1. A liquefied natural gas container comprising;
a loadbearing structure (11, 111) and an impermeable and thermally insulated tank designed to contain liquefied natural gas, said tank comprising a plurality of tank walls fixed to said loadbearing structure,
each tank wall having in succession, in a direction of thickness along the longitudinal direction of the tank wall, proceeding from an inside of said tank to an outside, a primary impermeable barrier, a primary thermally insulating barrier, a secondary impermeable barrier and a secondary thermally insulating barrier,
said tank walls comprising at least one vertical wall, the secondary impermeable barrier located on said vertical wall comprising a first impermeable sheet (16, 116) at the top of said vertical wall and a connecting device which impermeably connects said first impermeable sheet (16, 116) to said loadbearing structure (11, 111),
wherein said connecting device comprises a first metal plate (22, 122) parallel to said first impermeable sheet (16, 116) and a second impermeable sheet (17, 117),
wherein the second impermeable sheet (17, 117) comprises a first portion which is bonded to said first impermeable sheet (16, 116) and a second portion which is connected to said first metal plate (22, 122), the first portion and the second portion of the second impermeable sheet (17, 117) being parallel.
2. The liquefied natural gas container according to claim 1, wherein said second impermeable sheet (17, 117) is flexible, and has an unbonded zone between the first impermeable sheet (16, 116) and the first metal plate (22, 122).
3. The liquefied natural gas container according to claim 1, in which a third impermeable sheet (23, 123) is bonded to said first metal plate (22, 122), and
said second impermeable sheet (17, 117) is bonded to said third impermeable sheet (23, 123).
4. The liquefied natural gas container according to claim 1, wherein said first metal plate (22, 122) is welded to a metal component (21, 121) connected to the loadbearing structure (11, 111).
5. The liquefied natural gas container according to claim 4, wherein said metal component (21, 121) has a vertical part (29, 129) and a horizontal part (30, 130),
the first metal plate (22, 122) is welded to the vertical part (29, 129), and
the horizontal part (30, 130) is connected to the loadbearing structure (11, 111).
6. The liquefied natural gas container according to claim 1, wherein said first impermeable sheet (16, 116) is bonded to a layer of insulating material (15) or to a plate of plywood (132) forming part of the secondary thermally insulating barrier.
7. The liquefied natural gas container according to claim 1, wherein said loadbearing structure (11, 111) comprises vertical concrete wall sections configured to be installed on land.
8. The liquefied natural gas container according to claim 1, wherein said loadbearing structure (11, 111) is a double hull of a floating vessel.
9. The liquefied natural gas container according to claim 2, wherein a third impermeable sheet (23, 123) is bonded to said first metal plate (22, 122), said second impermeable sheet (17, 117) being bonded to said third impermeable sheet (23, 123).
10. The liquefied natural gas container according to claim 4, wherein the loadbearing structure (11, 111) includes:
a horizontal section (13),
a vertical part (14) extending downwardly from the horizontal section (13), and
a horizontal part (28) extending toward the metal component (21, 121).
11. The liquefied natural gas container according to claim 10, wherein the horizontal part (30) of the metal component (21, 121) includes:
an upper horizontal part (30) and a lower horizontal part (30) that extend from each end of the vertical part (29) in a direction away from the first metal plate (22), and
the loadbearing structure (11,111) is connected to a lower side of the upper horizontal part (30), and
wherein the gas container further comprises:
an L-shaped fixing bracket (20) arranged between a lower side of the horizontal part (28) of the loadbearing structure (11, 111) and an upper side of the lower horizontal part (30) of the metal component (21, 121).
12. The liquefied natural gas container according to claim 2, wherein said first impermeable sheet (16, 116) is bonded to a layer of insulating material (15) or to a plate of plywood (132) forming part of the secondary thermally insulating barrier.
13. The liquefied natural gas container according to claim 2, wherein the second impermeable sheet (17) is bonded to two sections of the first metal plate (22, 122) that join each other at an angle of approximately 90\xb0, and
the second impermeable sheet (17) is fixed in the angle by an angle bracket (31) bolted to the two sections of the first metal plate (22, 122).
14. A liquefied natural gas container comprising;
a loadbearing structure (11, 111) and an impermeable and thermally insulated tank designed to contain liquefied natural gas, said tank comprising a plurality of tank walls fixed to said loadbearing structure (11, 111),
each tank wall having in succession, in a direction of thickness along the longitudinal direction of the tank wall, proceeding from an inside of said tank to an outside, a primary impermeable barrier, a primary thermally insulating barrier, a secondary impermeable barrier and a secondary thermally insulating barrier,
said tank walls comprising at least one vertical wall, the secondary impermeable barrier located on said vertical wall comprising a first impermeable sheet (16, 116) at the top of said vertical wall and a connecting device which impermeably connects said first impermeable (16, 116) sheet to said loadbearing structure (11, 111),
wherein said connecting device comprises a first metal plate (22, 122) parallel to said first impermeable sheet (16, 116), and a second impermeable sheet (17, 117) which is bonded to said first impermeable sheet (16, 116) and connected to the first metal plate (22, 122),
wherein the container further comprises:
a metal component (21, 121) connected to the loadbearing structure (11,111), and having a vertical part (29, 129) and a horizontal part (30, 130),
wherein the first metal plate (22,122) is welded to the vertical part (29,129), and
the horizontal part (30, 130) is connected to the loadbearing structure (11, 111).
15. The liquefied natural gas container according to claim 14, wherein said second impermeable sheet is flexible, and has an unbonded zone between the first impermeable sheet (16, 116) and the first metal plate (22, 122).
16. The liquefied natural gas container according to claim 14, in which a third impermeable sheet (23, 123) is bonded to said first metal plate (22, 122), and
said second impermeable sheet (17, 117) is bonded to said third impermeable sheet (23, 123).
17. The liquefied natural gas container according to claim 14, wherein the horizontal part (30) includes an upper horizontal part (30) and a lower horizontal part (30, 130) that extend from each end of the vertical part (29) in a direction away from the first metal plate (22).
18. A liquefied natural gas container comprising;
a loadbearing structure (11, 111) and an impermeable and thermally insulated tank designed to contain liquefied natural gas, said tank comprising a plurality of tank walls fixed to said loadbearing structure (11, 111),
each tank wall having in succession, in a direction of thickness along the longitudinal direction of the tank wall, proceeding from an inside of said tank to an outside, a primary impermeable barrier, a primary thermally insulating barrier, a secondary impermeable barrier and a secondary thermally insulating barrier,
said tank walls comprising at least one vertical wall, the secondary impermeable barrier located on said vertical wall comprising a first impermeable sheet (16, 116) at the top of said vertical wall and a connecting device which impermeably connects said first impermeable sheet (16, 116) to said loadbearing structure (11, 111),
wherein said connecting device comprises a first metal plate (22, 122) having an upper portion extending parallel to said first impermeable sheet (16, 116), and a lower portion extending perpendicular to said first impermeable sheet (16, 116).
19. The liquefied natural gas container according to claim 18, wherein the secondary thermally insulating barrier comprises a prefabricated panel having a horizontal groove (25), and
the lower portion of the first metal plate (22, 122) extends horizontally into the horizontal groove (25).
20. The liquefied natural gas container according to claim 18, wherein the container further comprises:
a metal component (21, 121) connected to the loadbearing structure (11, 111), and having a vertical part (29, 129) and a horizontal part (30, 130),
wherein the first metal plate (22, 122) is welded to the vertical part (29,129), and
the horizontal part (30, 130) is connected to the loadbearing structure (11, 111).
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 nonvolatile memory, comprising:
an array of memory cells, wherein each memory cell is programmable to a respective target state;
readwrite circuits for reading and programming a group of memory cells in parallel;
said readwrite circuits performing programming that comprises:
providing a programming voltage incrementing with time for a finite period in the form of a staircase pulse train with a given step size; and
programming the group of memory cells in multiple programming passes, each successive programming pass having the staircase pulse train applied to program the group of the memory cells and wherein each successive programming pass has the staircase pulse train offset from the staircase pulse train of the previous programming pass by a predetermined offset level.
2. The non-volatile memory as in claim 1, wherein:
the predetermined offset level in each programming pass is less than the given step size and less than or equal to the predetermined offset level of a previous programming pass.
3. The non-volatile memory as in claim 1, wherein:
the multiple programming passes comprises:
a first programming pass using a first staircase pulse train;
a second programming pass using a second staircase pulse train similar to the first staircase pulse train but offset from the first staircase pulse train by one half of the step size.
4. The non-volatile memory as in claim 3, further comprising:
a third programming pass using a third staircase pulse train similar to the second staircase pulse train but offset from the second staircase pulse train by one quarter of the step size.
5. The non-volatile memory as in claim 1, further comprises:
a program index for each memory cell of the group under programming, the program index of a memory cell indicating the last programming voltage level used to program the memory cell;
said readwrite circuits performing programming that comprises:
applying the programming voltage as a series of incrementing voltage pulses in a programming pass to the group of memory cells; and
allowing programming or inhibiting programming of a memory cell during the programming pass according to the program index of the cell.
6. The non-volatile memory as in claim 5, wherein:
said readwrite circuits applying a programming voltage as a series of incrementing voltage pulses is performed without a verify step on the group of memory cells in between the voltage pulses during the programming pass.
7. The non-volatile memory as in claim 5, wherein:
the predetermined offset level in each programming pass is less than the given step size and less than or equal to the predetermined offset level of a previous programming pass.
8. The non-volatile memory as in claim 5, wherein:
the multiple programming passes comprises:
a first programming pass using a first staircase pulse train;
a second programming pass using a second staircase pulse train similar to the first staircase pulse train but offset from the first staircase pulse train by one half of the step size.
9. The non-volatile memory as in claim 8, further comprising:
a third programming pass using a third staircase pulse train similar to the second staircase pulse train but offset from the second staircase pulse train by one quarter of the step size.
10. The non-volatile memory as in claim 1, wherein each memory cell has a charge storing element which is a floating gate of a field effect transistor.
11. The non-volatile memory as in claim 1, wherein each memory cell has a charge storing element which is a dielectric layer in a field effect transistor.
12. The non-volatile memory as in claim 1, wherein the nonvolatile memory has memory cells with a NAND structure.
13. The non-volatile memory as in claim 1, wherein the non-volatile memory is a flash EEPROM.
14. The non-volatile memory as in claim 1, wherein the nonvolatile memory is embodied in a memory card.
15. A non-volatile memory as claim 1, wherein the memory cells under programming each stores more than one bit of data.