BUCYRUS DRYER.
Until a few years ago, the greater portion of all brick were dried in the open air.
One of the difficult problems for solution by brickmakers has been the successful drying of brick and other clay products.
The hot-floor, heated by coal fires, was the first artificial dryer known to the trade.
About 1864, the iron floor, heated with exhausted steam by day and live steam by night, came into practical use among fire-brick manufacturers. The next important step forward was the hot-air-tunnel dryer, heated with coal fires and smoke, so that when the brick came out dry, both the brick and the work men had a negroid appearance, caused by the smoke and dust from the coal used adhering to the brick while in a moist con dition. Aside from this objection, the danger of the buildings being consumed by fire was very great. The extreme waste fulness, and consequent cost of drying brick by this method, was the means of soon sounding the death-knell of this dryer.
In or about the year 1874 the steam tunnel dryer was first introduced, and at its inception was a very crude affair, being built without any provision for draft or circulation, and, owing to repeated failures, it was known by many brick-makers as a " sweating-box ;" but, as the clay-working industry progressed year by year, and as the perfection of a more economical and successful dryer became the great desideratum of the trade, strenuous efforts were made to overcome the defects of the first attempt, resulting in various modifications of, and additions to, the original design.
Another candidate soliciting the brick manufacturers' favor was the tunnel dryer, heated with coils of steam pipe, and the hot air circulated by a large revolving fan placed at one end. This process has, so far, not met with any perceptible encour agement, because of the fact that many clays will not stand the cyclone of hot air violently thrown upon its surface by the action of a fan, causing checks and cracks in the brick. The necessity of constantly keeping a man employed to operate a special engine day and night to run the fan proved to be one of the chief elements in destroying the usefulness and economy of this process.
A subsequent rival was the steam tunnel dryer, with natural circulation, effected by the use of air-ducts and one or two large stacks. By this method the whole amount of saturated air is drawn through and around the brick hacked in the end of the dry-kiln near the stacks, super-adding moisture thereto, and tending to make the brick very fragile.
To overcome all the difficulties encountered by the fore going processes, the Frey—Sheckler Co. were led to manufac ture what is known as the " Bucyrus Steam Tunnel Dryer." The circulation of this dryer is as near perfection as it can be. Cold air is first admitted to the warm-air chamber in the