US3523543A

US3523543A - Process and apparatus for the conveyance of an explosive oil

Info

Publication number: US3523543A
Application number: US668016A
Authority: US
Inventors: Gerhard Martin; Werner Sassmannshausen; Jakob Franz Roth
Original assignee: Dynamit Nobel AG
Current assignee: Dynamit Nobel AG
Priority date: 1966-09-14
Filing date: 1967-09-14
Publication date: 1970-08-11
Anticipated expiration: 1987-08-11
Also published as: CH464041A; AT273766B; NO118212B; GB1131779A; DE1571221A1; BE703825A

Description

0 United States Patent [111 3,523,543

[72] Inventors Gerhard Martin 2,383,707 8/1945 Carl 23/266XR Troisdorl, Germany; 2,694,404 1 l/ l 954 Luft et al. 137/ I Werner Sassmannshausen, Bergisch- Gladbach, Germany; Jakob Franz Roth, FOREIGN PATENTS p m y l,003,856 9/1965 ,Great Britain l37/l [21] Appl. No. 668,016

:gfs Primary Examiner- Robert G. Nilson [73] Assignee Dynamit Nobel Aktiengesellschaft, mmmey' cralg Antonen" Stewart &

Troisdorl, Germany [32] Priority Sept. 14, 1966 [33] Germany [31] ABSTRACT: The present disclosure relates to a process and ap aratus for the conve ance of an ex losive oil usin an F I 1 y I p g a I 54] PROCESS AND APPARATUS FOR THE emulsifying means, More particularly, the present disclosure IS CONVEYANCE OF AN EXPLOSIVE OIL directed to a process and apparatus for the conveyance of an 27 Claims3Drawing Figs explos ve Oll from a container to a point of consumption wherein water IS drawn into the conveying system during the [52] LS-Cl 137/1, i itiation of the process as well as before shutting off the 2 3 /5 system, that is, during the critical hases of the o eration of P P [51] lltLCl ..C06b 21/02 th y te a d a ordingly the entire conveying system is Field completely filled with water during these operational phases [3, 154, I72, 233, 590'; 22/64, 23/266 and explosive oil is introduced into the system only when the 56 R r d emulsifying means has substantially reached its full suction 1 e erences power. As a result of this operation there is no air present or UNITED STATES PATENTS introduced into the conduit conveyin system and thus, ex lo- 8 P 321,744 7/1 885 Millner 137/577 sive oil can be conveyed with little or no danger.

Patentd Aug. 11, 1970 Sheet PERCUSSION SENSITIVITY -MAx O I 2 3 4 5 6 7 8 9 IO AIR BUBBLES mm FIG. 'I

INVENTORS GERHARD MARTIN WERNER SASSMANNSHAUSEN JAKOB FRANZ ROTH Patented Aug. 11, 1970 3,523,543

Sheet 2 012 INVENTORS GERHARD MARTIN WERNER SASSMANNSHAUSEN JAKOB FRANZ ROTH BY r ATTORNEYS PROCESS AND APPARATUS FOR THE CONVEYANCE OF AN EXPLOSIVE OIL BACKGROUND OF THE INVENTION The present invention relates to a process and apparatus for the conveyance of an explosive oil such as nitroglycerin from one location to another. More particularly, the present invention is concerned with a process and apparatus which prevents air from being introduced into the conduit conveying system and thus substantially eliminates the dangers normally associated with the conveyance of explosive oils.

It is known to transport liquid nitric acid esters, for example an explosive oil such as nitroglycerin in transport lines by means of an injector. In such a process the explosive oil is drawn into the system from a storage tank by a hydraulically operated injector using a suction nipple or a suction pipe, is emulsified with the propellant water downstream of the propellant nozzle of the injector and is then further conducted in the form of an emulsion through the pipeline to the consumption site or the like where the emulsion is then again separated in a separator into explosive oil and water.

As is well known, emulsified explosive oil can be transported through conduits with relatively little danger. However, since the injector must initially withdraw pure explosive oil from the storage tank or the like, there are still considerable risks associated with the use of the previously known methods for conducting explosive oil by means of an injector. For example, one of these risks is the danger that during the transportation of the explosive oil air enters or is drawn into the oil. As can be readily seen from the diagram of FIGURE 1 which represents the relationship between the shock sensitivity of explosive oil and the size of air bubbles present therein, the shock sensitivity of the explosive oil increases from 26.5 kpm/cm in the absence of air to about 1.86 kpm/cm in the presence of small air bubbles having a diameter of about lmm, to about 0.8 kpm/cm in the presence of air bubbles having a diameter of about 2mm, and finally to almost kpm/cm in the presence of air bubbles having a diameter of about 8mm.

