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Fifty tons at one scoop
July, 1936.1
CURRENT TOPICS.
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players sometimes experienced difficulty in properly portraying the desired emotions. The studios of Samuel Goldwyn Inc., Ltd., now have an official fog maker who has become so adept that he can control the height and density of a fog within a few feet. Ordinary mineral oil is used. About 3 gallons of it is put into a steel tank, approximately I8 inches in diameter and I8 inches high, in which is a smaller steel container holding a cake of ice. When brought in contact with high-pressure air, the chilled oil gives off a vapor that is much like fog of nature's making. Compressed air at I Io lbs. is applied into the tank through a jet inserted in the side. Because of the noise, the paraphernalia is enclosed in a cabinet, the fog issuing thence by way of long hose connections. By heating the oil vapor to just the right degree, a London fog can be produced, rising only a short distance above the ground. To simulate an all-prevading San Francisco fog, the vapor must be raised to a high temperature in order that it may reach well above the set. The use of oil, however, is sometimes prohibited, as when it comes in contact with costly furniture. It is then that ordinary Chinese incense is burned. While unpleasant from the perfumers' standpoint, it is more satisfactory for this purpose. R. H. O. Fifty Tons at One Scoop.--( Power Plant Engineering, Vol. XL, No. 3-) With the ability to pick up a 5o ton load and place it on top of an ordinary six or seven story office building, a power shovel has recently been placed in operation by the Northern Illinois Coal Corporation for use in coal stripping service. One of the outstanding features of this giant is its immense dipper, or bucket, which has a rated capacity of 32 cubic yards. The dipper is fabricated from aluminum plates and castings with an armor of special wear-resisting steel at points of greatest wear. The machine has electric drive and control equipment, in fact it constitutes a large power plant in itself, the equivalent ratings of all the motors and generators on the shovel totaling more than 3,5oo hp. With the system of voltage control used, slight pressure of the operator's hands on master switch handles produces working pressures of several hundred thousand pounds at the dipper teeth. It is interesting to speculate upon the possibilities of this machinel Suppose that it could be used to fill the storage hoppers of a large power plant. Assuming this shovel to operate Io hr. a day, it would handle 9oo,ooo tons of coal a month. Operating at this rate it would handle the entire coal supply for a power plant having an installed capacity of three million kilowatts operating at 8o per cent. load factor. R. H. O.
CURRENT TOPICS.
1 19
players sometimes experienced difficulty in properly portraying the desired emotions. The studios of Samuel Goldwyn Inc., Ltd., now have an official fog maker who has become so adept that he can control the height and density of a fog within a few feet. Ordinary mineral oil is used. About 3 gallons of it is put into a steel tank, approximately I8 inches in diameter and I8 inches high, in which is a smaller steel container holding a cake of ice. When brought in contact with high-pressure air, the chilled oil gives off a vapor that is much like fog of nature's making. Compressed air at I Io lbs. is applied into the tank through a jet inserted in the side. Because of the noise, the paraphernalia is enclosed in a cabinet, the fog issuing thence by way of long hose connections. By heating the oil vapor to just the right degree, a London fog can be produced, rising only a short distance above the ground. To simulate an all-prevading San Francisco fog, the vapor must be raised to a high temperature in order that it may reach well above the set. The use of oil, however, is sometimes prohibited, as when it comes in contact with costly furniture. It is then that ordinary Chinese incense is burned. While unpleasant from the perfumers' standpoint, it is more satisfactory for this purpose. R. H. O. Fifty Tons at One Scoop.--( Power Plant Engineering, Vol. XL, No. 3-) With the ability to pick up a 5o ton load and place it on top of an ordinary six or seven story office building, a power shovel has recently been placed in operation by the Northern Illinois Coal Corporation for use in coal stripping service. One of the outstanding features of this giant is its immense dipper, or bucket, which has a rated capacity of 32 cubic yards. The dipper is fabricated from aluminum plates and castings with an armor of special wear-resisting steel at points of greatest wear. The machine has electric drive and control equipment, in fact it constitutes a large power plant in itself, the equivalent ratings of all the motors and generators on the shovel totaling more than 3,5oo hp. With the system of voltage control used, slight pressure of the operator's hands on master switch handles produces working pressures of several hundred thousand pounds at the dipper teeth. It is interesting to speculate upon the possibilities of this machinel Suppose that it could be used to fill the storage hoppers of a large power plant. Assuming this shovel to operate Io hr. a day, it would handle 9oo,ooo tons of coal a month. Operating at this rate it would handle the entire coal supply for a power plant having an installed capacity of three million kilowatts operating at 8o per cent. load factor. R. H. O.