US2191799A - Sterilization - Google Patents

Description

Feb. 27, 1940.

w, H. MCKENNA 222191,!99

STERILIZATION Filed April 22, 1936 Sheet$-5heet 2 INVENTOR,

BY .Mllwuza,

AWORNEY.

Patented Feb. 27, 1940 UNITED STATES PATENT OFFICE STEBILIZATION Application April zz, 1936, Serial No. 75,694

2 Claims.

This invention relates in general to sterilization and in particular to sterilizing apparatus of the self-contained unit type including means within the unit in which the sterilizing media are ll generated and within which articles to be treated are received and therein subjected to the action of the sterilizing media. coordinately therewith my invention relates to a method of sterilization.

While the particular apparatus dis-closed herein and the method of sterilization disclosed in connection therewith are particularly adapted for the sterilization of hollow vessels such as drinking glasses, it is to be understood that I do not limit my invention to such particular application, as the uses thereof may be many and varied, and require for particular application only the modification of subsidiary details of the particular embodiment disclosed herein.

The general objects of my invention may be stated to include a simple, convenient, effective and inexpensive method of sterilization and the provision of a simple, compact and efficient sterilizing unit that is low in cost of manufacture, installation and operation.

Among the particular objects may be mentioned the provision of means for sterilizing articles to be treated and for washing them to remove the sterilizing agent from the articles, the provision of a single receptacle in which the articles are subjected both to the sterilizing and the washing agents, the provision of a selfcontained unit having means therein for treating articles with sterilizing and washing media, 35 together with means for generating such sterilizing and washing media, the provision of means A for efliciently applying sterilizing and washing media, to hollow vessels, the provision in a sterilizing compartment of a system of jets for efficiently directing sterilizing and washing media against the walls of articles, whereby said articles are subjected to effective treatment; and the provision of means for protecting articles as they are being inserted into the sterilizer, from damage.

There may be further mentioned among the particular objects of my invention the provision of a water heater of novel and eflicient construction for applying heat to water and thereby making said water more effective as a washing agent, and giving it sterilizing properties as well; the provision of a novel and eflicient gas burner for use in heating the water; the provision of novel and efilcient' means for generating a sterilizing agent.

For the attainment of these objects and such other objects as will hereinafter appear .or be pointed out, I have illustrated one embodiment of my invention, and indicated its manner of use in connection with the method phase of my 5 invention, in the drawings, in which:

Figure 1 is a view in perspective illustrating the appearance of the outside of my sterilizing unit;

Figure 2 is a sectional view on the line 22 of 10 Figure 1, looking in the direction of the arrows;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2, looking in the direction of the arrows;

Figure 4 is a view in perspective of details of portions of the water heater;

Figure 5 is a view in perspective of the gas burner; and

Figure 6 is a detail sectional view, on a greatly 2o enlarged scale, on the line 6-6 of Figure 5, looking in the direction of the arrows.

Before describing my invention in detail I will briefly point out the main features thereof.

The method phase of my invention involves the 25 steps of exposing substantially the entire surface of the article to be sterilized to the action of a sterilizing agent and thereafter removing the sterilizing agent and the products of its action by the application of a washing agent, 30 which may at the same time be a sterilizing agent.

For carrying out the method just described, I have disclosed apparatus that comprises, first of all, a compartment for receiving articles to be sterilized and that contains means whereby a sterilizing agent may be sprayed against the Walls of the articles to be treated and also contains means whereby the walls of the articles to be treated may be subjected to the action of 40 a washing agent or a washing and sterilizing agent. A generator for sterilizing fluid forms another part of the sterilizer, and the particular type thereof herein disclosed comprises a container adapted to receive a cake or brick of disinfectant in solid form and means for applying water to the said brick of disinfectant so as to dissolve it. The sterilizing solution so formed is conducted into the sterilizing compartment by a suitable system of conduits.

My apparatus further comprises means for heating water for the purpose of raising its temperature to such an extent that it will act more efiectively as a washing agent, and, in addition, will have sterilizing properties due to its high temperature. The apparatus for heating water comprises a water heater of novel design associated with a gas burner for supplying the necessary heat, this gas burner being automatically controlled so that the temperature of the water will be maintained at the desired level. By a suitable system of conduits the heated water is led into the sterilizing chamber.

