Claims:WE CLAIM:
1. A flash steam and condensate recovery system (100) comprising:
• a collector unit (101) defined by a tank configured to receive a mixture (102) of flash steam and condensate therein to facilitate separation of flash steam (107) from the condensate (105) therein, said collector unit (101) having:
o a collector inlet (103) configured on an operative top portion of said collector unit (101) to allow the flow of said mixture (102) into said collector unit (101),
o a collector outlet (104) configured on an operative bottom portion of said collector unit (101), said collector outlet (104) configured to facilitate discharge of the separated condensate (105) from said collector unit (101), and
o a flash steam exhaust outlet (106) configured on an operative top portion of said collector unit (101), said flash steam exhaust outlet (106) configured to facilitate release of flash steam (107) from said collector unit (101),
wherein the transverse dimension (d’) of said collector unit (101) is greater than the vertical inside distance (d) between said collector inlet (103) and the collector outlet (104), such that vertical inside distance (d) is perpendicular to the axis of said transverse distance (d’), to ensure maximum area for separation of the flash steam (107) from the condensate (105);
• an overflow control unit (116) coupled to said collector unit, below the condensate inlet, said overflow control unit (116) configured to ensure removal of the condensate (105) from the collector unit (101) in overflow conditions, and maintain the volume of the condensate (105) in said collector unit (101) less than the volume of the flash steam (107);
• a pumping unit (108) in fluid communication with said collector unit (101), said pumping unit (108) disposed below said collector unit (101), and configured to receive the separated condensate (105) from the collector outlet (104) of said collector unit (101), wherein said pumping unit (108) includes a pump outlet (110) configured to facilitate discharge of said pumping unit (108);
• a sensing unit (111) coupled to said pumping unit (108), said sensing unit (111) configured to periodically sense the volume of said separated condensate (105) received inside said pumping unit (108), and generate a sensed volume value based on a sensed pre-determined volume;
• a control unit (112) configured to said sensing unit (111) for controlling said discharge of said condensate (105) through said pump outlet (110) based on said sensed volume value;
• a steam dryness enhancing unit (113) in fluid communication with said flash steam exhaust outlet (106), said steam dryness enhancing unit (113) configured to allow flash steam (107) to pass therethrough, and further configured to facilitate removal of the droplets of the condensate (105) suspended in the flash steam (107), thereby improving the dryness fraction of the flash steam (107); and
• a frame structure (118) for supporting said collector unit (101), said pumping unit (108) and said control unit (112).
2. The system as claimed in claim 1, wherein said overflow control unit (116) includes a level based volume regulating control system.
3. The system as claimed in claim 2, wherein said level based volume regulating control system is a ball and float type flow control system.
4. The system as claimed in claim 2, wherein said level based volume regulating control system is a control valve based system.
5. The system as claimed in claim 1, wherein said sensing unit (111) includes at least one sensor(s) (111a, 111b, 111c) positioned within said pumping unit (108), each said sensor (111a, 111b, 111c) is configured to generate a sensed volume signal based on the volume of said separated condensate (105) inside said pumping unit (108).
6. The system as claimed in claim 5, wherein said sensing unit (111) includes a signal conditioning unit configured to convert said sensed volume signal into said sensed volume value.
7. The system (100) as claimed in claim 6, wherein said sensing unit (111) is configured to cooperate with said control unit (112), said control unit (112) includes a processor configured to receive said sensed volume value detected by said sensing unit and further configured to generate a discharge signal if the volume of the condensate (105) in the pumping unit (108) increases from said sensed pre-determined volume, and a refill signal if the volume of the condensate (105) in the pumping unit (108) decreases from said sensed pre-determined volume.
8. The system (100) as claimed in claim 7, wherein said sensing unit (111) is configured to cooperate with said control unit (112), said control unit (112) comprising:
o a memory configured to store a threshold value corresponding to the volume of the condensate (105) in said pumping unit (108), and
o a processor cooperating with said memory, said processor configured to receive said sensed volume value from said sensing unit (111), and further configured to compare said sensed volume value with said threshold value, to generate a discharge signal if said sensed value is more than said threshold value and a refill signal if said sensed value is less than said threshold value.
9. The system (100) as claimed in claim 1, which includes a first check valve (115a) positioned upstream of said pumping unit (108) to prevent pressurization of said collector unit (101).
10. The system (100) as claimed in claim 1, which includes a second check valve (115b) positioned downstream of said pumping unit (108) to prevent the backflow of the condensate (105) into said pumping unit (108).
