MXPA00011212A - Supply system for transferring a fluid to a container - Google Patents

Abstract

The invention relates to a supply system for transferring a fluid to a container (1) fitted with a supply line (10). The system comprises a storage chamber filled with the fluid and a compressed gas store (14) which can be connected with said storage chamber (13). The storage chamber (13) and the compressed gas store (14) are positioned in direct proximity to each other and the storage chamber (13) can, if necessary, be connected to the supply line (10) by means of connecting elements (11, 12).

Description

SYSTEM OF SUPPLY TO FEED A FLUID TO A RECIPIENT A supply system for feeding a fluid to a container is used, in particular, for the final stabilization of substances that are normally stored in storage containers or tanks and which have a considerable tendency to undesirable chemical reactions, for example, the premature polymerization, or other physical reactions, crystallization. It is known that certain substances or combinations of substances, in solid or dissolved form, are suitable for re-stabilizing polymerizable substances that react in an undesirable time. These substances can be introduced into the stored material in a convenient manner and then they can be mixed with the contents of the tank using the pump that is normally provided for filling and emptying the storage tank device. One disadvantage is that the pumps themselves can form the starting point for premature polymerization, giving rise to the blockage of the pump. Therefore, if required, it is possible to no longer perform the mixing work. Another disadvantage is the need for an external power source to power the pump which, in an emergency or occasionally, may not be available, making it impossible to introduce the stabilizing liquid. Therefore, to be independent of external energy sources, it is also possible to use a mixing method that includes blowing gases. A drawback of this method is that it requires additional internal elements inside or in the tank, in general, these internal elements have to be fixedly fixed to the tank, so that they are not damaged or detached during normal operation. To be effective, that is, to achieve intimate mixing, the internal elements for injecting gases are usually located in the vicinity of the bottom of the tank. When these internal elements are not in use, the reactive substance can penetrate the internal elements, where it is generally polymerized due to the low level of material exchange, thus rendering the gas supply unusable when required. For this reason, a light air flow is often fed through the pipes to keep them clean. However, an airflow of this nature also requires that the apparatus be checked, to prevent the liquid stored in the tank from rising to the reserve equipment and keeping the pipeline open. These designs have proven to be expensive if they have to fulfill their reliability function. EP-B-0, 064, 628 describes a device for the Emergency interruption of the polymerization reactions in a closed reaction vessel by adding inhibitor solution. The solution of the inhibitor is added to a lower part of the container through a connection flange which is closed by means of a safety disc. A riser tube leading to an upper flange, to which a tube of compressed gas is connected, is arranged in this connection flange. The riser is filled with an inhibitor solution which, when required, is sent to the container at high pressure by means of a compressed gas. The compressed gas leaves a cylinder of compressed gas that is connected to the riser tube through the compressed gas tube. Due to the immediate proximity of the inhibitor solution to the container, the inhibitor solution itself can, especially in dangerous situations, have been damaged before being fed to the container, so that it can no longer fulfill its actual function. In addition, there is a risk, with the known security disk arrangement, of prematurely breaking the security disk, rendering the monomer stored in the tank unusable. The resulting contamination of the storage device then requires a prolonged cleaning work due to the high concentration of the inhibitor. In addition, supervision of the inhibitory solution within The ascending tube is a complex operation, since it requires that the riser tube be emptied and filled.

