Blastpipe

A blast pipe, the functioning according to the principle of a steam jet blower exhaust installation of a boiler, in particular for steam engines, respectively.

General

The exhaust installation is the heart of a steam locomotive: It drives metabolism, burning and convective heat transfer in the boiler and regulates the boiler output according to the needs of the steam engine. Thus, in comparison to stationary steam engines high performance of the locomotives is at all possible. For the exhaust installation spends a significant part of the expansion energy of the steam power process that 's going back on the effective Lokleistung. , The proportion of the power density of the boiler to be proportional, such that the efficiency of the exhaust installation is of particular importance in order to achieve an efficient and economic engine. The actual execution is therefore always a compromise.

As the investment in heat, dirt and corrosive media must work to turbo blower, despite better efficiency against the rugged blowguns can not enforce.

Operation

The blowing medium for blasting the exhaust steam from the locomotive cylinders used. This is passed into the nozzle-like blast pipe, which is vertically at a certain distance under the chimney ( flue ) in the smoke chamber. The blow pipe axis and the chimney axis must coincide exactly. The chimney widened slightly tapered towards the top and is the blowpipe diameter adapted to its diameter, that the flowing out of the blow-pipe exhaust steam up the chimney to the top fully covers approximately from the center out. The effluent vapor then exerts on the environment of the blow pipe suction from. As the smoke chamber is closed completely airtight, generates the absorbent vapor flow in the smoke chamber a vacuum that now nachsaugt air on the only remaining free lasting way, namely by the louver ashtray door, the grate, fire layer and the heating and smoke tubes into the smoke chamber. The air flowing through the ash pan air to the fuel bed to the necessary oxygen for combustion.

Is particularly advantageous in the fact that the suction and thus the fanning of the fire is greater, the more steam is consumed for driving. Thus, it is possible ( within certain limits ), already incorporate to supply ' fuel to the boiler, and when the additional energy is required only later, so that the heater can be greatly relieved may.

When you stop the locomotive and the kindling of the fire of suction can be generated with the auxiliary blowers.

History

The blowpipe in 1801 by Richard Trevithick, the British pioneer of steam locomotive technology, invented and first installed in his steam car. A little later translated by Timothy Hackworth and George Stephenson this technique in their locomotives, where it is unclear whether they had knowledge of Trevithick's invention or they developed independently. In the further course of blowguns were the standard for almost all steam locomotives. The system remained largely unchanged for almost 100 years.

From about 1900 there were tendencies to improve the efficiency and performance of the blow pipe to reduce the back pressure for the cylinder to achieve maximum energy efficiency for the drive and at the same time to get the best possible vacuum in the smoke chamber. For this, the blowguns were made ​​to be adjustable, and uses a variety of variants of series and parallel connection of jet blowers:

• Kylchap the Finnish engineer Kylälä and the French engineer André Chapelon
• Lemaître - blowpipe, Lempor and Lemprex by Jean Lemaître and Livio Dante Porta
• Giesl ejector by Dr. Adolph Giesl - Gieslingen

In the condensation locomotive finally the blower tube was replaced by a fan with steam turbine drive. The exhaust steam from the cylinder was condensed and thus recovered to replenish the water supply, take him to blow into the atmosphere. Thereby, the water consumption has been minimized and the energy efficiency is maximized.

• Steam locomotive technology
• Exhaust Technology
• Jet pump