command signal to be sent to the screw speed controller.
The corrective actions made are saved and reflect the volumetric behaviour of the system.

Refill :
The continuous measure of weight in the hopper allows, according to two configurable thresholds (high and low), to manage the refill system(s) feeding the hopper.
During this refill phase, the screw speed is controlled according to its volumetric efficiency, memorized during the previous controlled emptying phase(s).

Applications – Dosing :

  • Ground slag
  • Anhydrite
  • Silicium fumes
  • Coke fines
  • Plaster
  • Starch
  • Filter
  • Dust
  • Cement
  • Lime

Customer benefits

  • Accuracy : ± 0,5 %
  • Flow range from 12 l/h to 14 m3 /h
  • Accuracy consistency
  • Entirely tight system : no environmental impact
  • Low maintenance
  • No need for drop tests
  • Few wear parts
  • Manual or automatic refill


  • Horizontal stirrer in lower part that ensures material homogeneity. (Option: vertical stirrer for poor flowing products)
  • Bearing at screw outlet for a better centering in the tube (less cantilever).
  • Enforced tightness by glands, chicanes, and 4 teflon braids.
  • Inspection door in lower part for eventual replacement of horizontal stirrer without dismantling the whole feeder.
  • Execution: Steel S235-JRG2, stainless steel 304 and 316



  • Vertical stirrer
  • Forced fan P>0,55 kW
  • Inlet counter flange
  • Outlet counter flange
  • Digital load cells 
  • High level probe
  • Junction box for motor
  • Support feet
  • Feeding gate

Feeding examples

(~ 10 time of the max flow rate)

  • Gravitational
  • Vibrating float,
  • Fluidized float,
  • Flow control gate,
  • Archimedean screw
  • Big-bag, emptying station, etc. 


The flowrate at the feeder discharge point is maintained constant by electronic controller SCM-3* at the setpoint value. Detailed alarm informations are obtained via the display (SDU)

Flow controllers for SCM-3 weight loss feeders

* SCM-3: Field or Panel version : doc : SCM-3-F.260.001-E. or SCM-3-P.260.001-E.

Mobile application

The SCM-3 is supplied with a Process Display Unit off ering a 5-inch touch screen and 16.7 million colors.
As an option a mobile application is proposed.

Dimensions and flow range

ModelGravimetricScrewHopper capacity



Dim. "A"
Total feeder weight
100 L 706 ~ 247 kg
150 L 827 ~ 251 kg
250 L 1092 ~ 260 kg

Weight of frame : 57 kg

Inlet bellows


ø Total feeder weight D1 D2
ø 150 126 206
ø 200* 206 256

D1 : ø outlet feeding system
D1 : ø inlet weighing hopper RBP
* : except with vertical stirrer

ø ScrewMax flow
in dm3/h
Min flow
in dm3/h
Screw speed max./min.
Dimension "E"
Theoretical values of flow rateDistance inlet/outlet (screw)
ø 52120047256/10550650750-
ø 683100257/10----750850

Flow range : 10 to 100% of nominal
RScrew filling ratio : 90%
If flow < 100 kg/h : SFT loadcells

Dimensions and flow range

ModelGravimetricScrewHopper capacity



Dim. "A"
Total feeder weight
250 L 788 ~ 385 kg
500 L 1116 ~ 419 kg
750 L 1446 ~ 443 kg
1000 L 1776 ~ 469 kg

Weight of frame : 90 kg

Inlet bellows


ø inlet D1 D2
ø 150 168 206
ø 200* 219 256
ø 300 324 356

D1 : ø outlet feeding system
D1 : ø inlet weighing hopper RBP
* : except si agitateur vertical

ø ScrewMax flow
in dm3/h
Min flow
in dm3/h
Screw speed max./min
Dimension "E"
Theoretical values of flow rateDistance intlet/outlet (screw)
ø 804000200197/108001000--
ø 1007000430163/1080010001200-
ø 12510000810123/10-100012001400
ø 15014000140098/10-100012001400

Flow range : 10 to 100% of nominal
Screw filling ratio 90%

Download technical sheet