The present invention relates generally to an egg drying device, such as which is incorporated into an egg handling/transfer assembly. More particularly, the present invention discloses an improved egg drying device in which a lowered humidity (desiccated) air flow is introduced through a plenum in a generally parallel and opposing laminar condition relative to a path of travel of previously washed eggs conveying through an interior duct associated with the drier. The direction of the dried/heated airflow typically results in laminar flow across both upper and lower surfaces of the eggs, as well as of the continuously rotating spool bars upon which the eggs are supported. Additional subset flows of heated/desiccated air are also redirected from the supply plenum to one or more intermediate header tubes arranged at internal locations of the body and, in combination with impinging baffle plates mounted within the drying device in communication with the egg path of travel, provide targeting drying of such as the ends of the eggs upon which high speed ink printers subsequently apply coding data. In this fashion, continuous and concurrent drying of the spool bars assists in faster and more efficient drying of continuously introduced wet eggs.
The prior art is well documented with examples of egg drying devices, such as which can be incorporated into an egg transfer machine including such interconnected components as an inlet/orienter, washer, sorter, packager and, optionally, an egg breaker. Examples of existing egg drying apparatuses include such as those described in McCord, U.S. Pat. No. 4,173,831 and Heyer, U.S. Pat. No. 6,357,140.
U.S. Pat. No. 4,358,341, to Bergquist, further discloses a spray dryer incorporating an air flow system for moving air through a drying chamber at generally atmospheric pressure with a controlled laminar air flow. The product being dried is sprayed into the drying chamber by an air distributor plate with a rapid air flow through and immediately surrounding the product spray and with a surrounding air flow of lower velocity.
It has further been found that conventional egg drying devices employ room conditioned air (defined as standard interior air exhibiting ambient temperature and humidity) and which is directed in a perpendicular/downward fashion against the tops of the conveyed eggs and in the attempt to blow” water off the eggs and as opposed to drying the eggs. Such perpendicular airflow often includes properties of ambient temperatures (e.g. such as in the 75° F. range) and related humidity (such as further in the 60%-100% range depending upon the geographical location of the facility in which the egg transfer assembly is located).
Issues with the drying of eggs according to such prior art technologies include unequal drying of the egg upper and lower surfaces, as well as the inability to sufficiently dry the spool bars which are continuously wetted by the introduction of previously washed eggs. It has been found that the inability to consistently dry the spool bar surfaces within the dryer will result in continual transfer of moisture to newly admitted eggs, and in counteracting fashion to the efforts of the normal/angled airflow. An associated disadvantage resulting from the relative inability of existing egg dryer (blower) assemblies to adequately dry the eggs coming out of the dryer is the inability to apply various inking patterns or identifying logos to the outer egg shells, such as which are desired in order to identify type and grade.
Also, and given that the final rinse temperature of the eggs traveling through the preceding washer stage is often in the 120° F. range, the internal pasteurization and other advantages provided by heating the eggs below its effective boiling range tend to be quickly lost as the film condition formed upon the eggs rapidly equalize to the wet bulb temperature. Additionally, and as is often attendant with high humidity environments, a dew point temperature near that of the wet bulb temperature further results in the removal of most, if not all, of the driving force for mass (drying) transfer.
It has also been determined that, in instances where an egg core temperature is also within this range, the egg can actually become further wettened. In view of these disadvantages, it is found that an airflow dew point must be significantly less than an egg temperature in any given facility application. It has further been found that off line plants with refrigeration components require special consideration as a result of this dynamic of physics.
The present invention discloses an egg drying device, such as which is incorporated into an egg handling/transfer assembly, in which a lowered humidity (desiccated) air flow is introduced from a dehumidifier component through a supply plenum for introduction at a generally outlet location of the dryer. The introduced airflow is redirected in a generally parallel and opposing laminar condition, counter to the direction of conveyance of the previously washed eggs supported upon the spool bars within the dryer, and towards the inlet end of the dryer. The direction of the dried (and typically heated) airflow typically results in laminar flow across both upper and lower surfaces of the eggs, as well as of the continuously rotating spool bars upon which the eggs are supported, and in order to provide more complete drying of the eggs, as well as continuous drying of the spool bars.
Additional subset flows of heated/desiccated air are also redirected from a branching location of the supply plenum for delivery to one or more intermediate header tubes arranged at internal locations of the body. Impinging baffle plates are mounted within the drying device in communication with the internal spool bar conveyor and proximate to the mounted location of associated header tubes.
The header tubes each exhibit pluralities of air discharge nozzles which are impinged upon and redirected by the configuration of the baffle plates for providing targeting drying of such as the ends of the eggs, such as upon which high speed ink printers subsequently apply coding data. In combination with the targeted delivery through the intermediate header tubes, the overall laminar flow associated with the plenum supplied desiccated air (at the outlet) assists in continuous and concurrent drying of both the eggs and associated spool bars upon which the eggs are translated/rotated, thereby achieving faster and more efficient drying of wet eggs, in part by preventing the spool bars from transferring moisture back to the conveyed eggs.