The cause for such a strong increase in the shock sensitivity of the explosive oil is to be seen in the fact that the impedance or the shock resistance coefficient of air amounts to only l/5,000 of the impedance of liquids, that is, of explosive oil as well as water. Accordingly, shocks are drawn into the readily compressible air with an asymmetrical implosion of the air bubbles and the production of so called hot spots. The same phenomena also occurs when gas or steam bubbles are produced by cavitation and collapse.

A further dangerous factor is also represented by the presence of valves or control elements provided in or at conduits for the conveyance of pure and/or emulsified explosive oil, as required, for example, in German Auslegeschrift (published application) 1,085,448, British Patent 320,778 and Belgian Patent 529,430 in the previously known systems. Even if the dangers which arise from the use of metallic contact or sealing surfaces are avoided by the utilization of squeegee valves, diaphragm multiway valves, membrane valves, or the like, there still remains the danger of cavitation due to sudden change in cross section or the formation of a vacuum by the injector.

An examination of the conventional injector conveying systems presently known with respect to the above-mentioned disadvantages results in the following observations:

a) With respect to the arrangement of the injector above the explosive oil.

Due to the stream of propellant water in the injector, a vacuum is produced in the suction pipe effecting the intake of the explosive oil. For control purposes, a valve is necessary in the suction pipe. Upon opening of the valve, a shock is exerted upon the explosive oil which, in conjunction with any air bubbles present and/or in conjunction with cavitation, can become an acute danger. Although a considerable weakening of the explosive oil impact can be achieved by the incorporation of a bypass line, the dangers associated with valves and control elements are not at all eliminated thereby, not considering the fact that the bypass line in certain cases generally requires an additional valve to be added. Furthermore, in this arrangement there is also the danger that the explosive oil tank may become emptied and consequently, as mentioned above, air may be deleteriously drawn into the system. Finally, any leak in the injector creates the danger of the introduction of air into the system.

b) Arrangement of the injector at the level of the explosive oil or below said level.

In this arrangement, when the device is inoperative the injector as well as the connecting conduits are filled with explosive oil. Consequently, when the device starts operating, at

least the explosive oil present downstream of the injector in the conduit will be conveyed in the form of a plug of pure explosive oil in front of the emulsion following thereafter, which represents a dangerous situation. Another dangerous factor is also represented by explosive oil which has penetrated into the propellant water conduit, since this oil is pressed through the injector nozzle at a high speed when the operation of the system is initiated.

With respect to the aforementioned type of injector arrangements, it should be noted that without the use of valves, be it in the suction line leading from the explosive oil tank to the injector or in the emulsion line leading from the injector to the consumer site, it has been heretofore impossible to conduct a preliminary rinsing or a post-rinsing step or an operation in accordance with the so-callcd inoculation method, which is a periodic introduction of explosive oil into the continuous stream of propellant water. Consequently, the abovementioned disadvantages inherent in valve-containing systems had to be tolerated.

SUMMARY OF THE INVENTION An object of the present invention is to avoid the prior art disadvantages inherent in the conventional processes and apparatus for conveying explosive oil.

Another object of the present invention is to provide an improved process and apparatus for the conveyance of an explosive oil from one location to another which avoids the introduction of air into the conduit conveying system.

A further object of the present invention is to provide an im'- proved process and apparatus for the continuous conveyance v of an explosive oil from one location to the other wherein the use of valves in operating the conduits carrying the explosive therewith.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

Pursuant to the present invention, it has been found that the above-mentioned disadvantages may be eliminated and a much improved process and apparatus for the conveyance of an explosive oil from one location to another can be obtained by covering the explosive oil to be conveyed with water, drawing water into the conveying system when it is initially used as well as each subsequent time the injector is put to use, thereafter continuously drawing explosive oil or alternately explosive oil and water and finally, before the injector is stopped, again drawing water into the conduit conveying system until they are completely filled with said water.

Since water is drawn into the system during the initiation of the process as well as before shutting off the system, that is, during the critical phases of the operation of the system, the entire conveying system is completely filled with water during these operational phases and explosive oil is introduced only when the injector has substantially reached its full suction power. As a result there is no air introduced into the conduit conveying system and thus all of the above-mentioned disadvantages are effectively eliminated. Due to this particular mode of operation according to the present invention, it is possible to operate the conduits carrying explosive oil without any valve so that the above-mentioned dangers associated with valve operation are likewise avoided. In this connection it is of little or no importance with respect to the mode of operation of the present invention at which location the injector is provided.

