PROCESS AND EQUIPMENT CAPABLE TO ACHIEVE ZERO-ENERGY HEATING, VENTILATION, AIR CONDITIONING OPERATION
20180149386 ยท 2018-05-31
Inventors
Cpc classification
F24F3/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F1/00075
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D9/0037
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F13/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Y02B30/54
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
F24F1/0007
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F3/044
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F1/0071
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F24F13/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F3/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F24F3/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
Process and equipment for managing air properties allowing to achieve Zero-Energy HVAC operation allowing 24/7 air recycling capability with up to 100% re-feed capability independent of internal and external factory air conditions with air humidity controller or with dedicated air humidity controllers for both factory air and process air.
Claims
1. A manufacturing set up (210) for the manufacturing of hygiene products comprising: an air property management system (200) said hygiene products being selected from the group consisting of baby and adult incontinence absorbent articles, feminine hygiene articles, and materials adapted to be used in such articles, selected from the group consisting of nonwoven, films, and composites thereof said manufacturing set up (210) comprising: a) a production area (215) comprising: walls (217) adapted to separate the production area (215) from an external ambient environment (205); a manufacturing room comprising space for at least one manufacturing equipment (230) of said baby and adult incontinence absorbent articles, feminine hygiene articles, and materials adapted to be used in such articles, a multiplicity of said manufacturing equipment, and for operators (236), said manufacturing room further comprising an aerial environment (220); b) said at least one manufacturing equipment (230) of said articles in said manufacturing room, said at least one manufacturing equipment comprising: a manufacturing equipment housing (235) separating process air of a manufacturing equipment aerial environment (240) from room air of said aerial environment (220), said manufacturing equipment housing being integral with a sound retarding housing; said baby and adult incontinence absorbent articles, feminine hygiene articles, and materials adapted to be used in such articles forming elements (245) inside said housing adapted to change at least one process air properties (250), said properties being selected from the group consisting of temperature, moisture content, dust content, and pressure; and said baby and adult incontinence absorbent articles, feminine hygiene articles, and materials adapted to be used in such articles forming said elements (245) being selected from the group consisting of hot melt application systems, ultrasonic systems, separation systems, defiberization systems, separation systems, web handling drive system, and web handling friction systems; c) an air treatment system (260), wherein said air treatment system is a HVAC system; and d) a duct work (270) adapted to connect said manufacturing equipment housing (235) to said air treatment system (260) in a closed loop system; wherein said air property management system comprises: an indirect heat exchange system as said air treatment system (260) and adapted to transfer energy from said external ambient environment (205) to said aerial environment (220) or said process air of said manufacturing equipment aerial environment (240) without mixing of the energy transferring air streams, wherein said indirect heat exchange system is an adiabatic heat exchange system.
2. The manufacturing setup of claim 1, wherein the air management system further comprises one more elements selected from the group consisting of one or more temperature adjustment element(s) (282) comprising indirect heat exchange elements, selected from the group consisting of cooling elements cooling water at ambient temperature, heating elements, energy exchange elements between other elements connected via said duct system, and heat pumps; closing valves (288) in said duct work, said duct work adapted to be closed, manually or automatically, in case of an opening of said housing; a fan element (280); an air humidity adjustment element (286) adapted to allow increase or decrease of the absolute humidity (water content) of the air; a dust reduction system (284), filter, wherein said dust reduction system is a HEPA filter; and an automated control system for adjusting process settings according to production processing variables as well as external ambient air conditions.
3. The manufacturing setup of claim 1, wherein the air management system further comprises: an air flow distribution system comprising valves (288), and side ducts, wherein further air treatment systems are adapted to provide predetermined air flows to various parts of the system and to different article forming elements.
4. The manufacturing setup of claim 1, wherein said indirect heat exchange system of said air property management system is a multi-way heat exchanger, comprising multiple layers consisting of a 3D surface structure of materials separating airflows within the heat exchanger, and of a high-surface area honeycomb type.
5. The manufacturing setup of claim 1, wherein said indirect heat exchange system of said air property management system is adapted to match dimensions of a standard ISO 668 container, whereby the housing provides structural integrity to achieve ISO 668 standards and to support material layers of said indirect heat exchange system.
