Food Science Packaging – Thaddeus J. Polny, Jr., Michael Foods Inc, Michael Foods of Delaware Inc

Abstract for “Apparatus to heat food using concentric electrodes”

An electroheating device for continuously heating pumpable food is composed of several connected electroheating cell. One embodiment of the cell includes a pair concentric electrodes that are used to pump the food. The electrodes are connected with a high frequency energy source that passes current through the food to heat it based on their resistance and electrode gap. Another embodiment uses two different functioning electrodes, which are connected in series to ensure long run times and high temperatures.

Background for “Apparatus to heat food using concentric electrodes”

“Electroheating is used to heat treat and cook foodstuffs. In U.S. Pat., David Reznik describes an important method for electroheating. No. No. 4,739 140, incorporated by reference. According to Mr. Reznik, heating food with an AC current of more than 100 Hz can be achieved without significant electrolysis or reaction between electrodes and food.

“Mr. Reznik?s patent doesn?t describe the use concentric electrodes for heating food or the benefits of using concentric electrodes in order to heat liquid eggs. Similar to the ‘140 patent, Mr. Reznik does not describe how electroheating cells work in a particularly beneficial way as described herein. The ‘140 patent of Mr. Reznik also doesn’t describe pasteurizing eggs. This patent doesn’t recognize any unique characteristics or problems that can be associated with continuous pasteurization.

“U.S. Pat. No. No. These methods and apparatus involve repeated application of high voltage, high current densities, and discrete electrical pulses on fluid food products. The minimum field strength used is 5,000 volts/cm. Disclosures include voltages up to 37,128 Volts. Pulse frequencies between 0.1 to 100 are also disclosed. Current densities of at least 12 amps/cm2 and current densities below 12 amps/cm2 respectively are also disclosed. The ‘472 Patent describes preferred treatment methods that involve the application of at most 2 or more pulses, preferably 5 pulses with high energy to the material being treated. Direct current is the principal method of treatment disclosed in the patent ‘472.

The techniques described in the patent ‘472 have many disadvantages. Electrolysis can lead to electrode loss, food contamination, and even detrimental coagulation. The ‘472 Patent requires that membranes be used between electrodes and food products to mitigate this problem. It is also not clear from the patent that an egg with exceptional storage stability and highly functionality can be obtained without the need to undergo the complex pulsed electrical treatment described in ‘472.

“The ‘472 reference does not recognize the difficulties associated with continuous pasteurization liquid egg. The ‘427 patent does not describe elevating the temperature liquid egg or liquid whole egg to minimal pasteurization temperatures. The ‘472 patent does not specifically address the issues associated with ensuring that there is no detrimental coagulation. Although the ‘472 Patent does mention arcing as an issue, the only effect that such arcing can cause is damage to electrodes. It is not clear how such phenomena affect the egg’s organoleptic properties or the viability for continuous processing. All of the liquid egg tests performed in accordance to the patent ‘472 include static bench testing at voltages up to 34,000 volts and currents between 7,200 and 14,200 amperes. “No continuous egg processing was done.”

“The patent ‘472 does not describe concentric electrodes, the benefits they provide, or the arrangement of electroheating cell advantageously described in this document.”

“Geren, U.S. Pat. No. No. 4,457 221, issued Jul. 3 1984 shows a three-phase sterilization apparatus. Three parallel electrodes are placed in a circular arrangement to form three channels through which the materials are passed. The voltages used are about 100 volts RMS, with voltages as high as 1000 volts preferable. The current density is at least 50 milliamperes/square centimeter (ma/cm2), but they are in practice between 500 ma/cm2 to 1.25 ampere/cm2. The currents are applied in less than 200 milliseconds. The frequency is 50 Hz. The device of the “221” is described as an apparatus that sterilizes by killing bacteria and other similar organisms in a host, which can be either liquid or solid. The problems associated with the processing of liquid eggs are not mentioned. The unique arrangement of elements in the invention is not described or appreciated.

“Bushnell and al. Include in this teaching the U.S. Patent substance No. No. The concentric electrode apparatus is used with various pumpable products. However, the use of this device with liquid eggs is not. There is no example of continuous processing liquid egg or any other coagulable liquid. Bushnell et. al. will likely face the same problems as the ‘472 Patent due to similar parameters to the pulsed high-voltage system.

“Bushnell and al. They do not recommend the use of high frequency alternating current to prevent electrolysis, nor do they suggest that high frequency electric energy could be used for pasteurizing liquid eggs in a continuous long-term process. Bushnell et.al. Bushnell et al. are not clear on whether concentric electrodes can work with high frequency energy over a long-term continuous process. Bushnell and colleagues. Bushnell et al.

“Instead, Bushnell et al. The addition of electrical pulse energy can be used to kill systems that are not at pasteurization temperatures. Bushnell et. al. They do not teach pasteurizing, heat treating, or any other methods, but instead, how to produce improved microbial kill. Bushnell et. al. Bushnell et al. do not appear to instruct or divulge the use of other pasteurization equipment, such as holding tubes.

“As any person with ordinary skill in the arts can attest, using different types or electrical energy in different kinds of electrical processes has its own set of benefits, disadvantages and complications. Bushnell and al. Bushnell et al. do not employ high frequency alternating current in the manner described by the present invention and therefore are unaware of the benefits and problems associated with it. The ‘472 patent, which is incorporated in Bushnell and al., discloses current densities at least 12 amps/cm2. Although such current densities might be possible in the context of a pulse-system when applied to liquid eggs, the present inventor believes they are impossible in the current system. Bushnell et.al. Bushnell et al. Soon thereafter, you will see fouling, arcing, and caking.

The present inventor discovered that if electrodes are cooled sufficiently efficiently, the coagulated eggs may not stick to them. This means that very efficient cooling is one way of controlling arcing. However, AC energy applied at too high current density can cause serious and even fatal coagulation. It is possible to cook or coagulate liquid eggs by using relatively high current densities and efficient cooling. If you do not want to have any harmful coagulation, which is often the case with liquid eggs, then lower current densities should be used, even with efficient cooling. Bushnell et.al. These patents and Bushnell et al.

“In copending U.S. patent application Ser. No. No. 07/862,198 filed April. 07/862,198 filed Apr. The egg is heated at a frequency that is sufficient to heat it without electrolysis or harmful coagulation. The electroheated liquid egg must be kept for at least one hour to reach pasteurization before being cooled enough to be used for storage or packaging.

