1. A method of forming a stent comprising the steps of:
utilizing an elongated composite member including an outer member and a core member disposed within a lumen of the outer member;
shaping the composite member into a stent pattern including a waveform having a plurality of struts interconnected by crowns;
forming openings through the outer member;
after the step of shaping the composite member into the pattern, processing the composite member such that the core member is removed from at least a plurality of the struts of the waveform without adversely affecting the outer member and such that the core member is not removed from at least a plurality of the crowns of waveform, thereby leaving the outer member with a lumen in at least a plurality of the struts and the outer member with the core member in at least a plurality of the crowns.
2. The method of claim 1, further comprising the step of filling the lumens with a biologically or pharmacologically active substance after the core member has been removed.
3. The method of claim 2, wherein the biologically or pharmacologically active substance is selected from the group consisting of antineoplastic, antimitotic, antiinflammatory, antiplatelet, anticoagulant, anti fibrin, antithrombin, antiproliferative, antibiotic, antioxidant, and antiallergic substances as well as combinations thereof.
4. The method of claim 1, wherein the step of processing the composite member comprises exposing the composite member to an etchant that reacts with the core member to remove the core member, wherein the etchant does not react with the outer member.
5. The method of claim 4, wherein the etchant is a liquid chemical that dissolves the core member.
6. The method of claim 5, wherein the etchant is a gas.
7. The method of claim 6, wherein the outer member is formed from MP35N, the core member is formed from one of tantalum, tungsten, molybdenum, niobium, rhenium, carbon, germanium, and silicon, and the etchant is xenon difluoride.
8. The method of claim 4, wherein the core member is soluble in the etchant and the outer member is not soluble in the etchant.
9. The method of claim 1, wherein the core member is removed from all of the struts.
10. The method of claim 1, wherein the core member is not removed from any of the crowns.
11. The method of claim 1, wherein the core member is more radiopaque than the outer member.
12. The method of claim 1, further comprising the step of removing a portion of the core member in the at least a plurality of crowns with the core member remaining such that a lumen is provided through the crowns while a portion of the core member remains in the crowns.
13. A method of forming a stent comprising the steps of:
utilizing a plurality of elongated composite members, each composite member including an outer member and an inner member disposed within a lumen of the outer member;
shaping each composite member into a waveform having a plurality of struts interconnected by crowns;
wrapping each waveform into a cylindrical element;
aligning the cylindrical elements along a common longitudinal axis and joining the cylindrical elements together to form a tubular stent;
forming openings through the outer members;
after the step of shaping the composite members into a waveform, processing the composite members such that the inner member is removed from at least a plurality of the struts of the waveform without adversely affecting the outer member and such that the core member is not removed from at least a plurality of the crowns of the waveform, thereby leaving the outer member with a lumen in at least a plurality of the struts and the outer member with a core member in at least a plurality of the crowns.
14. The method of claim 13, further comprising the step of filling the lumens with a biologically or pharmacologically active substance after the core member has been removed.
15. The method of claim 14, wherein the biologically or pharmacologically active substance is selected from the group consisting of antineoplastic, antimitotic, antiinflammatory, antiplatelet, anticoagulant, anti fibrin, antithrombin, antiproliferative, antibiotic, antioxidant, and antiallergic substances as well as combinations thereof.
16. The method of claim 13, wherein the step of processing the composite member comprises exposing the composite member to an etchant that reacts with the core member to remove the core member, wherein the etchant does not react with the outer member.
17. The method of claim 16, wherein the etchant is a liquid chemical that dissolves the core member.
18. The method of claim 17, wherein the etchant is a gas.
19. The method of claim 18, wherein the outer member is formed from MP35N, the core member is formed from one of tantalum, tungsten, molybdenum, niobium, rhenium, carbon, germanium, and silicon, and the etchant is xenon difluoride.
20. The method of claim 16, wherein the core member is soluble in the etchant and the outer member is not soluble in the etchant.
21. The method of claim 13, wherein the core member is removed from all of the struts.
22. The method of claim 13, wherein the core member is not removed from any of the crowns.
23. The method of claim 13, wherein the core member is more radiopaque than the outer member.
24. The method of claim 13, further comprising the step of removing a portion of the core member in the at least a plurality of crowns with the core member remaining such that a lumen is provided through the crowns while a portion of the core member remains in the crowns.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A device for cooling a coolant in a gas turbine, comprising:
a plurality of interconnected evaporator tubes arranged in a coolant channel connected to the gas turbine to accommodate a flow of the coolant and to provide a forced through-flow steam generator, whereby the coolant evaporates completely in the evaporator tubes in a single pass through the evaporator tubes and each of the evaporator tubes has internal fins and the coolant channel is designed for direct flow of the coolant for the gas turbine in an substantially horizontal direction, an longitudinal axis of the evaporator tubes substantially aligned in a vertical direction.
2. The device according to claim 1, wherein compressor air from the gas turbine is applied to the coolant channel.
3. The device according to one of claim 1, wherein the flow medium is applied to the evaporator tubes via a supply line preceding them on the inlet side, wherein mechanisms to select the throughflow rate of the flow medium are connected to the supply line.
4. The device according to claim 3, wherein the means of setting the throughflow rate of the flow medium include a flow restrictor connected to the supply line.
5. The device according to claim 2, wherein the flow medium is applied to the evaporator tubes via a supply line preceding them on the inlet side, wherein means to select the throughflow rate of the flow medium are connected to the supply line.
6. The device according to claim 1, wherein the forced throughflow steam generator functions by using heat produced while cooling the coolant to generate high quality steam.
7. A gas and steam turbine, comprising:
a device for a coolant cooling of a gas turbine, in which a number of interconnected evaporator tubes are arranged in a coolant channel connected to the gas turbine for a flow medium for a formation of a forced throughflow steam generator, whereby the flow medium is adapted to evaporate completely in the evaporator tubes in a single operation;
a waste heat steam generator connected to an exhaust gas side of the gas turbine, wherein the heating surfaces are connected to a water-steam circuit of the steam turbine; and
a supply line connecting the evaporator tubes on the inlet side to the feedwater train of the water-steam circuit of the steam turbine,
wherein the supply line is connected on the inlet side via a first partial flow line to a first partial component of the feedwater train preceding a feedwater preheater and via a second partial flow line to a second partial component of the feedwater train downstream of the feedwater preheater.
8. The gas and steam turbine according to claim 7, wherein the evaporator tubes of the device assigned to the gas turbine for coolant cooling are connected on the outlet side to a high-pressure stage of the water-steam circuit.
9. The gas and steam turbine according to claim 7, wherein in each of the first and second partial flow lines, mechanisms of setting the throughflow rate of the respective partial flow are connected to flow medium to which a control system is assigned, via which the flow ratio of the partial flows is adjustable in the partial flow lines as a function of a characteristic value for a temperature value of the coolant to be cooled.
10. A device for cooling a coolant in a gas turbine, comprising:
a plurality of interconnected evaporator tubes arranged in a coolant channel connected to the gas turbine to accommodate a flow of the coolant and to provide a forced through-flow steam generator, whereby the coolant evaporates completely in the evaporator tubes in a single pass through the evaporator tubes and at least some of the evaporator tubes have internal fins and the coolant channel is designed for direct flow of the coolant for the gas turbine in an substantially horizontal direction, an longitudinal axis of the evaporator tubes substantially aligned in a vertical direction.