Particularly if there is a plurality of containers, this represents a considerable disadvantage, finally, there is also the risk that the inhibitor solution will freeze if the temperatures drop excessively. The problem on which the invention is based, therefore, consists in offering a supply system for feeding a fluid to a container that is provided with a power line, whose system has a reliable and simple structure and only requires a level of low investment. According to the invention, the reservoir and the compressed air store are arranged in immediate proximity to each other, and the tank can, when required, be put into communication with the supply line through a connecting piece. This supply system can be attached or separated from the container at any time, as a result, its correct operation can be easily tested at periodic times. Due to the structure of the supply system, it can be used in containers of very different volumes without changing their structural dimensions. In the supply system according to the invention, liquid or gaseous substances are introduced into the material and the substances are at the same time mixed with the material. The high-pressure fluid can be introduced into a container for purposes of stabilizing the substances within the container and can be a mixture of gas and a liquid. The preferred configurations are explained below. To prolong the period during which the fluid is fed into the container, means is provided to reduce the pressure between the storehouse of the compressed gas and the tank for the fluid, by means of which the pressure of the compressed gas acting on the tank may be reduced to such a degree that a desired flow velocity of the fluid is not exceeded. In this case, it is also important that the compressed gas that follows after the fluid that has been expelled from the mode reservoir does not exceed a certain flow velocity, so that the discharge of the compressed gas into the container filled with liquid can be used to mix the contents of the container intimately. One convenience is that the compressed gas storage and warehouse are designed as a portable unit. This makes possible the use of the supply system for a plurality of containers. Since at least some fluid stored in the tank remains in the feed line and the container is not fed by the compressed gas, it is convenient, to maintain compact supply systems, if the length of the feeding line that leads the container does not exceed 500 m and is at least 10 m for security reasons. To obtain intimate mixing when fluid is fed to a liquid that is located in the container, it is convenient if the pressure inside the storage container does not exceed 10 bar, preferably 6 bar. The feeder fluid or compressed gas in the liquid located in the container gives rise to intimate mixing due to the formation of relatively large bubbles. If an excessively high pressure is selected, the bubbles are small and the mixing effect of the ascending bubbles is slight. Another advantage of a relatively low pressure in the feed line is the fact that the supply system can be connected to the feed line of the container, by means of a connecting piece, even when the storage of the compressed gas is open , without requiring this an excessive application of force. A diameter transmission ratio that is active in the transmission of force to the connecting piece for the hydraulic diameter of at least 2: 1 allows to reduce more the application of force. A supply system according to the invention is illustrated in the drawing, in which: Figure 1 shows a diagram of the supply system connected to a container, Figure 2 shows a side view of a supply system that can be moved by hand, Figure 3 shows a side view of the supply system of Figure 2, moved through 9 °, and Figure 4 shows a plan view of the supply system illustrated in Figure 2. Figure 1 shows a diagram of a supply system according to the invention which is connected to a container 1. The container 1 has a opening 2 with a vertical connection flange 3, a tube 4 of a device for introducing fluid into the interior 5 of the container 1 exits through the opening 2. The end 6 shown on an amplified scale of the tube 4 which is located in the Inside 5 is provided with a hole 7 for a security disk 8. At least when activated, the security disk 8 is arranged inside the liquid of the container and in the vicinity of the bottom of the container, so that the bubbles of ascending gas obtained by the injection gas cause a flow directed upwards, as illustrated by the arrows A. This upward flow in the area of the tube 4 also induces a corresponding flow, illustrated by the arrows B in adjacent areas. The other end of the tube 4 is provided with a bearing flange 9 for connection to the flange 3 of the container 1, it being possible for the connection to be direct or with the use of an intermediate flange. A feeding tube 10 for the fluid to be introduced into the interior 5 is connected to the tube 4. The supply system according to the invention is fed with the liquid to be introduced by a feeding tube 10 which is connected to the flange of the tube 9. A convenient volume