Патент USA US2411681код для вставки
Nov. 21;, 1946. " H_ EGLI _ PROCESSA AND APPARATUS FOR PASTEURIZING MILK A Filed Feb. 19,. 1941 2,411,681 Parenteel Nov. 26, 1946 ' ,_ ' ' ' 2,411,681 2,411,681 ' PRòoEss'AND Ari’ARA'rUs Fon *y ' .PAs'rEUmzrNG MILK ` nulareich Egli, ßalt'iniorejMd. " n Í Application February 19, 19111, serial No. 379,731 ~ ioclaims. (Cres-211) 2 ’ ’,)I'he particular apparatus` .for warming the »milk is somewhat immaterial, steam, electric con nections, or hot water being suitable agents. My ‘preferencev is largely in favor of hot Water be _ ’This ,invention relates 4to a method and an ap paratus for vhandling ,and storing of ' fluids and has for its principal object the provision of lmeans to handle and store, with a minimum _amount of foaming and shrinkage, aliquid composed Vof a plurality of ingredients, such for example as milk. YAn important object of the present invention is the provision of a system for pasteurizing milk cause of its easy control. The hot water enters at 24, past a stop valve 25 and a control valve 26, the latter being `governed by a thermostat 21 set in the vat or container at a convenient height preferably nearer the bottom .than the top. Un in an eflicient manner and under conditions which minimize the presence of bacteria in .the ñnished 10 der each containerthere is a suitable heatingY de viceindi'cated generally by the numeral 30 which product. While for convenience lof illustration inthe case vof hot Water would be a simple jacket and description’of the process, «the apparatus will having yanzentry valve 3 I and an exit valve 32 lead be described in connection with a system for pas ing .to 4the return conduit 33 which leads to the 'teurizing milk, it should be obvious that .the inven tion is not thus limited and that the method may 15 heater, not shown, which delivers the Water to the pipe 24. By` placing the heater under the be used in connection with any fluid whether of tank the rising ofthe warmer particles by change a single ingredient or a mixture of ingredients, of -,density with vincreased Itemperature takes the for example,` the process issuitable for a fluid place of an otherwise necessary agitating means.> either gaseous or liquid', i. e., beer, milk, or any of the various beverages on the market. ,l consistsof a method of storing fluids, the' lower vfluid being atene temperature and the upper fluid being »at a díiferent' temperature. A still further object lies in the provision of a system of'holding milk during .thepasteurizing process in a plurality of containers each cross-connected to the others so that the pressure on each batch is identical. “It is desired to'have the temperature ofthe ` ' 'A Vstill further object of the present invention fluid a‘bove the liquid »at all times greater than >that of .the lower fluid, the pressure of the fluid above the liquid being greater than atmospheric. To this end the pipe 40 supplies heated and ñl 25 tered ,air to each of _the tanks .through the ver tical feeder pipes 4I. Jackets 43 surround the vfpipe 40 as shownand might use electrical re sistance wires or steam or hot Water, preferably va liquid’ controlled'by a stop valve 44 and an elec . Still further minor lobjects of 'the invention will 30 trical control valve 45'which admits the heating v be apparent from the following description and „ ‘fluid at such a' rate as to keep the air at the chosen ftemper’ature, for example, at 150° F. at the tops was'set forth in the claims, A . The/drawing illustrates a system primarily in tended for the pasteiirizing of milk. `Í' . of the containers, the pressure varying in accord v'ance with the hydrostatic pressure on> the milk or The apparatus illustrated in the figurel con OJ CA- other liquid, for example, it might be ñve pounds 'corresponding to la lift of over ten feet. The hot sists of a plurality of containers' Illa to Iûe each 'wa-ter, if used, might be as highvas 180° F.,'the "receiving hot milk _from a main line II feeding famount vbeing controlled bythe valve'45 and by Vr`to branches' I2 leading’to e-ach of theseveral vats the valve 48', which latter however need 'onlybe or tanks which are of Well: known type and may a stop' valve for emergency use being located in 'ibe jacketed `or insulated as indicated at„I4l in ‘connection with container |01). The advantage of Va plurality of containers Vlies in the' provision of continuous flow, one container is'iilled -as another is emptied. The several branch lines I 2 each lead Y to Aa valve' I5 electrically controlled to discharge "the hot milk through a `pipe ` I6 toa point close . 