US 3455348 A
Description (OCR text may contain errors)
J ly 1969 A. STINGELE ETAL 3,455,348
APPARATUS AND METHOD FOR FILLING GLOVEBOXES WITH A PURE ATMOSPHERE Filed Jan. 16, 1967 INVENTORS United States Patent 3,455,348 APPARATUS AND METHOD FOR FILLING GLOVE- BOXES WITH A PURE ATMOSPHERE Alwig Stingele, Alkmaar, North Holland, and Robert De Cat, Groet, Schoorl, Netherlands, assignors to European Atomic Energy Community (Euratom), Brussels, Belgium Filed Jan. 16, 1967, Ser. No. 609,666 Claims priority, application Germany, Feb. 4, 1966, E 30,999 Int. Cl. B65b 31/04, 31/02 US. Cl. 141-65 1 Claim ABSTRACT OF THE DISCLOSURE An enclosure having a first valved inlet with an inflatable balloon which substantially fills the enclosure when inflated attached thereto on the inside of the enclosure, and a second valved inlet. The atmosphere in the enclosure may be changed by inflating the balloon while expelling the actual atmosphere through the second inlet and admitting a new atmosphere through the first inlet.
The invention relates to an apparatus and method for replacing the gaseous atmosphere in an enclosure, such as gloveboxes, hot cells and similar equipment, by a pure or exactly controlled atmosphere.
This replacement, for example, for filling a glovebox with inert gas, is at present generally carried out by cleansing with the gas in question, when the air that was originally present is gradually expelled by the cleansing gas. But as gas diffusion and turbulent flow prevent the quantitative expulsion of the air in this case, large quantities of cleansing gas are always consumed, and this may be very expensive, for example, in the case of highly purified inert gases.
It is also doubtful whether the desird degree of purity is obtained at all, for example, because of rediffusion.
The method used in the art whereby gas is drawn oif from a glovebox by means of a pump only permits reduced pressures and pressures in excess of a few mm. Hg in the case of gloveboxes, and the repeated pumping-out to a low reduced pressure followed by the admission of the pure gas to a low excess pressure is very time-consuming. In one case, for example, it took three weeks and the consumption of several cylinders of high-purity argon to obtain an anhydrous argon atmosphere in a glovebox.
The desired atmosphere can easily be produced in steel gloveboxes by pumping out to a high vacuum and then filling with the purified gas. But these steel boxes are expensive, and the vacuum pump required must also be taken into account.
A simple, inexpensive and rapid method of simplifying the replacement of gaseous atmospheres, particularly in gloveboxes, has not yet been possible.
The problem is encountered in chemical laboratories, at both high and low temperatures, for scientific and industrial operations in general which must be carried out in an exactly defined gaseous atmosphere.
The main feature of the invention is as follows: to separate the gas to be expelled in the enclosure from the purified gas with which it is to be filled, a rubber or plastics balloon is mounted on a gas inlet nozzle in the enclosure, this balloon being dimensioned so that when inflated it expels substantially all the gaseous atmosphere in the enclosure through an outlet provided for the purpose.
The enclosure is then filled with the desired gas, for example, through the valve through which the gaseous atmosphere was previously expelled.
FIGURE 1 shows, by way of example, a specific embodiment of a glovebox according to the invention.
When the glovebox 1, on which a pressure lock 2 is disposed, is to be filled with a high-purity gaseous atmosphere, any desired gas (air, CO or nitrogen) is first pumped through the gas-inlet valve 3 into a balloon 4 made of suitable, readily expandable and gas-tight material, which is mounted gas-tightly on a nozzle 6 in the glovebox 1, for example, by means of a clamping ring 5. Gas is blown through the gas-inlet valve 3 into the balloon 4, so that the latter is inflated and expels thegaseous atmosphere originally in the glovebox 1 through the open valve 7. When the balloon 4 is well inflated, it occupies substantially the whole of the volume of the glovebox 1, so that over 99% of the gaseous atmosphere of the glovebox 1 is expelled through the valve 7. The desired highpurity gas is then admitted into the glovebox 1 through the valve 7, and the balloon 4 is evacuated through the valve 3. The atmosphere in the balloon 4 is thereby expelled from the glovebox 1 through the valve 3. Both when the balloon is being filled and also when the desired gas is being admitted, a slight excess pressure permissible for the glovebox type in question may be used to reduce the remaining volume as far as possible.
A similar procedure may be followed to fill the lock 2 with pure atmosphere. The balloon 9, which is disposed there attached to the valve 8, is filled until it has substantially expelled the gas originally in the lock through the valve 10, and the desired high-purity gas is then admitted through the valve 10 into the lock 2, the balloon 9 being compressed again and the gas it contains being forced out through the valve 8. FIGURE 1 also shows a possible alternative; the three-way valve 11 enables either the lock 2 or the glovebox 1 to be used for the admission of the desired pure gas. This simplifies the operation. Of course, the three way valve 11 may also be used in cooperation with pressure comparison equipment to compare the pressures in the lock and in the enclosure.
After the operation has been repeated two or three times, the purity of the atmosphere in the glovebox closely corresponds to that of the pure gas that has been admitted.
The filling process may easily be carried out completely automatically, if a valve is used that switches off automatically if the pressure rises suddenly in the balloon, when the glovebox is completely full.
The introduction and removal of equipment or material by means of the lock can therefore be greatly simplified; for the gaseous atmosphere of the lock can be replaced rapidly, conveniently and cleanly and independently of the atmosphere in the glovebox itself.
The invention is not restricted, however, to the embodiments described and indicated.
Thus, for example, the nozzle carrying the balloon may be in a recess in the wall of the glovebox or lock, the recess may be large enough to receive the balloon when empty, and can also be sealed gas-tightly with respect to the interior of the glovebox, for example, by a lid. This may be advantageous, for example, when substances that are liable to attack the balloon material are used.
According to another useful and technologically advantageous embodiment of the invention, the two nozzles for the admission and discharge of gas, and the desired measuring equipment and gas cylinders are assembled to form a transportable unit, which can easily be transferred when required from one glovebox to another. This may be done, for example, by means of locks or couplings specially provided for the purpose. The unit can then be taken off the glovebox after gas exchange has taken place and the specially provided lock has been closed from within.
It is advantageous to connect the unit to the lock provided for the connection in a readily detachable gastight manner. This can easily be done by known priorart means.
The apparatus and the method according to the invention results in a considerable saving of time and expensive protective gases, such as pure helium and argon, while the cost of the apparatus is low.
1. An enclosure such as a glovebox, hot cell and like equipment having a first valved inlet, an inflatable balloon attached to said inlet on the inside of said enclosure, said balloon in an inflated condition substantially filling said enclosure, and a second valved inlet in said enclosure by which a gaseous atmosphere is selectively introduced and expelled in conjunction with inflation and deflation of said balloon, a pressure lock attached to said enclosure and providing access thereto, duct means interconnecting References Cited UNITED STATES PATENTS 1/1956 Meyer 222389 X 9/1959 Bender et a1 14165 X HOUSTON S. BELL, JR., Primary Examiner US. 01. X.R.