“The above-described electroheating cell contains at least one pair electrodes with egg engaging surfaces that are spaced apart so that the liquid egg can be passed through it. The electrodes are usually parallel plate electrodes with smooth, non-wetting surface and rounded edges that do not touch the liquid egg being processed through them. The electrodes have a very smooth surface that is difficult to adhere to or wet. This allows for a smooth, uninterrupted flow of liquid egg through the cell.

“It is the object of the present invention that an electroheating device be provided for pasteurizing liquid eggs.”

“It is also the object of this invention to provide an apparatus for heating liquid egg using concentric electrodes.”

“It is also an object of the present invention that an electroheater can be used to pasteurize liquid eggs. The electrodes can be adjusted so that electronic conditions within the cells can easily controlled.”

“Methods for pasteurizing liquid eggs using such electroheating apparatus” are also objects of the present invention.

“According to one aspect of the invention, there is provided an apparatus for continuous heat treatment of liquid eggs using an electroheating device. It comprises:

“A minimum of one electroheating cells, including a primary electrode with a cylindrical liquid egg-engaging inner surface that extends from a first to a second ends with an inside diameter equal to a predetermined value,”

“A second electrode with a cylindrical liquid egg-ensuring outer surface that extends from a first to a second ends and has an outer diameter of a predetermined second value that is less than the first;”

“means to position the second electrode within the first electrode, with the outer electrode of the second electrode spaced from the inner electrode of the first to create a continuous gap between them through which the liquid egg is pasteurized;”

“And a source AC of high frequency AC electricity current having a frequency that is effective in heating the liquid egg without electrolysis, operably connected to the first electrode to supply continuous high frequency AC electrical current to the cell.”

“Also, in accordance the present invention, there’s an electroheating device as described above that further includes adjustment means connected at least to one of the first or second electrodes. This allows for the electrodes to be moved relative to the first electrode, and to alter the amount of the second surface adjacent to the first electrode.

“In accordance to this aspect of the invention, an electroheater consisting of a plurality electroheating cells may be used to control current density. But, it is possible to fine tune current densities even more precisely. According to the invention, an electroheating device is made that allows the precise and relatively simple adjustment of the current density within the cell. Bushnell and his colleagues have not proposed any devices or recognition of the need to minimize current density.

“Also, in accordance with an additional aspect of the invention, provided is a process of pasteurizing liquid eggs including the steps:

“Providing liquid eggs;”

“Passing the liquid eggs through an electroheater, which includes at least one electrode heating cell, at least one concentric electrode separated by a gap through the liquid egg flows;

“Electroheating the Liquid Egg by passing high frequency AC electricity current across the electrodes, and through the liquid eggs as the liquid egg passes between the electrodes;

“The high frequency AC electric current with a frequency that is effective to heat the liquid egg substantially without electrolysis,”

“and holding the egg in an electroheated container for a sufficient time to pasteurize.”

“It is another object in the present invention that provides for an electroheater to heat food.”

“It is another object in the present invention to provide an electric heater capable of large temperature rises and long run times.”

“It is another object in the present invention to provide an electrodeheater for heating food that can be used with coagulable foods, but can also impart longer run times at higher temperatures than can be achieved using other heating methods and apparatus.”

“In accordance to this further aspect, the present invention provides an apparatus for heating food using electroheating.

“an apparatus for electroheating food comprising:”

“A minimum of one first electroheating cells having a pair of electrodes separated and a gap through which food may flow;”

“A minimum of one second electroheating cells having a second pair electrodes separated by a gap through which food may flow and in fluid communication to the first gap;

“And a source AC electric power having a frequency that is effective in electroheating the food without electrolysis, operably linked to at least one of the first and at least two second electroheating cell, the source AC electric potential applying a relatively high, relatively low-current, high frequency AC electricity across the first pair, and the source AC electric curent applying a relatively low, relatively high current AC electric across the second pair.

“In a preferred embodiment, an apparatus for heating food is provided that further comprises the apparatus for cooking food according to claim 32. The apparatus also includes the apparatus for heating food according to claim 32. It further comprises at least one additional electroheating device having at least one electrode pair separated by a third gap through the food. The at least one-third electroheating battery being linked electronically with the first and second electroheating cells. Food can be moved from one gap in one electroheating unit to another in fluid communication. In this case, the third pair of two electrodes.

“Another aspect of the invention is that an electroheater described herein has a food outlet which is in fluid communications with an electroheating device. An electroheating cell contains a first and second electrically conductive electrodes, with each electrode having an opening through which food can flow. A hollow insulating material separates the first and second electrodes so that food can flow from the first electrode’s apertures into the interior of this hollow member to the second electrode. Both electrodes are electrically connected to an AC high frequency AC current source. This current has a frequency that is efficient in heating food without electrolysis. The electric current flows parallel to food. A source of high frequency AC electric current is also available.

“In accordance with the preferred embodiment of the invention, the electroheater described has at least one second electrodeheating cell that is electrically connected in series with at least one first electronheating cell and in fluid communications therewith. The electronic link between the at least one first and at least one second electrodeheating cells is designed to reduce or retard fouling. The outlet can be connected to holding tubes, cooling devices, and packagers, as described previously. This allows the electroheater for use in a pasteurization system or sterilization system for food like liquid eggs. It is possible to add additional electroheating units.

“In another embodiment, the present invention allows the electroheater to be described as an electrodeheater that includes:

“A first plurality electroheating cells, with the cells being electrically connected in parallel;”

“A second plurality electroheating cells, which are electrically connected in parallel;

“The first plurality and second plurality electroheating cell being electrically connected in series;”

“And a source AC electrical current that is applied across each electroheating cell.”

“It is also a object of the present invention to provide heat treatment methods for foods using the electroheaters.”

“There is therefore, according to a further aspect of the invention, there is provided an apparatus for electroheating food that includes the following steps:

“Providing food that can be electroheated;

“Passing food through an electricheater consisting at least one electroheating cell with a first pair separated by a gap through which food can flow;

“Electroheating food by passing relatively high voltage and relatively low current AC electric current through the first pair electrodes and through it as the food passes through its first gap;

“Passing food through at least one more electroheating cell with a second pair electrodes separated by a gap through which food can flow;

“Electroheating food by passing relatively low voltage and relatively high current, high-frequency AC electric current through the electrodes as the liquid egg passes through second gap between second pair of electrodes. The high frequency AC current has a frequency that is effective in heating the food without electrolysis.