6. A process for management of air properties in manufacturing of products in a manufacturing set up, said products selected from the group consisting of baby and adult incontinence absorbent articles, feminine hygiene articles, and materials adapted to be used in such articles, selected from the group consisting of nonwoven, films, and composites thereof, said process for management of air properties comprising the steps of: providing a manufacturing set up (210) comprising: a) a manufacturing room (215) comprising: walls (217) adapted to separate the manufacturing room from an external ambient environment (205), said manufacturing room comprising space for manufacturing equipment (230) of said articles, a multiplicity of manufacturing lines and for operators (236) said manufacturing room further comprising an aerial manufacturing environment (220); b) said manufacturing equipment (230) of said articles in said manufacturing room, said manufacturing equipment comprising: a manufacturing equipment housing (235) separating process air of manufacturing equipment aerial environment (240) from room air of said aerial manufacturing environment (220), said housing being integral with sound retarding housing; a plurality of article forming elements (245) inside said housing adapted to change at least one air properties (250) in said manufacturing equipment aerial environment, said properties being selected from the group consisting of temperature, moisture content, dust content, and pressure; and said plurality of article forming elements (245) being selected from the group consisting of hot melt application systems, ultrasonic systems, separation systems, defiberization systems, separation systems, web handling drive system, and web handling friction systems; c) an indirect heat exchange system (260); and d) duct work (270) adapted to connect said manufacturing equipment housing (235) to an indirect heat exchange system (260) in a closed loop system; changing the properties of said manufacturing equipment aerial environment (240) by operating said plurality of article forming elements; transferring said process air from said manufacturing equipment aerial environment (240) to said indirect heat exchange system; treating the process air from said manufacturing equipment aerial environment (240) and said room air of said aerial manufacturing environment (220), if present, by exchanging energy with ambient air in an indirect heat transfer that is an adiabatic heat transfer, wherein the content of the ambient air in an air stream leaving said indirect heat exchange system is selected from the group consisting of less than 50%, less than 80%, less than 10%, less than 1% and essentially zero; whereby the indirect heat transfer between said ambient air and said processing air is an adiabatic heat exchange.
7. The process for management of air properties of claim 6, further comprising the step of submitting the process air and room air, if present, to one or more steps selected from the group consisting of further heating or cooling, adjusting water content by adding or removing moisture, reducing dust level, creating a further pressure differential, interrupting said air flow of said processing and said treated air by stop valves upon opening said walls of said manufacturing equipment, collecting air from more than one of said manufacturing equipment, directing more than one air flow to said indirect heat exchange system, by operating a multi-way heat exchanger, and diverting said air flow of treated air towards two or more endpoints.
Description
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0040] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
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DETAILED DESCRIPTION OF THE INVENTION
[0046] The present invention relates to manufacturing set-ups or factories, which require for a good operation active management of the air properties. Whilst there are many types of manufacturing operations that have such requirements, a particular manufacturing set ups for producing hygiene products are particular sensitive to uncontrolled air properties, among others for hygienic reasons but in particular since the introduction of superabsorbent polymers also to allow smooth operation. Whilst such facilities used to operate without any HVAC capability, developments covered the introduction of HVAC capability, air recycling capability, optionally with valve systems to control the amount of recycled air entering the factory, and also heat exchanger technology. The present invention builds on such developments.
[0047] Combining this adiabatic cooling process with a heat exchanger (two-way or a multi-way exchanger) allows the humid air exiting the adiabatic cooling processes to remain separated from the air exiting the production process thereby not having any negative effects on the factory air.
[0048] Further embodiments of this invention are to return the recycled air back to the convertor process and not back into the factory air that is common today. With more and more production systems having higher sound emission criteria and with this trend most likely to continue, most production equipment are fully enclosed with sound retarding housing. This sound retarding housing can also be used to adequately separate the factory and process air. In the scenario where filter exhaust air is being returned to the production system, process air remains separated from factory air, and as such both air streams can operate at different temperature levels and moisture levels. Being able to run both air streams at separate temperature and moisture levels has distinct advantages for the end-user that is described herein below.
[0049] Further performance enhancements to the process are further described herein. The majority of hygiene factories operate at positive pressure versus ambient conditions, where new fresh air is injected into the air handing process to provide this positive pressure, but also to introduce fresh air into the factory or the manufacturing set-up that is a very important design feature of any well design HVAC system. A well designed HVAC system typically exchanges/replaces the air about 10 times per hour, and this air which is continuously being re-circulated has new fresh conditioned ambient air from outside injected into this air stream at values of around ten percent. As this newly injected air enters the process and factory, air within the factory is typically vented to the environment and the energy invested to heat, chill or de-humidity this air is lost. Further embodiments of this invention are to reduce the percentage of air exiting the factory, and to divert this air to an adiabatic cooling processes thereby reducing the wet-bulb temperature further.
