CA1217735A - Slope bottom tank - Google Patents
Slope bottom tankInfo
- Publication number
- CA1217735A CA1217735A CA000460008A CA460008A CA1217735A CA 1217735 A CA1217735 A CA 1217735A CA 000460008 A CA000460008 A CA 000460008A CA 460008 A CA460008 A CA 460008A CA 1217735 A CA1217735 A CA 1217735A
- Authority
- CA
- Canada
- Prior art keywords
- tank
- valves
- liquid
- emptying
- steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
- B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
- B65D88/00—Large containers
- B65D88/02—Large containers rigid
- B65D88/06—Large containers rigid cylindrical
- B65D88/08—Large containers rigid cylindrical with a vertical axis
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Filling Or Discharging Of Gas Storage Vessels (AREA)
Abstract
Abstract In frac tanks it is generally considered best for ease of operation and maintenance to have the emptying valves affixed to the outside wall of the tank. In this invention the bottom of the tank is sloped upwards away from the emptying valves. The tank therey has virtually no liquid remaining in it when emptied, making it more efficient and easier to clean when necessary.
Description
~2~ 7735 This invention relates to frac tanks.
Frac tanks for liquids are often used successively for a variety of liquids. These tanks are emptied by suction through various openings towards the bottom of the tank which are regulated by valves. Even when ostensibly completely emptied> the tanks tend still to retain a residue of the stored liquid. To prevent contamination of the next liquid to be stored by the residue left by the previous liquid the tank must be thouroughly cleaned. Both the emptying of the tanks by suction and their cleaning present certain difficulties.
At present frac tanks have one of the two configurations.
Either the bottom of the tank is flat horizontally or it is conical in shape. The flat bottom type of tank has its valves for emptying the tank at its outer edge and as close to the bottom as possible.
This permits ease of operation and maintenance of the valves, but when liquid is removed by suction, which is done s~nce the hydrostatic pressure within the tank is not usually suffic~ent to develop an adequate flow of the liquid, a loss of suction develops whlle the tank still has about 6 to 8 inches of liquid in the bottom.
Not only is this unproductive but the residue of the liquid makes the tank more difficult to clean. The conical based tank has a bottom shaped like an inverse cone and has pipes extending from the bottom center of the tank to control valves just beyond the edge of the tank. Th~s type of tanks, therefore, leave no liquid in the bottom when emptied by suction but in cold weather the liquid in the pipes below the tanks tends easily to freeze and is difficult to thaw. In a flat bottom tank, if the liquid immediately next to the valves for emptying the tank freezes, it can easily be thawed by circulating lZ1~735 warmer liquid in the tank. The circulating warmed liquid easily reaches the location where the liquid is frozen.
I have found that these disadvantages may be overcome by differently sloping the bottom of the tank. The bottom may remain a flat plane but it ;s sloped up at an angle not in excess of 10 from the horizontal and not less than 3 from the horizontal in such a manner that it is highest at a point directly opposite the valves for empting the tank and lowest at the valves for emptying the tank. The bottom of the tank immediatly adjacent one set of valves for emptying the tank, is thereby the lowest point of the tank. This configuration ensures that minimual residue of liquid remains at the bottom of the tank when emptied and, therefore, also makes it easier to clean. The valves being at the edge of the tank are easily accessible and remain easy to operate and maintain. If liquid immediately next to the valves becomes frozen it is just as easy to thaw it by circulating warmer liquid in the tank as it is for the usual flat bottom type tank.
~Z~7735 In the drawing which illustrate this invention embodiments of the invention, Figure 1 ., is a perspective view of one embodiment , Figure 2 ., is an elevation view of this embodiment , Figure 3., is an elevation view of this embodiment at right angles to figure 2., Figure 4., is an elevation view of this embodiment at right angles to figure 2. and directly opposite to figure 3., Figure 5., is a top plan view of this embodiment, Figure 6., is a bottom plan view of this embodiment.
The tank wall 1. is a large steel cylinder of appropriate diameter having various openings as hereinafter further mentioned with a conical top 2. also of steel and also having various openings and a bottom 3. which is sloped in the manner hereafter described.