of this fluid, at a convenient pressure, is located in the supply system and is only connected to the supply pipe 10 (for which purpose the coupling means 11, 12) is provided in in the case of dangerous situations, in general, the fluid to be introduced that is placed in a tank 13. This tank 13 is fixedly connected to a store of compressed gas in the form of a cylinder of propellant gas 14. The opening of the propellant gas cylinder 14 first ejects the liquid from the container expels the liquid from the container 13 and introduces it to the contents of the tank through the tube 4. The excess gas flowing from the well performs intimate mixing in the tank liquid with the injected fluid due to the vertical flows generated by rising gas bubbles. It is sufficient that the pressure vessel is connected to the supply pipe 10 immediately before the gas cylinder is opened, by means of a quick-fit coupling 11, 12. The quick-fit coupling 11, 12 is connected to the tank 13 to through a flexible hose 15. A discharge pipe 16, one end of which extends almost to the bottom of the tank 13 while the other end is connected to the hose 15, is located inside the tank 13. The tank 13 is filled with an inhibiting solution 17, but in its upper part it has a connection 18 for a compressed gas supply line 19 which is connected to the compressed gas store 14. The tank 13 is provided with rollers 20, 21 and a handle 22, of so that the supply system can be moved manually. If the supply system is activated, pressure builds up in the tube 4. When the pressure required to break the safety disc 8 is reached, the fluid pressure is released into the container 5 through the tube 4. If the fluid that then flows is a mixture of liquid and gas, the gas that flows later mixes the liquid that has been expelled inwards with the contents of the container. Figure 2 shows a side view of the supply system, which includes the wheels 20, 21, the wheel 20 mainly supporting the weight of the supply system, and the wheel 21 being designed as a pivoting wheel. For ease of handling, a handle 22 is arranged in the reservoir 13. The compressed gas store 14 is in communication with the upper end of the reservoir 13 through a connecting tube 19, also arranged in the tank 13. Between the tank and the compressed gas store there is a pressure reducing valve 23, by means of which the gas pressure leaving the compressed gas store 14 at a high pressure can be reduced at a constant pressure of approximately 6 bar. The reservoir 13 has a filling hole, the closure 24 of which is provided with a safety valve for pressure control. With respect to Figure 3 it should be noted that the supply system is shown in a straight position, without the inclination shown in Figure 2, which represents approximately 9o. Figure 4 also shows a plan view of the supply system in a straight position. It is possible to observe the tank 13, the compressed gas store 14 attached thereto, the wheels 20, 21 and the handle 22. The hose 15, the end of which is provided with a connecting piece 12, is wound around the reservoir 13. This connecting piece 12 is designed in such a way that the introduction of force necessary to make the connection can be exerted on a diameter B that is at least twice as large that as the hydraulic diameter D. It is therefore possible, within the established pressure range of about 6 bar, to manually connect the hose 15 to the pipe 10 even though the compressed gas store is already open and therefore is applying pressure to the reservoir 13. In this case, the evacuation is by an external tube 25 that receives the inhibitory solution in the lower part of the reservoir. The tube 25 is connected to the hose 15. In view of the fact that it is preferable that the large containers with recent volumes are square in their cross section, the preferred application range for the invention is for containers for a volume from 20 to 1000 m, corresponding to a vertical tube length of 3 to 11 meters. The total result, together with convenient containers to accommodate the stabilizing liquid and quick-fit couplings, is an inexpensive supply system that operates reliably and requires little maintenance, particularly for storing reactive substances. The supply system is particularly It is convenient to carry out a method for immediately terminating the free radical polymerization reactions by adding an inhibiting solution containing phenothiazine (PTZ) to the system that performs free radical polymerization, at least 45% by weight of the solvent in the inhibitor solution containing a N-alkylpyrrolidone. The N-alkylpyrrolidone may be N-methylpyrrolidone and / or N-ethylpyrrolidone. Furthermore, it is advantageous if the phenothiazine forms at least 10% by weight, preferably approximately 45-55% by weight of the inhibitor solution, based on the weight of the inhibitor solution. It is possible to use the device for a particular effect if the system that performs free radical polymerization includes (meth) acrylic monomers that undergo mass free radical polymerization, where the (meth) acrylic monomer can be a (meth) acrylic acid, and in particular, a (meth) acrylate.