“According to a further aspect of the invention, there are also provided here methods of killing microbes from food. These include the following:

“Providing food containing microbes”

“Passing food through an electricheater, including at least one electroheating cell with a first pair separated by a gap through which food can flow,”

“Electroheating food by passing relatively high voltage and relatively low current AC electric current through the first pair electrodes and through it as the food passes through its first gap;

“Passing food through at least one more electroheating cell with a second pair electrodes separated by a gap through which food can flow;

“Electroheating food by passing relatively low voltage and relatively high current high frequency AC electric power across the electrodes as well as through the liquid egg, as the liquid egg passes through second gap between the two electrodes;”

“and holding the electroheated food for a period that is sufficient to inactivate, destroy or at least partially destroy the microbes.”

“In particular methods of pasteurizing or methods of sterilizing are considered.”

The term “liquid egg” as used in the present invention includes not only liquid yolk and egg white, but also combinations thereof in any desired or predetermined ratio. Liquid egg white, liquid yolk, and combinations thereof are also included in the term “liquid egg”. These additives include salt, sugar, milk stabilizers, antibiotics cyclodextrins peroxides, acids like citric acid, stabilizers, stabilirs, stabilizers, dextrins cyclodextrins as well as stabilizers, antibiotics, dextrins, cyclodextrins and dextrinst or particulate food. Also included is liquid egg from which cholesterol was removed.

According to the invention, the term “electroheating” is used to describe a process that generates heat in liquid eggs by passing current through it. Heat is generated by the liquid egg acting as a resistor. U.S. Pat. describes a preferred method for heating food by electroheating. No. No. 4,739,140, previously incorporated by reference. The flow of current does not heat the electrodes during electroheating. In fact, the disclosed embodiment takes affirmative steps to ensure that the electrodes don’t get too hot. Only heat is used to heat the liquid egg or other food to pasteurize or treat it.

“Extended refrigerated shelf live” refers to the fact that liquid eggs are safe to eat for at least three weeks after being treated according the the present invention. This assumes that the liquid egg is properly stored in a refrigerated environment. The term “extended refrigerated storage life” is preferred to mean that the liquid egg can be consumed for at least four weeks following treatment according to the present invention, and sometimes up to 10 to 12 weeks, or even longer. The practice of the invention can also allow for extended refrigerated shelf lives to other perishable foods.

Electrolysis is a chemical process that can take at least one of two forms. Electrolysis is the process of removing metal electrodes from the food being processed. Electrons flow between two electrodes and the metal inside them becomes ionized. This results in the release of electrons. These ions dissolve in the food being processed and are easily soluble. Electrolytic problems can also be caused by conversion of conductive Ionic species in the food to radicals or gases. This includes the conversion of hydrogen ion into hydrogen gas, and chlorine ions into chlorine gas. Hydrogen ions can be transformed into water and oxygen. The conversion can have adverse effects on the taste and other beneficial qualities of the treated food due to the depletion and conversion of ions to other species as well as other reactions such as oxidation.

“Coagulation is the process of a food’s protein being denaturated and agglomerated. Certain foods, such as orange Juice do not coagulate when heated. Some foods, like liquid egg, do not coagulate when heated.

“In accordance to the present invention, liquid egg and other food coagulable can be reduced. Some coagulation may occur at pasteurization temperatures for liquid eggs. However, the present invention states that if the liquid egg is not to be cooked, “detrimental” coagulation should be avoided. Detrimental coagulation refers to an increase in viscosity that causes the liquid food to become difficult to pour. This is when visible egg particles appear and the functionality of the liquid food is affected.”

The FIG. 1 schematic diagram will help you to better understand the methods and apparatus of this invention. 1. This is a typical device for pasteurizing liquid eggs. The typical egg pasteurizer can be modified to use an electroheater 7, which could be used in place of a plate heat exchanging device or another conventional heating device. These and other similar devices can be used to heat treat a variety of foods.

The present invention also allows for the use of a Cherry-Burrell Model EQ3 and EQ4. This packaging type has a higher failure rate, or more accurately, an increased incidence of the introduction microorganisms during packaging than an aseptic system. A clean pack could introduce one microorganism per 100,000 packages. This is just an illustration. Although this packaging technology is not considered aseptic, it can be used in accordance with the present invention. You can also use these Cherry-Burrell boxes to make plain, clean containers. If the packages are not sprayed with peroxide before filling, they may be considered sanitized but not aseptic or clean packs.

Plain sanitized clean containers are also useful according to the invention. They must be produced using “good manufacturing practices” and comply with all applicable government regulations. For illustration purposes, such containers that have been properly cleaned may contain one cell per 100 packages. This is because of the superior kill of electroheating and growth inhibitive effect of proper refrigerated stored, so such an addition of cells cannot be considered significant.

These packages are useful for practicing the invention of extended shelf life. They can be contrasted to a “dirty package”, which hasn’t been cleaned or packaged in clean or aseptic conditions. These containers can contain 1,000 cells or more, which is statistically significant in relation to the number remaining in pasteurized liquid eggs after pasteurization. Any other package type can be used, depending on the requirements of individual customers. This overview will help you understand the different aspects of the invention.

“The following is an explanation of the function and structure of different electroheaters 7′ according to the present invention. It is useful to present a set of electrical parameters and structural dimensions that can be used for illustration purposes to aid in understanding the operation and organization of these electroheaters 7?. The present invention’s scope of use is not limited to these parameters. A Westinghouse model 12K67 RF generator, which generates about 3200 volts peak-to-peak and around 400 amps, is used for the illustration. All voltages are reported as peak to peak. The generator adjusted the voltage automatically to maintain a constant current. For example, current densities exceeding 6 amps/cm2 are not possible in normal conditions. In accordance with the invention, it is preferred that current densities are kept at 3 amps/cm2 (or less) and, preferably, below 1 amp/cm2. The current densities through the different electrodes in this illustration are below 2 amps/cm2. The RF generator can produce high frequency AC current, including frequencies high enough to prevent the electrolysis of food between 100 Hz and 455. High frequency, as defined by the invention, refers to voltages with frequencies between 100 kHz – 450kHz and more preferably between 150 kHz – 450kHz. A frequency of 180 to 220 kHz was used for illustration. This explanation will also include liquid whole eggs sold under the brand “Table Ready” by Papetti’s Hygrade Egg Products, Inc., Elizabeth, N. J. The Table Ready brand liquid whole eggs contain citric acid in the amount required to stabilize the egg yolk’s color. For the purposes of this illustration, flow rates between 380 and 400 pounds per minute are considered.

“Turning to FIGS. A concentric electrode containing an electroheater 7′ is shown in FIGS. 2 through 4. FIG. FIG. 2 shows that electroheating cell 7” consists of a body 20. This can be made from stainless steel, or other metals that won’t react with food and will conduct electricity. Although the body 20 is usually made of steel for strength, it can also be made from other materials that conduct electric current and act as an electrode, such as conductive ceramics or conductive porcelain. The first electrode in the concentric pair of electrodes included in the electroheating cell 7 is body 20. A preferred configuration of body 20 includes a first cylindrical section 22 and a second cylindrical section 24 with a smaller outer diameter, connected by a tapered 26 to the first cylindrical part 22. An inlet tube 30 is located at the end of the cylindrical portion 24, which allows food to be introduced into the gap between electrodes in the direction of 31. The outlet tube 34 is located adjacent to the opposite end 32 of the cylindrical section 22. This is where electroheated food can exit in the direction shown in FIG. 3. The outlet tube 34 in the leftmost electroheating cells 7″a connects to the 7″b at the inlet tube 30 by suitable tubes or piping 36.

A cylindrical cooling jacket 38 can be placed around the cylindrical portion 24 of the body 20. An inlet tube 40 connects to the cooling jacket 38 at the cylindrical portion 24. A tapered portion 26 is adjacent. 42 is adjacent to the outlet tube 42. Cooling Jacket 38 can be used to circulate fluids, such as water, glycol, or alcohol. It also allows heat to be absorbed by gases or electroheating within the cell 7.

In a preferred embodiment, flow diverters or baffles can be installed in the lumen of the cooling jacket 38. This will ensure that cooling liquids flow smoothly from the inlet tube 40 through the outlet tube 42. Flow diverters are also helpful in ensuring even cooling across the entire outer electrodes cylindrical portion 24. FIG. 2. A spring or coil 200 may be placed inside the cooling jacket 38 around the cylindrical portion 24. The coil 200 does not need to form a watertight seal with the water jacket’s interior 38. It is preferable that spring 200 flows most of the water between its coils. Spring 200 can be made from any suitable material, such as plastic, metal, such as copper or aluminum, and stainless steel. Alternately, you can increase the flow of water through the Jacket via inlet tube 40 to achieve the same results.

“If required, a Jacket 66 or any other protective material may be placed outside the body 20 and cooling jacket 38 to prevent heat loss or cooling loss and/or protect nearby operators.”

“An aperture 44 is also located in the free end 32 of cylindrical section 22. This aperture can be used to fit an insulator 46. It may be made from non-tracking materials such as rubber, ceramics, or plastic. The preferred embodiment of the insulator 46 is made from DELRIN, a homopolymer of polyacetate available from DuPont, or CELCON, which is an acetyl copolymer from Celanese Corporation.

“Insulator 46 has a central aperture 47, into which is placed central electrode 50. O-rings, such as 49 or 51, are placed in central aperture 47. These O-rings engage the outer surface central electrode 50 when it’s placed in aperture 47. This prevents liquid egg from passing through cell 7” along its outside. It also helps to stop external contaminants entering the cell via the same route. A hollow cap 53 is fitted above insulator 46 at the free 32 end of cylindrical portion 22. Two threaded screws 55 are attached to insulator 46 at the one end. They exit through corresponding holes in cap 53. The 55-mm threaded studs pass through the corresponding holes in support plate 57. The adjustment nuts 59 are attached to the threaded holes on both sides of support plate 56. By tightening the adjustment nuts 59 above support plate 57, the entire central electrode 50 can move upwardly within hollow cap 53. The ones below plate 57 limit upward movement. The inclined shape of the insulator 46 can allow the central electrode 50 to be dropped into the body 20 by loosening the nuts 59 over plate 57.

“The central electrode 50 can be made of stainless steel, or any other metals that will not react with food or get wet. Non-metallic, but other conductive, and non-reactive materials can be used to make electrode 50. The central electrode 50 can be composed of a central tube 52 and a distal end 54 that has the appearance of a test tube. The support plate 57 connects to tube 52 and each of the central electrodes of each cell 7′. This allows the central electrodes 50 to act as the second electrodes of the electroheating device.

“A tube 60 is inserted in tube 52, so its distal ends are short of the distal 54 of tube 52. As described previously, a cooling fluid source is connected to tube 60’s inlet 62. The fluid flows out of tube 52 to outlet 64.

“A source for high frequency alternating voltage 70 (shown at FIG. 3) is connected to electrode 50 via a matching coil, tuning coil, or directly. However, the coil can be used in lieu. Five concentric electrodes, as shown in FIG. 3. Twelve inches of electrode 50 were exposed. Electrode 50 measures 1″. Body 20 measures 14 inches in length and taper vertically from its widest point, which is approximately 3″, to its narrowest point, which is about 2″. This results in an electrode with a 12″ heating zone. This electroheating zone’s length is determined by how much electrode 20 is exposed to the cavity. The gap between electrode 50 & electrode 20 is approximately 3/4”. When the voltages are applied in the range of approximately 3200 volts to the RF input on support plate 56, there will be a voltage drop of around 200 volts across electrodes 20 and 50. The voltage drop at terminal 35 will be measurable as 3000 volts.

The resistance of the egg to current flow is what makes it heat. This resistance is also known as resistivity. You can alter the resistivity by adding salts or liquids to the food. You can adjust the resistivity by changing the dimensions or relative spacing of electrodes according to the invention.

“The current density applied to food in a cell is also decreased by using a larger number of cells 7.” This is one method according to the invention to control current densities.

The addition or removal 7 cells is one method to adjust current density. This is a brute method, as any addition or subtraction to a cell with electrodes of a defined surface area will have an effect on current density. If the desired current density falls between what is obtained using, for instance, 4 or 5 electroheating cell 7″, another method of adjusting it must be found. Alternatively, a number of cells with electrodes of different surface areas must be available. The present invention allows for an adjustable electrode surface area, and therefore an adjustable current density, to alleviate this problem.

The amount of electrode 50 in electroheating cell 7 is adjustable by the amount of it inserted into body 20. You can raise electrode 50 by, e.g. The effective surface area of electrode 50, e.g., can be partially removed from the cell’s interior. This increases the current density. In the opposite direction, electrode 50 can be inserted further into body 20’s cavity. This increases the electrodes’ surface area and decreases cell 7’s effective current density. The electrode 50 was placed so that 12″ of it was visible for the purposes of this discussion.

Summary for “Apparatus to heat food using concentric electrodes”

“Electroheating is used to heat treat and cook foodstuffs. In U.S. Pat., David Reznik describes an important method for electroheating. No. No. 4,739 140, incorporated by reference. According to Mr. Reznik, heating food with an AC current of more than 100 Hz can be achieved without significant electrolysis or reaction between electrodes and food.

“Mr. Reznik?s patent doesn?t describe the use concentric electrodes for heating food or the benefits of using concentric electrodes in order to heat liquid eggs. Similar to the ‘140 patent, Mr. Reznik does not describe how electroheating cells work in a particularly beneficial way as described herein. The ‘140 patent of Mr. Reznik also doesn’t describe pasteurizing eggs. This patent doesn’t recognize any unique characteristics or problems that can be associated with continuous pasteurization.

“U.S. Pat. No. No. These methods and apparatus involve repeated application of high voltage, high current densities, and discrete electrical pulses on fluid food products. The minimum field strength used is 5,000 volts/cm. Disclosures include voltages up to 37,128 Volts. Pulse frequencies between 0.1 to 100 are also disclosed. Current densities of at least 12 amps/cm2 and current densities below 12 amps/cm2 respectively are also disclosed. The ‘472 Patent describes preferred treatment methods that involve the application of at most 2 or more pulses, preferably 5 pulses with high energy to the material being treated. Direct current is the principal method of treatment disclosed in the patent ‘472.

The techniques described in the patent ‘472 have many disadvantages. Electrolysis can lead to electrode loss, food contamination, and even detrimental coagulation. The ‘472 Patent requires that membranes be used between electrodes and food products to mitigate this problem. It is also not clear from the patent that an egg with exceptional storage stability and highly functionality can be obtained without the need to undergo the complex pulsed electrical treatment described in ‘472.

“The ‘472 reference does not recognize the difficulties associated with continuous pasteurization liquid egg. The ‘427 patent does not describe elevating the temperature liquid egg or liquid whole egg to minimal pasteurization temperatures. The ‘472 patent does not specifically address the issues associated with ensuring that there is no detrimental coagulation. Although the ‘472 Patent does mention arcing as an issue, the only effect that such arcing can cause is damage to electrodes. It is not clear how such phenomena affect the egg’s organoleptic properties or the viability for continuous processing. All of the liquid egg tests performed in accordance to the patent ‘472 include static bench testing at voltages up to 34,000 volts and currents between 7,200 and 14,200 amperes. “No continuous egg processing was done.”

“The patent ‘472 does not describe concentric electrodes, the benefits they provide, or the arrangement of electroheating cell advantageously described in this document.”

“Geren, U.S. Pat. No. No. 4,457 221, issued Jul. 3 1984 shows a three-phase sterilization apparatus. Three parallel electrodes are placed in a circular arrangement to form three channels through which the materials are passed. The voltages used are about 100 volts RMS, with voltages as high as 1000 volts preferable. The current density is at least 50 milliamperes/square centimeter (ma/cm2), but they are in practice between 500 ma/cm2 to 1.25 ampere/cm2. The currents are applied in less than 200 milliseconds. The frequency is 50 Hz. The device of the “221” is described as an apparatus that sterilizes by killing bacteria and other similar organisms in a host, which can be either liquid or solid. The problems associated with the processing of liquid eggs are not mentioned. The unique arrangement of elements in the invention is not described or appreciated.

“Bushnell and al. Include in this teaching the U.S. Patent substance No. No. The concentric electrode apparatus is used with various pumpable products. However, the use of this device with liquid eggs is not. There is no example of continuous processing liquid egg or any other coagulable liquid. Bushnell et. al. will likely face the same problems as the ‘472 Patent due to similar parameters to the pulsed high-voltage system.

“Bushnell and al. They do not recommend the use of high frequency alternating current to prevent electrolysis, nor do they suggest that high frequency electric energy could be used for pasteurizing liquid eggs in a continuous long-term process. Bushnell et.al. Bushnell et al. are not clear on whether concentric electrodes can work with high frequency energy over a long-term continuous process. Bushnell and colleagues. Bushnell et al.

“Instead, Bushnell et al. The addition of electrical pulse energy can be used to kill systems that are not at pasteurization temperatures. Bushnell et. al. They do not teach pasteurizing, heat treating, or any other methods, but instead, how to produce improved microbial kill. Bushnell et. al. Bushnell et al. do not appear to instruct or divulge the use of other pasteurization equipment, such as holding tubes.

“As any person with ordinary skill in the arts can attest, using different types or electrical energy in different kinds of electrical processes has its own set of benefits, disadvantages and complications. Bushnell and al. Bushnell et al. do not employ high frequency alternating current in the manner described by the present invention and therefore are unaware of the benefits and problems associated with it. The ‘472 patent, which is incorporated in Bushnell and al., discloses current densities at least 12 amps/cm2. Although such current densities might be possible in the context of a pulse-system when applied to liquid eggs, the present inventor believes they are impossible in the current system. Bushnell et.al. Bushnell et al. Soon thereafter, you will see fouling, arcing, and caking.

The present inventor discovered that if electrodes are cooled sufficiently efficiently, the coagulated eggs may not stick to them. This means that very efficient cooling is one way of controlling arcing. However, AC energy applied at too high current density can cause serious and even fatal coagulation. It is possible to cook or coagulate liquid eggs by using relatively high current densities and efficient cooling. If you do not want to have any harmful coagulation, which is often the case with liquid eggs, then lower current densities should be used, even with efficient cooling. Bushnell et.al. These patents and Bushnell et al.

“In copending U.S. patent application Ser. No. No. 07/862,198 filed April. 07/862,198 filed Apr. The egg is heated at a frequency that is sufficient to heat it without electrolysis or harmful coagulation. The electroheated liquid egg must be kept for at least one hour to reach pasteurization before being cooled enough to be used for storage or packaging.

“The above-described electroheating cell contains at least one pair electrodes with egg engaging surfaces that are spaced apart so that the liquid egg can be passed through it. The electrodes are usually parallel plate electrodes with smooth, non-wetting surface and rounded edges that do not touch the liquid egg being processed through them. The electrodes have a very smooth surface that is difficult to adhere to or wet. This allows for a smooth, uninterrupted flow of liquid egg through the cell.

“It is the object of the present invention that an electroheating device be provided for pasteurizing liquid eggs.”

“It is also the object of this invention to provide an apparatus for heating liquid egg using concentric electrodes.”

“It is also an object of the present invention that an electroheater can be used to pasteurize liquid eggs. The electrodes can be adjusted so that electronic conditions within the cells can easily controlled.”

“Methods for pasteurizing liquid eggs using such electroheating apparatus” are also objects of the present invention.

“According to one aspect of the invention, there is provided an apparatus for continuous heat treatment of liquid eggs using an electroheating device. It comprises:

“A minimum of one electroheating cells, including a primary electrode with a cylindrical liquid egg-engaging inner surface that extends from a first to a second ends with an inside diameter equal to a predetermined value,”

“A second electrode with a cylindrical liquid egg-ensuring outer surface that extends from a first to a second ends and has an outer diameter of a predetermined second value that is less than the first;”

“means to position the second electrode within the first electrode, with the outer electrode of the second electrode spaced from the inner electrode of the first to create a continuous gap between them through which the liquid egg is pasteurized;”

“And a source AC of high frequency AC electricity current having a frequency that is effective in heating the liquid egg without electrolysis, operably connected to the first electrode to supply continuous high frequency AC electrical current to the cell.”

“Also, in accordance the present invention, there’s an electroheating device as described above that further includes adjustment means connected at least to one of the first or second electrodes. This allows for the electrodes to be moved relative to the first electrode, and to alter the amount of the second surface adjacent to the first electrode.

“In accordance to this aspect of the invention, an electroheater consisting of a plurality electroheating cells may be used to control current density. But, it is possible to fine tune current densities even more precisely. According to the invention, an electroheating device is made that allows the precise and relatively simple adjustment of the current density within the cell. Bushnell and his colleagues have not proposed any devices or recognition of the need to minimize current density.

“Also, in accordance with an additional aspect of the invention, provided is a process of pasteurizing liquid eggs including the steps:

“Providing liquid eggs;”

“Passing the liquid eggs through an electroheater, which includes at least one electrode heating cell, at least one concentric electrode separated by a gap through the liquid egg flows;

“Electroheating the Liquid Egg by passing high frequency AC electricity current across the electrodes, and through the liquid eggs as the liquid egg passes between the electrodes;

“The high frequency AC electric current with a frequency that is effective to heat the liquid egg substantially without electrolysis,”

“and holding the egg in an electroheated container for a sufficient time to pasteurize.”

“It is another object in the present invention that provides for an electroheater to heat food.”

“It is another object in the present invention to provide an electric heater capable of large temperature rises and long run times.”

“It is another object in the present invention to provide an electrodeheater for heating food that can be used with coagulable foods, but can also impart longer run times at higher temperatures than can be achieved using other heating methods and apparatus.”

“In accordance to this further aspect, the present invention provides an apparatus for heating food using electroheating.

“an apparatus for electroheating food comprising:”

“A minimum of one first electroheating cells having a pair of electrodes separated and a gap through which food may flow;”

“A minimum of one second electroheating cells having a second pair electrodes separated by a gap through which food may flow and in fluid communication to the first gap;

“And a source AC electric power having a frequency that is effective in electroheating the food without electrolysis, operably linked to at least one of the first and at least two second electroheating cell, the source AC electric potential applying a relatively high, relatively low-current, high frequency AC electricity across the first pair, and the source AC electric curent applying a relatively low, relatively high current AC electric across the second pair.

“In a preferred embodiment, an apparatus for heating food is provided that further comprises the apparatus for cooking food according to claim 32. The apparatus also includes the apparatus for heating food according to claim 32. It further comprises at least one additional electroheating device having at least one electrode pair separated by a third gap through the food. The at least one-third electroheating battery being linked electronically with the first and second electroheating cells. Food can be moved from one gap in one electroheating unit to another in fluid communication. In this case, the third pair of two electrodes.

“Another aspect of the invention is that an electroheater described herein has a food outlet which is in fluid communications with an electroheating device. An electroheating cell contains a first and second electrically conductive electrodes, with each electrode having an opening through which food can flow. A hollow insulating material separates the first and second electrodes so that food can flow from the first electrode’s apertures into the interior of this hollow member to the second electrode. Both electrodes are electrically connected to an AC high frequency AC current source. This current has a frequency that is efficient in heating food without electrolysis. The electric current flows parallel to food. A source of high frequency AC electric current is also available.

“In accordance with the preferred embodiment of the invention, the electroheater described has at least one second electrodeheating cell that is electrically connected in series with at least one first electronheating cell and in fluid communications therewith. The electronic link between the at least one first and at least one second electrodeheating cells is designed to reduce or retard fouling. The outlet can be connected to holding tubes, cooling devices, and packagers, as described previously. This allows the electroheater for use in a pasteurization system or sterilization system for food like liquid eggs. It is possible to add additional electroheating units.

“In another embodiment, the present invention allows the electroheater to be described as an electrodeheater that includes:

“A first plurality electroheating cells, with the cells being electrically connected in parallel;”

“A second plurality electroheating cells, which are electrically connected in parallel;

“The first plurality and second plurality electroheating cell being electrically connected in series;”

“And a source AC electrical current that is applied across each electroheating cell.”

“It is also a object of the present invention to provide heat treatment methods for foods using the electroheaters.”

“There is therefore, according to a further aspect of the invention, there is provided an apparatus for electroheating food that includes the following steps:

“Providing food that can be electroheated;

“Passing food through an electricheater consisting at least one electroheating cell with a first pair separated by a gap through which food can flow;

“Electroheating food by passing relatively high voltage and relatively low current AC electric current through the first pair electrodes and through it as the food passes through its first gap;

“Passing food through at least one more electroheating cell with a second pair electrodes separated by a gap through which food can flow;

“Electroheating food by passing relatively low voltage and relatively high current, high-frequency AC electric current through the electrodes as the liquid egg passes through second gap between second pair of electrodes. The high frequency AC current has a frequency that is effective in heating the food without electrolysis.

