Exhaust port

“ But in the two-cycle Diesel type of engine, the high pressure of the pure air is used for scavenging, and as this is admitted with so large an initial force, the exhaust port may remain uncovered for a longer period than would be the case were the air to rely entirely on the up-stroke of the piston for its compression. ”

“ For instance, at 90° advance, the valve opens very rapidly indeed and fully satisfies our requirements of a perfect valve. This is one good point, and in this position also the exhaust and compression can be regulated very closely and as desired without much lap, and as the opening of the exhaust port comes with the eccentric at its most rapid movement the release is very quick and as we would have it. This is only possible at the most uneconomic position of the valve as regards cut off. ”

“ Although we have spoken throughout as if the eccentrics were so set in relation to the crank, and the slide valve so proportioned that the steam was all pushed out by the piston when exhausting, it should be understood that the exhaust port is closed just before the piston reaches the end of each stroke, so that a small quantity of steam is what is called 'trapped' in the cylinder. ”

“ The exhaust gases of the ordinary two-cycle motor pass out of the exhaust port as it is uncovered by the descent of the piston. Those that remain are forced out by the sudden admission of the fresh charge, which is deflected upward and is intended to scavenge the top of the cylinder. But it is claimed that thus employing the fresh mixture as a scavenging agent is162 wasteful of the fuel-permeated charge and does not conduce to efficient running. The system is simple in the extreme, however, and does its work well in small installations in which fuel economy is not of vital importance. ”

“ In designing a slide-valve the breadth of the steam ports in the direction of the valve’s motion- is determined with reference to the volume of the exhaust steam to be discharged in a given time the area of the ports being generally such that the mean velocity of the steam during discharge is less than 100 ft. per second The travel is made great enough to keep the cylinder port fully open during the greater part of the exhaust ”

“ The valve-ring, D, is so arranged, in regard to the ports, that the movement of the piston to the lowest point moves the valve-ring down, and closes the exhaust and opens the inlet-port. When the piston moves to the other end of the stroke, the ring is moved in the other direction, and the inlet is closed and the exhaust is opened. K is the inlet passage. L is the exhaust passage. m is a small opening into the exhaust passage to allow any steam which may pass the piston to escape. ”

“ Exhaust System. The exhaust system consists of muffler and tailpiece assembly, front exhaust pipe assembly, and rear exhaust pipe. Exhaust pipe ends are a slip fit in cylinder exhaust ports.
76. AIR CLEANER (figs. 46 and 47) . a. General. Air cleaner should not be submerged in water, nor should high‐pressure stream be directed into cleaner louvers (where air enters on rear of body) when cleaning vehicle. Either water or dirt entering air cleaner in excessive quantities will raise the oil level in oil cup and choke off proper air supply to carburetor. ”

“ The proportion of cross-section area to the stroke being fifty per cent. greater than in my table of sizes increased in the same degree the proportion of waste room to the piston displacement. I felt that there was need here for improvement. By far the greatest amount of waste room was in the exhaust ports. I accepted a modification of the exhaust valves by which this item of the waste room was reduced fully one half and made a new pair of cylinders for this engine. The improvement in the economy was so marked that I determined to change the exhaust valves of all the engines. ”

“ The exhaust occurs through the valve chamber, which, at each stroke, puts the large cylinder in connection with the eduction port, M.
The volume of air included between the two pistons is displaced at every stroke, so that, according to the position occupied by the pistons, it is held either by the large or small cylinder. The necessary result of this is that a compression of the air, and consequently a resistance, is brought about. In order to obviate this inconvenience, the constructor has connected the space between the two pistons at the part, A', of the frame by a bent pipe. ”

“ Exhaust Piping
From each atmospheric exhaust valve, which is direct-connected to the condensing chamber at each low-pressure cylinder, is run downward a 30-inch riveted-steel exhaust pipe. At a point just under the engine-room floor the exhaust pipe is carried horizontally around the engine foundations, the two from each pair of engines uniting in a 40-inch riser to the roof. This riser is between the pair of engines and back of the high-pressure cylinder, thus passing through the so-called pipe area, where it also receives exhaust steam from the pump auxiliaries. ”

“ The deterioration of piston-packing, and the rounding of valve-seats, which produce an asthmatic exhaust, may be followed in their downward course if the engineer gets into the habit of listening to the exhaust, and marking its changes. It is very important that he should do so. The man whose ear from long practice has become sensitive to a false tone of the exhaust, needs not to make experiments, by applying steam to the engine while it stands in various positions, in order to find out where a blow comes from,—whether it is in the pistons or in the valves. ”

“ These exhaust valves allow any water of condensation to run out of the cylinder. Moreover, as the steam when it leaves the cylinder is much colder than when it enters, the exhaust always cools the steam ports, and when the same ports are used for exhaust and admission the fresh steam has to pass through ports that have been cooled and cause condensation. In the Corliss engine the exhaust does not have an opportunity to cool the live steam ports and the condensation is reduced. This works considerable economy. ”

“ The ability to detect a slight derangement by the sound of the exhaust, can only be acquired by practice in watching those steam-notes day after day, as they play their tune of labor through the smoke-stack. When the steam-ports are even, and the valves correctly set, with tight piston-packing, and valves free from leaks, the notes of the exhaust will sound forth in regular succession in sharp, ringing, clear tones, every puff seeming to cut the steam clean off at the top of145 the stack. ”

