TW201433702A - A pump system for pumping light gases, as well as the use of such pump system - Google Patents

Abstract

A pump system for pumping light gases comprises a first dry-compressing pump (12) connected with the chamber to be evacuated, and a second dry-compressing pump (14) connected with the first dry-compressing pump (12). The pump system also comprises further dry-compressing pumps arranged parallel or in series with these pumps. In the interest of avoiding contamination of the light gases due to the provision of oil-sealed pumps or the provision of purge gas, these pumps are, according to the invention, dry-compressing pumps hermetically sealed against the environment so that low process pressures can be generated in the chamber (10) to be evacuated.

Description

Pump system for pumping light gases and use of the pump system [Priority Request]

The present invention claims priority to German Patent Application No. DE 20 2012 012 359.9, the entire disclosure of which is incorporated herein by reference.

The present invention relates to a pump system for pumping light gases such as helium, hydrogen or its isotopes. The invention further relates to the use of a pump system for pumping such a light gas.

When pumping light gases, these gases have problems with leakage in the pump and backflow. For example, a screw-type pump has a gap between the screw-shaped pump element and the housing so that light gas can flow back through the gap. In an attempt to prevent backflow of light gases, it is known to add a purge gas to the light gas to be pumped. It is also known to improve the inner seal of the pump by sealing the interior with a fluid such as oil. The disadvantage of using both purge gas and oil seal pumps is that the pumped light gases are contaminated. As a result, these gases must be extremely laborious to purify. Corresponding purification is technically complicated and expensive. This is particularly disadvantageous, for example, if pumped light gases are used in the circuit and are returned to the process. In this case, even the corresponding light Slight contamination of the gaseous gas can still cause adverse changes in the process. For example, when light gas enthalpy is transported in a nuclear melting experiment, even slight contamination is still disadvantageous.

It is an object of the present invention to provide a pump system for pumping light gases, thereby avoiding contamination of light gases while achieving high pumping speeds with low inlet pressure. It is a particular object of the invention to provide a pump system for pumping light gases whereby a pressure of less than 100 mbar can be achieved in the chamber to be vented. The object of the invention is in particular to achieve a sufficient pumping speed with an inlet pressure of between 100 mbar and 0.1 mbar.

According to the invention, this object is achieved by the features of the pump system as defined in claim 1 and the use of the pump system as defined in claim 12.

The pump system for pumping light gases includes a first dry compression pump. The inlet of the first pump is preferably directly connected to the chamber or vessel to be vented. The second dry compression pump is in particular directly connected to the first dry compression pump, that is to say in particular to the outlet of the first dry compression pump. Dry compression pumps are particularly screw-type or Roots pumps, where the necessary sealing of these pumps is not achieved by oil or the like, but by high precision manufacturing. The present invention is achieved in order to achieve a low process pressure in the chamber or vessel to be vented as set forth in the present invention, particularly below 100 mbar, while avoiding contamination of the pumped light gas by a purge gas or oil seal pump A dry compression pump is provided which forms a hermetic seal to resist the environment. In this context, a hermetic seal is defined as the separation of the gas mixture in the vacuum pump from the space outside the vacuum pump. Sealing prevents gas contamination from the environment So that it significantly affects the application.

Thus, according to the present invention, a gap-sealed vacuum pump is basically used. These pumps are not sealed with oil or friction/sliding seals. In particular, these vacuum pumps are screw type pumps. By using such a pump, a part of the lubricant or seal is prevented from entering the gas being conveyed.

In a preferred embodiment, a further third dry compression pump is disposed in parallel with the first dry compression pump. The third dry compression pump is also connected to the chamber or vessel to be vented. Preferably, the two dry compression screw type pumps connected in parallel with each other are connected to the second downstream dry compression screw type pump. Preferably, the two outlets of the first and third dry compression pumps are combined and commonly connected to the inlet of the second dry compression screw type pump. With the configuration of the three dry compression screw pumps, the overall pumping pressure can be further increased by a pressure of less than 100 mbar.

In an alternate embodiment, three dry compression pumps are arranged in a row behind one another to connect the second dry compression pump directly to another dry compression pump. In this way, an extremely high pump speed, in particular for hydrogen and hydrogen isotopes, can be achieved in the vessel with a low pressure of less than 100 mbar without the use of an oil seal pump or a purge gas.

Of course, the two dry compression pumps can also be configured in parallel, and then the other two dry vacuum pumps in series with the former are provided. With this configuration of a total of four dry compression pumps, very high pump speeds, especially for hydrogen and hydrogen isotopes, can be achieved at low pressures below 100 mbar.

In order to further reduce the pressure that can be achieved in the container, the last dry compression pump, ie the second or fourth dry compression pump, can be arranged as shown in the pumping direction, together with the primary pump to resist the atmosphere. give away. For example, the primary pump is a dry displacement pump, in particular a Roots pump, a Claw pump, a piston pump and/or a screw pump. According to the invention, the primary pump is designed as a dry compression pump to avoid contamination of the light gases to be pumped.

As provided by the present invention, in particular, by providing only a dry compression pump, and due to the use of the aforementioned purge gas, a light gas can be efficiently pumped by a pump that is hermetically sealed from the environment to achieve a high efficiency in the container. Low processing pressure. Since the gas is not contaminated, the trouble of cleaning can be avoided, in particular, it can be reused, for example, in the pumped gas in the circuit system.

Depending on the embodiment, it is preferred that the first and/or third pumps are directly connected to the chamber or vessel to be vented. Further, depending on the embodiment, it is preferred that the second pump is directly connected to the first and/or third pump. Moreover, it is preferred that all of the dry compression pumps used are configured as screw type pumps.

In particular, the entire pump system forms a hermetic seal to resist external systems.

With the pump of the present invention, light gases can be pumped in a very efficient manner while avoiding gas contamination. Specifically, the light gas system hydrogen, hydrogen isotope, krypton, xenon, krypton, xenon isotope or a mixture thereof.

The pump system for pumping light gases is particularly suitable for compressing light gases from a fine vacuum, i.e., from about 0.01 mbar to about 1 bar atmospheric pressure, at a sufficient effective pump speed.

The invention further relates to the use of a pump system having at least two dry compression pumps that are hermetically sealed against the environment for pumping light gases. The pump system used is advantageously implemented as described above, and in particular Pump the above light gases.

10‧‧‧ room or container

12‧‧‧First dry compression pump

14‧‧‧Second dry compression pump

16‧‧‧ pipeline

18‧‧‧ Third dry compression pump

20‧‧‧fourth dry compression pump

22‧‧‧ primary pump

The disclosure of the present invention and the versatility of the present invention which can be implemented by the present invention are described in more detail in the following description, which contains references to the accompanying drawings, in which: Figures 1 to 3 show Different schematic diagrams of the pump system.

The drawings are intended to illustrate the general aspects of the structure and are not necessarily The detailed description is shown in the drawings and the specific exemplary embodiments are described in detail herein. It is to be understood, however, that the invention is not intended to

In a first preferred embodiment, the chamber to be vented or vessel 10 is in particular directly connected to the inlet of a first dry compression pump 12 designed as a screw-type pump. The outlet of the screw-type pump 12 is connected to the intake port of the second dry compression pump, which is also designed as a screw-type pump 14 in the illustrated embodiment. The outlet of the second dry compression pump 14 can be coupled to other components of the system or via line 16 to a primary pump, not shown. Both dry compression screw pumps provided in the first embodiment are designed to be hermetically sealed against the environment.

According to the development of the embodiment shown in Fig. 1, as shown in Fig. 2, the third dry compression screw type pump 18 is disposed in parallel with the first dry compression screw type pump 12. The dry compression screw type pump 18 is directly connected to the container 10. The two outlets of the screw pumps 12, 18 are combined and subsequently snail The air inlet of the rod pump 14 is connected. Via the line 16, the outlet of the screw pump 14 is connected to the atmosphere or a primary pump (not shown).

Another preferred embodiment of the present invention shown in Fig. 3 is a combination of the embodiments shown in Figs. 1 and 2. According to this embodiment, the container 10 is directly connected to two screw-type pumps 12, 18 that are connected in parallel with each other. The outlets of the two screw-type pumps 12, 18 are combined and generally connected to the inlet of the screw-type pump 14. A further fourth dry compression pump 20, preferably also a screw type pump, is coupled to the outlet of the screw type pump 14. In the illustrated embodiment, the outlet of the fourth screw type pump 20 is coupled to a primary pump 22 that is resistant to atmospheric pumping.

In all embodiments, the screw-type pump is configured as a dry compression pump that is hermetically sealed to resist the environment. The primary pump 22 is also a dry compression pump to avoid contamination of the light gases to be pumped.

All citations in this article are submitted in full reference. In this article, there is no inconsistency between this and clear teaching.

While the invention has been illustrated and described with respect to the specific exemplary embodiments, the invention It will be apparent to those skilled in the art that the present invention may be modified and modified without departing from the true scope of the invention as defined by the appended claims. Accordingly, all such changes and modifications are intended to be included within the scope of the invention.

10‧‧‧ room or container

12‧‧‧First dry compression pump

14‧‧‧Second dry compression pump

16‧‧‧ pipeline

Claims (13)

A pump system for pumping light gas, comprising: a first dry compression pump (12) connected to a chamber to be exhausted; and a second dry compression pump (14) coupled to the first dry compression pump ( 12) Connections characterized in that the dry compression pumps (12, 14) are hermetically sealed against the environment and are not provided with a source of purge gas. The pump system of claim 1, wherein the third dry compression pump (18) is disposed in parallel with the first dry compression pump (12), and the third dry compression pump (18) is connected to the to-be-vented chamber (10) . The pump system of claim 2, wherein the first and third dry compression pumps (12, 18) are coupled to the second dry compression pump (14). A pump system according to any one of claims 1 to 3, wherein the further dry compression pump (20) is in particular directly connected to the second dry compression pump (14). The pump system of any one of claims 1 to 4, wherein the primary pump (22), particularly resistant to atmospheric pumping, is coupled to the second dry compression pump (14) or the further dry compression pump (20). The pump system of any one of claims 1 to 5, wherein the first and/or the third dry compression pump (12, 18) is directly connected to the to-be-vented chamber (10). The pump system of any of claims 1 to 6, wherein the second dry compression pump (14) is directly coupled to the first and/or the third dry compression pump (12, 18). The pump system of any one of claims 1 to 7, wherein the first and / or second and / or third and / or fourth dry compression pump is designed as a screw type Pump. The pump system of any one of claims 5 to 8, wherein the primary pump (22) is a dry displacement such as a (Roots pump, a Claw pump, a piston pump or a screw pump) Pump. The pump system of any one of claims 1 to 9, wherein the entire pump system forms a system that resists an external hermetic seal. A pump system according to any one of claims 1 to 10, wherein the light gases, in particular hydrogen, hydrogen isotopes, ruthenium, osmium, iridium, osmium isotopes and/or mixtures thereof, are pumped. A use of a pump system according to any one of claims 1 to 11 for transporting light gases from a chamber to be vented without purifying a source of gas. The use of claim 12, wherein only gas from the chamber to be vented is pumped by a vacuum pump of the pump system.