'to .the bottom of the tank I0. Asimilar pipe I1 leadingr from a Well `I8' discharges the milk through 4branch lines I 9 to thejexit header 20 when permitted by the electrically- controlled exit valve 2I. It might be noted here that while the `-valves I5 and 2l maybe mechanically operated Yor may `be electrically controlled in any manner it is my preferencethat these valves shall'beop .erated by timealone;v _, .; ., >the returnline 49 which discharges back to the lheater, »not shown, kwhich supplies the pipe 42. y Theelectric panel 50 controls the various me chanismsy and its vspeciñc construction forms no ' part ofthe present invent-ion.r Theïpanel is con nected by the cable 5I with each inlet valve and isïconnected by the cable 52 with each of the exit The thermostat 56 extendinginto the > valves. air space above the liquid in the last container 50 Ille actuates mechanically or electrically, prefer ably `the latter, the heat supply control valve 45 through the Wire 51 which may,'but need not, be connected to the panel 50. , ì , , Theshrinkage 0f the liquid. which is thought 55 „tolbe inseparablefromthe process of pasteurizing 2,411,681 3 is practically eliminated in my process by pre venting air from taking moisture from the milk. This is accomplished by using the same air over and over again during an indeñnite number of cycles of filling, holding, and emptying. As the air is displaced from one container, as Iûa, the same air at constant temperature and pressure is entering another container, as 10e, without need for appreciable make-up air from outside. vHence 4 header 40 in the ñrst tank it is entering the ñnal tank Ille at precisely the same rate and the same temperature and pressure, The valve 62 on each container insures that the temperature of the air or other iluid at the top of the container shall Y remain constant. The thermostatically operated valve opens at a chosen temperature, say 148° F. and lets out the air which at this temperature is colderV than desired and'by lowering-the pressure this air after first being saturated with Water va causes air' to enter fromA the heated air line 43 'por ís incapable of taking up further moisture and, corresponding to its pressurey counteracts' which itself is kept at a constant pressure by the the vapor pressure of the liquid and consequently Y ordinary mechanism and its temperature is maintained by the automatic Valve 45 controlled avoids shrinkage. In my process foaming is minimized by increas by' thermostat 56 in the removable top of con tainerv Ille. As is quite obvious, the valve 62 will ing the surface tension so as to prevent the open. upon a rise of temperature when the sys tem is used for chilling the liquid as in that case theY temperature of the upper fluid will be lower than that of the liquid beneath, and the heater ules of gas from coalescing. In froth or foam an enormous area of gas surface is produced as 20 30 will be a refrigerating device. As milk rises in the tank AIlia it receives heat the gas phase is dispersed as minute bubbles- in from the heater in contact> with only a portion of the liquid phase.. The gas bubbles persist. for the bottom of the container.A The thermometer some time. owing to the presence of milk colloids t5 indicates the temperature and the adjacent in a solid condition.v Foamingv tends to convey thermostat operated by the temperature opens or bacteria, is wasteful, and tends to hinder eñicient closes the valve 26,' thus insuring precisely the handling of the milk or the ñuid being treated. correct temperature in the containers at all As stated in Department of Agriculture Circular gathering of the active colloids to spread in ñlms sufficiently tough and elastic as to keep the glob’ 108, March 1930, foaming> in pasteurizersr may present a public health problem. hence its. avoid ance is of paramount importance. By having relatively deep containers with increased pres sure above the liquid therein, the gap or diiîer ential between the boiling point of the water at the bottom of the tank and` that of the water near the top of the tank is reduced so a greater surface tension of the liquid is obtained and with it. a substantialv absence of foaming anda material reduction of skin formation. A simple experiment will show that when a foaming liquid is discharged. into a container held at a positive or above. atmosphere pressure an appreciable amount of the foaming at once collapses with coalescence of the occluded gas bubbles.l The temperature con-trol is essential. in the pasteurizing process; also in holding processes of beverages consisting of mixed ingredients. At times it is desirable to maintain a slightly higher temperature. at the exposed. surface to air> pres sure of the contents than that of the contents times. ' Assuming the chosen' temperature for pasteuriz ing is 145° and the' cycle is one hour, the ther mostat 21 will operate to close the valve 26V at a temperature of 146°, thus insuring the tempera ture of the milk. The temperature of the' air is greater and this is' controlled' -by the Valve 62 as` noted. With the arrangement illustrated it ,would take 12> minutes to empty or tov fill any one of the tanks, these two operations always being simultaneous in the'series.. Any one tank or container which began iìlling at the even hour starts’to empty 36 minutes after' it has been filled, i. e., at 48‘minutes after the hour, thus complet ing the hour when it is' fully empty. While I ñnd it best to have a separate temperature con‘ trol of the compressed air above the liquid in the holding containers, there seems to be no need for an independent control of the temperature in the various heaters 3'0, nor‘is there need for in dividual control of the heat- in the several' jackets 43 as the> pressureV in' the pipes 4l) and’ 4l is au itself. For this: reason the pressure. equalizing conduit, which is cross connected withV all containers, is independently controlled. as to tem tomatically maintained by the pressure equaliz ing features described'. As previously'suggested the sameequipment', with somewhat differentcon peratures governed by the. thermostat. inserted nections, also serves at otherv times to chill the milk, the mains 431 and 24‘ now carrying a re into the air space abovev the liquid line. in. the containers. Further details of the invention can. best. be understood through a description. of the opera tion of the> mechanismy when the process com prises the pasteurizing4 of milk. In the. drawing frigerant. What I claim is: 1‘. The process‘of minimizing frothing inchang i'ng a liquidvv into -containers which consists' in providing two containers with the liquid' beneath the three center containers are each` full and are a fluid at a pressure above atmospheric„ cross being held at> chosen ten-rperaturer and pressure connecting th'e'fluids to equalize. their pressure, and introducing further liquid under pressure both for thev milk at the bottom and» for the air th-roughpipe Il", branch line- i2, past electrically into one container as liquid at theI same rate is withdrawn from the other container. 2. The process of claim 1V in which .the tem perature of the fluid is maintained at a. predeter controlled entry‘valve t5 and tank pipeA` I6 which mined degree in each containerrand` the fur is secured toV the> removable cover 6l)> which' car ries a. thermometer 6l' and a relief valve B2i as stant pressure. above.- The ñnal. containerr Ite is- being emptied and the ñ-rst container- ma is being filled, the milk at a- temperature; of say 145.»o F; entering therv liquid isv introduced ata substantially con ' 3. The process. of claim, 1 in whichy the fluid well as the entryV andexit valves 70 is compressed air, the temperature of which is This,A milk is under pressure which might be maintained atthe sameV degree,'in each con added by a pump but. preferably’ the pressure is above atmospheric but of. course. isf lower than ‘tai-ner,` and thev further liquid is» introducedy at a `substantially constantv pressure; the> pressure< head on the> milk. However, asA air isf discharged through' pipe` #il to the heated 4. A constant pressure liquidholdingï system 2,411,681 ing the ñow through the entrance pipes and the comprising a plurality of closed containers, an exit pipes, an air pipe having an open end near air conduit, means for holding air in said con the top of each container and Within the same, duit at a chosen pressure and temperature, means an air conduit joining all of said air pipes, means connecting the conduit with each of the con tainers, a relief valve on each container dis Ul for heating the air in the conduit controlled by the temperature adjacent the open end of one of charging air from vthe container when its tem the air pipes, means for maintaining a pressure» perature departs from a chosen value whereby air above atmospheric in the conduit and the air at the chosen pressure and temperature will now pipes, and means for charging liquid through the into the container from the air conduit. _ 5. The device of claim 4 with means for charg 10 distributing system and simultaneously forcing air through the closed path of the conduit and air ing a liquid under pressure to any one of the pipes, whereby shrinkage of the liquid is min-V containers, and means for discharging another imized and the paths taken by the ñuid and of said containers at the same rate as the first container is charged. 6. In combination a jacketed container, means for maintaining a ñuid under pressure in the con tainer, a container relief valve, opening to dis charge the ñuid if the temperature of the fluid the liquid are widely separated, the air entering and leaving the containers at the top only Aand the liquid entering and leaving the containers at the bottom only. 9. The device of claim 8 in which the heating means below the containers is controlled by the falls below a chosen amount, means for charg ing and discharging a liquid into the container 20 temperature within the container separately of the heating means for the air conduit, and a below said fluid, including piping partly within relief valve on one of the containers discharges the container and time operated valves in the air from above the liquid should such air fall be low a predetermined degree of temperature. 7. The process of claim 1 in which the fluid is 10. In a milk pasteurizing system, a jacketed compressed air saturated with water vapor, the 25 container, means for admitting heated air under liquid is milk, and the air driven from one con pressure to the container above the milk, means tainerby the incoming milk is discharged into for releasing air from the container as it falls be said other container which is simultaneously be low a predetermined degree of temperature, and ing emptied, whereby the water vapor saturated time controlled means for admitting milk to the air is reused. 30 container and for discharging milk therefrom, 8. In combination, a series of closed contain said last means including piping, the open ends of ers, each having a bottom, heating means below which are widely spaced from the open ends of each container and having horizontal dimensions charging and discharging piping. the air admitting and releasing means, whereby less than those of the bottom, a liquid distribut ing system leading to each container, including 35 to avoid passage of milk through any part of the air system. an entry pipe and an exit pipe in each container, having their bottom open ends near the bottom of the container, time controlled valves govern HULDREICI-I EGLI.