1. A process for treating a crude containing natural gas, which process comprises:
(a) supplying the crude to a stabilization unit to obtain a gaseous stream and crude oil;
(b) cooling the gaseous stream at an elevated pressure and supplying the gaseous stream at a low temperature to the bottom of a first column;
(c) removing from the top of the first column a first gaseous overhead stream, partly condensing the gaseous overhead stream, separating the liquid phase from the partly condensed overhead stream to obtain a methane-rich stream, returning the liquid phase to the top of the first column and supplying the methane-rich stream to a liquefaction plant;
(d) removing a bottom stream from the first column, allowing the bottom stream to expand to a lower pressure, and supplying the expanded bottom stream at a low temperature to the top of a second column;
(e) removing from the top of the second column a second gaseous overhead stream, and removing from the bottom of the second column a liquid bottom stream;
(f) vaporizing part of the liquid bottom stream and introducing the vapour into the bottom of the second column; and
(g) introducing the remainder of the liquid bottom stream into a crude oil stream at an appropriate point in or upstream of the stabilization unit, wherein the amount of heat removed from the first gaseous overhead stream is so adjusted that the concentration of C5 in the first gaseous overhead stream is below a predetermined value, and wherein the fraction of the liquid bottom stream from the second column that is vaporized is so selected that the concentration of C2 in the liquid bottom stream is below a predetermined level.
2. The process of claim 11, wherein the elevated pressure in step (b) is in the range of from 4 to 7 MPa, and wherein the low temperature is in the range of from 10 to 20 C.
3. The process of claim 1, wherein the expanded bottom stream in step (d) is supplied to the top of a second column at a temperature that is below the low temperature in step (b).
4. The process of claims 1 wherein the lower pressure in step (d) is in the range of from 2.5 to 3 MPa, and wherein the low temperature is in the range of from 20 to 40 C.
5. The process of claim 2 wherein the expanded bottom stream in step (d) is supplied to the top of a second column at a temperature that is below the low temperature in step (b).
6. The process of claim 2 wherein the lower pressure in step (d) is in the range of from 2.5 to 3 MPa, and wherein the low temperature is in the range of from 20 to 40 C.
7. The process of claim 3 wherein the lower pressure in step (d) is in the range of from 2.5 to 3 MPa, and wherein the low temperature is in the range of from 20 to 40 C.
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 method of manufacturing a thin-film magnetic head that works a part to be worked of an object to be worked to a target length by carrying out an etching process on the part to be worked using an etching apparatus, the method of manufacturing comprising:
a measuring process that measures a length before working of a part to be worked using a measuring apparatus; and
a calculation process that calculates a processing time of the etching process required to work the part to be worked from a length before working to the target length based on a first calculation result correcting parameter obtained in advance corresponding to the measuring apparatus, a second calculation result correcting parameter obtained in advance corresponding to a position of the part to be worked, a third calculation result correcting parameter obtained in advance corresponding to a value of a current supplied to an electrode of the etching apparatus during the etching process, a fourth calculation result correcting parameter obtained in advance corresponding to a total usage time of the electrode, the length before working, and the target length,
wherein the etching process is carried out on the part to be worked of the object to be worked for the calculated processing time.
2. A method of manufacturing a thin-film magnetic head according to claim 1, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
3. A method of manufacturing a thin-film magnetic head according to claim 1, wherein when the part to be worked has been formed of a predetermined material out of a plurality of types of material, the processing time is calculated during the calculation process using a fifth calculation result correcting parameter corresponding to the predetermined material out of a plurality of the fifth calculation result correcting parameters that are obtained in advance for the plurality of types of material.
4. A method of manufacturing a thin-film magnetic head according to claim 3, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
5. A method of manufacturing a thin-film magnetic head according to claim 1, wherein when the length before working has been measured during the measuring process for a predetermined part to be worked out of a plurality of the parts to be worked, the processing time is calculated during the calculation process using a second calculation result correcting parameter corresponding to the predetermined part to be worked out of a plurality of the second calculation result correcting parameters that are obtained in advance for the plurality of the parts to be worked.
6. A method of manufacturing a thin-film magnetic head according to claim 5, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
7. A method of manufacturing a thin-film magnetic head according to claim 5, wherein when the part to be worked has been formed of a predetermined material out of a plurality of types of material, the processing time is calculated during the calculation process using a fifth calculation result correcting parameter corresponding to the predetermined material out of a plurality of the fifth calculation result correcting parameters that are obtained in advance for the plurality of types of material.
8. A method of manufacturing a thin-film magnetic head according to claim 7, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
9. A method of manufacturing a thin-film magnetic head according to claim 1, wherein when the length before working has been measured during the measuring process using a predetermined measuring apparatus out of a plurality of the measuring apparatuses, the processing time is calculated during the calculation process using a first calculation result correcting parameter corresponding to the predetermined measuring apparatus out of a plurality of the first calculation result correcting parameters that are obtained in advance for the plurality of the measuring apparatuses.
10. A method of manufacturing a thin-film magnetic head according to claim 9, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
11. A method of manufacturing a thin-film magnetic head according to claim 9, wherein when the part to be worked has been formed of a predetermined material out of a plurality of types of material, the processing time is calculated during the calculation process using a fifth calculation result correcting parameter corresponding to the predetermined material out of a plurality of the fifth calculation result correcting parameters that are obtained in advance for the plurality of types of material.
12. A method of manufacturing a thin-film magnetic head according to claim 11, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
13. A method of manufacturing a thin-film magnetic head according to claim 9, wherein when the length before working has been measured during the measuring process for a predetermined part to be worked out of a plurality of the parts to be worked, the processing time is calculated during the calculation process using a second calculation result correcting parameter corresponding to the predetermined part to be worked out of a plurality of the second calculation result correcting parameters that are obtained in advance for the plurality of the parts to be worked.
14. A method of manufacturing a thin-film magnetic head according to claim 13, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.
15. A method of manufacturing a thin-film magnetic head according to claim 13, wherein when the part to be worked has been formed of a predetermined material out of a plurality of types of material, the processing time is calculated during the calculation process using a fifth calculation result correcting parameter corresponding to the predetermined material out of a plurality of the fifth calculation result correcting parameters that are obtained in advance for the plurality of types of material.
16. A method of manufacturing a thin-film magnetic head according to claim 15, wherein when the part to be worked is worked to a predetermined worked shape out of a plurality of types of worked shape during the etching process, the processing time is calculated during the calculation process using a sixth calculation result correcting parameter corresponding to the predetermined worked shape out of a plurality of the sixth calculation result correcting parameters that are obtained in advance for the plurality of types of worked shape.