11. The system (100) as claimed in claim 1, wherein said pumping unit (108) includes an actuating mechanism (112a) configured to cooperate with said control unit (112) to:
(a) cause the pressurization of condensate (105) in the pumping unit (108) such that said actuating mechanism (112a) is configured to pump a motive fluid (114) into said pumping unit (108) upon the receipt of said discharge signal, for pushing the condensate (105) out of said pumping unit (108); and
(b) cause the depressurization of the condensate (105) in the pumping unit (108) by releasing the motive fluid (114) from said pumping unit (108) after condensate discharge.
12. The system (100) as claimed in claim 1, wherein said collector unit (101) is connected to a safety valve (117) configured on the operative top portion of said collector unit (101), said safety valve (117) is configured to periodically release the flash steam (107) therethrough and regulate the pressure in said collector unit (101).
13. The system (100) as claimed in claim 1, wherein said steam dryness enhancing unit (113) includes a demister pad or a dry pan for absorbing the droplets of the condensate (105) suspended in the flash steam (107).
14. The system (100) as claimed in claim 1, wherein said control unit (112) includes a display unit for presenting the operational parameters of the system (100) to a user.
15. The system (100) as claimed in claim 1, wherein said control unit (112) includes a communication module configured to transmit and receive instructions from a remote device.
, Description:FIELD
The present disclosure relates to flash steam and condensate recovery systems.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
Steam is a common media used in the process industry for heating. Condensate is formed when steam liberates heat and converts from vapor to liquid phase. When high pressure condensate is discharged from steam traps to low pressure condensate return line, excess energy is released in the form of flash steam. This flash steam contains high amount of energy and can be further used in heat recovery processes to heat boiler feed water or in process utility.
The condensate often mixed with the flash steam is relatively pure compared to most water sources. Hence, it can be an excellent source of feed water for boilers. Due to less concentration of dissolved solids in the feed water, heat lost through blow-down is reduced, which simultaneously reduces the amount of heat required to maintain operating pressures. This condensate can be recovered for any process utility wherein hot water is pre-requisite saving the energy & mass of the water.
Condensate and flash steam recovery system are configured to separate the flash steam and the condensate. The condensate separated is then recirculated to be reused in the process utility. Similarly, the flash steam separated is also recovered and recirculated for reuse.
The condensate and flash steam recovery system employs condensate recovery unit that is positioned below the flash steam recovery unit to receive the condensate by gravity. The condensate recovery unit is operated by pressurized pumping means which is adapted for selectively receiving the condensate into the condensate recovery unit, discharging the condensate to process equipments through an outlet steam trapping unit, and discharging the exhaust gas via an exhaust gas outlet. However, some of the conventional systems limit the flash steam separation area due to their vertical orientation realized through a smaller cross-sectional diameter which provides for higher separation velocity leading to carry over of condensate in recovered flash steam, thus leading to increased possibility of hammering in the pipeline. Furthermore, the conventional system also necessitates the use of an additional steam trapping device, which may decrease the discharge capacity of the pump and increase backpressure due to the implementation of steam trapping unit in the system.
There is, therefore, felt a need for a flash steam and condensate recovery system that alleviates the drawbacks of the conventional recovery systems.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a flash steam and condensate recovery system.
An object of the present disclosure is to provide a flash steam and condensate recovery system which provides improved dryness of the recovered flash steam leading to its more efficient utilization.
Yet another object of the present disclosure is to provide a flash steam and condensate recovery system which minimizes hammering, thereby, improving the life of the peripheral equipments.
Another object of the present disclosure is to provide a flash steam and condensate recovery system which improves the amount of condensate that can be accommodated in the receiver (flash vessel conventionally) with respect to steam and condensate mix received for optimal management of surge load conditions.
Another object of the present disclosure is to provide a flash steam and condensate recovery system that has low maintenance.
Still another object of the present disclosure is to provide a flash steam and condensate recovery system that increases discharge capacity.
