The accompanying engravings represent a new disinfecting apparatus invented by Mr. W.E. Thursfield, M. Inst. C.E., of Victorgasse, Vienna. The principle on which its action is based is that the complete destruction of all germs in wearing apparel and bedding, without any material injury whatever to the latter, is only to be obtained by subjecting the articles infected, for a period proportionate to their structural resistance, to a moist heat of at least 212 deg. Fah. Recent experiences in Berlin have shown that, for security's sake, a temperature of 220 deg. is better. To insure the thorough penetration of this temperature in every fiber, a heat of from 260 deg. to 270 deg. must be maintained in the disinfecting chamber itself. To obtain this by means of ordinary or superheated steam involves the employment of boilers working under a pressure of 2½ to 3 atmospheres, of disinfecting chambers capable of resisting an equal tension, and of skilled labor in attending to the same; in other words, a large initial outlay and correspondingly heavy working expenses in fuel and wages.
The disinfecting apparatus, illustrated in a portable and stationary form, of the dimensions adopted by the sanitary authorities of Vienna, Budapest, Prague, Lemberg, Teplitz, etc., and by the Imperial and Royal Theresianum Institute, and sanctioned for use in barracks, military hospitals, etc., by the Austrian Ministry of War, and for ambulance hospitals by the Red Cross, acts by means of a mixture of steam and hot air in such proportion that the steam, after expending its mechanical energy in inducting the hot air into the disinfecting chamber, is, by contact with the clothes or bedding of a lower temperature, not only condensed, but by condensation completely neutralizes the risk of injury through any chance excess of hot air. The boiler being practically open is inexplosive, and requires neither safety valves nor skilled attendance.
The heat generated in the furnace is utilized to the utmost, and the escaping vapors form a steam jacket in the double casing of the disinfecting chamber. The method of manipulation reduces the danger of contagion to a minimum, as the clothes or bedding are placed in specially constructed sacks in the sick chamber itself, and, after being tightly closed, the sacks are removed and hung in the disinfector. The stationary apparatus, which is constructed to disinfect four complete suits of clothes, including underlinen, or one complete set of bedding, including mattress, is specially adapted for hospitals, barracks, jails, etc. Its dimensions can easily be increased, but the size shown has proved itself, from an economical point of view, the best, as, where the quantity of articles to be disinfected varies, several apparatus can be erected at a less cost than one large one, and one or more be heated as the quantity of infected articles be small or large. In the accompanying drawing A is the boiler, which is filled by pouring water into the reservoir, B, until the same, entering the boiler at its lowest part through the tube, C, rises to the desired height in the water gauge, G. C acts also in the place of a safety valve. D is the fire space, E a movable grate, and F the coal hopper.
The fuel consists of charcoal or coke. The boiler is emptied by the cock, H. I is a steam pipe connecting the steam space with the hot air tube, L¹. K is an auxiliary pipe to admit the steam into the chimney during stoppage for emptying and recharging the disinfecting chamber in continuous working. The admission of air is regulated by the handle, L, and the draught in the chimney, M, by the handle, N. O is the disinfecting chamber inclosed by the space, P, which acts at the same time as a steam jacket and as a channel for the downward passage of the vapors escaping from the chamber through the outlets, S. The lower portion of the disinfecting chamber, Q, is funnel-shaped for the better mixture and distribution of the steam and hot air, and to collect any condensation water. Q¹ is a sieve to catch any fallen article. The vertical tubes, S, which serve at the same time to strengthen the chamber, connect the lower portion of the steam jacket, P, with the circular channel, T, which is again connected with the chimney, M, by the tube, T'. The disinfection chamber is hermetically closed by the double cover, R, to the lower plate of which hooks for hanging the sacks are fastened.
The cover fits in a sand bath, and is raised and lowered by means of the pulley chain, W, and the swinging crane, X. U is a thermometer indicating the temperature of the steam and hot air in the disinfecting chamber, V a cock for drawing off any condensation water, Y a battery connected with an electrical thermometer to be placed in the clothes or bedding, and Z the sacks in which the infected articles are hung.
The portable apparatus, as shown, for heating with gas, or even spirits of wine, can also be heated with a similar steam and hot air apparatus as the stationary disinfector. In country towns or villages, or even in cities, whose architectural arrangements permit, the portable disinfector can easily be drawn by one man into the courtyard or garden of any house, and the process of disinfection conducted on the spot. Its usefulness in campaigns for ambulance hospitals is self-evident. The letters denoting the several parts are the same as in the stationary apparatus. The portable disinfector is constructed to disinfect two complete suits of clothes or one mattress. The extremely favorable results are shown in the accompanying table of trials. - The Engineer.
TABLE OF RESULTS WITH WM. E. THURSFIELD'S STEAM AND HOT AIR DISINFECTORS.