The tank wall 1. rests on an L-shaped skid which supports the tank when standing upright and which permits the entire tank assembly to be rested horizontally for transporting. The skid may be of any configuration but of such a nature as to permit the entire tank 20 assembly to be stood upright or laid horizontal, primarially for the purpose of transportation. In the embodiment illustrated, the skid is made of 5 steel beams and various spacers. Two of the steel beams, which are the longer steel beams 4. are of a length somewhat longer than the overall length of the tank wall 1. By means of a steel spacer 5. which may be a circular steel tube, as illustrated, the longer steel beam 4. is attached at right angles to the shorter steel beam 6. The shorter steel beams are of a length somewhat longer than the section of the tank wall 1. they support and ~2~
sufficiently long that the longer beam 4. and the braces 8. may be attached to it. A number of steel spacers 7. all of which may be circular steel tubes are attached between the right side of the skid and the left side of the skid. All the spacers are such a length as to make the skid of a width that it is easily transportable. A steel beam 9. is used as a spacer underneath the tank and is a beam rather than a circular steel tube for ease of affixing ~he supports for the bottom 3. The circular tank wall 1. is welded as illustrated to the short steel beams 6. of the skid. By means of saddles 10. the tank wall 1. is also attached to the longer beams 4. of the L-shaped skid. In the illustration the saddles 10. rest upon some of the spacers 7. In order to grant somewhat more stability braces 8. also of being a steel beams are attached to the L-shaped skid and tank on the side opposite the longer side of the L-shaped skid as shown in the illustration. A steel ladder 11. may be pro~ided to enable individuals to climb to the top of the tank. Around the top of the tank a small guard rail 12. may be provided. The bottom of the tank 3. is supported by steel beams 13. resting on posts 14. which in turn rest on both the steel beams 6. and the beam spacers 9. wh~ch are all attached as shown. The bottom 3. is a steel plate of appropriate thickness to support the weight of the liquid to be contained in the tank as is the structure supporting the bottom 3 and is sloped upward as illustrated at an angle not in excess of 10 from the horizontal and not less than 3 from the horizontal.
The top 2. is of a very flat conical shape to shed water and has vent collar 15. in it which may be in the center of the top
Frac tanks for liquids are often used successively for a variety of liquids. These tanks are emptied by suction through various openings towards the bottom of the tank which are regulated by valves. Even when ostensibly completely emptied> the tanks tend still to retain a residue of the stored liquid. To prevent contamination of the next liquid to be stored by the residue left by the previous liquid the tank must be thouroughly cleaned. Both the emptying of the tanks by suction and their cleaning present certain difficulties.
At present frac tanks have one of the two configurations.
Either the bottom of the tank is flat horizontally or it is conical in shape. The flat bottom type of tank has its valves for emptying the tank at its outer edge and as close to the bottom as possible.
This permits ease of operation and maintenance of the valves, but when liquid is removed by suction, which is done s~nce the hydrostatic pressure within the tank is not usually suffic~ent to develop an adequate flow of the liquid, a loss of suction develops whlle the tank still has about 6 to 8 inches of liquid in the bottom.
Not only is this unproductive but the residue of the liquid makes the tank more difficult to clean. The conical based tank has a bottom shaped like an inverse cone and has pipes extending from the bottom center of the tank to control valves just beyond the edge of the tank. Th~s type of tanks, therefore, leave no liquid in the bottom when emptied by suction but in cold weather the liquid in the pipes below the tanks tends easily to freeze and is difficult to thaw. In a flat bottom tank, if the liquid immediately next to the valves for emptying the tank freezes, it can easily be thawed by circulating lZ1~735 warmer liquid in the tank. The circulating warmed liquid easily reaches the location where the liquid is frozen.
I have found that these disadvantages may be overcome by differently sloping the bottom of the tank. The bottom may remain a flat plane but it ;s sloped up at an angle not in excess of 10 from the horizontal and not less than 3 from the horizontal in such a manner that it is highest at a point directly opposite the valves for empting the tank and lowest at the valves for emptying the tank. The bottom of the tank immediatly adjacent one set of valves for emptying the tank, is thereby the lowest point of the tank. This configuration ensures that minimual residue of liquid remains at the bottom of the tank when emptied and, therefore, also makes it easier to clean. The valves being at the edge of the tank are easily accessible and remain easy to operate and maintain. If liquid immediately next to the valves becomes frozen it is just as easy to thaw it by circulating warmer liquid in the tank as it is for the usual flat bottom type tank.