In a further embodiment of the process and apparatus of the present invention the propellant water employed for conveying the explosive oil and for covering the explosive oil can be reused. Thus, on the one hand a favorable water economy is obtained for the operation of the plant while on the other hand there is obtained the additional advantage that after the emulsion has been separated into explosive oil and water, the water which still contains traces of the explosive oil need not be subjected to a waste water purification step since it is re-introduced into the process. Additionally, the residues of explosive oil present in the water are not lost.

In connection with the apparatus used for conducting the explosive oil conveying process of the present invention, it is proposed to make the suction port of the injector and the tank or tanks containing the explosive oil adjustable in height relative to each other. This can be accomplished, for example, by connecting to the injector a flexible suction line wherein the end which is introduced into the explosive oil tank can be lifted and lowered by means of a lifting device. However, in place of this device it is also possible to make the suction port of the injector stationary and make the explosive oil tank or tanks liftable and lowerable by means of a lifting and lowering mechanism so that the suction port can be positioned in the explosive oil or in the water, as desired. The adjustability provided as a result of these features of the present invention is not dependent upon time, and is very advantageous since it affords the flexibility of adapting well to the respective conditions and thus is substantially free from restrictions.

In order to ensure maximum safety, even in case of operating problems, it is further suggested to provide the adjusting device with a control element which automatically controls the adjusting device upon each purposeful and also involuntary interruption of the conveyance of explosive oil in such a manner that the injector suction port adjusts to be in the water zone ofthe tank. In order to make sure that the conduit system in this case is also completely freed from explosive oil, an auxiliary source of pressurized water is suitably connected between the injector and the pressurized water source, to the hydraulic line. In this connection, the hydraulic source and the auxiliary hydraulic source can advantageously be in communication with each other in such a manner that the auxiliary hydraulic source is automatically actuated when the hydraulic source, although set into operation, does not yet supply the required pressure for the propellant water.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only and thus are not limitative of the present invention and wherein FIGURE I shows the relationship between the shock sensitivity of explosive oil and the size of air bubbles present therein,and

FIGURE 2 shows the explosive oil conveyance system of the present invention.

FIGURE 3 shows a lifting device for raising and lowering a tank as defined by the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings the apparatus of the present invention according to FIGURE 2 comprises two

explosive oil tanks

1 and 2 which are in communication with each other at their lowest point by means of conduit 4, so that the explosive oil supplied to tank 2 via line 3 adjusts itself to the same level in both tanks. The feeding of explosive oil into the container 2 is controlled by devices such as, liquid level control means, 27, a dual blocking means, in such a manner that the level of explosive oil in both

tanks

1 and 2 is always maintained between a maximum and a minimum level. Water is provided above the explosive oil in

tanks

1 and 2. The injector 5 with the following conveying conduit llis provided outside of the container 1 at the level of the water zone and is supplied with propellant water from the collecting tanks 6 using pump 7. The suction line 9 which is connected to the injector at one of its ends is introduced into tank 1 at its other free end, said free end being liftable and lowerable by means of a lifting and lowering device 10, the stroke being set so that the end of the suction line is always in the lower terminal position, below the minimum level and, in the upper terminal position above the maximum level of the explosive oil level. Furthermore, the elevating mechanism is of such a construction that the mouth of the suction line, when the system is shut off or if a breakdown in operation occurs, automatically adjusts to be in the water zone of the tank 1. The automatic adjustment is controlled by control means 28. The elevating device, which is not shown in detail, can function pneumatically, as well as hydraulically or mechanically. The material for the suction line 9 should be as soft a substance as possible, for example a rubber material or a synthetic resinous material which is resistant to explosive oil.

Water is provided in the

tanks

1 and 2 above the explosive oil. For balancing the water level in

tanks

1 and 2 the tanks communicate with each other near the upper rim thereof by means of conduit 19. For the overflow of excess water, conduit 20 is connected to tank 1 at the same level as the conduit 19. Conduit 20 leads to separator 21 which in turn is in communication with the propellant water tank 6 via conduit 22. The propellant water tank 6 is connected by a conduit 23, provided with a control valve, to a source of propellant water which is not shown, and via outlet conduit 24 to a waste water station which is likewise not shown.

In order to insure that even in the case of breakdown the injector 5, the emulsion conduit 11, and the suction line 9 are freed from any residual explosive oil, fresh water line 25 is provided along with control valve 26. In this case the check valve 8 prevents the water coming from the fresh water source from flowing in the direction of the propellant water collecting tank 6. In place of a fresh water connection, it is of course also possible to employ a storage tank of pressurized water or another source of pressurized water.