“According to a further aspect of the invention, there are also provided here methods of killing microbes from food. These include the following:

“Providing food containing microbes”

“Passing food through an electricheater, including at least one electroheating cell with a first pair separated by a gap through which food can flow,”

“Electroheating food by passing relatively high voltage and relatively low current AC electric current through the first pair electrodes and through it as the food passes through its first gap;

“Passing food through at least one more electroheating cell with a second pair electrodes separated by a gap through which food can flow;

“Electroheating food by passing relatively low voltage and relatively high current high frequency AC electric power across the electrodes as well as through the liquid egg, as the liquid egg passes through second gap between the two electrodes;”

“and holding the electroheated food for a period that is sufficient to inactivate, destroy or at least partially destroy the microbes.”

“In particular methods of pasteurizing or methods of sterilizing are considered.”

The term “liquid egg” as used in the present invention includes not only liquid yolk and egg white, but also combinations thereof in any desired or predetermined ratio. Liquid egg white, liquid yolk, and combinations thereof are also included in the term “liquid egg”. These additives include salt, sugar, milk stabilizers, antibiotics cyclodextrins peroxides, acids like citric acid, stabilizers, stabilirs, stabilizers, dextrins cyclodextrins as well as stabilizers, antibiotics, dextrins, cyclodextrins and dextrinst or particulate food. Also included is liquid egg from which cholesterol was removed.

According to the invention, the term “electroheating” is used to describe a process that generates heat in liquid eggs by passing current through it. Heat is generated by the liquid egg acting as a resistor. U.S. Pat. describes a preferred method for heating food by electroheating. No. No. 4,739,140, previously incorporated by reference. The flow of current does not heat the electrodes during electroheating. In fact, the disclosed embodiment takes affirmative steps to ensure that the electrodes don’t get too hot. Only heat is used to heat the liquid egg or other food to pasteurize or treat it.

“Extended refrigerated shelf live” refers to the fact that liquid eggs are safe to eat for at least three weeks after being treated according the the present invention. This assumes that the liquid egg is properly stored in a refrigerated environment. The term “extended refrigerated storage life” is preferred to mean that the liquid egg can be consumed for at least four weeks following treatment according to the present invention, and sometimes up to 10 to 12 weeks, or even longer. The practice of the invention can also allow for extended refrigerated shelf lives to other perishable foods.

Electrolysis is a chemical process that can take at least one of two forms. Electrolysis is the process of removing metal electrodes from the food being processed. Electrons flow between two electrodes and the metal inside them becomes ionized. This results in the release of electrons. These ions dissolve in the food being processed and are easily soluble. Electrolytic problems can also be caused by conversion of conductive Ionic species in the food to radicals or gases. This includes the conversion of hydrogen ion into hydrogen gas, and chlorine ions into chlorine gas. Hydrogen ions can be transformed into water and oxygen. The conversion can have adverse effects on the taste and other beneficial qualities of the treated food due to the depletion and conversion of ions to other species as well as other reactions such as oxidation.

“Coagulation is the process of a food’s protein being denaturated and agglomerated. Certain foods, such as orange Juice do not coagulate when heated. Some foods, like liquid egg, do not coagulate when heated.

“In accordance to the present invention, liquid egg and other food coagulable can be reduced. Some coagulation may occur at pasteurization temperatures for liquid eggs. However, the present invention states that if the liquid egg is not to be cooked, “detrimental” coagulation should be avoided. Detrimental coagulation refers to an increase in viscosity that causes the liquid food to become difficult to pour. This is when visible egg particles appear and the functionality of the liquid food is affected.”

The FIG. 1 schematic diagram will help you to better understand the methods and apparatus of this invention. 1. This is a typical device for pasteurizing liquid eggs. The typical egg pasteurizer can be modified to use an electroheater 7, which could be used in place of a plate heat exchanging device or another conventional heating device. These and other similar devices can be used to heat treat a variety of foods.

The present invention also allows for the use of a Cherry-Burrell Model EQ3 and EQ4. This packaging type has a higher failure rate, or more accurately, an increased incidence of the introduction microorganisms during packaging than an aseptic system. A clean pack could introduce one microorganism per 100,000 packages. This is just an illustration. Although this packaging technology is not considered aseptic, it can be used in accordance with the present invention. You can also use these Cherry-Burrell boxes to make plain, clean containers. If the packages are not sprayed with peroxide before filling, they may be considered sanitized but not aseptic or clean packs.

Plain sanitized clean containers are also useful according to the invention. They must be produced using “good manufacturing practices” and comply with all applicable government regulations. For illustration purposes, such containers that have been properly cleaned may contain one cell per 100 packages. This is because of the superior kill of electroheating and growth inhibitive effect of proper refrigerated stored, so such an addition of cells cannot be considered significant.

These packages are useful for practicing the invention of extended shelf life. They can be contrasted to a “dirty package”, which hasn’t been cleaned or packaged in clean or aseptic conditions. These containers can contain 1,000 cells or more, which is statistically significant in relation to the number remaining in pasteurized liquid eggs after pasteurization. Any other package type can be used, depending on the requirements of individual customers. This overview will help you understand the different aspects of the invention.

“The following is an explanation of the function and structure of different electroheaters 7′ according to the present invention. It is useful to present a set of electrical parameters and structural dimensions that can be used for illustration purposes to aid in understanding the operation and organization of these electroheaters 7?. The present invention’s scope of use is not limited to these parameters. A Westinghouse model 12K67 RF generator, which generates about 3200 volts peak-to-peak and around 400 amps, is used for the illustration. All voltages are reported as peak to peak. The generator adjusted the voltage automatically to maintain a constant current. For example, current densities exceeding 6 amps/cm2 are not possible in normal conditions. In accordance with the invention, it is preferred that current densities are kept at 3 amps/cm2 (or less) and, preferably, below 1 amp/cm2. The current densities through the different electrodes in this illustration are below 2 amps/cm2. The RF generator can produce high frequency AC current, including frequencies high enough to prevent the electrolysis of food between 100 Hz and 455. High frequency, as defined by the invention, refers to voltages with frequencies between 100 kHz – 450kHz and more preferably between 150 kHz – 450kHz. A frequency of 180 to 220 kHz was used for illustration. This explanation will also include liquid whole eggs sold under the brand “Table Ready” by Papetti’s Hygrade Egg Products, Inc., Elizabeth, N. J. The Table Ready brand liquid whole eggs contain citric acid in the amount required to stabilize the egg yolk’s color. For the purposes of this illustration, flow rates between 380 and 400 pounds per minute are considered.

