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Exhaust gases from engines using ethyl gasoline
Feb., i925.]
U.S.
BUREAU OF MIXES NOTES.
27I
United States, and to indicate the principal sources of such pollution. Certain typical methods and devices in use and proposed for the separation of oil from water, and for the disposal of oily wastes from ships and industrial plants, have been studied. An attempt has also been made to point out the nature of the fire hazard resulting from oil pollution and to indicate the effect of such pollution on bathing beaches. With the aid of duly qualified government authorities, the effect of coastal oil contamination on marine and wild life has been outlined and its effects upon the public health have been briefly dealt with. Finally, a study has been made of typical oilburning vessels, in order to visualize the conditions prevailing in marine practice and to aid in an appreciation of the difficulties and problems involved in the operation of such vessels. A fuller account of the results of this investigation is contained in Serial 2658 , now available. E X H A U S T GASES FROM E N G I N E S U S I N G E T H Y L G A S O L I N E . By R. R. Sayers and A. C. Fieldner.
O~E of the outstanding problems confronting automotive engineers in attempting to construct motors of greater economy is that of eliminating the " knock " from the operation of the engine. Recent investigations of this detonation or knock in internalcombustion engines, especially of the high-compression type, have demonstrated that it can be eliminated or reduced by decreasing the reaction velocity of combustion by adding small quantities of certain compounds to the gasoline. This makes it possible to use engines of a higher compression ratio, thereby greatly increasing the mileage per gallon of gasoline consumed. The savings in fuel reserves from increasing the proportion of crude oil marketable as motor fuel and in permitting the designing of more efficient engines are obvious. Ethyl gasoline, one of the widely used anti-knock fuels, is ordinary motor gasoline to which has been added 3 c.c. of tetraethyl lead and 2 c.c. of a halogen carrier, as ethylene dibromide or trichlorethylene, or approximately o.o4 per cent. of the lead compound and o.o6 per cent. of ethylene dibromide by volume. Ethyl gasoline should not be confused with ethyl fluid, which is a mixture of concentrated tetraethyl lead and ethylene dibromide in the proper proportions for mixing with gasoline, but is not a
272
U.S.
BUREAU OF MINES NOTES.
[J.F.I.
motor fuel and is not sold to the public. Also tetraethyl lead is not a motor fuel, and likewise is not sold to the public. The Bureau of Mines, in co6peration with the General Motors Research Corporation (later the General Motors Chemical Co.), is conducting an investigation to determine whether any public health hazards, especially lead poisoning, will result from the use of ethyl gasoline. The laboratory work is conducted at the Pittsburgh experiment station of the bureau under the direct supervision of its technical staff, and the bureau has reserved the privilege of publishing the results of the work, favorable and unfavorable. The purpose of the investigation is to determine whether there is any additional hazard to health ( I ) in breathing air which contains appreciable concentrations of exhaust gases from engines using ethyl gasoline and (2) in handling and using the raw ethyl gasoline, that is, by inhalation of the vapors or by absorption through the skin. The second phase of this work has only recently been started, and enough data have not been obtained from which to draw conclusions. Experiments have been completed on exhaust gases from engines using ethyl gasoline as commercially sold. Various types of animals were exposed for certain periods of each day to a definite concentration of exhaust gas from an engine using ethyl gasoline. These exposures were made to simulate the worst conditions, as to time of exposure and concentration of gas in the air, to which people could be exposed without being poisoned by the carbon monoxide in the exhaust gases. The tests were continued over a period of eight months, in order to bring out cumulative effects. Animals of several species, sizes, and ages were used to take care of a possible tolerance or susceptibility. Study of an additional phase, using an increased quantity of ethyl fluid in gasoline, is in progress. The apparatus used consisted of a IOOO-CU. ft. gas-tight chamber, having an anteroom or air lock for entering and leaving during the course of the test without causing changes in or escape of the gas. During the period from December 6, 1923, to April 5, I924, the chamber was ventilated by air entering through several small pipes near the bottom of the chamber and exhausted near the top of the chamber. From April 5, I924, to July 27, 1924, the air ventilating the chamber entered near the ceiling of the cham-
Feb., i925.]
U.S.
BUREAU OF MINES NOTES.
273
ber and, after a general circulation through the chamber, passed out through a duct which opened near the floor. The quantity of air circulated was that which was found necessary for diluting the exhaust gases to the test conditions. The average amount of air going through the chamber was approximately 3o,ooo cubic feet per hour, or sufficient to make one complete air change every two minutes. With the exception of animals dying from causes ascertained to be other than lead, all remained normal as to activity, growth, appetite, and general signs of health. Those that died had normal appetites and were active up to within a couple days before death, which is not in accordance with lead poisoning. This non-occurrence of lead poisoning is further substantiated by the small quantity of lead present in the exhaust gas-air mixture, together with observations on men that 75 per cent. or more of the lead coming from the exhaust is again exhaled when inhaled, leaving the remainder of less than 25 per cent. to be absorbed from the lungs and swallowed, a part of which will be further eliminated in body excretions and expectoration. The only danger of lead poisoning to the public from products of combustion from ethyl gasoline seems to be confined possibly to the mechanic who is continually cleaning carbon from motors. Although this is but a possibility, it merits precaution, although the occupation would appear to be no more hazardous than painting, lead being the common base of paints. In summing up, there has been no indication of plumbism in any of the animals used, though they were exposed for I88 days during a period of approximately eight months to exhaust gases from ethyl gasoline in concentrations with respect to lead content that are several times that allowable from the standpoint of carbon monoxide. Additional details are presented in Serial 2655, just published by the Bureau of Mines. New High-power Locomotive.--The status of steam railroad transportation may be very much modified by the introduction of a new type of locomotive stated to be capable of developing one-third more power with one-third less consumption of fuel and water. This engine was installed by the Delaware and Hudson Company. A trial trip was taken on a special train with a large number of guests, running from Albany to Colonio. The new locomotive has been named " Horatio Allen." Mr. L. F. Loree, President of the
U.S.
BUREAU OF MIXES NOTES.
27I
United States, and to indicate the principal sources of such pollution. Certain typical methods and devices in use and proposed for the separation of oil from water, and for the disposal of oily wastes from ships and industrial plants, have been studied. An attempt has also been made to point out the nature of the fire hazard resulting from oil pollution and to indicate the effect of such pollution on bathing beaches. With the aid of duly qualified government authorities, the effect of coastal oil contamination on marine and wild life has been outlined and its effects upon the public health have been briefly dealt with. Finally, a study has been made of typical oilburning vessels, in order to visualize the conditions prevailing in marine practice and to aid in an appreciation of the difficulties and problems involved in the operation of such vessels. A fuller account of the results of this investigation is contained in Serial 2658 , now available. E X H A U S T GASES FROM E N G I N E S U S I N G E T H Y L G A S O L I N E . By R. R. Sayers and A. C. Fieldner.
O~E of the outstanding problems confronting automotive engineers in attempting to construct motors of greater economy is that of eliminating the " knock " from the operation of the engine. Recent investigations of this detonation or knock in internalcombustion engines, especially of the high-compression type, have demonstrated that it can be eliminated or reduced by decreasing the reaction velocity of combustion by adding small quantities of certain compounds to the gasoline. This makes it possible to use engines of a higher compression ratio, thereby greatly increasing the mileage per gallon of gasoline consumed. The savings in fuel reserves from increasing the proportion of crude oil marketable as motor fuel and in permitting the designing of more efficient engines are obvious. Ethyl gasoline, one of the widely used anti-knock fuels, is ordinary motor gasoline to which has been added 3 c.c. of tetraethyl lead and 2 c.c. of a halogen carrier, as ethylene dibromide or trichlorethylene, or approximately o.o4 per cent. of the lead compound and o.o6 per cent. of ethylene dibromide by volume. Ethyl gasoline should not be confused with ethyl fluid, which is a mixture of concentrated tetraethyl lead and ethylene dibromide in the proper proportions for mixing with gasoline, but is not a
272
U.S.
