NOVEMBER, 1933
ISDUSTRIAL AND ESGINEERING CHEMISTRY
commonly used and needs the protection to a rnuch greater extent. The impregnation process used and the superior penetrating power of the preservative itself permit ample protection to be obtained by the Bruce process without the necessity of using the high pressures required to accomplish sufficient penetration in many of the older processes. Another interesting feature of this process is that the preserved lumber is ready for use immediately after treatment. Lumber delivered to the treating plant in the morning can be delivered to the contractor the same day. This feature allows the architect to specify any kind of construction without danger of long and costly delay.
tank, penetration still continues for a time because of further contraction of the air in the interior of the lumber. Apparent rapid drying of stock thus processed is due rather to this progressive penetration than to rapid volatilization of solvent from the surface. With 35 gallons per 1000 feet absorption of Bruce Preservative, there is approximately twenty times as much toxic principle in the lumber as is required to inhibit fungus and termite attack. The penetration secured is beyond any probable depth of checking. The lumber has been sterilized completely during the heating process. I n commercial treatment 20 to 30 gallons of preservative per 1000 feet is common practice. The sapwood usually absorbs the preservative more readily than the heartnrood, which is fortunate since sapwood is most 0
1303
RECEIVED April 27, 1935.
0
0
Fire Prevention and Protection in Chemical Industries BERNARD F. FLOOD R o p l Li>erpool Groups, Columbus, Ohio
Courtesy, A merican-LaFrance and Foarnzte I n d u s t r i e s , Inc.
FOI~TY-GALLON FOAMITE ENGINEBEING~ J S E I I O N 4N INFL43lMABLE LIQUIDFIRE ORIPARATITELT little published information can be found on the subject of fire and explosion hazards of the chemical industries. Reports of inveFtigations of government bureaus. fire insurance companies, the Cnderwriters’ Laboratories, and inspection and fire insurance rating bureaus are available upon request. These, however, do not corer the entire subject, nor is their availability well known in the industry. Although the chemical industry is still young and primarily interested in developing new processes and products, the importance of prevention of fire and explosion cannot be overemphasized. The chemical industry deals with hazardous materials. Nearly all organic compounds are combustible. Many of them are highly inflammable or explosive, and Some
are auhject to spontaneous ignition, e.specially when storetl under certain conditions or in contact with certain other materials. Inorganic compounds are generally considered noncombustible but there are exceptions, such as oxidizing agents or explobives, x-hich are quite hazardous. Xot only are the handling and storing of these compounds hazardous, but there are also hazards encountered in processing them 77-hich are distinct from the hazards of either the raw materials or the finished products. I t is not intended to set forth all the hazards of chemical processes in this article but rather to describe some of the methods of controlling arid preventing weeping fires in chemical plants by proper construction and protection of the buildings which house the industry. When a new chemical plant is to be designed or an old plant remodeled, the following general points are important: 1. Construction should be as nearly fireproof as feasible. 2 . The hazardous processes should be isolated within separate
fire areas.
3. All specially hazardous processes should be properly
safeguarded. 4. -411 hazardous conditions not’inherent to the process should be eliminated or safeguarded. 5 . Ample fire-fighting equipment should be provided. Construction The word “fireproof” is a misnomer. Records show many instances of so-called fireproof buildings that have been seriously damaged or destroyed by fire. However, a building is
NOVEMBER, 1935
INDUSTRIAL AND ENGINEERING CHEMISTRY
1307
masonry fire wall on the side of the building housing the explosive operation toward the balance of the plant. The roof and the side away from the plant may be made of light construction fastened lightly to the more substantial part of the building.
Special Hazards The proper safeguarding of specially hazardous processes is a matter of common sense. Some processes and materials which have become rather common in the industry today have been studied by fire prevention engineers and standards set up for their proper protection. Pamphlets are available on numerous subjects, including the use of combustible anesthetics, w e of artificial coloring of fruits and vegetables, storage and use of nitrocellulose film and similar products, spraying and dipping hazards, and many others involving chemical and physical processes in industry. Besides separating especially hazardous processes from the balance of the plant, such processes as nitration, sublimation, distillation, grinding, and, in general, all processing of organic materials where temperature and pressure control is essential or where inflammable vapors or dust are generated, require close supervision. The requirements of proper ventilation must be studied carefully. The explosive range of most vapors is now available in the literature and should be considered in determining the natural or artificial ventilation necessary for a room or building housing vapor hazards. Recent investigations of the hazards of dust explosion should be consulted. Sight glasses and fragile attachments on stills, tanks, and other equipment should be eliminated or safeguarded fr'oni mechanical injury. Antisiphon and aritiflooding devices afford a means of safety where pumps handling hazardous liquids take suction under head or from tanks at a higher level. The use of nonsparking tools and even the regulation of the clothes and shoes of the workmen must often be a part of the program. The electrical grounding of all equipment, proper venting to the outside, and use of screen5 on these vents, as well as on windows and doors, must be considered.
Courlesy, Walter Kadde & Company LOCAL APPLICATION CARBON DIOXIDE PROTECTION FOR LEATHER COATINGMACHINE
Common Hazards Ordinary hazards found in all types of manufacturing plants should not be overlooked in the chemical industry. Boiler rooms, engine rooms, maintenance shops, warehouses, and shipping rooms should be in separate fire divisions. Where buildings are of combustible construction, proper clearances should always be maintained to boilers, furnaces, stills, kettles, etc. When repairs become necessary on machinery and e q u i p ment used in process divisions, special supervision should be given to the repair crew. First the safe condition of the equipment undergoing repairs should be checked, particular attention should be paid to such operations as cleaning out and steaming of equipment where hazardous liquids and vapors have been used, and extreme caution should be demanded in the use of torches and other equipment by the workmen.
Electrical Hazards Too much stress cannot be placed on the proper installation of electrical wiring. Either for power or light, all wiring should be installed in strict accordance with the rules of the National Electrical Code. This code is revised biannually, and special rules are set up for the installation of wiring in hazardous locations. Vapor-proof switches and globes, conduit wiring, and explosion-proof motors play a large part in the safeguarding of hazardous operations. The plant electrician should be thoroughly familiar with this code, and his work should be checked by an authorized inspector.
Miscellaneous Hazards
Courtesy, Pyrene Manufacturing Company
FOAMINSTALLATION PIPEDTO SEVERAL FIRE HAZARDOUS LOCATIONS
General housekeeping should not be overlooked. The handling of oily waste, rags, and rubbish, oil-soaked wood floors, wood lockers for oily clothing, the smoking hazard, the handling and storage of combustible packing materials, all are important items to watch in fire prevention. These hazards can be eliminated from chemical plants without changing process or equipment. They are mentioned as a reminder that they are causative hazards which have a long criminal record in fire-loss history. After all precautionary measures have been taken, one wonders whether i t is necessary to take steps toward fire protection. Even with fireproof construction and the proper
Ixl~i~si’lil~zards,a plant inigirt still be subject to severe loss by fire or explosion iE the means w r e not provided to control small incipient fires. These arc l x n ~ i i rto l occiir rind every plant should be prcpnred Eor t h e m
Chemical Extinguishers several types of first-aid fire-fighting equipment a :tlj!e. Their extingnishing effect depends upon either blankrting or cooling t.he fire. IIccaiise of specialized suliervisim and imnrance regulations it is best to use only those eat,inguislicrs Iiited by the Underwriters’ Laboratories. They slionld he distributed in the buildings and secbiims wiiere they arc recogiiioed as adapted and most effective Eor nso on tile type
