Automatic dry coke weight system

Abstract

An analog electrical system utilizes a signal from a coke weighing system and a signal from a coke moisture gauge to correct for prior errors in hopper weighings due to delivery overshoot as well as moisture variations in prior batches of coke.

We claim: 
     
       1. Apparatus for automatically measuring and controlling the net dry weight of discrete quantities of moisture-containing material, comprising: (a) means for producing a first signal indicative of the actual weight of each discrete quantity of material;   (b) means for producing a second signal indicative of the moisture content of said material;   (c) means for producing a third signal indicative of the target dry weight for each weighing of said material;   (d) means adapted to receive said first, second and third signals and compute and store a fourth signal indicative of the target dry weight, plus the difference between said target dry weight and the actual dry weight of the instant weighing, plus the error in dry weight existing after the next preceding weighing;   (e) means adapted to receive said second signal and said fourth signal and compute and store a fifth signal indicative of the actual desired weight for the next weighing;   (f) timing means for controlling when said fourth and fifth signals are computed and stored; and   (g) means for shutting off the supply of said material to said next weighing when said first signal equals said fifth signal.   
     
     
       2. Apparatus as recited in claim 1, in which means (d) comprises: i. means for converting said first signal into an adjusted signal indicative of the actual dry weight of the instant weighing;   ii. .[.means for summing said third signal, said adjusted signal, and a signal indicative of the error in dry weight existing after the next preceding weighing;.]. .Iadd.means for subtracting said adjusted signal from said third signal to obtain the error in actual dry weight of the instant weighing, and for adding to said error a signal indicative of the sum of the error in actual dry weight existing after all previous weighings and the target dry weight.Iaddend.;   iii. means adapted to sample the signal from means (ii) during a compute period and to store said signal during all other periods; and   iv. means adapted to store the output of means (iii) during said compute period and to sample said output during all other periods. .Iadd.   
     
     
       3.  Apparatus for automatically measuring and controlling the net dry weight of a batch of moisture-containing material, said batch comprising a plurality of weighings of said material, comprising: (a) means for producing a first signal indicative of the wet weight of the material of each weighing;   (b) means for producing a second signal indicative of the moisture content of the material of the instant weighing;   (c) means for producing a third signal indicative of the target dry weight of the material for each weighing;   (d) means adapted to receive said first signal and said second signal after the instant weighing is completed and compute a signal indicative of the dry weight of the material of the instant weighing;   (e) means adapted to receive said last-named signal and said third signal and compute and store a signal indicative of the sum of the target dry weight, the error in dry weight existing after the next preceding weighing, and the difference between the target dry weight and the computed dry weight of the instant weighing;   (f) means for controlling the timing of the computation and storage of signals;   (g) means for shutting off the supply of said material to said next weighing when a signal, indicative of the sum of the target dry weight, the error from all preceding weighings, and the error of the instant weighing, equals a signal indicative of the weight of the material of said next weighing; and   (h) means utilizing said second signal for modifying one of the signals supplied to means (g) to include the effect of the moisture content of the material of the instant weighing. .Iaddend.