There is further provided in conjunction with my apparatus convenient manual control means whereby either the sterilizing fluid or the heated water may be applied as desired but whereby they can never be simultaneously applied.

All of these parts are mounted on a frame so as to form a unit adequately enclosed so as to prevent access to all of the parts except the sterilizing compartment.

Referring now to the drawings in detail and particularly to Figure 3, the general arrangement of parts will be observed, and attention will be called to the positioning of the sterilizing chamber S, the water heater H, the generating chamber D, the thermostatic control means for the water heater T, and the control means C by which the operator regulates the admission of the sterilizing fluid or the water into the sterilizing chamber.

On referring to Figure 1 it will be seen that the whole apparatus except the control lever C is surrounded by a cover K. Access may however be had to the sterilizing compartment S through an opening 0 in the cover, this opening having its edges padded so as to prevent damage to articles as they are inserted into the sterilizing compartment, and there is further provided in the cover K a ventilating opening V positioned directly over the water heater H. This opening how ver is shown as having a screen provided therein, so as to permit the circulation of heated air therethrough and yet protect the interior of the apparatus.

All the parts of the apparatus including the cover K are shown as supported on a bed plate B resting on legs L.

Referring now to the sterilizing compartment S in detail, it will be seen, as clearly appears from Figures 2 and 3, that it comprises a container l0, shown in its illustrative embodiment as rectangular in cross-section, although not necessarily so, and it is open at the top so that articles to be treated may be inserted thereinto.

Within the container I0 is shown a system of conduits adapted to receive heated water through the pipe l2 (see Figure 3), and comprising a central upwardly directed passage It provided with a spray head l6, whereby the heated water will be sprayed upwardly as indicated in Figure 2, and into contact with the walls of a hollow vessel, such as a glass G. Branching oif laterally from the conduit [4 are shown two tubes l8 provided with spray heads 20, adapted to direct a spray of water along the outside of the glass G, as indicated in Figure 2. These spray heads may be of any suitable or preferred form. I have shown by way of illustration a form in which an angularly positioned splash plate 2| receives a jet of water against its lower surface and suitably spreads and directs it.

Surrounding the centralpassage I4 is an annular conduit 22 provided with outlets 24,v and shown as in communication therewith, by means of a tube 26, and positioned above the same is a second annular conduit 28 provided with openings 30. This upper tube 28 is adapted to receive sterilizing fluid from the generator D through a tube 32. It will be observed that the openings 24 are shown as so directed that sterilizing fluid will be discharged against the inner walls of the glass G (see Figure 2) while the openings 36 areshown as so directed that the sterilizing fluid will be discharged against the outer walls of the glass G.

The annular conduits 22 and 28 are conveniently mounted on a frame 34 that is shown as mounted on brackets 36 provided onthe walls of the compartment Ill and that may carry pads 36 of, any suitable material, such as rubber, that will serve as a resting place for the glass and prevent damage thereto.

The bottom 40 of the compartment Ill is shown as sloping toward an outlet 42 at the lowest point thereof, this outlet being in communication with a drain pipe 44, whereby the sterilizing fluid and through the opening 0, such as rubber for instance.

At its upper rim the compartment It) may be provided with a gasket 52 in contact with the cover K, for the purpose of preventing the splashing of fluids from the chamber l0 into the other portions of the apparatus, and for this purpose the gasket is made of material, adapted for this purpose, such as sponge rubber.