One object of the present disclosure is to provide a flash steam and condensate recovery system that has high reliability.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a flash steam and condensate recovery system. The system comprises a collector unit, an overflow control unit, a pumping unit, a sensing unit, a control unit, a steam dryness enhancing unit and a frame structure. The collector unit is defined by a tank configured to receive a mixture of flash steam and condensate therein to facilitate separation of flash steam from the condensate therein. The collector unit has a collector inlet configured on an operative top portion of the collector unit to allow the flow of the mixture into the collector unit. The collector outlet is configured on an operative bottom portion of the collector unit. The collector outlet is configured to facilitate discharge of the separated condensate from the collector unit. The flash steam exhaust outlet is configured on an operative top portion of the collector unit. The flash steam exhaust outlet is configured to facilitate release of flash steam from the collector unit. The transverse dimension (d’) of the collector unit is greater than the vertical inside distance (d), between the collector inlet and the collector outlet, such that vertical inside distance (d) is perpendicular to the axis of the transverse distance (d’) to ensure maximum area for separation of the flash steam from the condensate.
The overflow control unit is coupled to the collector unit, below the condensate inlet. The overflow control unit is configured to ensure removal of the condensate from the collector unit in overflow conditions, and maintain the volume of the condensate in the collector unit less than the volume of the flash steam. The pumping unit is configured in fluid communication with the collector unit. The pumping unit is disposed below the collector unit, and is configured to receive the separated condensate from the collector outlet of the collector unit. The pumping unit includes a pump outlet configured to facilitate discharge of the pumping unit. The sensing unit is coupled to the pumping unit. The sensing unit is configured to periodically sense the volume of the separated condensate received inside the pumping unit, and generate a sensed volume value based on the sensed pre-determined volume. The control unit is configured to the sensing unit for controlling the discharge of the condensate through the pump outlet based on the sensed volume value. The steam dryness enhancing unit is configured in fluid communication with the flash steam exhaust outlet. The steam dryness enhancing unit is configured to allow flash steam to pass therethrough, and further configured to facilitate removal of the droplets of the condensate suspended in the flash steam, thereby improving the dryness fraction of the flash steam. The frame structure supports the collector unit, the pumping unit and the control unit.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A flash steam and condensate recovery system of the present disclosure will now be described with the help of the accompanying drawing, in which:
Figures 1 and 2 illustrates isometric views of the system of the present disclosure; and
Figure 3 illustrates a schematic view of the system of Figure 1.
LIST OF REFERENCE NUMERALS
100 – Flash steam and condensate recovery system
101 – Collector unit
102 – Flash steam and condensate mixture
103 – Collector inlet
104 – Collector outlet
105 – Condensate
106 – Flash steam exhaust outlet
107 – Flash steam
108 – Pumping unit
109 – Pumping unit inlet
110 – Pumping unit outlet
111 – Sensing unit
111a, 111b, 111c – Sensors
112 – Control unit
112a – Actuating mechanism
113 – Steam dryness enhancing unit
114 – Motive fluid
115a – First check valve
115b – Second check valve
116 – Overflow control unit
117 – Safety valve
118 – Frame structure
120 – Clamp arrangement
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, elements, components, and/or groups thereof.
When an element is referred to as being "mounted on," “engaged to,” "connected to," or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
The terms first, second, third, etc., should not be construed to limit the scope of the present disclosure as the aforementioned terms may be only used to distinguish one element, component, region, layer or section from another component, region, layer or section. Terms such as first, second, third etc., when used herein do not imply a specific sequence or order unless clearly suggested by the present disclosure.
Terms such as “inner,” “outer,” "beneath," "below," "lower," "above," "upper," and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
A flash steam and condensate recovery system (100) of the present disclosure will now be described with reference to Figure 1 through Figure 3.
The flash steam and condensate recovery system (100) (hereinafter referred to as ‘system 100’) comprises a collector unit (101) which is configured to receive a mixture (102) of steam and condensate therein. Flash steam is generated whenever the liquid at a high pressure and at a temperature is allowed to drop to a lower pressure and at a corresponding saturation temperature or less than the temperature of condensate at a high pressure. The flash steam (107) is separated from the condensate (105) in the collector unit (101). The collector unit (101) is defined by a tank having a collector inlet (103), a collector outlet (104) and a flash steam exhaust outlet (106).
The collector inlet (103) is configured on an operative top portion of the collector unit (101) to allow the flow of the flash steam and condensate mixture (102) into the collector unit (101). The collector outlet (104) is configured on an operative bottom portion of the collector unit (101). The collector outlet (104) is configured to facilitate discharge of the condensate (105) from the collector unit (101). The flash steam exhaust outlet (106) is configured on an operative top portion of the collector unit (101). The flash steam exhaust outlet (106) is configured to facilitate release of flash steam (107) from the collector unit (101).