“ When the exhaust steam is used to feed the boiler, do not open the valve that lets the exhaust steam into the feed-water tank until a little while after the engine has started, because the oil fed to the cylinder will otherwise pass into the feed tank and may cause priming. ”

“ Drivers should know by the ‘feel’ of their engine whether it is firing correctly or not, and any member of a crew ought to be able to detect and report at once any irregularity in the sound of an exhaust from outside the machine. ”

“ It is easy to tell by the sound of the exhaust if the ports are rightly proportioned, and whether running at high or low speed, the engine should give a clear and distinct exhaust at every stroke of the piston. ”

“ In the [Pg 21] engine house four of Beal's exhausters occupy prominent positions, they are used to exhaust or suck the gas from the retorts and afterwards force it through the vessels for purification; two of these driven by engines of 20 horse power work 150,000 cubic feet per hour each. Two driven by engines of 12 horse power work 100,000 per hour each. Attached to the inlet of each exhauster is one of Wright's exhauster governors, it is made on the principle of pressure or suction elevating or depressing a light cylinder working in a water-lute of sufficient depth. ”

“ In regard to the question of relative economy of the two systems, we will say that when long tubes are used, requiring high pressures, or, more strictly speaking, a large difference of pressure, to maintain the desired velocity of air-current, there seems to be some advantage in using an exhaust system. The reason is this: the friction of the air in the tube, which absorbs most of the power, increases as the air becomes heavier and more dense. ”

“ In some central stations, as at Findlay, Ada, and Springfield, Ohio, the exhaust steam is utilized for district heating, so that the generation of motive power is merged into the larger field of fuel economy treated as a whole. ”

“ Allowing all loss of weight aboard ship during a cruise, and which never exceeds twenty tons, we can always decrease our buoyancy and sink to the bottom, if necessary. Now, here,” pointing to the left, and along the walls of the vessel, “are the dynamos for the electric lights, fans for circulating the fresh air, steering apparatus, electric heaters, exhaust pumps for expelling the vitiated air and drawing in the fresh, and many other inventions, the uses of which you can learn at your leisure.”
The engine-room of the Tracer was indeed a curiosity-shop to Junius Cobb. ”

“ Again we make large exhaust valves and provide a free escape through the silencer for the exhaust gases, so that when we have snatched our useful one-third of the heat supply we may throw the remainder away into the atmosphere as rapidly as possible.—this part is of no use to us, we cannot turn it into work, then why let it stay here and heat our cylinder walls and piston still further? ”

“ We have just set up a new engine; the cylinder is 8 x 12, has a common slide valve. We think the valve is too short; it is set 0.125 inch open when on center, takes steam 10 inches before cutting off; the exhaust is very free. The engine runs about 110 revolutions per minute. We think we could save steam by using a longer valve, and cut-off about 5⁄8 stroke, and make the exhaust space in the valve shorter, so that it will shut in a portion of the exhaust and form a cushion for the piston. ”

“ Air handler, air supply and exhaust fans, ducting, steam separator, diesel generator and heat exchanger, switch gear, main circuit breakers, motor control center, shower and eyewash, two blast valves (intake and exhaust) , control station for retractable platforms on levels 3 and 4, manhole to hard storage tank, and retractable platform hydraulic power valve panel. Level 4. Exhaust fan, air washer and water tank, two blast valves (air intake and exhaust) , retractable platform hydraulic power valve panel, and silo blast valve control station. ”

“ If the secondary circuit is proven to be in good condition, attention should be paid to the carburetor, for a poor mixture, or water in the gasoline, will cause the engine to miss. A badly fitting exhaust valve will permit the burned gases to be drawn back into the cylinder, the fresh charge thus being weakened, and as the valve will shift around on its seat, this may happen irregularly. ”

“ As will be seen, the exhaust valves lay with their backs towards the cylinder, worked under the pressure of the steam in the cylinder, made four openings for release and exhausted through the cover.
I consented to the change in Philadelphia because this arrangement involved too much waste room, but the change was not satisfactory after all. I had become possessed with the idea that the engine running at high speed needed 50 per cent. more room for exhausting than for admission. ”

“ The governor to shut off steam and apply the brakes when any determined speed is attained is actuated either by the engine wheels or by an independent wheel to prevent the possibility of the brakes being put on when the driving-wheels slip. An effectual way of rendering the exhaust steam invisible is to condense it by passing it through water in a tank, or through a shower of water let off at each blast, but when the water gets hot it must be changed, and in streets it is difficult to get rid of the hot water. ”

“ The Exhaust Nozzle, as generally constructed, is an elbow attached to the end of the exhaust pipe in the smoke box or smoke stack of the boiler, the end of which points upward, with the opening reduced so that the exhaust steam will be forced up the stack, and thereby produce the same effect as a blower. ”

“ The leakage that passes into the exhaust will be seen escaping from the stack while it is practically impossible to have the valves absolutely tight at all times, the steam should not escape so rapidly that it roars through the openings. ”

“ The exhaust pipe from the engine which conducts off the exhaust gases after they have done their work in the cylinder is connected to a peculiarly constructed chamber, called a Silencer, attached to the frame of the car. ”

“ The exhaust steam passes down to a jet condenser, provided with a supply of water from a containing tank, from which the injection is admitted through a regulating valve. The air pump, which draws the air and water from the condenser and discharges them through a pipe passing out at the end of the tank, is a rotary machine constructed like the engine and driven by spur gearing from the fly-wheel shaft. Some efforts have been made to prevent leakage [121] by forming grooves in the sides of the revolving piston and filling them with soft packing. ”