Referring next to the sterilizer D it will be observed that it is shown as comprising a jar or container 60 of any suitable or preferred type in which is contained the sterilizing ingredient in brick form as shown at I6. This container is shown as provided with a cover 62 that may be clamped in place thereon by an arrangement shown illustratively as comprising wing nuts 66 engaging the threaded ends of rods 66 projecting upwardly from the bed plate B of the sterilizer. A gasket 10 of suitable material, such as sponge rubber, is interposed between the cover 62 and the container 60, for preventing leakage, and two openings are provided in the cover, through one of which sterilizing fluid is supplied to the sterilizing chamber S by a system of conduits comprising the elbow I2, shown as connected, by a flexible tube 14 with the conduit 32 leading into the sterilizing chamber, while the other opening is in communication with the valve I26 through which as will be subsequently described, water may be admitted from a source of water supply into the generator D. The latter system comprises a flexible tube I30 leading from the valve I26 into a pipe 16 shown as carried by the cover 62, and extending centrally to a point well toward the bottom of the container 60 and into such a position that it may pass through the opening in the cake or brick 18 of solid, but soluble disinfecting or sterilizing material, and a stand that is shown in Figure 2 as positioned in the bottom of the container and asv produced by the solvent action of water in the container 88 on the brick 18.

To attain the purposes of my invention more effectively the brick I8 is of such a nature that when it is exposed to the action of water, a portion of it will be dissolved and impart sterilizing properties to the water. At the same time however it is of such a character that it will not disintegrate, as this might result in an undesirable increased rate of solution, and a sweeping away of the small particles with the water stream every time water is admitted into the jar 88, and before they could dissolve.

A further desirable characteristic is that the bricks will not readily lose their effectiveness when stored, prior to use.

I have found calcium hypochlorite, Ca(OCl)z, to be a suitable substance for sterilizing purposes and I have found sodium metasilicate, NazSiO3, to be a substance that efliciently performs the necessary binding function when incorporated with the calcium hypochlorite.

As an example of suitable proportions that may be used, I may state that sodium metasilicate will prevent disintegration of the brick when its quantity amounts to about 15 to 20% of the weight of the brick.

I have also found that I may secure a binding effect with a brick of 'calcium hypochlorite by adding thereto a mixture of approximatelyflve parts by weight of lime to one part by weight of sucrose. About one quarter of the weight of the brick may consist of this mixture.

I have further found that either of the binding agents hereinabove mentioned will be effective to conserve the available chlorine content of the bricks prior to use, and this whether they are kept in air or in sealed containers.

It will be understood, of course, that after being subiectedto'the water in jar 68, for a time, the bricks 18 will lose their potency. and that during use the operator will insert bricks into the jar 68 as often as they are required, and this is very conveniently done since the cover of Jar 88 is readily removable merely by unscrewing the wing nuts 84.

If the jar 68 is made transparent, it will render the brick I8 visible-to the-operator and will aid him in judging whether a fresh brick is needed.

I will, next describe the water heater H, shown' in place on the apparatus in Figure 3, and the water conduits of which are shown in detail in Figure 4, while the gas burner features are shown in Figures and 6.

In Figure 4 I have shown a water heater that comprises a central tube 8| flanked by a pair of tubes 82 and 84, of lesser cross section, and these tubes 8|, 82 and 84 are carried by flanges 88 and 88. A pair of end plates 88 and 82 are adapted to seat respectively on the flanges 88 and 88, in water tight engagement therewith.

The plate 88 is shown as provided with a groove or channel 84 serving to establish communication between the tubes 8| and 84, and the plate 82 is shown as provided with a groove or channel 88 serving to establish communication with tubes 82 and 84. The plate 88 is further providedwlth a water inlet ,88, while the plate 82 is provided with a tubular extension I88 through which an element I82 of the thermostatic regulator 'I' may be inserted into the tube 8|.

The system of tubes 8 I, 82 and 84 together with the flanges 88 and 88 are shown as so designed that they may be cast in one piece, and this construction I have found very advantageous although it is to be understood, of course, that if desired the parts may be assembled from separate pieces.

I have also shown a water outlet tube I84 mounted on the central tube 8|.

It will be understood that when the parts just described have been assembled, that the water will enter through the inlet 88 and will pass through the tube 82, the channel 88, the tube 84, the channel 84 and into the central tube 8| from which it will be discharged through the outlet I84. The water inlet 88 is shown as connected to a source of water supply II8 through a valve H2 and a pipe I88.

Branching off from the pipe I88 is shown a pipe II4 leading to a safety valve II6 of any suitable or preferred form that discharges into the water outlet 44 through the pipe H8, and the function of which is to relieve excess pressure in the water heater H, if for any reason the pressure therein rises slightly above the normal or water supply pressure.