[0050] For explanatory and exemplary purposes, a diaper factory located close to the equator is considered that is recirculating air at ten air changes per hour whilst adding 10% of newly conditioned fresh air from the HVAC system back into this air stream, whereby this additional air being pumped into the factory is exiting the factor via doors, windows, air vents etc. Assuming for such a scenario external air temperature at 32 C. with 65% relative humidity with air pressure at 1011 millibar, the wet-bulb temperature is at 26.2 C., whilst the dew point is at 24.1 C. Taking this external factory air at 32 C. and passing it through the two-way heat exchanger and then back-out of the heat-exchanger exiting outside of the factory to an area where this hotter air will not be sucked back into in inlet ducting means internal factory air and external factory air are not mixed. With the process air exiting the diaper production process at a temperature of 46.5 C., remaining in the factory and passing this air also through the two-way heat-exchanger and then exiting back inside of the factory reduces the air stream temperature without changing the relative humidity of this internal air stream. In an ideal process the production process at a temperature of 46.5 C. would be reduced to 32 C. however, due to inefficiencies in the heat exchanger process and adiabatic cooling process, a value of around 34.4 C. can be achieved.
[0051] Comparing this to an adiabatic cooling processes to chill the external factory air entering the heat exchangers, this air stream originally at 32 C. can be chilled down to 28.3 C. prior to entering the heat exchanger. This allows the air that was previously exiting the heat exchanger at 34.4 C. to be reduced to 28.3 C.
[0052] If now a proportion of the conditioned air, that was previously exiting the building, is fed into the incoming external factory air stream prior to the adiabatic cooling processes, say 80% of the overfeed air-flow thereby still allowing the factory to be pressurized increases the efficiency of the adiabatic cooling processes. The wet-bulb temperature that was previously at 26.2 C. is reduced to 24.1 C., meaning, the previous factory air-flow stream that was chilled to 28.3 C. with the standard adiabatic cooling processes can now be chilled down to 27.2 C., essentially with no additional energy requirements.
[0053] If the air flow exiting the heat-exchanger and going back into the factory is returned directly to the process as was mentioned earlier, then, this air stream can operate at a higher temperature without increasing the factory room environment, e.g. for the operators.
[0054] If a close circuit air-flow used for process air and this airstream becomes separate to factory air, the heat exchanger can be further split, in that internal factory air can also be passed through the heat exchanger and exit back into the factory. Further improvements to this would be to divert all external air-flows (vertical flow in cross flow heat exchanger and parallel flow in parallel flow heat exchanger and counter flow in counter flow heat exchanger) from the overfeed adiabatic cooling process into this zone of the heat exchanger to further enhance performance.
[0055] Considering again the above discussed diaper factory scenario and assuming the same adiabatic cooling processes to chill the external factory air entering the heat exchangers, then the external air stream originally at 32 C. can be chilled down to 28.3 C. prior to entering the heat exchanger, the heat exchanger would then essentially cool the hot production air circuit from 46.5 C. to 34.4 C. And as part of the heat exchanger would be used to chill internal factory air, the hot production air circuit cannot reach 34.4 C. but can reach 36.5 C.
[0056] As this air stream in closed loop and does not come into contact with the factory room air, this has no negative effect on the factory environment and system, provided that the ductwork has sufficient heat insulation. Assuming again, that in the heat exchanger 80% of the overfeed air-flow are fed back through the heat exchanger prior to it exiting the building. Assuming further an adiabatic cooling process and that the factory room environment exhibits 48% relative humidity at 25 C. at 1011 millibar, then a theoretical wet-bulb temperature of 18.42 C. can be achieved via the adiabatic cooling process. With inefficiencies in the adiabatic cooling process and the heat exchanger, the theoretical temperature of 18.42 degrees C. cannot be reached however output temperatures of about 20 C. can be achieved. With the factory room at 25 C., this lower temperature can be used to off-set heat loading that is added to the factory space through items such as glue tanks, and heat being expelled from the convertor.
