Data on several standard diffusion pumps indicate that the speed for hydrogen may be con&iderably less than times the rated speed for air depending on the. Sprengel's mercury dropping pump (Chemistry World, February , p67) changed things By then Gaede was studying diffusion in gases. (Cl. ) ABSTRACT OF THE DISCLOSURE An all-metal mercury diffusion pump capable of withstanding high baking temperatures and including an.


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The oil is also relatively safe from the standpoint of toxicity and flammability. The only caution when using silicone oil is that it must not be exposed to air when it is heated or the oil will gel.

Silicone Diffusion Pump Oil Silicone oil was not always the fluid of choice, however. In the early days, diffusion pumps used mercury as the operating fluid. As you might imagine, such a thing would be frowned upon today mercury diffusion pump to the toxicity of mercury vapors.

Today, the use of mercury in diffusion pumps is essentially zero. To replace mercury, hydrocarbon oils were used as the working fluid. These had two major drawbacks.

The Theory of the Mercury-Vapour Vacuum Pump and a New High-Speed Pump - IOPscience

They were not always made from a single component or the oil would break down into lighter fractions during use. He won many awards but never worked again. Gaede died inbut he had one last ace in mercury diffusion pump sleeve - the idea of a ballast valve for oil pumps.

Published posthumously, it suggested that flushing air through the oil would free it of emulsified moisture. No rotary pump today is without one. So when, from time to time, I find myself in the rush-hour crush, my thoughts turn to Gaede and his miraculous pumps.

Diffusion pump - Wikipedia

Andrea Sella is a lecturer in inorganic chemistry at University College London. All mercury diffusion pump groups using these pumping stations report that they produce lower ultimate vacuum and faster pumping speeds than other glass diffusion pump designs.

Mercury diffusion pump traditional glass diffusion pumps have advertised pumping speeds of 7 to 30 liters per second. The 4" pump operates at liters per second.

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The outside of the diffusion pump is cooled using either air flow or a water line. As the vapor jet hits the outer cooled shell of the diffusion pump, the working fluid condenses and is recovered and directed back to the boiler. The pumped gases continue flowing to the base of the pump at increased pressure, flowing out through the diffusion pump outlet, where they are compressed to ambient pressure by mercury diffusion pump secondary mechanical forepump and exhausted.

Although incidental elements of the apparatus are composed of Kovar or Pyrex, mercury diffusion pump all practical purposes, the pump is defined as an all-metal pump.

The pump can withstand heating to temperatures in excess of C.

The geometry of the jet assembly and the incorporation of a highly efficient annular water jacket of radically different design greatly extend the low pressure capability of the pump.

Moreover, a glass segment is provided in the return line to permit mercury diffusion pump of the condensate return action and a glass port in mercury diffusion pump boiler enclosure of the pump permits viewing of the surface of the pumping fluid.

Specific design features such as the incorporation of an isolation chamber between the manifold and the boiler and the interposition of an expansion diaphragm between the pump barrel and the annular Water jacket implement the efficient operation of the pump.

Perhaps the key component of the pump is the manifold, to the top of which the water jacket and jet assembly are welded in such a fashion that the manifold is well-cooled during normal pump operation.

The annular base of the water jacket substantially surrounds the manifold, being mercury diffusion pump only by a plug in the water jacket through which a passage is formed. Portions of the condensate return line and the fore-vacuum line are combined in the walled passage through the water jacket whereby the dual-purpose line is cooled.


The fore-vacuum line is continued through an annular passage external to the water jacket which lengthens the cooling path. For a better understanding of the present invention together with other and further objects, features and advantages, reference should be made to the following specification which should be read in conjunction with the appended drawing in which: The flange may be of the type known as a Conflat flange and it is Welded to a pump barrel The barrel mercury diffusion pump preferably made of low-carbon stainless steel as are all other elements of the mercury diffusion pump with the exception of those specifically noted as being of other materials.

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Also, all welded joints between mating elements are made by Heliarc and, wherever practical, within an inert atmosphere Welding chamber filled with a gas such as argon.