GB2115303A

GB2115303A - A method of and apparatus for mixing separately stored materials

Info

Publication number: GB2115303A
Application number: GB08204762A
Authority: GB
Inventors: Bryan Colville Mcgee
Original assignee: Henry Simon Ltd
Current assignee: Simon Corrugating Machinery Ltd
Priority date: 1982-02-18
Filing date: 1982-02-18
Publication date: 1983-09-07

Abstract

A blend of different grain types separately stored in a number of individual bins (A, B, C), according to predetermined desired proportions thereof, is produced by operating a variable rate feeder (10) for each bin, to supply materials to a blender (11) for producing a uniform mix of the different grain types, a variable-rate weighing device (12) dispensing the mix at the required rate to a sampling device (13) and analyser (14) which continuously or intermittently take and analyse samples of the blended grains. A signal representative of the actual proportions is compared in a computer (15) with a signal representative of the desired proportions, whereby in the event of a discrepancy, the computer (15) emits a control signal to one or more of the feeders (10) to re-establish the desired proportions of the different grain types. <IMAGE>

Description

SPECIFICATION A method of and apparatus for producing a blend of different materials separately stored This invention concerns a method of and apparatus for producing a blend of different materials separate stored, according to pre-determined desired prop ortions thereof and is particularly though notexclusively applicable to the automatic blending of various grain types stored in separate bins in orderto obtain a required grist quality at minimum cost.

Selectivityofgrain type in the flour milling industry is achieved by producing a blend of different wheat varieties. For example, there is a type of Canadian wheat which has a high protein content resulting in high cost; a type of wheat grown in the United States of America, again with a high protein content and lower but nevertheless substantial cost; types of French wheat having medium protein content and at medium cost; and English wheat having a low protein content and consequently at least cost. Each of these typical broad types is available in different varieties.

Thus it is necessary for a supplier, and for the miller himself, to be able to produce a blend of the various different grain types, and forthe proportions of these to be known and monitored in order to achieve optimum results.

Otherfactors are contributory to the classification ofdifferenttypes of grain, such as moisture content, amylolytic activity and hardness, all of which, and in particularthe protein factor, will determine the cost per unit weight of the grain. Thus it is normal practice to blend various different grains to achieve the required grist quality and conventionally such blending has been achieved using adjustablevolumetric feeders or gravimetricfeeders. Disadvantages in herent in these devices are apparent in that volumetric feeders do not compensate for differences in density ofthe stock, whilst gravimetric feeders of sufficient accuracy involve high capital cost.Further, neither volumetric or gravimetric types of feeder can com pensate for variations in quality from that expected in a particular storage bin.

An object of the present invention isto provide a system in which grains ofvarious qualities can be dispensed from a number of bins to produce an accurate blend whilst maintaining the cost as low as possible.

According to the present invention there is provided a method of producing a blend of different materials separately stored, according to pre-determined desired proportions thereof, comprising the steps of feeding the materials from store at different selected rates expected to produce said desired proportions, causing same to produce a uniform mix, continuously or intermittently taking from said mix a sample thereof, analysing said sample by automatic means capable of producing a signal representative ofthe proportions of said materials, comparing said signal in a computer with a signal representative of the desired proportions, and in the event of a discrepancy, said computer producing a control signal which adjusts the feed rate of one or more of said materials thus to establish said desired proportions.

Further according to the invention, there is provided apparatus adapted and arranged to carry out the aforesaid method.

The invention will become further apparentfrom the following description, given by way of example only, with reference to the accompanying drawing which is a schematic illustration of apparatus for carrying out the method.

The embodiment of the invention to be described is designed to handle the blending of three different grain types. These are stored separately in bins A, B, and C, and for convenience the type most noticeably affecting the quality of the blend, i.e.thatwith the highest protein content is stored in bin A.

The contents ofthe bins are discharged via respective variable-rate feeders 10 into a common blending device 11 which produces a uniform mix of the different grain types. The output of the blender 11 feeds a weighing device 12 which discharges the grist for use, i.e. in a milling system. A sampling device 13 is adapted intermittently or continuouslyto extract a sample of the material leaving the blender 11, and an analyser 14whose purpose is to be described in greater detail is included to produce an analysis of the sample material. Signals to be produced bythe weighing device 12 and the analyser 14 are fed to a computer 15adaptedto produce an outputtocontrol the individual rates of feed of the feeders 10.

The weighing device 12may be an accurate but simple device such as a load cell scale which has facilities either alone or in conjunction with the computer 15, to determine the rate of flow ofthe blended grain. The sampling device may be ofthe so-called Near Infra Red type which is capable accurately of measuring the protein content of the grain.

The computer or microprocessor 15 which preferably includes a time delay, a key pad for manually entering certain required parameters, and a display to indicate the rates of flow produced bythe feeders 10 and the weighing device 12, operates to control the whole system to produce the desired proportions of the different materials.

In the operation of the system initial settings of the feeders 10 at different selected rates which are expected to produce the desired proportions, are entered in the computer 15 using the key pad selector therein.Thusthesystem is readyforuse. In operation there is an initial delay period to allow the system to stabilise. Then, signals from the analyser 14are averaged and compared in the computerwith a preset signal representative ofthe required characteristics of the blended grain. Provided there is no discrepancy, then there is no variation in the output signal from the computer to the feeders 10, but if a discrepancy does a rise then appropriate signals are emitted to adjustthe rates of feed from the individual feeders 10 until the required characteristics of the blended grain are restored.In a simpler form the output signal produced by such a discrepancy can be used simply to energise an alarm so that the miller or operator of the system can make suitable adjustments manually.

The interface between the weighing device 12 and the computerwill enable the required flow rate to be achieved such that after adjustment of one or more of the feeders lotto establish the desired proportions of the different ingredients of the blend, the flow rate of thewhole stream can be adjusted by comparing the actual rate of flow as detected by the device 12, with the required rate as programmed in the computer whereby in the event of a discrepancy a signal may be transmitted by the computer to all ofthe feeders simultaneouslyto increase or reduce their rates of flowwhile maintaining the same proportions.

Preferably, an override facility will be provided in the system whereby the feeders 10 can be adjusted manually.

Claims

1. A method of producing a blend of different materials separately stored, according to predetermined desired proportions thereof, comprising of steps offeeding the materials from store at individually selected rates expected to produce said desired proportions, producing a uniform mix of the materials, continuously or intermittently taking from said mix a sample thereof, analysing said sample by automatic means capable of producing a signal representative of the proportions of said materials, comparing said signal in a computerwith a signal representative of the desired proportions, and in the event of a discrepancy, said computer producing a control signal which is used to adjustthe feed rate of one or more of said materialsthusto establish said desired proportions.

2. A method according to Claim 1, wherein said mixed materials are weighed by a device which is capable of adjustment thus to select a desired feed rateforthe mixed materials.

3. A method according to Claim 2, wherein said feed rate is selected on and controlled by said computer.

4. A method according to any preceding claim, in which said materials are differenttypes of grain possessing between them at least two different protein contents, and said automatic means produces a signal representative of the overall protein content ofthe blended grain types.

5. A method according to any preceding claim, including an initial delay period to allowthe system to stabilise, whereupon signals from said automatic means are averaged and compared in said computer with a pre-setsignal representative ofthe desired proportions ofthe materials.

6. Apparatus for producing a blend of different materials separately stored, according to predetermined desired proportions thereof, comprising means forfeeding the materials from store at individually selected rates, means for blending said materialsto a uniform mix, sampling means for continuously or intermittently taking a sample from said blend, automatic meansforanalysing said sample and for producing a signal representative of the proportions of said materials, and a computer in which said signal from said automatic means is compared with a signal representative of the desired proportions, and which in the event of a discrepancy is adapted to produce a control signal to adjust one or more of said feeding meansthus to establish said desired proportions.

7. Apparatus according to Claim 6, including weighing means which is adjustable to discharge the blended materials at a selected overall feed rate.

8. Apparatus according to Claim 7, wherein said weighing device is connected to said computer and is interactive therewith such as to maintain said overall feed rate.

9. Apparatus according to Claim 6, wherein said automatic means is capable of measuring the protein content ofthe materials sample.

10. Apparatus according to Claim 9, wherein said automatic means is of the so-called Near Infra Red type.

11. Apparatus according to Claim 6, including an override facility operable to enable said feeding means to be adjusted manually.

12. A method of producing a blend of different materials separately stored, substantially as hereinbefore described.

13. Apparatus for producing a blend of different materials separately stored, substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawing.