Another masher (Fig. 301) designed by Sorrell, and extensively used, consists of a casting forming three cylindrical chambers connected by intermediate psssages, about 8 in. in length. Each chamber ia fitted with a shaft, carrying a number of pins. These pins extend across the chamber, and are arranged so that all parts of the chamber are subject to their action. The three shafts each carry a bevel wheel at one end, gearing into three level wheels on a longitudinal shaft, carried by brackets on one aide of the machine. The bevel wheels are arranged ao that the shaft in the central chamber ia driven in the opposite direction to that of the other two. The shafts are driven at a speed of about 200 revolutions a minute. The first chamber, to the left in the figure, is constructed with a vertical neck, which is attached to the gronnd-malt hopper or grist case ; and in the neck there ia a feed-roll, B, which regulates .the supply of malt to the masher. The feed-roll is driven by a belt from a pulley on the stirring-shaft pasaing through the first chamber. Below the feed-roll there is fixed to the outside of the neck the water-box C ; this box ia aupplied with liquor from the oopper, and communicatea with the interior of the machine through holes in the casting. Another water-box, H, is also fixed on the neck between the second and third chambers to receive water of a higher temperature.
The operation of working this masher is as follows :—The cock communicating with th. e water box C having been opened, and a supply of liquor at the tempemture of 76° (168° F.), admitted., the motion is communicated to the shafts, when the malt, as it falls from the feed-roll, is met by liquor entering through the holes in the casting. Any liquor not absorbed by the falling malt is received in the first chamber, where it is thoroughly mixed with the partially wetted malt by the action of the pins on the agitating shaft. From the first, the partially formed mash is passed on to,the emend chamber, traversing on its way the intermediate neck. These intermediate neoks are an important feature in the machine, as the malt during its passage has time to absorb the liquor. In the second chamber, the 'mashing process is repested, and the mash is then passed on through the neck between the central and third chambers, whero it is met by a second quantity of liquor admitted through a number of holes communicating with the water-box H. Thie second supply. of liqunr is at a higher temperature than the first, the malt having been prepared, by the stilt mashing i't has already undergone, to receive a higher heat. The mixture of the second supply of liquor with the malt is completed ie the third chamber, and from this the mash 1.8 delivered into the mash tun, where it remains from one and a half to two hours. Sparging can then be com menced, and continued until the required length has been run over.
Another mashing machine, designed by R. Wilson, of Alloa, differs from those described in being self-acting. It is driven not by power externally applied, but by the action of the malt and water. This masher, Fig. 305, is attached by the flange N to the spout leading from the griet-case, and the admission of the ground malt is regulated by the valve G, the spindle of which carries a lever handle fitted to a catch. The
malt, as it falls, has to pass through a thin sheet of hot liquor which issues from the pipe E, the opening of this pipe being fitted with a sluice F, by which the quantity of liquor admitted can be regulated. Passing on, the malt and liquor fall into the buckets of the breaker wheel D, and cause the latter to revolve at a high speed. The buckets of the breaker wheel am of V form, and by their action and that of knives between which they work, the mash is mixed as it passes to the lawer part of the machine.
The spindle of the breaker wheel passes through the sides of -the machine, and carries at one end the fly-wheel, which tends to equalize the motion, and also serves as a hand-wheel when neces sary. The mash is delivered into the mash tun through the nozzle P, this nozzle being fitted with a, serrated balance plate H, hinged at its upper side, and working over the discharging mash, levelling it, and preventing it from splashing into the mash tun.
It is desirable to have the contents of a mash tun at all times completely under control, and several arrangements are employed for this purpose. Beneath the false bottom of the mash tun there is sometimes placed a pipe, coiled spirally. Into this pipe, steam can be admitted and the temperature of the mash increased, the action of an arm working above the false bottom tending to some extent to equalize the temperature in the different parte of the tun. This arrange ment is simple, but it is scarcely applicable for ordinary use, as the increase of temperature is not sufficiently uniform in all parts of the mash.
A more suitable apparatus for controlling the heat of the mash is the mash tun attemperator, designed by J. Crockrard. Tho attemperator, Fig. 306, is shown as fixed to wooden mash-tun with sliding doors and fixed roof, as used in the Burton breweries. It consists of a circular cistern, fixed on the tap of the mash tun, and containing a coiled steam pipe. When it is desired to raise the temperature of the mash, the wort is drawn from the tun by the pipe A, and the centrifugal pump B is set in action, the wort being raised into the attemperator through the pipe C. There it is heated by the action of the steam in the coiled pipes, and is then led down through the pipe E to the central vessel of the sparger J, which distributes it over the goods. The pipe C conducts the wort to the bottom of the attemperator, whilst the pipe E draws off the wort from near the surface, where it has greatest heat. The central pipe in the attemperator is for admitting the ordinary supply of hot liquor to the sparger. So long. as the pump B is in action, a constant current is maintained through the goods, the wort being drawn nff at the bottom, heated, and again sparged on the top continuously. By the use of the attemperator, the temperature of the mash Call be maintained for any period; and in the ease of small brewings, where the loss of heat from radiation is proportionately very great, the apparatus is particularly valuable.