Force convection milk pasteurizer

A milk pasteurizing unit having a force fluid convection chamber which is adapted to hold a milk product mass therein. There is an ejection nozzle which is in communication with a pressurization device such as a pump which forcefully ejects a nozzle over a separator plate which separates the milk product mass from a direct heat source such as a combustion chamber. The force convection of the milk prevents scalding of the same and allows for a more rapid heat transfer from the heat source to the milk product mass.

BACKGROUND AND GENERAL DISCUSSION

In general, the subject matter relates to pasteurizers for pasteurizing milk from harmful bacteria. The prior art devices generally have heat exchangers where water is used in a countercurrent between the tube or plate heat exchangers to heat up milk passing therethrough. The disadvantage of this is that water heaters can generally be rather expensive, and further, there are issues of cleaning the heat exchangers in the event that scalding or other depository type buildup occurs within the heat exchanger. Heat exchangers are not known for being easy to clean, so an alternative method of heating the milk for pasteurizing purposes is a present need in the marketplace.

The water contained in prior art heat exchange systems is in a close loop circulation which is the sole purpose of having heat transferred to the product. This water is not potable, and the heater is absolutely dedicated to the pasteurizer.

In general, for proper pasteurization, there is an FDA scale that has a valuation for determining the proper amount of time and temperature for pasteurization of milk products. In one form, a lower temperature at a longer period of time will function as a proper pasteurization duration. Alternatively, a higher temperature for a lower period of time will function as well. For example, having the milk product at approximately 145° F. for 30 minutes is considered a proper pasteurization cycle. Alternatively, having the milk at approximately 161° for 15 seconds will also be a sufficient temperature and time combination for proper pasteurization.

As described herein in detail, the disclosure provides a central chamber region, there is a first end having a discharge nozzle from a pump unit where on the opposing longitudinal end there is an intake portion which is in communication with the discharge. The discharge and input ends are adapted to circulate the product rather violently across the lower base surface of the central chamber region. It should be noted that the bottom portion is in direct contact (or direct thermal communication) with an open-flame chamber positioned therebelow. The open-flame chamber is powered by a gaseous, combustible fluid such as liquid propane or natural gas. Heat transfer passes up vertically and is essentially contained in the lateral and lower portions as well as longitudinal forward rearward portions by a fire block which has insulating properties. Therefore, the least path of thermal resistance is upward to the milk chamber where the milk product is contained. By passing the milk product at a fairly high rate of velocity, the milk convection is adapted to have a high rate of heat transfer without having a localized heat transfer to any milk particle which hence causes scalding. However, there is further a thermal couple which is connected to a PLC controller which monitors the temperature of the milk.

Present analysis indicates in various journals that having the high temperature short time (HTST) is more advantageous because there are theories presently circulating indicating that the hemoglobin around certain particles of milk will act as an insulating layer, thereby not allowing heat transfer to the inner particle portions. The present embodiment employs force convection across the heating surface, which should perhaps assist not only in preventing scalding and having a higher temperature heat source, but further prevent any such insulating boundaries within the particles from being formed, or if they are formed, breaking them up.

With regard to additional features of the disclosure, there is a “Clean in Place” (CIP) system. This system is in effect after all the product is removed after a pasteurization cycle. In general, after the unit is emptied, the unit is rinsed out with warm water to clear out all high volume of foam milk solids and so forth.

The pump has the synergistic effect of working as three different functions at three different times during the operation of the unit. Of course, the first and primary unit is circulation of the product during the pasteurization where the high volume flow prevents any scalding or increasingly high localized heat transfer to any portion of the fluid product. Further, the hose in the longitudinally rearward portion can be detached where the pump can function as filling up small container bottles that are adapted to have nipples placed thereon and fed to calves or any other external container for transporting of the pasteurized milk. Further, on the inward portion within the chamber region of the cleaning unit, an additional nozzle can be placed there to disperse cleaning fluid in a desirable pattern to clean out the central chamber area after a pasteurization cycle.

There is further a throttle control with the valve for reducing the rate of flow to the dispersion nozzles for filling external smaller tanks or containers. In one form the pump is adapted to operate at variable forms.

As noted in the figure showing the exposed fire blocks, the flame jet extends in the longitudinally forward direction with the under-portion exposed to allow flames to disperse therefrom. In this orientation the flame jet extends to the forward longitudinal portions for a dispersion of the flame throughout the under-portion of the milk chamber. In the lower portion there is a discharge flute where there is a desirable flow of the combusted gas to the discharge flute which of course is fluted up to a proper external exhaust away from the unit.

Therefore, it should be reiterated that the general theme of the invention is that conventional wisdom is to heat milk with a thermal capacitance intermediate layer between a heat source such as a wire coil, combusted material, or any other conventional heat source, and the actual product which cannot get too hot because of scalding and other associated problems. Therefore, having a heat source which is in direct thermal communication by a thin piece of highly conductive material such as stainless steel is not an intuitive leap. However, by having a strong convection current of the milk passing over this directly heated unit where the convection is at a constant, continuously flowing rate, there is not a localized heat transfer to any one single water molecule or portion of that fluid. Further, present theoretical analysis indicates that a higher temperature is advantageous for purposes of having heat transferred to potential water clumplets within the product that act as a thermal barrier for having heat transfer to the center of those “hemoglobin clumplets”. However, as mentioned previously, present analysis indicates that the circulation has a synergistic effect of breaking up or preventing such clumplets so such heat transfer is provided to all portions of the product. Essentially, there is a lot of stirring going on so that the milk doesn't clump or heat up too much. There is further agitated air in the combustion chamber having a force convection effect down thereunder to have a more uniform heat transfer coming from the under-portion.

It should be reiterated that the lower substantially planar surface of the chamber is not an ideal heat transfer surface area. Normally, if you look at any type of heat transfer unit such as a radiator, there is a plurality of thin-like structures that are adapted to have heat conducted therethrough. In general, the thin structures are made of a highly thermally conductive material, such as metal, and are adapted to draw heat from the heat source to the low temperature area. However, this heat transfer may have adverse effect in this application where the transfer of the heat could have localized hot spots which cause an undesirable scalding and other effects to the milk product.

Therefore, the unit described herein has thermal efficiency in that it utilizes energy by way of the combustible gas and there is a believed to be a lower gradient of heat transfer throughout the X and Y coordinates of the baseplate.

It should be noted that in one form, in the lower portion, there is one heat exchanger that is adapted to be used for cooling the product after it has finished pasteurizing. Essentially, the tube cooler located in the lower portion will cool the milk to a desirable temperature such as to a calf feeding temperature which is typically about 100° F. The tube coolers and the water passing therethrough in the countercurrent flow arrangement comes out warmer, which is either discarded or ran into a trough to give feeding cows warm water for direct consumption.

In one form in the lower lateral portion, there can be a bank array of solenoid valves in fluid communication with hot and cold water sources whereby the PLC controller will control these at various time portions during the run cycle to allow the various functions described above, such as after the milk is pasteurized, the PLC controller allows the product to pass through the lower heat exchanger where the cold water valve is open in a countercurrent flow arrangement to cool the milk and essentially warm the cool water passing therethrough.

The transition from pasteurization to cooling is done in a batch process as well where the fluid is circulated through the heat exchanger contained in the lower region to bring it to the calf feeding temperature. The PLC controller is fully adjustable by the user for the heating temperature and the cooling temperature time durations. In one preferred form, once the pasteurizing is done and the temperature is brought to the appropriate level for calf feeding, the machine unit subset shuts off and is done the batch process.

SUMMARY OF THE DISCLOSURE

Recited below is a pasteurization unit for pasteurizing milk product. The pasteurization unit comprises a force convection chamber having a central chamber region with a lower separator plate. The force convection chamber further has a first region having an injection nozzle that is adapted to be positioned near the lower separator plate.

There is further a direct heating system comprising a combustion chamber positioned below the lower separator plate of the force convection chamber. The direct heating system has a combustion nozzle adapted to disburse and propagate a flame throughout the combustion chamber. An exhaust outlet is in communication with the combustion chamber adapted to eject combustion gas therefrom.

There is further a fluid convection system comprising a fluid pump in communication with the ejection nozzle and adapted to transmit milk product through the nozzle. A recirculation conduit is in communication with the central chamber region to allow milk product to circulate therethrough.

The milk product returning from the recirculation conduit is adapted to recirculate to the fluid pump and the ejection nozzle is positioned in a manner within the central chamber region to transmit milk product therethrough and create a flow of milk product across the lower separator plate to prevent overheating of the milk product and to allow pasteurization of the same.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown inFIG. 3, the force convection chamber comprises a central chamber region30which is made up of first and second lateral walls32and34and the lower separator plate36. Referring back toFIG. 1, the force convection chamber22is further comprised of first and second longitudinal walls38and40and in one form, has an upper open region42. The upper open region can be covered by a like device or remain open during the pasteurization batch process. The first and second longitudinal lateral walls in conjunction with the lower separator plate should form a hermetically sealed region which is defined as the central chamber region. As shown inFIGS. 3 and 5, the central chamber region30is adapted to hold a milk product mass60therein. The milk product mass60has an upper milk surface62which can be at a variety of heights but is below the upper open rim44which defines the upper open region42introduced above. Preferably, as described further below, the upper milk product surface62is above the ejection nozzle80described further herein.

The lower separator plate in a preferred form is made from stainless steel, as are the other walls comprising the force convection chamber22. However, other forms of materials could be utilized which are conducive to be used with milk products in the various standards placed around the handling of milk products.

The fluid convection system26as shown inFIG. 1essentially comprises a fluid line70that is in communication with the fluid pump72. An assortment of valves such as74can be placed along the fluid line70for selecting the milk product median to be redirected about various conduit paths described herein.

The fluid line70comprises an input line76which is downstream of the fluid pump72and as shown inFIGS. 3 and 5, in communication with the chamber line78. The chamber line78in a preferred form extends downwardly within the central chamber region30and is in communication with the ejection nozzle80. Essentially, the ejection nozzle80as shown inFIG. 5is adapted to violently and in a force convection manner eject milk therefrom as indicated by arrow82. The ejection nozzle is positioned adjacent to the lower separator plate36to induce a relatively high flow rate thereabove. The ejection nozzle as indicated by dimension84is within a few inches of the separator plate36. Pursuant to milk product handling standards by a variety of authorities, a sufficient spacing of the chamber line and the ejection nozzle should be arranged for proper cleaning of the unit. In other words, the items should be properly spaced apart to allow inspection and cleaning to prevent bacterial growth.

As shown inFIG. 1, in one region of the forced convection chamber an ejection port90is positioned which is in communication with a recirculation line92that in some form is in communication with the fluid line70as shown in the left-hand portion ofFIG. 1. In other words,FIG. 1schematically shows the recirculation line92where the positioning of an orientation of the recirculation line in one form can be within the frame100and a variety of channels and conduits be adapted to recirculate to the fluid line70. For example, the recirculation line92may be in communication with filters or other processing steps or can be directed back to the fluid line70to be pumped through the fluid pump72for recirculation.

As described further herein, the preferred form of pasteurization is in a batch process. The ejection port and recirculation line can further be in communication with a transfer line94which is schematically shown in the left-hand portion ofFIG. 1. Essentially, a valve such as that shown at74can redirect the fluid to a transfer line94so the fluid pump72would transfer the pasteurized milk product to such a location for proper storage or direct bottling. In other words, the transfer line94can be used to fill small milk bottles that are adapted to be distributed to calves for feeding of the same. Alternatively, the transfer line94could be in communication with a spray-type nozzle where in a cleaning mode, the spray nozzle could manually be used by an operator to spray out and clean the force convection chamber30. This illustrates the versatility of utilizing the pump72for various functions. The ejection port90can be positioned in a variety of locations within the central chamber region30. In one form, the ejection port90can be positioned in a corner area93that is perhaps a lower region of the lower separator plate36where the upper surface37of the lower separator plate is adapted to utilize the gravitational force acting on the fluid to transfer it to the low spot where the ejection port90is located. This would occur when the fluid is not ejected through the ejection nozzle, and essentially the milk product mass60is being drained from the central chamber region30(seeFIG. 5).

There will now be a description of the direct heating system24with initial reference toFIG. 1.

To recapitulate, essentially there is a force convection chamber22that is adapted to store milk product and provide a heat transfer to the lower separator plate36. The lower separator plate is in direct thermal communication with a combustion chamber120described herein.

It should be noted that the lower separator plate as shown inFIGS. 3 and 5is essentially in direct thermal communication with the combustion chamber30described herein. In other words, instead of having a thermal capacitance layer such as a boundary of steam and water add atmospheric pressure to limit the upper temperature, essentially, the pasteurization unit20relies on the convection of the milk product from the ejection nozzle80to prevent overheating. Therefore, without the force convection of the milk product through the ejection nozzle80, the milk product mass60may scald rather quickly the lower portions61indicated inFIGS. 3 and 5.

With the above-mentioned background information in mind, reference is now made toFIG. 2where the direct heating system24comprises a combustion chamber120and a combustion nozzle122. The direct heating system24further comprises an air/fuel compressor126that is in communication with the combustion nozzle and adapted to provide fuel thereto.

As shown inFIG. 2, the combustion chamber120is comprised of first and second lateral walls130and132and first and second longitudinal walls134and136. Further, there is a combustion chamber comprised of the lower base wall138. Now referring toFIG. 5, the combustion chamber120is finally comprised of a lower surface140of the lower separator plate36. The walls130,132,134,136, and138shown inFIG. 2in a preferred form are comprised of some form of firebrick to properly maintain the heat therein given its insulating properties and not combust or otherwise break down due to the intensity of the combusted flame. However, the lower separator plate is comprised of a thermally conductive material such as stainless steel or any other suitable material where heat is transferred from the combustion chamber directly through the lower separator plate to be conducted to the milk product mass60. Referring back toFIG. 2, the combustion nozzle122comprises a forward portion150and a rearward portion152. As shown inFIG. 5, the upper forward portion154is positioned further in the lower forward portion156. As shown inFIG. 4, a flame propagation slot am160defined by the surfaces162and164extends therealong the lower portion166as shown inFIG. 5. As shown inFIG. 3, the flame propagation slot160adapted to disperse a flame170therealong the lateral portions172and174of the combustion chamber120.

As shown inFIG. 2, an exhaust outlet180is in communication with the combustion chamber120to allow combusted gas to exhaust therefrom. As shown inFIG. 1, the fuel compressor126is in communication with a duel line127that can be connected to any type fuel supply such as a natural gas or propane line or a natural gas and propane tank or other form of combustible material.

It should be noted that the direct heating system24in the broader scope could be other heating methods such as electric burner plate, a wood burner, or any other heat source which incites a high temperature that could scald milk.

With the foregoing description in mind, there will now be a description of the method of using the pasteurization unit20. Essentially, the fluid pump72as shown inFIG. 1can initially pump milk product from a milk supply into the central chamber region30of the force convection chamber22.

Essentially, a variety of valving and pumping methods can be utilized to fill the force convection chamber22. However, in a preferred form, a valve similar to the valve indicated at74can redirect the fluid line72to be in communication with a milk supply which is not shown inFIG. 1. After the chamber is full with a milk product as shown inFIGS. 3 and 5, pressurized milk product is recirculated through the input line76by way of the fluid pump72and ejected out of the nozzle80. The fluid pump72draws fluid from the ejection port90where the milk product mass is recirculated in a batch-like process. At some point, the fuel compressor126is activated and an igniter ignites the fuel to provide a direct heat source. As shown inFIG. 3, the direct heat source indicated by the flames170provides a heat transfer to the lower separator plate36which is conducted to the milk supply60.

It should be reiterated that the nozzle80, which can be of a variety of arrangements, forcefully thrusts the milk product in a turbulent manner to prevent any amount of the milk product from being in contact with the upper surface37of the lower separator plate36. In other words, instead of relying upon natural convection of the milk product to recirculate the milk, the force convection of the milk allows for a more uniform heating and further, more importantly, prevents scalding of the milk. The heat transfer from the propagated flames170can be rather significant although it is not specifically quantified. However, if the milk supply60were to remain static, the applicant would have a high level of confidence that the milk would scald and essentially overheat at certain portions, which would ruin the batch.

As shown in the table below, there are a variety of temperatures and associated times that relate to the temperature of the milk product and time at that particular temperature to properly pasteurize the milk.

Essentially, the force convection of the milk product by the nozzle allows for a more substantial uniform temperature about the milk product mass60. Therefore, temperature transducers can be strategically positioned within the central chamber region30to properly measure the temperature and the PLC controller can record this temperature reading and utilize it for a decision-making process. Basically, the PLC controller can be controlled to properly pasteurize the milk product preprogrammed table similar to the table shown above, where essentially the milk is heated at a sufficient temperature for a sufficient length of time.

After the milk is properly pasteurized, a valve such as that shown schematically at74inFIG. 1can be activated to redirect the fluid to a transfer line94for proper storage or direct use of the milk product. In one form, the fluid pump72can have another function of pumping the milk product to a supply location such as a bottling procedure where the milk product is bottled for consumption of calves or animals. In one form, the pasteurization unit20is utilized in a small-scale such as directly on a dairy farm or beef cattle farm where it is desirous to have pasteurized milk given to calves or other animals. it should be noted that the standards of pasteurization for nonhuman consumption are different than the standards for human consumption.

While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general concept.