Loss-in-weight gravimetric feeder

A loss-in-weight feeding system comprising:

• first means for receiving material and discharging said material at a controlled rate;
• second means for receiving material and discharging said material at a controlled rate;
• means for providing a representation of a predetermined discharge rate;
• means responsive to said respresentation and to the weight of material in said first and second means for controlling said first and second means to continuously discharge material alternately from said first and second means at a continuous discharge rate substantially equal to a predetermined discharge rate;
• third means, responsive to said controlling means, for feeding the material alternately to each of said first and second means at a controlled feed rate when it is not discharging;
• and
• wherein each of said first, second, and third means are coupled to said controlling means such that said controlled feed rate and each of said discharge rates of said first and second means are maintained substantially equal to said predetermined discharge rate.

A loss-in-weight material feeding system comprising:

• first means for receiving material and discharging material;
• at least second and third means for receiving material from said first means and discharging said received material;
• means for alternately feeding material discharged from said first means to said at least second and third means;
• means for generating first and second signals representative of the weight of material in a respective one of said second and third means;
• means for generating a reference signal representative of a desired material flow rate;
• means for alternately comparing said reference signal with said first and second signals;
• means for controlling said second and third means in response to said comparison with said first and second signals, respectively, to alternately control the discharge of material from said second and third means, respectively;
• wherein said means for controlling is coupled to said first means such that said first means first discharges material into one of said second and third means while the other of said second and third means is controlled in response to said comparison between the reference signal and the associated signal representative of the weight of that means;
• and
• wherein said means for controlling controls the rate of discharging of said first means and the rate of discharging of said second and third means so that the rate of discharging of said first means is substantially equal to the rate of discharging of said second and third means.

A loss-in-weight-feeding system comprising:

• first means for receiving material and discharging material;
• at least second and third means for receiving material from said first means and discharging said received material;
• means for alternately feeding material discharged from said first means to said at least second and third means;
• means for generating first and second signals representative of the weight of material in a respective one of said second and third means;
• means for generating a reference signal representative of a desired material flow rate;
• means for alternately comparing said reference signal with said first and second signals;
• means for controlling said second and third means in response to said comparison with said first and second signals, respectively, to alternately control the discharge of material from said second and third means, respectively;
• wherein said means for controlling is coupled to said first means such that said first means first discharges material into one of second and third means while the other of said second and third means is controlled in response to said comparison between the reference signal and the associated signal representative of the weight of that means;
• wherein said first, second and third means each includes a motor driven feeder for discharging material and wherein said control means is coupled to drive the motors of said first, second and third means with a common control signal.

A continuous loss-in-weight material feeding system comprising:

• a prefeeder for receiving and discharging material;
• at least first and second feeders for receiving material from said prefeeder and discharging the received material to a common collector;
• means for diverting discharged material from said prefeeder to said first feeder in a first position of the divertig means to said second feeder in a second position of the diverting means different from the first position;
• means for generating first and second signals representative of the weight of material in said first and second feeders respectively;
• means for generating a reference signal representative of a desired material flow rate;
• means for alternately comparing said reference signal to one of said first and second weight signal synchronous with the discharge of material from the prefeeder to the other of said first and second feeders;
• means for controlling the discharge of material from each of said first and second feeders based on the comparison of said reference signal with the first and second weight signals, respectively, to maintain the feeder discharge rate of that feeder at said desired material flow rate;
• and
• wherein said controlling means controls the discharge rate of said prefeeder and the discharge rate of each of said first and second feeders so that the discharge rate of said prefeeder is substantially equal to the discharge rate of each of said first and second feeders and to said desired material flow rate.

A continuous loss-in-weight material feeding system comprising:

• a prefeeder for receiving and discharging material;
• at least first and second feeders for receiving material from said prefeeder and discharging the recieved material to a common collector;
• means for diverting discharged material from said prefeeder to said first feeder in a first position of the diverting means and to said second feeder in a second position of the diverting means different from the first position;
• means for generating first and second signals representative of the weight of material in said first and second feeders, respectively;
• means for generating a reference signal representative of a desired material flow rate;
• means for alternately comparing said reference signal to one of said first and second weight signal synchronous with the discharge of material from the prefeeder to the other of said first and second feeders;
• means for controlling the discharge of material from each of said first and second feeders based on the comparison of said reference signal with the first and second weight signals, respectively, to maintain the material discharge rate of that feeder at said desired material flow rate;
• and
• wherein said prefeeder and said first and second feeders are coupled to said controlling means such that the discharge rate of each is controlled by a common signal.

A technique for loss-in-weight material feeding comprising:

• discharging material from a first source;
• alternately feeding material discharged from said first source to at least second and third sources;
• alternately discharging material from said second and third sources to a common source;
• detecting the weight of material in each of said second and third sources;
• generating signals indicative of the weight of material in said second and third sources respectively;
• generating a reference signal representative of a desired material discharge rate;
• alternately comparing said reference signal with each of said signals indicative of the weight of said second and third sources;
• controlling the discharge of material from the discharging one of said second and third sources in response to said comparison to cause the rate of discharge from that source to be equal to the desired material discharge rate during the time that material from said first source is being fed to the other of said first and second sources;
• and
• wherein said step of discharging material from said first source comprises discharging material at a rate substantially equal to the rate at which material is discharged from said second and third sources.