[0057] The above described executions do not control air-humidity within the factory and as such, further embodiments are preferred to combine hygiene production processes with stand-alone air moisture control systems to maintain factory room air at a pre-set level. The separate control of process air and factor air allows the factory air to be maintained at an air humidity level most suited for humans, whilst the process air can be maintained at a humidity level most suited for the process. In most instances, the process air humidity would be very dry which further reduces cleaning effort and also reduces and even eliminates process issues such as SAP screen blinding on core-laydown processes, as well as it gives significant longer life expectancies of filtration media.
[0058] Further embodiments of the present invention are to combine the heat-exchanger frame-work with a frame-work that corresponds to shipping container dimensions for transportation processes.
[0059] Even further embodiments of the present invention include honeycomb profiles within the heat exchanger rather than conventional fin/plate technology. A heat exchanger made from honeycomb profiles has a high strength profile thereby allowing a thinner metal profile to be used. Furthermore, automatic honeycomb production methods allow a combine structure to be made that require little or no assembly effort hereby allowing the heat-exchanger to be produced at a more attractive cost for the end-user.
[0060] Further embodiments of this invention are to equip the outer interface of the heat exchanger with a common control interface that allows a plug & play common interface with other ancillary devices such as fan, filtration and HVAC equipment.
[0061] Further embodiments to this invention are to incorporate air humidity control devices within the total machine assembly.
[0062] Further embodiments of the present invention are to combine channels within the heat exchanger to allow water flows such as water that has been chilled or heated using geo-thermal energy. With the two-way heat exchanger having a high surface area and being an efficient means to change air temperature with low pressure drop, using geo-thermal energy to change the heat exchanger plates allows air temperatures to be modified further without the pressure drops that are associated with incumbent HVAC coil technology. This technology is of particular benefit in sandy regions such as Saudi Arabia where drilling costs are very low and as such the installation of geo-thermal ground pipes is also very low. For this particular usage, further embodiments to this invention are to combine channels within the heat exchanger to allow water flows such as water that has been chilled or heated using solar energy. With the two-way heat exchanger having a high surface area and being an efficient means to change air temperature with low pressure drop, using geo-thermal energy to change the heat exchanger plates allows air temperatures to be modified further without the pressure drops that are associated with incumbent coil technology.
[0063] Further embodiments of the present invention are to use the elevated air temperature of the closed circuit system in secondary drying processes. This higher air temperature combined with low humidity levels make this an ideal drying medium. This can for instance be used for the making curly fibers on-line where a significant drying load and heat is required.
[0064] Further embodiments of the present invention are to install additional valve technology in the filter process. To date, many filter processes consist of multiple filtration stages. In these processes, air exits the filter after the HEPA stage, however, if the air is exiting the factory to an external environment, then, it is not preferred to pass this air through a HEPA air filter as this requires further energy in the main system fan to pull the air through the HEPA filter media, and, the HEPA filter media has a reduced life span, also adding costs to the end-user on top of the higher energy costs. Installing a valve prior to the HEPA filter media allows factory exhaust air to exit the external environment prior to entering HEPA filter media, whilst, air being recycling back into the factory passes through the HEPA filter media prior to entering the factory.
[0065] A well-designed HVAC system typically exchanges/replaces the air about 10 times per hour, and this air which is continuously being re-circulated has new fresh conditioned air from outside injected into this air stream at values of around ten percent. As this newly injected air enters the process and factory, air within the factory is typically vented to the environment and the energy invested to de-humidity this air is lost. Further embodiments of this invention are to reduce the percentage of air exiting the factory, and to divert this air back into the adiabatic cooling processes thereby reducing the wet-bulb temperature further.
[0066] Considering for explanatory and exemplary purposes, a diaper factory located close to the equator, that is recirculating air at ten air changes per hour whilst adding 10% of newly conditioned fresh air from the HVAC system back into this air stream, whereby this additional air being pumped into the factory is exiting the factor via doors, windows, air vents etc.
[0067] Whilst the figures used for the explanation of the present invention outline cross-flow heat exchanger it should be noted that equivalent executions can also be used, such as parallel flow heat exchangers and counter flow heat exchangers or combinations of any type.
[0068] Without wishing to limit the present invention by the following, exemplary executions of the hygiene product manufacturing environment are described by referring to the figures to allow a better understanding.