BUREAU OF MINES NOTES.
[J.F.I.
motor fuel and is not sold to the public. Also tetraethyl lead is not a motor fuel, and likewise is not sold to the public. The Bureau of Mines, in co6peration with the General Motors Research Corporation (later the General Motors Chemical Co.), is conducting an investigation to determine whether any public health hazards, especially lead poisoning, will result from the use of ethyl gasoline. The laboratory work is conducted at the Pittsburgh experiment station of the bureau under the direct supervision of its technical staff, and the bureau has reserved the privilege of publishing the results of the work, favorable and unfavorable. The purpose of the investigation is to determine whether there is any additional hazard to health ( I ) in breathing air which contains appreciable concentrations of exhaust gases from engines using ethyl gasoline and (2) in handling and using the raw ethyl gasoline, that is, by inhalation of the vapors or by absorption through the skin. The second phase of this work has only recently been started, and enough data have not been obtained from which to draw conclusions. Experiments have been completed on exhaust gases from engines using ethyl gasoline as commercially sold. Various types of animals were exposed for certain periods of each day to a definite concentration of exhaust gas from an engine using ethyl gasoline. These exposures were made to simulate the worst conditions, as to time of exposure and concentration of gas in the air, to which people could be exposed without being poisoned by the carbon monoxide in the exhaust gases. The tests were continued over a period of eight months, in order to bring out cumulative effects. Animals of several species, sizes, and ages were used to take care of a possible tolerance or susceptibility. Study of an additional phase, using an increased quantity of ethyl fluid in gasoline, is in progress. The apparatus used consisted of a IOOO-CU. ft. gas-tight chamber, having an anteroom or air lock for entering and leaving during the course of the test without causing changes in or escape of the gas. During the period from December 6, 1923, to April 5, I924, the chamber was ventilated by air entering through several small pipes near the bottom of the chamber and exhausted near the top of the chamber. From April 5, I924, to July 27, 1924, the air ventilating the chamber entered near the ceiling of the cham-
Feb., i925.]
U.S.
BUREAU OF MINES NOTES.
273
ber and, after a general circulation through the chamber, passed out through a duct which opened near the floor. The quantity of air circulated was that which was found necessary for diluting the exhaust gases to the test conditions. The average amount of air going through the chamber was approximately 3o,ooo cubic feet per hour, or sufficient to make one complete air change every two minutes. With the exception of animals dying from causes ascertained to be other than lead, all remained normal as to activity, growth, appetite, and general signs of health. Those that died had normal appetites and were active up to within a couple days before death, which is not in accordance with lead poisoning. This non-occurrence of lead poisoning is further substantiated by the small quantity of lead present in the exhaust gas-air mixture, together with observations on men that 75 per cent. or more of the lead coming from the exhaust is again exhaled when inhaled, leaving the remainder of less than 25 per cent. to be absorbed from the lungs and swallowed, a part of which will be further eliminated in body excretions and expectoration. The only danger of lead poisoning to the public from products of combustion from ethyl gasoline seems to be confined possibly to the mechanic who is continually cleaning carbon from motors. Although this is but a possibility, it merits precaution, although the occupation would appear to be no more hazardous than painting, lead being the common base of paints. In summing up, there has been no indication of plumbism in any of the animals used, though they were exposed for I88 days during a period of approximately eight months to exhaust gases from ethyl gasoline in concentrations with respect to lead content that are several times that allowable from the standpoint of carbon monoxide. Additional details are presented in Serial 2655, just published by the Bureau of Mines. New High-power Locomotive.--The status of steam railroad transportation may be very much modified by the introduction of a new type of locomotive stated to be capable of developing one-third more power with one-third less consumption of fuel and water. This engine was installed by the Delaware and Hudson Company. A trial trip was taken on a special train with a large number of guests, running from Albany to Colonio. The new locomotive has been named " Horatio Allen." Mr. L. F. Loree, President of the