THE DUNNACHIE KILN.
Mr. James Dunnachie, of the Glenboig Union Fire-clay Works, Glasgow, Scotland, has recently perfected an improved regenerative kiln for burning fire-brick, which is constructed upon the principles just described, and for which Charles T. Davis, of Washington, D. C., is the agent in the United States. Figs. 8o to 88 represent the Dunnachie kilns arranged in two opposite rows or series of five each, the end kiln of each series being connected to the corresponding end kilns of the. other series by means of flues.
Fig. 8o is a general plan of the series of kilns. Fig. 81 is an end elevation of the same. Fig. 82 is a front elevation of one of the series or rows. Fig. 83 is a longitudinal vertical section of the same. Fig. 84 is a plan of the same, partly in section, on the line I 2, Fig. 83.
The following figures are drawn to a larger scale, the beter to exhibit the flues and passages : Fig. 85 is a longitudinal ver tical section of a kiln of the series, with portions of the adjacent kilns on either side. Fig. 86 shows one-half of a horizontal section of the same, taken on the lines 3 4, Fig. 85. Fig. 87 is a vertical transverse section on the line 5 6, Fig. 85, show ing the side wall of the kiln, indicated by the arrow 7. Fig. 88 is a section on the line 5 8, Fig. 85, but showing the other side wall of the kiln, as indicated by the arrow 9.
The gas to be employed for the burning process is obtained from any convenient source. For example, it is produced in gas producers, indicated at A, Fig. 8o, and is led threfrom by the main passage a, wherefrom lead branch passages for the gas to each kiln, a valve being upon each such passage to regu late the supply of gas to each kiln. The gas passes into the kilns by openings and a'. In the division walls which sepa rate the kilns are duplex hollow spaces or flues (marked re spectively B and communicating the one with the other by openings b, which openings are regulated or closed by dampers c. In the side of the flue C are passages opening from the flue just above the outlets for gas a' in the one kiln, the flue B being in communication by the slots b', or flue b', and slots with the lower part of the adjacent flue. A duplex passage consisting of flues D and E is also formed in the upper part of the walls of the kilns, the one passage D communicat ing by means of the openings d with the one kiln, and the other passage E communicating by means of the openings e with the adjacent kiln. The flues D and E communicate with each
other by openings which can be regulated by dampers Openings f are made in the roofs of the kilns, which openings are covered by slabs or dampers In operation, when one kiln is in fire the effluent gases pro duced therein are passed into the adjacent kilns through the openings passage b', openings b', passage B, openings b, and passage C into the adjacent kiln next in the series through the openings and will heat the contents of the kiln. When the first kiln has been fired off the air paSses through that kiln into the adjacent one through the passages B and C, as before de scribed, issuing thereinto by the openings Gas is then turned on to this kiln, and, meeting with hot air, burns and bakes the brick. The quantity of air passing through the one kiln to be heated on its passage to the adjacent one is regulated by the dampers c, and the quantity of gas admitted to this kiln is regulated by the valve a. When this last-mentioned kiln is burned off, the supply of gas is turned off therefrom, and this one becomes in its turn the regenerator or heater of air for the next kiln, and so on through the series, the passages marked and in Fig. 8o giving free communication between the respective end kilns of each row of kilns. If it is desired to admit hot air to the upper part of any kilns, this may be done by opening the dampers at the top of a fired-off kiln, and air heated by the kiln thus being caused to pass from the kiln through the openings d, passage D, openings and passage E, and into the adjacent kilns through the openings e to raise the temperature of the upper part of the kiln, or to assist in the combustion of the gas, Where cold air is to be admitted, air passes through the flue E, which is open to the atmosphere at both ends. The outlet-passages from each kiln, and the main flues to the chimney into which these passages open, are indi cated in Fig. 80, and are there marked g.