The explosive oil drawn in via the suction line 9 is emulsified with the propellant water in the injector and conducted in emulsion form through conduit ll into separator 12 which separates the emulsion into explosive oil and water. While the explosive oil is conducted via line 13 to further use or processing, the separated water flows through line 14 and supply container 15 into the waste water collector 16 from where the pump 17 recycles the waste water via conduit 18 into the tank 2. In case the separator 12 is at such a level that the waste water can flow by free gravity flow from container 15 into the explosive oil tank 2, the waste water collecting tank 16 and the pump 17 can accordingly be eliminated. By recycling the separated water into the tank 2 it is practically ensured that tank 1 connected therewith is also never without water, and in fact, will always be filled to overflow since in this manner the entire propellant water flows through the tank 1. Even if no explosive oil is in the tank, the system can still be operated continuously with pure water.

From the illustration of FIGURE 2 it can be readily seen that not a single valve is provided in the conduits of the entire system which carries explosive oil. Thus, it is of no significance whether the transportation of the explosive oil or the explosive oil emulsion is continuous or is conducted by the socalled inoculation method. It is merely a question of immersing the end of the suction line into the explosive oil, or the length of time the mouth of the suction line remains in the explosive oil and in the water. Likewise, it is of no import for the process of the present invention whether only a single storage tank for the explosive oil is employed or, as in the example, two or more tanks are connected in series. However, the use of two or more containers has the disadvantage when compared to using only a single tank that any emulsion introduced into tank 2 is first separated before it enters tank 1 from which the explosive oil is then withdrawn by the injector in pure form.

The arrangement of the injector 5 is of no significance in the arrangement and construction of the present invention. However, it is advantageous to provide the injector at the height of the water zone, for example approximately to cm above the maximum level of the explosive oil, since in this case the injector, when the system is not in operation, is always filled with water due to the communication between the injector 5 and the suction line 9.

As can be clearly seen from FIGURE 2, the lifting stroke of the suction line 9 can be kept relatively small by providing the

tanks

1 and 2 with a large inside cross section. in this connection, it is likewise advantageous if the transition from water intake to the intake of explosive oil and vice versa is conducted very slowly and smoothly in correspondence with the speed of the lifting motion of the suction line.

In FIGURE 3, a lifting device 10 is illustrated wherein the height of tank 1 can be adjusted relative to the suction nozzle of the pipe line 9. The range of height adjustability is greater than the difference between the maximum and minimum levels of the explosive oil in the tank. All of the other components in FIGURE 3 bear the same reference numerals as shown in FIGURE 2.

In describing the process and apparatus for conveying explosive oil, for example nitroglycerin, according to the present invention, the suction nozzle of the suction pipe line 9 is disposed in the water layer of tank 1 while the plant is in a standstill state. When the plant is put into operation, water is first conveyed in this position and thereafter the suction pipe line 9 is lowered by means of the lifting and lowering device 10 to the extent that the suction nozzle is immersed in the nitroglycerin. The nitroglycerin can now be transported. In this connection, it is of no importance whether or not the conveyance of the nitroglycerin is conducted continuously or by the so-called injection process. In the injection process the suction pipe line 9 is lifted from time to time by means of the lifting unit 10 so that the suction nozzle is again immersed in the water layer and water is taken in. Subsequently, the suction pipe line is again lowered. Before the plant is shut down, the suction nozzle is lifted into the water layer and water is drawn in until all of the pipe lines are filled with water and are free of nitroglycerin or nitroglycerin emulsion. The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be apparent to one skilled in the art are intended to be included.

We claim:

1. A process for the conveyance of an explosive oil from a container to a point of consumption which comprises maintaining a level of water over the explosive oil in the container, drawing water from the container through a suction conduit and introducing it into an emulsifying means and into the conveying system at the beginning of the process, moving said container and said suction conduit relative to each other to position the suction conduit in the water or the explosive oil layer, thereafter continuously drawing explosive oil or alternately explosive oil and water from the container through a. suction conduit and introducing it into an emulsifying means,

emulsifying the oil or oil/water mixture with propellant water supplied to the emulsifying means, conveying the emulsion to a point of consumption and, before the'process is stopped, again drawing water from the container through the suction conduit into the system until the conduits in said system are filled with said water.

2. The process of Claim 1 wherein the explosive oil is introduced into the system only when the emulsifying means has substantially reached its full suction power.

3. The process of Claim 1 wherein the propellant water employed for covering and conveying the explosive oil is recycled for re-use.

4. The process of Claim 1 wherein an auxiliary source of pressurized water is introduced into the system at a point upstream of the emulsifying means.

