844
INDUSTRIAL AND ENGINEERING CHEMISTRY
Vol. 39, No. 7
Muriatic furnace operation also involves the presence of sulfur trioxide. I n order to determine the effect of t h i h ronstituerit, tests were made on cast iron, carbon steel, and nirkel in :Lmixture' of approximately 90% hydrogen chloride and 10% sulfui, tiioside. T h e results, within experimental error, were the came :IC i n 100% hydrogen chloride on all three materiala. I n the relatively few instances where it \vas po,+ilile to ( . I i r ~ k the experimental data with operating experience, agi,winerit quite good. In muriatic furnace operation, exposure of s,pec.irnrii. .of several different materials, as \re11 as service life of rsst iroti and SHA-1 parts not controlled by other factoi.s, correlatcd \vel1 with the laboratory results. Xickel \vas satisfactory i n an :ipplic:ition involving chlorine at about, 950" F. hut was uniuitablr :it
PHOTOSENSITIZATION IN CHLORINATION Recent improvements i u quartz inercur? arc latiips have led to a re-evaluation of the economich of the photosensitization in chlorinations. The ititestigation i r i cluded consideration of reaction chaniher design for maximum light utilization, admixture of reactatit., and temperature control. Results indicated that t.onc,etitric* glass annular reaction Iessels, including temperatil re control chambers about a linear, high wattage, high pressure, mercury-arc lamp, offer ail impro\ed de\ice f o r chlorinations in the *apor and liquid phases. i Lerhniqirr was eiolved which is considered conitnerciallj promising.
T
HE photosensitizat,ion of chlorine has txrn known for many years. There are many patents and a vast literature on t h c h subject. Some processes have found comnicrcGd applic,:ttion, but usually the difficulties encountiwd with light s o u r i w Iiavi: made the processes uneconomical. Prior t o 1937 light sources availablr for the scnsitizat ion included the quartz mercury-arc lamp with liquid mercury p i d electrodes, the incandescent filanient lamp, and the c-arhon arc lamp. Mercury arc lamps were limited to a few huntlrcd Jvatts of electrical input each and were difficult to control thermally, and the considerable quantities of liquid mercury in each lamp inad(. them cumbersome and fragile. The incandescwt lamp had a low radiation out,put in t,he spectral region effective. for the sensitization of chlorine. The rarhon arc introduocd a fire hazard, produced excessive heat,, and offered difficult icw of light utilizat.ion. These factors in the light sources materially inhibited commercial development of photosensitizd chlorinations. During the past few years developmtbnts in electronics havo resulted in the product,ion of elcctron-c,initting cathodes suit,able for use in quartz mercury-arr l a m p a- a.