[0069] At the onset of many production technologies, production started in factories that had no HVAC systems. A typical example of this is in
[0070] As the factories evolved, many factories migrated to HVAC systems, enclosed their building and slightly pressurised the building. With active air circulation and a regulated fresh air injection into the factory many advantages were gained. Workers were able to work in a comfortable work environment, with no significant temperature or humidity changes. In hot climates, staff attrition rates dropped and staff morale was boosted. Factories requiring a clean environment, such as food and hygiene production had the added benefit that insect and other contamination risks were eliminated as the build was sealed and air entering into the factory was filtered. A typical example of this is in
[0071] As production systems evolved further, production speeds increased, the number of processes increased and air volumes also increased. In the hygiene sector, the move from tissue only cores to pulp and SAP cores increased air volumes significantlyin many cases by a factor of 15-20 times. As all air exiting the building had to be replaced, incoming air also had to increase by the same amount. A hygiene production system requiring say 5010.sup.3 m.sup.3/hr requires an air replacement back into the factory of 5010.sup.3 m.sup.3/hr, a total factory requiring say 50010.sup.3 m.sup.3/hr requires an air replacement back into the factory of 50010.sup.3 m.sup.3/hr. As such, HVAC systems had to be increased to meet demand and the power requirements for the HVAC systems also increased.
[0072] As power consumption of HVAC systems sky-rocketed, enhancements in efficiency were urgently needed and as such many new systems evolved where the air filtration performance installed that cleaned the air to a very high specification thereby allowing the return of air back into the factory whilst not jeopardizing the health of factory workers. In
[0073] This new technology made great inroads into reducing HVAC tonnage and the respective power requirements to operate the HVAC systems. As the installation numbers of such technology slowly increased around the world, it was clearly evident that the benefits of the technology varied significantly from industry to industry and from process to process and from location to location. In scenarios where air exiting the filter had an elevated air temperature, the incoming air would significantly heat the manufacturing room of the factory. In some locations, say in northern or southern hemisphere locations during the winter period, this heat was put to use and used as free heating. As such, to achieve this, additional valve systems (140) were installed as shown in
[0074] Whilst a set-up as shown in
[0075] Connecting a heat exchange to the outlet of the filtered air that allows external factory air to enter the heat exchanger and exit back outside the factory without coming into contact with the filtered air solved this issue and allows air recycling on a 24/7 basis.
[0076] As outlined above, the mind-set within industry to date has been to recirculate the filtered air back into the factory production area when this has made economic sense. However, options do exist with some production processes to send this air directly back to the production process and operate a close loop system. This closed loop system has three key benefits in that (1) it fully separates all interactions with process air and factory room HVAC air, (2) it allows the process air to operate at a different temperature to the factory room air, (3) it allows the process air to operate at a different moisture level to the factory air.
[0077] A method to enhance this process is to capture air-conditioned air that would normally exit the building and use this cooler dryer air to boost the performance of both the heat exchanger and the adiabatic cooling process. A well designed HVAC system typically exchanges respectively replaces the air about 10 times per hour, and this air which is continuously being re-circulated has new fresh conditioned air from outside injected into this air stream at values of around ten percent. As this newly injected air enters the process and factory, air within the factory is typically vented to the environment and the energy invested to de-humidity this air is lost. By reducing the percentage of air exiting the factory and diverting this air back into the adiabatic cooling processes thereby reducing the wet-bulb temperature further. This concept is shown in
[0078] By utilizing the wasted air and also by adding efficient moisture control devices, standard HVAC systems are no longer required. This concept is shown in
[0079]
[0080] Such production step equipment may bewithout any limitationhot melt application systems, ultrasonic system, separation or cutting systems, defiberization systems, separation systems, web handling drive system, web handling friction systems, etc. During the operation of such production step equipment (245) the air properties of the process air in the direct vicinity of this equipment are often impacted (250) such as by an increase in temperature, dust level, or change in relative or absolute humidity, thusly also the aerial environment of the production system, i.e. the process air (240) exhibits a change in properties. In order to separate this process air from the areal environment (220) of the production room or area (210), the production equipment may be separated by a housing (235) from the production area (210). Such a housing may preferably also function as a sound retarding element, or also as a safety element for the health or safety of an operator (236). The air management system further comprises an air treatment system (260). Duct work (270) may transfer air from the process (240) and/or the production room (220) to the air treatment system (260) and back to the production system or the production area. The air treatment system may comprise filter elements (not shown) but very preferably comprises a heat exchange system for exchanging energy between the process and optionally production room air and external ambient air as entering the air treatment system at an air entry (262) and leaving it at air exit (268).
[0081] In
[0082] In
[0083] In
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