5. A process for the conveyance of an explosive oil from a container to a point of consumption which comprises maintaining a level of water over the explosive oil in the container, supplying propellant water to an emulsifying means, drawing water from the container through a suction conduit and introducing it into the emulsifying means, moving the container and the suction conduit relative to each other to position the suction conduit in the water or the explosive oil layer, continuously drawing explosive oil or alternately explosive oil and water from the container through the suction line and introducing it into the emulsifying means where it is emulsified with the propellant water and conducted in emulsion form to the point of consumption, and before the process is stopped, drawing water into the system until the conduits in said system are filled with water.

6. The process of Claim 5 wherein the propellant water supplied to the emulsifying means is a pressurized water source.

7. The process of Claim 6 wherein an auxiliary source of pressurized water is supplied to the system between the propellant pressurized water source and the emulsifying means and is actuated when the pressurized propellant water source although initiated does not yet supply the required pressure to the emulsifying means.

8. The process of Claim 5 wherein the explosive oil in the container is always maintained between a maximum and minimum level and the free end of the suction line for supplying said explosive oil to the emulsifying means is always maintained below the minimumoil level or in the water level above the maximum oil level. v

9. The process of Claim 5 wherein after the emulsi n is conveyed to the point of consumption it is separated into explosive oil and water, and the water is thereafter recycled to the container for reuse.

10. The method of Claim 9 wherein excess water supplied to the container is conveyed to a collecting tank where it is utilized as propellant water to be supplied to the emulsifyingmeans.

ll. An apparatus for conveying an explosive oil froma container to a point of consumption which comprises container means containing explosive oil and a level of water covering said oil, an emulsifying means communicating with the explosive oil and water in the container means by conduit means, said conduit means having a terminal free end portion extending intosaid container, means for changing the height of the free end of the conduit means disposed in said container means, means for supplying propellant water to the emulsifying means and conduit means for conveying the emulsion from the emulsifying means to the point of consumption.

12. The apparatus of Claim 11 wherein a lifting and lowering device is associated with the free end of the conduit means disposed in the container.

13. The apparatus of Claim 12 wherein the stroke of the lift ing and lowering device is such that the free end of the conduit is below the minimum oil level in its lower terminal position and in the water level above the maximum oil level in its upper terminal position.

14. The apparatus of Claim 13, wherein the lifting and lowering device is provided with a means to dispose the free end of the conduit in the water level upon any interruption of the process.

15. The apparatus of Claim 12, wherein the lifting and lowering mechanism functions pneumatically.

16. The apparatus of Claim 12, wherein the lifting and lowering mechanism functions hydraulically.

17. The apparatus of Claim 12, wherein the lifting and lowering mechanism functions mechanically.

18. The apparatus of Claim 11 wherein means are provided for raising and lowering the container means thereby changing the height of the free end of the conduit means disposed in the container.

19. The apparatus of Claim 11 wherein at the point of consumption, means are provided for separating the emulsion into explosive oil and water and the water is recycled to the container means.

20. The apparatus of Claim 19 wherein means are provided for conveying excess water supplied to the container means to a collecting tank from where it is conveyed to the emulsifying means as propellant water.

21. The apparatus of Claim 11 wherein means are provided to maintain the level of explosive oil in the container means between a maximum and minimum value.

22. The apparatus of Claim 11 wherein means are provided for introducing an auxiliary source of water into the propellant water downstream of the emulsifying means.

23. An apparatus for conveying an explosive oil from a container to a point of consumption which comprises container means containing an explosive oil zone and a water zone disposed thereabove, an injector means communicating with the container means by conduit means, said conduit means having a terminal free end portion extending into said container, means for changing the height of the free end of the conduit means disposed in said container means between the oil zone and the water zone, means for supplying pressurized propellant water to the injector means via conduit means, means communicating with said propellant water conduit means downstream of said injector means for supplying auxiliary fresh water to the system, and conduit means for conveying the emulsion leaving the injector means to the point of consumption.

24. The apparatus of Claim 23 wherein the container means comprises two tanks which communicate with each other at their upper and lower portions in the water zone and oil zone respectively to maintain the same water-oil levels in said tanks.

25. The apparatus of Claim 23 wherein the injector means is provided at the same level as the water zone in the container.

26. The apparatus of Claim 23 wherein means are provided for separating the water from the explosive oil at the point of consumption and recycling the water to the container means.

27. The apparatus of Claim 23 wherein means are provided for recycling excess water from the container means to a collecting tank and pump means are provided for conveying this water from the collecting tank to the injector means as pressurized propellant water.