Sorption pump with mechanical activation of getter material and process for capturing of active gases

Abstract

A sorption pump working according to the principle of mechanical activation of reactive getter materials at ambient temperature is presented. Pumps of the given type allow maintaining vacuum in different devices and apparatuses by sorption of any active gases with a controllable rate.

1 . A sorption vacuum pump, comprising:
 a gas impermeable casing with a reaction zone;   ports for connecting to the vacuum system;   a disintegrator, the constituents of which are a mechanical milling tool ( 3 ,  4 );   an ingot of a reactive alloy in a tube container;   an actuator as a source of mechanical energy;   a collector for collecting cut particles of the reactive alloy, preferably connected with the casing; and   a feedthrough transferring the motion from the actuator to the milling tool without breaking the hermiticity of the pump and sorbing at room temperature with a controlled pumping speed all active gases due to mechanochemical activation of the reactive alloy.   
     
     
         2 . The sorption vacuum pump according to  claim 1 , where the ingot is obtained by the method of vertical directional solidification of a melt of a metal alloy in a stationary regime leading to the formation of a monolithic solid product with a constant composition lengthwise. 
     
     
         3 . The sorption vacuum pump according to  claim 2 , where for the production of ingots of the reactive alloy a melt with a high concentration of an alkali or an alkaline-earth metal, with a high concentration of lithium and/or barium, or a melt with a ternary or polynary composition of these metals, is used. 
     
     
         4 . The sorption vacuum pump according to  claim 2 , for which the ingots of the reactive alloy are grown from the melt, the composition of which satisfies one of the following concentration ranges: Ba x Ag 1-x , where 0.60<x<0.78, Ba x Mg 1-x , where 0.33<x<0.65, Ba x Zn 1-x , where 0.67<x<0.75; Ba x Ga 1-x , where 0.54<x<0.92, Ba x Ge 1-x , where e 0.67<x<0.96, Ba x Si 1-x , where 0.50<x<0.87; Li x Mg 1-x , where 0.23<x<0.30, Li x Ba 1-x , where 0.80<x<0.90, or Li x Pd 1-x , where 0.67<x<0.93. 
     
     
         5 . The sorption vacuum pump according to  claim 4 , where the mechanochemical activation is carried out by cutting or scratching off thin surface layers or particles of the ingot and pushing the formed powder into the reaction zone of the pump. 
     
     
         6 . The sorption vacuum pump according to  claim 5 , where the mechanochemical activation of the reactive alloy takes place under the influence of two forces, viz. the force which presses the cutting edges of the tool to the ingot surface, and the force which causes the motion of the cutting edges of the milling tool perpendicular to the axis of the ingot or alternatively, wherein the ingot is moved over the fixed cutting tool. 
     
     
         7 . The sorption vacuum pump according to  claim 6 , where the size of the powder particles is varied—depending on the milling regime—in the range from approximately 1 μm to several hundreds of microns. 
     
     
         8 . The sorption vacuum pump according to  claim 7 , where the control over the pumping speed is executed by changing the rate of the milling of the ingot. 
     
     
         9 . The sorption vacuum pump according to  claim 8 , where the pumping speed is regulated by aid of a feedback system, including a gas analyzer measuring the parameters of the state of the gas phase in the vacuum chamber, and a controller converting the gas analyzer data into commands controlling the work of the actuator. 
     
     
         10 . The sorption vacuum pump according to  claim 9 , where the sorbed active gases or vapors or gases of lower activity include gases or vapors selected from the group consisting of hydrogen, oxygen, nitrogen, the halogens, hydrogen halides, carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides, water, hydrogen sulfide, ammonia, methane, heptane, and other common gaseous components or mixtures thereof. 
     
     
         11 . A process of controlled pumping down of a vessel at room temperature by removing any active gases or vapors and gases of lower activity by a reactive alloy, which is activated by its mechanical milling directly in the medium of the gases to be sorbed, in which process a sorption vacuum pump according to  claim 1  is used. 
     
     
         12 . The pumping down process according to  claim 11 , where the control over the speed of pumping the gases is achieved by changing the rate of milling of a monolithic ingot of a reactive alloy. 
     
     
         13 . The pumping down process according to  claim 12 , where the control over the speed of pumping the gases is achieved in a programmed way using feedback tracking of the state of the gas phase in the vacuum chamber and regulating the work of the actuator. 
     
     
         14 . The pumping down process according to  claim 13  where the sorbed active gases or vapors include gases or vapors selected from the group consisting of hydrogen, oxygen, nitrogen, the halogens, hydrogen halides, carbon monoxide, carbon dioxide, sulfur dioxide, nitrogen oxides, water, hydrogen sulfide, ammonia, methane, heptane, and other common gaseous components or mixtures thereof.