Reference will now be made to the attached drawings, when read in combination with the following detailed description, wherein like reference numerals refer to like parts throughout the several views, and in which:
As previously described, the present invention teaches an improved egg drying device for more quickly and efficiently drying pre-washed eggs and in which a lowered humidity (desiccated) and typically heated air flow is introduced in a generally parallel and opposing laminar condition relative to a path of travel of the eggs conveying through an interior duct or defined tunnel associated with the drier. The egg drying device is typically incorporated into an egg transfer/handling assembly, such as between an egg washer and subsequent positioned grader and packer components, with it further being understood that the dryer can, without limitation, be employed in any manner or configuration of egg transfer or process assembly for drying washed eggs.
Referring now to
In one non-limiting application, the egg dryer can exhibit a length in the range of 65″ and which, given a routine spool conveyor speed associated with the transported eggs, results in an interior egg transit time of approximately 12-15 seconds between inlet and outlet ends. Although not shown, preceding the dryer is an egg washer station which is commonly employed for cleaning the eggs, such as which are communicated directly from hen laying houses, and for providing a continuous flow of wet eggs to the dryer 10.
Following the dryer is any type of equipment not limited to an egg printer, grader and/or packer stations and which are interconnected by individual pluralities of the afore mentioned sections of rotatable driven spool conveyors (see as shown in
As best shown in the plan view of
The dehumidification component 19 depicted is incorporated into the body of the dryer 10, at any suitable location within the interconnecting plenum structure and such as which can incorporate either or both of dryers and/or burners for assisting in reducing the humidity of the intake air. A blower structure or the like is also incorporated into the plenum and communicates the heated and reduced humidity air via the plenum ductwork 18 and 20 to the location identified and 22 approximate the dryer outlet.
A corresponding desiccant structure is concurrently employed to achieve a desired reduction in the humidity, such as by adding heat to the air stream after employment of a drying process. Other features include any type of pre-filtering of intake air and, as further shown in
Alternative to a standard burner/dehumidification application, it is also envisioned that a direct expansion (DX) stage of a refrigeration cycle can be employed, this in effect occurring between the evaporation and condensation stages in which the heated/dried by-product of the cycle can be employed as the treated air medium. It is contemplated that removal of water by DX dehumidification can employ an evaporation temperature in a range of 32° F. to 40° F.t, this resulting in eventual dried air outputted in a desired range of 120° F. The use of condensation heat to warm and dry the air to a useful level corresponds to an amount equivalent to the latent heat removed from the return air, such as resulting in a desired airstream on the order of 110° F. with 10% humidity or less.
The desired interior conditions associated with the lengthwise interior passageway associated with the dryer are again promoted through the incorporation of the trays 24 and 26 (or other suitable enclosure), and which are typically three sided in order to substantially seal the interior extending length of the egg passageway within the dryer between its inlet and outlet ends. While not providing an absolutely airtight environment (given the open inlet and outlet ends of the dryer) the purpose of the trays or other suitable enclosing structure can be designed so as to be either fixedly or removably secured to the undersides of the dryer and in order to create a substantially controlled interior environment for the introduction of an opposing heated laminar airflow relative to the direction of the egg transfer.
Following the heater 46, the now regenerated and reheated/desiccated subset airflow is fed, via an outlet tube 48 to one or more intermediate header tubes 50 mounted in widthwise extending and passageway communicating fashion within the egg flow conveying interior of the dryer.
The invention contemplates in one non-limiting variant redesigning the outlet 48 to feed up to three individual header tubes 50 installed in spaced locations approximating the inlet, intermediate and outlet locations of the dryer. The non-limiting design of the selected header tube 50 depicted in the cutaway of
When viewed in combination with the overall cutaway perspective of
The design of the header baffle plates is such that each promotes targeted airflow delivered from the header tube nozzles 56 and 58 and redirected in a slightly downward fashion along the undersides of the baffle plates 52 (see again
As further best shown in
Concurrent with the targeted location drying achieved through the employment of the regenerative assembly and intermediate header tubes 50,
As described, one non-limiting performance variant of the assembly contemplates the outlet delivered airflow (performing according to the operational parameters described in reference to
It is further understood that the interior ductwork associated with the dryer 10 may be designed in order to allow the heated/desiccated airflow to be calibrated to any desired parameters, this in one non-limiting variant including such as airflow of 10-15 mph (equivalent to approximately 9″ per second). The ability of the airflow to pass across the eggs entire surface (as shown by the depicted airflow in
It is further found that the vacancies upon the spool bar conveyor when, in use with such as a cross current airflow as previously disclosed in reference to the prior art, tends to cause low pressure distortions which tend which reduces the effectiveness of the cross flow units. With the counter flow application of the present invention, such vacancies upon the spool bars are not exploited to create localized pressure disparities. In this fashion, continuous and concurrent drying of the spool bars assists in faster and more efficient drying of newly introduced wet eggs.
Having described my invention, other and additional preferred embodiments will become apparent to those skilled in the art to which it pertains, and without deviating from the scope of the appended claims.
This application claims the benefit of U.S. Provisional Application 61/253,937 filed on Oct. 22, 2009.
Number | Date | Country | |
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61253937 | Oct 2009 | US |