The amount of phenothiazine required to immediately terminate the free radical polymerization reactions depends on the amount of free radicals involved in the reaction. Tests have shown that in many cases concentrations of between 200 and 300 ppm of phenothiazine are sufficient to limit the polymerization to such an extent that it no longer poses any threat. A 50% solution of phenothiazine concentration in N-alkylpyrrolidone remains sufficiently fluid for practical use below temperatures of -10 ° C. In addition, it has been found that freezing does not occur even at temperatures as low as -20 ° C. However, the solution and, therefore, The supply system must be stored in a heated warehouse.In this case, there is no need to take special measures related to the risk of explosion or fire.The 50% solution of phenothiazine / N-alkylpyrrolidone (w / w) can be stored under normal storage conditions of about 5 years.The tests carried out for 6 months at 60 ° C with the exclusion of oxygen only caused slight changes, in view of the fact that 250 ppm concentrations of phenothiazine are sufficient for the immediate termination of the free radical polymerization reactions, it is possible to use few supply systems to protect all possible container sizes. The sample shows the quantities needed based on the volume of the particular container and a height / diameter ratio, as well as the volume of the mixing gas and the mixing time.

Table 1: Tank volume [m] 20 100 1000 Ratio [H / D] 1 1.5 2 1 1.5 2 1 1.5 2 PTZ amount in [kg] 5 5 * "5 25 25 25 250 250 250 250 ppm Tank [liter] 10 10 10 50 50 50 500 500 500 Gas cylinder [liter] [2] [2] [2] 6 6 6 60 60 60 200 bar Gas volume of 0.2 0.2 0.2 1.2 0.8 0.6 12 8 6 mixed in [m] 1 bar Mixing time in 7.0 5.5 5.0 8.5 7.5 7.0 16 15 14 [min] The feeding time of a 50% PTZ solution through a 100 m long horizontal tube with a 10 m long riser tube at a feed pressure of 6 bar is shown in Table 2. The duration of the feeding is shorter than the duration of the total injection. Table 2 shows the time needed to feed fluid to a container for a volume of 50 1, a 3 3 container of 100 m and 500 1 for a container of 1000 m. These times take into account the losses in the pipe for a horizontal pipe of 100 m long and a vertical feed pipe of 10 m long. Feeding times depend not only on the length and diameter of the pipes but also of the dosed volumes. From this, it can be assumed that, based on the actual conditions, a higher metering volume will give rise to a longer feeding time despite the increased cross sections of the pipe.

Table 2: The high concentration of the solution makes it possible to use small supply systems. To store the phenothiazine solution, it is advisable to use stainless steel processing tanks, since although the solution does not attack normal steel, it can be affected by rust. The low weight of the supply systems used means that they are portable. Therefore, they can be stored in protected sites and moved to the appropriate site and location when required. This has a beneficial effect on maintenance costs. For warehouses with more than one container, a single supply system, or a small number of supply systems, is sufficient, with the result that the investment costs are low compared to the individual connections between the containers in question, and normally a supply system for each or a central supply system is customary. The intimate mixing of the contents of the container is mainly for polymerization reactions to be terminated immediately. To achieve this, it is convenient if the gas is fed at a comparatively low mass flow rate, to form large gas bubbles. As these gas bubbles rise to the surface, they produce a continuous convective flow of the contents of the container. The limit of the gas pressure fed to 10 bar, preferably 6 bar takes this into account. The pressure reduction can be established by means of special pressure reducing valves within a certain interval or by means of restrictor holes installed in a fixed manner. An advantage of the system consists in the fact that the fluid can be injected from a safe place and at a considerable distance from the container, which is conveniently from 10 to 500 m. The diameter of the line of Feeding depends on the size of the container, and for containers up to 100 m3 it is between 25 and 40 mm, and for containers between 100 and 1000 m3 it is at least 50 mm. In this case, it is necessary to take into account the fact that the feeding lines with excessive dimensions cause a loss of fluid and the mixing gas due to incomplete transport of the fluid inside the pipe. Although the compressed gas flows out of the compressed gas store initially it only compresses the fluid within the tank to the pipe, so that the gas in the pipe is already compressed and, if appropriate, causes the flow to flow into the vessel 1. As soon as all the fluid has been transported out of the reservoir 13 to the pipe 10 there is a risk that the compressed gas will not push the fluid in front of it in the form of a plug, but rather will flow between the inner wall of the pipe 10 and the fluid without transporting the fluid inward. This is only possible when the fluid in the tank 13 has been discharged to a sufficient degree that the compressed gas can flow into the evacuation tube 16.

Claims (1)

1. CLAIMS A supply system for feeding a fluid to a container (1) that is provided with a feed tube (10), having a reservoir that is filled with the fluid and a store of compressed gas (14) that can be put in communication with this tank (13), wherein the tank (13) and the compressed gas store (14) are arranged in close proximity to each other, wherein the tank (13) can be put in connection with the supply pipe (10) by placing in contact the elements (11, 12), the feeding tube (10) including a pressure regulating valve and communicates [sic] with the container (1), the ascending bubbles in the container (1) inducing a convective flow A directed upwards in an open area (8), thereby inducing a corresponding B stream. The supply system as claimed in claim 1, wherein the reservoir (13) and the compressed gas store (14) are designed as a portable unit. The supply system as claimed in claim 1, wherein the internal pressure of the storage container (1) does not exceed 10 bar, preferably 6 bar. ________ki________ The supply system as claimed in claim 1, wherein the connection piece (11, 12) can be connected to the feed tube (10) of the container (1) even when the compressed gas store (14) is open . The supply system as claimed in claim 4, wherein the ratio of the diameter D that is active in the transmission of the force to the connecting piece (11, 12) to the hydraulic diameter D is at least 2: 1.