The collector unit (101) is configured in such a way that the transverse dimension (d’) of the collector unit (101) is greater than the vertical inside distance (d) between the collector inlet (103) and the collector outlet (104), such that the vertical inside distance (d) is perpendicular to the axis of the transverse distance (d’). This configuration of the collector unit (101) ensures that it provides maximum area for separation of the flash steam (107) from the condensate (105). More specifically, maximum area for separation of the flash steam means reduced velocity of separation of the flash steam (107) from the condensate (105). As a result of which, the dryness fraction of the flash steam (107) increases. Additionally, water hammering and its resultant effects in the steam line is reduced, and the life of the steam line and the system (100) increases. This configuration of the collector unit (101) also ensures that the volume occupied by the flash steam (107) in the collector unit (101) is relatively greater than the volume for the condensate (105) accumulated therein. The increased hold-up volume of the condensate (105) in the collector unit (101) further ensures efficient surge load handling without causing any overflow from the collector unit (101). Further the configuration of the collector unit (101) and the manner in which the condensate (105) falls into it guarantees free fall of the flash steam and condensate mixture (102) in the collector unit (101) and efficient separation of the flash steam (107) from the condensate (105).
The collector unit (101) further includes a safety valve (117). The safety valve (117) is configured to periodically release the flash steam (107) therethrough and regulate the pressure in the collector unit (101).
The system includes an overflow control unit (116) coupled to the collector unit, typically below the condensate inlet. The overflow control unit (116) is configured to ensure removal of the condensate (105) from the collector unit (101) during overflow conditions, and maintain the volume of the condensate (105), in the collector unit (101), less than the volume of the flash steam (107). More specifically, the overflow control unit (116) is adapted to maintain the desired volume of the condensate (105) in the collector unit (101) and avoid flooding thereof by allowing the condensate (105) to flow in the pumping unit (108). This in turn ensures that flooding does not take place, and carryover of the condensate (105) in flash steam is avoided leading to reduced steam hammering in the collector unit (101) and peripherals of the collector unit (101).
Typically, the overflow control unit (116) is a ball and float type flow control system. The ball and float type control flow system ensures removal of the condensate (105) from the collector unit (101) in overflow conditions which also ensures that the volume of flash steam (107) is always greater than the volume of condensate (105) in the collector unit (101) and volume of the condensate (105) in the collector unit (101) is greater than that of the volume of condensate (105) in pumping unit (108).
In another embodiment, the overflow control unit (116) is a level based volume regulating control unit which includes a control valve (not specifically shown in figures) for maintaining the level outlet of the overflow control unit (116), and is positioned in such a way that the volume of flash steam (107) is always greater than the volume of condensate (105) in the collector unit (101) and volume of the condensate (105) in the collector unit (101) is greater than that of the volume of condensate (105) in the pumping unit (108). The control valve is opened to allow flow of condensate (105) if operated above desired levels.
The system (100) further includes a steam dryness enhancing unit (113) in fluid communication with the flash steam exhaust outlet (106). The steam dryness enhancing unit (113) includes a demister pad or a dry pan which is configured to allow the flash steam (107) to pass therethrough and further facilitate the removal of the droplets of the condensate (105) suspended in the flash steam (107). The demister pad can be a mesh-type coalesce or a vane pack intended to aggregate fine mist into droplets that are heavy enough to separate from the steam of the flash steam (107). The demister pad further reduces the time required to separate the droplet by reducing the volume of the separator equipment. The dry pan is a chamber with perforations therein, wherein the leftover moisture is collected at the lower surface of the chamber and drained through perforations therein whereas the dry steam exits through a conduit disposed at the top of the collector unit (101).
The collector unit (101) is operated with the help of a pressurized pumping unit (108) which is in fluid communication with the collector unit (101). The pumping unit (108) is configured to receive the condensate (105) from the collector outlet (104) and pump out the condensate (105) to a receiving unit (not shown in figures).
The pressurized pumping unit (108) comprises a pair of check valves for controlling the operation of the system (100) by means of a pressurized fluid typically, pressurized gas/steam which is sourced externally. In a preferred embodiment, the pressurized fluid is a steam/air/nitrogen. In another embodiment, the pressurized fluid is an inert gas. More specifically, the check valves regulate the flow of the condensate (105) into and out of the pumping unit (108). The discharge from the pumping unit (108) depends on the back pressure against which it is required to pump, the operating pressure of the pressurized gas/steam, the condensate inlet size, and the condensate outlet size.
A first check valve (115a) and a second check valve (115b), of the pair of check valves, are connected to the inlet and outlet of the pumping unit (108) respectively. The first check valve (115a) is positioned upstream of the pumping unit (108), and the second check valve (115b) is positioned at downstream of pumping unit (108). The first check valve (115a) is configured to prevent pressurization in the collector unit (101) due to motive fluid (114), and the second valve (115b) is configured to prevent backflow of condensate (105) into the pumping unit (108).
Condensate (105) from the collector unit (101) flows to pumping unit (108) due to the effect of gravity until a predetermined level of the condensate (105) is detected by the sensing unit (111). Once the predetermined level is detected, an actuating mechanism (112a), coupled to the pumping unit (108), pumps the pressurized motive fluid (114) in pumping unit (108). The pressurized motive fluid (114) pushes the condensate out from the pumping unit (108).
The actuating mechanism (112a) is configured to cooperate with the control unit (112) to effect pressurization of condensate in the pumping unit (108) such that, the actuating mechanism (112a) is configured to pump the motive fluid (114) into the pumping unit (108) upon receipt of the discharge signal, for pushing the condensate (105) out of the pumping unit (108). The actuating mechanism is further configured to cooperate with the control unit (112) to cause depressurization of condensate in the pumping unit (108) by releasing the motive fluid (114) from the pumping unit (108) after the condensate (105) is discharged.
A sensing unit (111) is coupled to the pumping unit (108). The sensing unit (111) is configured to periodically sense the volume of condensate (105) received in the pumping unit (108), and is further configured to generate a sensed volume value. More specifically, the sensing unit (111) comprises a plurality of sensors (111a, 111b, 111c) located at various positions in the pumping unit (108). The sensors are configured to sense the volume of condensate (105) received in the pumping unit (108) and generate the sensed volume signal. The sensing unit (111) further includes a signal conditioning unit configured to convert the sensed volume signal into the sensed volume value.
The system (100) includes a control unit (112) configured to cooperate with the sensing unit (111). In a first embodiment, the control unit (112) includes a processor (not specifically shown in figures) which is configured to receive the sensed volume value from the sensing unit (111). The processor is further configured to generate a discharge signal if the volume of the condensate (105) in the pumping unit (108) increases from the sensed pre-determined volume, and a refill signal if the volume of the condensate (105) in the pumping unit (108) decreases from the sensed pre-determined volume.
In a second embodiment, the control unit (112) comprises a memory and a processor. The memory is configured to store a threshold value corresponding to the volume of the condensate (105) in the pumping unit (108). The processor is configured to cooperate with the memory, and with the sensing unit (111). The processor is configured to receive the sensed value, and compare the sensed volume value with the threshold value. The processor is further configured to generate a discharge signal if the sensed value is more than the threshold value, and a refill signal if the sensed value is less than the threshold value.
The actuating mechanism (112a) is configured to receive the discharge signal, and is further configured to pump the pressurized fluid into the pumping unit (108), based on the discharge signal. Pumping the pressurized fluid into the pumping unit (108) causes the pressurization of the pumping unit (108) in order to facilitate pushing of the condensate (105) out of the pumping unit (108).
In an embodiment, the control unit (112) includes a display unit for presenting the operational parameters of the system (100) to a user. More specifically, parameters related to the amount of condensate (105) that is being discharge out of the pumping unit (108) are displayed. In yet another embodiment, the display unit is further configured to display parameters such as pressure and temperature inside the collector unit (101) and the volume of the condensate (105) inside the collector unit (101).
In one embodiment, the control unit (112) includes a communication module (not specifically shown in figures) configured to transmit the working parameters of the system (100) and receive instructions from a remote device. In another embodiment, the remote device is a server or a terminal device.
Absence of moving parts in the system (100) increases the reliability and decreases the maintenance that would have otherwise required in case of moving parts. Further, the system eliminates the need of a steam trap, thus enhancing the discharge capacity of the condensate (105), reducing further back pressure on system (100), and negating steam locking chances.
All the components of the system (100) are supported on a frame structure (118)
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a flash steam and condensate recovery system that:
• improved dryness fraction of flash steam;
• has low maintenance;
• eliminates hammering life;
• increases discharge capacity;
• has high reliability; and
• Provides an interactive system for users for transmitting working parameters and receiving instructions from a remote device.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation