Newport

Flour Production 1890

We believe this was why changes were made in the production of flour at Wootton Mill in 1892

This article describes the introduction of new production methods for the grinding of wheat on the Island.

The new process dispenses with millstones and replaces them with grinding wheels, which produces lighter and stronger flour. The new method was first introduced on the island at Pan Mill, Newport, followed by Home Mills, located on Lukely Brook opposite the present Sainsbury’s store, Newport, [no trace of this mill exists today] the latter installation being carried out by Thomas Robinson & Son of Rochdale a leading manufacturer of the day.

The new method aims to obtain flour by a better means thereby improving the quality of the finished product. Using too much pressure during the grinding process, as was the case in the earlier methods, ‘killed’ the wheat resulting in a ‘heavy’ bread.

The equipment installed by Robinson’s was technically described as a ‘four-sack’ mill, that is, its flour producing capacity is four sacks per hour. Power at Home Mills was derived from compound condensing beam engine nominal rated at 16 horse power but producing almost twice that amount, the system also allow for the utilisation of water power when available.

A description is given herewith of the mill layout, basement contains the main engine and line shafting together with 14 elevators, the first floor housing six sets of double horizontal rolls and the facilities for bagging the flour. On the second floor three patented semolina and middlings purifiers, three eccentric sieves and a bran buster. The third floor housed the rotary sifters, ‘break’ meal reel, six centrifugal flour dressing machine machines, also on the same floor is an interesting feature protecting the health of the mill workers ‘A machine for collecting dust made by the different operations, so that the operatives are entirely free from any injury by inhaling floating particles’.

For those interested in the actual milling process at the end of the nineteenth century the following information is included: -
The wheat for milling process is stored in silos for a week to allow the different degrees of hardness in the corn to become assimilated allowing for easier production and improving the quality of the flour. From the silos the corn moves to the ‘aspirator’ by an elevator [a series of cups on an endless belt], here the corn is sifted; a strong draft of air removes all the dust and unwanted particles. Next the corn moves into the ‘grader’, which separates it into three sizes; the two smaller sizes then go into two ‘cockle cylinders’, which extract all the cockle and small seeds [these are found in most wheat’s]. The three sizes come together again and conveyed by an elevator to ‘scourer and brush’ machine before going through the ‘aspirator’ again.

From the ‘aspirator’ the clean corn move by a continuous worm to the first of the ‘break rollers’. These rollers consist of two solid chilled iron cylinders or rolls 24inch long by 9 inch dia, spirally grooved on the surface revolving at different speeds [100 and 300 rpm.], the gap is set to break open the grains as the wheat passes through, releasing the kernel [known as semolina]. The material then moves on to a patent rotary double sifter, an arrangement of wire and silk sieves which separates it into three layers: -
1. The ‘break’ or broken wheat, consisting of husk with a considerable amount of flour still attached.
2. The semolina or kernel of corn, which is retained by the second set of sieves, this is sent direct to the ‘purifier’.
3. The third level are the ‘middlings or ‘break’ flour which has passed through the finest of the sieves.
The ‘break’ from stage 1, is now passed through a second ‘break’ roller and sifted again, this is repeated twice more, each time the ‘break rollers have been set closer together. After the forth roller the material is sent to a ‘reel scalper’ which sifts out the fine meal or ‘chop’ from the bran. This bran then drops into a bran duster, a conical cylinder with internal and external brushes, any remaining flour is extracted and the bran falls into a sack.

Semolina, or second product is conveyed to purifier, this is a silk covered sieve vibrating inside a tightly cased frame with a fan mounted above drawing air through the sieve whilst the it is in motion, this eliminates any remaining light particles of bran. The clean semolina then passes through smooth chilled rollers, which have again, had the gap reduced, then into the flour-dressing machine. This is a cylinder covered with fine silk through which the flour is forced by revolving iron beaters. The material that does not pass through is recycled again and that which fails a second time is rejected. The process is repeated until all the flour has been extract from the semolina and ‘middlings’.

The middling from the third filter of the first ‘break’ rollers are mixed with some ‘break’ flour and then go to a long silk reel as described for semolina, to extract any remaining flour. The remaining material goes through rolls again to extract the last of the flour before being rejected. Running below all the final processes is a continuous worm, which collects the flour, and bags ready for shipment. From start to finish the process is automatic with no handling involve prior to he flour being bagged.

The machine collecting the dust and rejected material consist of a series of flannel sleeves into which the material is blown by fans, the material only allows the air to pass through. At short intervals the fans are switched off and the sleeve are shaken allowing the dust to fall into sacks. Not only does this process protect the operators, it also ensures there is no build up of dust to cause an explosion.

Source: Isle of Wight County Press