“Turning to FIGS. A concentric electrode containing an electroheater 7′ is shown in FIGS. 2 through 4. FIG. FIG. 2 shows that electroheating cell 7” consists of a body 20. This can be made from stainless steel, or other metals that won’t react with food and will conduct electricity. Although the body 20 is usually made of steel for strength, it can also be made from other materials that conduct electric current and act as an electrode, such as conductive ceramics or conductive porcelain. The first electrode in the concentric pair of electrodes included in the electroheating cell 7 is body 20. A preferred configuration of body 20 includes a first cylindrical section 22 and a second cylindrical section 24 with a smaller outer diameter, connected by a tapered 26 to the first cylindrical part 22. An inlet tube 30 is located at the end of the cylindrical portion 24, which allows food to be introduced into the gap between electrodes in the direction of 31. The outlet tube 34 is located adjacent to the opposite end 32 of the cylindrical section 22. This is where electroheated food can exit in the direction shown in FIG. 3. The outlet tube 34 in the leftmost electroheating cells 7″a connects to the 7″b at the inlet tube 30 by suitable tubes or piping 36.

A cylindrical cooling jacket 38 can be placed around the cylindrical portion 24 of the body 20. An inlet tube 40 connects to the cooling jacket 38 at the cylindrical portion 24. A tapered portion 26 is adjacent. 42 is adjacent to the outlet tube 42. Cooling Jacket 38 can be used to circulate fluids, such as water, glycol, or alcohol. It also allows heat to be absorbed by gases or electroheating within the cell 7.

In a preferred embodiment, flow diverters or baffles can be installed in the lumen of the cooling jacket 38. This will ensure that cooling liquids flow smoothly from the inlet tube 40 through the outlet tube 42. Flow diverters are also helpful in ensuring even cooling across the entire outer electrodes cylindrical portion 24. FIG. 2. A spring or coil 200 may be placed inside the cooling jacket 38 around the cylindrical portion 24. The coil 200 does not need to form a watertight seal with the water jacket’s interior 38. It is preferable that spring 200 flows most of the water between its coils. Spring 200 can be made from any suitable material, such as plastic, metal, such as copper or aluminum, and stainless steel. Alternately, you can increase the flow of water through the Jacket via inlet tube 40 to achieve the same results.

“If required, a Jacket 66 or any other protective material may be placed outside the body 20 and cooling jacket 38 to prevent heat loss or cooling loss and/or protect nearby operators.”

“An aperture 44 is also located in the free end 32 of cylindrical section 22. This aperture can be used to fit an insulator 46. It may be made from non-tracking materials such as rubber, ceramics, or plastic. The preferred embodiment of the insulator 46 is made from DELRIN, a homopolymer of polyacetate available from DuPont, or CELCON, which is an acetyl copolymer from Celanese Corporation.

“Insulator 46 has a central aperture 47, into which is placed central electrode 50. O-rings, such as 49 or 51, are placed in central aperture 47. These O-rings engage the outer surface central electrode 50 when it’s placed in aperture 47. This prevents liquid egg from passing through cell 7” along its outside. It also helps to stop external contaminants entering the cell via the same route. A hollow cap 53 is fitted above insulator 46 at the free 32 end of cylindrical portion 22. Two threaded screws 55 are attached to insulator 46 at the one end. They exit through corresponding holes in cap 53. The 55-mm threaded studs pass through the corresponding holes in support plate 57. The adjustment nuts 59 are attached to the threaded holes on both sides of support plate 56. By tightening the adjustment nuts 59 above support plate 57, the entire central electrode 50 can move upwardly within hollow cap 53. The ones below plate 57 limit upward movement. The inclined shape of the insulator 46 can allow the central electrode 50 to be dropped into the body 20 by loosening the nuts 59 over plate 57.

“The central electrode 50 can be made of stainless steel, or any other metals that will not react with food or get wet. Non-metallic, but other conductive, and non-reactive materials can be used to make electrode 50. The central electrode 50 can be composed of a central tube 52 and a distal end 54 that has the appearance of a test tube. The support plate 57 connects to tube 52 and each of the central electrodes of each cell 7′. This allows the central electrodes 50 to act as the second electrodes of the electroheating device.

“A tube 60 is inserted in tube 52, so its distal ends are short of the distal 54 of tube 52. As described previously, a cooling fluid source is connected to tube 60’s inlet 62. The fluid flows out of tube 52 to outlet 64.

“A source for high frequency alternating voltage 70 (shown at FIG. 3) is connected to electrode 50 via a matching coil, tuning coil, or directly. However, the coil can be used in lieu. Five concentric electrodes, as shown in FIG. 3. Twelve inches of electrode 50 were exposed. Electrode 50 measures 1″. Body 20 measures 14 inches in length and taper vertically from its widest point, which is approximately 3″, to its narrowest point, which is about 2″. This results in an electrode with a 12″ heating zone. This electroheating zone’s length is determined by how much electrode 20 is exposed to the cavity. The gap between electrode 50 & electrode 20 is approximately 3/4”. When the voltages are applied in the range of approximately 3200 volts to the RF input on support plate 56, there will be a voltage drop of around 200 volts across electrodes 20 and 50. The voltage drop at terminal 35 will be measurable as 3000 volts.

The resistance of the egg to current flow is what makes it heat. This resistance is also known as resistivity. You can alter the resistivity by adding salts or liquids to the food. You can adjust the resistivity by changing the dimensions or relative spacing of electrodes according to the invention.

“The current density applied to food in a cell is also decreased by using a larger number of cells 7.” This is one method according to the invention to control current densities.

The addition or removal 7 cells is one method to adjust current density. This is a brute method, as any addition or subtraction to a cell with electrodes of a defined surface area will have an effect on current density. If the desired current density falls between what is obtained using, for instance, 4 or 5 electroheating cell 7″, another method of adjusting it must be found. Alternatively, a number of cells with electrodes of different surface areas must be available. The present invention allows for an adjustable electrode surface area, and therefore an adjustable current density, to alleviate this problem.

The amount of electrode 50 in electroheating cell 7 is adjustable by the amount of it inserted into body 20. You can raise electrode 50 by, e.g. The effective surface area of electrode 50, e.g., can be partially removed from the cell’s interior. This increases the current density. In the opposite direction, electrode 50 can be inserted further into body 20’s cavity. This increases the electrodes’ surface area and decreases cell 7’s effective current density. The electrode 50 was placed so that 12″ of it was visible for the purposes of this discussion.

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