The water outlet I84 is connected by a pipe I28 to a control valve I22 from which the water is led into the conduit system I4 and I8 of the sterilizer compartment S, by means of a pipe I24. The valve I28 is mounted adjacent to a similar valve I28 that serves to conduct water from an inlet pipe I28 through the tube I38 into the inlet pipe I8 of the generator D.

The valves I22 and I26 are arranged for operation by the control lever C'so that the sterilizing compartment S may be supplied either with heated water or with sterilizing fluid from the generator D. The lever C is carried on a rock shaft I32, shown as mounted below the bed plate B of the machine, as clearly appears from Fig-; ure 2, and as carrying a pair of lugs I 34 and I38, shown in dotted lines in Figure 3, and these lugs are intended to press respectively against and to actuate members associated with the valves I22 and I26 so as to cause said valves to open. By way of example, I have shown the valve stem I38, associated with valve I26 (see Figure 2) operable by the lug I36, and a similar valve stem is associated with the valve I22. The valve stems associated with the valves I22 and I28 may be caused to return to their normal or closed position by any suitable means such as springs, which may serve, at the same time to cause the control lever C to assume its central or inoperative position.

When the control lever C is moved rearwardly, as seen in Figure 2, the lug I 34 will be lowered and the lug I38 will be raised, thereby raising the valve stem I38 01' the valve I28 and admitting sterilizing fluid into the conduits 22 and 28. When, on the other hand, the lever is moved forwardly the lug I 34 will be raised, raising the valve stem of the valve I22 and admitting the heated water into'the conduit system I4, I8. It will be observed that the two valves can never be opened at the same time, and that the arrangernent offers a maximum of convenience in manipulating the valves successively.

Positioned beneath the water tube system 8|,

82, 84 is a gas burner, of which an illustrative form is shown in detail in Figures 5 and 6. The burner as shown is suitable for use with ordinary illuminating gas or gaseous fuels of similar type.

By referring to these figures it will be observed that I show the gas burner proper, at I48, as a conduit of flattened cross section, having two lateral rows of openings I42 on the upper sur- .face thereof, through which the gas escapes,

and when ignited serves to heat the water in the heater just described. The conduit I is in communication with a conduit I44, positioned therebeneath, through the elbow section I46, and it will be observed that the system I44, I48 and I40 is shown as substantially U-shaped, which assures a suitable length of conduit disposed within a small space. It will further be observed that the system I44, I48 and I40 may be cast in one piece if desired.

At the entrance portion of the conduit I44 I have shown a bushing I48, with a conically flared entrance I49, threaded into the conduit I44, and this bushing is adjustable in position within the conduit I42 for a purpose that will appear hereinafter.

It is to be understood that the parts just described are mounted in a suitable position in the frame of the machine in any suitable or preferred manner. I have indicated one manner of support in Figures 4 and 5, in which the flanges 86 and 88 are shown as having bolt holes 81 therein, that are adapted to register with threaded openings 89 provided on the ends of the burner I40, whereby the water conduits of the heater may be supported on the burner I40.

The gas burner is shown as having flanges I43 projecting laterally from the lower leg I44 thereof, through the openings I45 of which suitable fastening devices, such as screws, may pass for the purpose of attaching the gas burner and, in fact, the whole water heater to the frame.

Projecting into the conical mouth portion I48 of the bushing I48 is a tapered nozzle I50 shown as carried in a bushing I52 adapted to be mounted on the end of a pipe I53 through which gas may enter the nozzle. It will be observed that the end of the nozzle I50 is shown as conically tapered and that the walls of the tapered portion are spaced from the conical mouth por- I tion I49 of the bushing I48, and that this conically tapered portion of the nozzle is provided with two outlets I54, that are directed laterally and forwardly, and serve to conduct gas from the pipe I53 through the central bore I55 of the nozzle I 50 into the conduit I44. By adjustin the bushing I48 the passage between the said bushing and the nozzle I50 may be regulated in cross-sectional area, and thereby the flow of gas increased or diminished, as desired. This serves to regulate not merely the admission of gas but the admission of air as well, as will be understood from Figure 6, from which it appears that adjustment of the bushing I48 varies the cross-sectional area of the air inlet between the bushing I48 and the nozzle I50.

The advantages of this construction may be stated to be absence of flare-back", which may be accounted for partly by the fact of the great length of the conduit between the burner proper I40 and the air inlet, andyet, while I have provided a length of conduit that will prevent the flare-back, owing to the peculiar disposition of the parts, as already explained, the burner occupies very little space. v v

The pipe I53, already mentioned, is connected to the gas control valve of the thermostat T, whichat its other side is connected to the gas inlet pipe I56. It will be understood that the thermostatic regulation is effected through the element I02 already described, that enters the water heater through the extension I00 of the end thereof, and by the eifect of the temperature within the water heater thereon regulates the aforementioned control valve.

Attention will further be called to the cover I48, shown as placed over the water heater H and provided with an opening I50 therein, registering with the opening V of the cover K (see Figure 1), and which permits the products of combustion to escape through the opening V. It will, of course, be understood that the function of the cover I58 is to confine the heat as far as possible within the space surrounding the water heater so as to make the heating action more effective, as well as to protect the surrounding parts from any injury by the heat.

By referring to Figure 2 it will be observed that I have shown the cover K as provided with flanged portions 48 on the inside surface thereof, adjacent its lower edge, and these flanged portions are shown as supported by brackets 48 projecting from the bed plate B of the machine.

After a reading of the foregoing description the great convenience and effectiveness of my method and apparatus may be more fully appreciated. The operator may position himself so that he can manipulate the control lever with one hand and then insert glasses or other articles into the sterilizing compartment with the other. The necessary operations in the case of a glass would include merely the steps of inserting the glass, bottom up, into the sterilizing compartment, moving the lever C in one direction to admit the sterilizing fluid, moving. the lever C in the opposite direction, so as to admit the heated water, and thereafter removing the glass from the apparatus.

The times of exposure to the sterilizing fluid and the water need be only very brief, because the exposure is simultaneous on all the surfaces of the glass that require sterilization. I have found in practice that an exposure of the order of three seconds to the action of the sterilizing fluid will ordinarily be suficient to destroy substantially all bacteria on the glass surface, and where this is followed by the application of scalding hot water, also for a brief interval, which water has a further sterilizing action, and which serves to wash away the sterilizing fluid, the effectiveness of the treatment, even though brief is readily appreciated.

While I have herein disclosed one illustrative embodiment of my invention and one manner of practicing the same, it will be understood that the same may be embodied in many other forms and practiced in many other ways without departing from the spirit of my invention, as will be obvious to those skilled in the art, and I do not limit myself in relation thereto other than as called for by the prior art.

Having thus described my invention and illustrated its use, what I claim as new and desire to secure by Letters Patent is:

1. A sterilizer having a sterilizing compartment, a water supply pipe, a pair of pipes branching off from said water supply pipe, a valve associated with each of said branch pipes, and

adapted to open or close its associated branch pipe, means for opening and closing saidvalves alternately, one of said branch pipes leading into means for charging the water thereof with a chemical sterilizing agent, means for discharging the chemically charged water into said sterilizing compartment communicating with said chemical charging means, the other of said branches leading into means for raising the water therein to a sterilizing temperature, means for leading the I heated water from said heating means to said sterilizing compartment and discharging it thereinto, and an outlet pipe for draining the spent chemically charged water and the spent heated water from said compartment.

2. A sterilizer having a sterilizing compartment, 9. water supply pipe, a pair of pipes branching of! from said water supply pipe, a valve associated with each of said branch pipes, and adapted to open or close its associated branch pipe, a single means for opening and closing said valves alternately, one of said branch pipes leading into means for charging the water thereof with a chemical sterilizing agent, means for discha g g the chemically charged water into said sterilizing compartment communicating with said chemical charging means, the other of said branches leading into means for raising the water therein to a sterilizing temperature, and means for leading the heated water from said heating means to said sterilizing compartment and discharging it thereinto.

WILLIAM H. MCKENNA.

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