~Z~7735 In the drawing which illustrate this invention embodiments of the invention, Figure 1 ., is a perspective view of one embodiment , Figure 2 ., is an elevation view of this embodiment , Figure 3., is an elevation view of this embodiment at right angles to figure 2., Figure 4., is an elevation view of this embodiment at right angles to figure 2. and directly opposite to figure 3., Figure 5., is a top plan view of this embodiment, Figure 6., is a bottom plan view of this embodiment.
The tank wall 1. is a large steel cylinder of appropriate diameter having various openings as hereinafter further mentioned with a conical top 2. also of steel and also having various openings and a bottom 3. which is sloped in the manner hereafter described.
The tank wall 1. rests on an L-shaped skid which supports the tank when standing upright and which permits the entire tank assembly to be rested horizontally for transporting. The skid may be of any configuration but of such a nature as to permit the entire tank 20 assembly to be stood upright or laid horizontal, primarially for the purpose of transportation. In the embodiment illustrated, the skid is made of 5 steel beams and various spacers. Two of the steel beams, which are the longer steel beams 4. are of a length somewhat longer than the overall length of the tank wall 1. By means of a steel spacer 5. which may be a circular steel tube, as illustrated, the longer steel beam 4. is attached at right angles to the shorter steel beam 6. The shorter steel beams are of a length somewhat longer than the section of the tank wall 1. they support and ~2~
sufficiently long that the longer beam 4. and the braces 8. may be attached to it. A number of steel spacers 7. all of which may be circular steel tubes are attached between the right side of the skid and the left side of the skid. All the spacers are such a length as to make the skid of a width that it is easily transportable. A steel beam 9. is used as a spacer underneath the tank and is a beam rather than a circular steel tube for ease of affixing ~he supports for the bottom 3. The circular tank wall 1. is welded as illustrated to the short steel beams 6. of the skid. By means of saddles 10. the tank wall 1. is also attached to the longer beams 4. of the L-shaped skid. In the illustration the saddles 10. rest upon some of the spacers 7. In order to grant somewhat more stability braces 8. also of being a steel beams are attached to the L-shaped skid and tank on the side opposite the longer side of the L-shaped skid as shown in the illustration. A steel ladder 11. may be pro~ided to enable individuals to climb to the top of the tank. Around the top of the tank a small guard rail 12. may be provided. The bottom of the tank 3. is supported by steel beams 13. resting on posts 14. which in turn rest on both the steel beams 6. and the beam spacers 9. wh~ch are all attached as shown. The bottom 3. is a steel plate of appropriate thickness to support the weight of the liquid to be contained in the tank as is the structure supporting the bottom 3 and is sloped upward as illustrated at an angle not in excess of 10 from the horizontal and not less than 3 from the horizontal.
The top 2. is of a very flat conical shape to shed water and has vent collar 15. in it which may be in the center of the top
2., as illustrated. The vent collar 15. may consist of a short 4 inch circular extension welded to the top 2. and threaded on the outside to permit a cap to be screwed onto it, thereby permitting it to be completely closed. The top 2. aiso has a square thief hatch lZ~7735 16. which permits visual inspection of the llquid contained in the tank and also permits manual measurement of the amount of liquid in the tank. The thief hatch 16. has a flange extending out from the top 2. with holes drilled into ~t so that it can be closed by a cover of sufficient dimensions to permit the cover to be bolted to the flange.
From the tank wall 1. immediately below the top 2., a riser vent 17. extends out and down the side of the tank. The riser vent may be a 4 inch circular tube, as illustrated. This permits the tank to be filled, whether initially or while recirculating liquid, as well as forming a further vapour vent for fumes created by the stored liquid. Towards the bottom of the riser vent 17. a brace 18. is added to give the riser vent 17. support.
The tank wall 1. also has an access hatch 19. which is an opening cut into the side of the tank sufficiently large to enable a person to comfortable enter the tank for cleaning or inspection purposes and which may be rectangular as illustrated. The access hatch 19. has a flange with holes drilled into it extending out on all sides so that a metal cover 20. which is sufficiently large may be bolted to it thereby completely closing the access hatch 19. The access hatch 19. may be located at any convenient locaton of the tank wall 1. but so as not to interfere with the various valves and valve openings.
At the location where bottom 3. is highest, when standing upright, an opening 21. with a valve attached into the side of the tank may be located. At the opposite side of the tank at approximately the same elevation as the opening 21. another opening 22. may be provided and again a valve attached. The openings 21. and 22. may be used at various times for emptying or filling the tank.
In the illustration directly below opening 22., but nevertheless located in the tank wall 1. where the bottom 3. is lowest when the tank is standing upright, there are a number of openings for emptying the tank, all having valves attached. In the illustration three openings 23., 24., and 25. are provided and all have valves attached. One further opening namely a drain plug 26.
may be provided and is located in the tank wall 1. as close to the bottom 3. as practicable but in such a manner that when the entire tank assembly is horizontal for transit, resting on the longer steel beams 4., the drain plug 26. is at the lowest point in the tank wall.
and it may therefore be used to drain the tank while in that position. The drain plug 26. may be a short four inch circular steel tube attached to the tank wall 1. and threaded on the outside to permit a cap to be screwed onto it. A measuring gauge 27. may be added to the tank so that manual inspection of the volume of liquid in the tank is not necessary and a spacer 28. may be added to the top end of the skid to provide the skid with some addition rldgity at its top end when it ~s being changed from a hor~zontal to a vertical position.
From the tank wall 1. immediately below the top 2., a riser vent 17. extends out and down the side of the tank. The riser vent may be a 4 inch circular tube, as illustrated. This permits the tank to be filled, whether initially or while recirculating liquid, as well as forming a further vapour vent for fumes created by the stored liquid. Towards the bottom of the riser vent 17. a brace 18. is added to give the riser vent 17. support.
The tank wall 1. also has an access hatch 19. which is an opening cut into the side of the tank sufficiently large to enable a person to comfortable enter the tank for cleaning or inspection purposes and which may be rectangular as illustrated. The access hatch 19. has a flange with holes drilled into it extending out on all sides so that a metal cover 20. which is sufficiently large may be bolted to it thereby completely closing the access hatch 19. The access hatch 19. may be located at any convenient locaton of the tank wall 1. but so as not to interfere with the various valves and valve openings.
At the location where bottom 3. is highest, when standing upright, an opening 21. with a valve attached into the side of the tank may be located. At the opposite side of the tank at approximately the same elevation as the opening 21. another opening 22. may be provided and again a valve attached. The openings 21. and 22. may be used at various times for emptying or filling the tank.
In the illustration directly below opening 22., but nevertheless located in the tank wall 1. where the bottom 3. is lowest when the tank is standing upright, there are a number of openings for emptying the tank, all having valves attached. In the illustration three openings 23., 24., and 25. are provided and all have valves attached. One further opening namely a drain plug 26.
may be provided and is located in the tank wall 1. as close to the bottom 3. as practicable but in such a manner that when the entire tank assembly is horizontal for transit, resting on the longer steel beams 4., the drain plug 26. is at the lowest point in the tank wall.
and it may therefore be used to drain the tank while in that position. The drain plug 26. may be a short four inch circular steel tube attached to the tank wall 1. and threaded on the outside to permit a cap to be screwed onto it. A measuring gauge 27. may be added to the tank so that manual inspection of the volume of liquid in the tank is not necessary and a spacer 28. may be added to the top end of the skid to provide the skid with some addition rldgity at its top end when it ~s being changed from a hor~zontal to a vertical position.
Claims (4)
1. A tank with emptying valves at the outer edge tank and with the bottom of the tank sloped upwards away from those valves which are lowest on the tank when it is standing upright at an angle not in excess of 10° from the horizontal and not less than 3° from the horizontal.
2. A tank as described in claim 1. which is cylind rical.
3. A tank as described in claim 1. where the bottom which slopes up and away from the valves which may be used for emptying the tank, forms a flat plane.
4. A tank as described in claim 3. which is cylindrical.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000460008A CA1217735A (en) | 1984-07-30 | 1984-07-30 | Slope bottom tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000460008A CA1217735A (en) | 1984-07-30 | 1984-07-30 | Slope bottom tank |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1217735A true CA1217735A (en) | 1987-02-10 |
Family
ID=4128427
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000460008A Expired CA1217735A (en) | 1984-07-30 | 1984-07-30 | Slope bottom tank |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1217735A (en) |
-
1984
- 1984-07-30 CA CA000460008A patent/CA1217735A/en not_active Expired
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |