NBC FILTRATION SYSTEM WITH AIR EXCHANGE BACKUP UNIT
20210178197 · 2021-06-17
Inventors
Cpc classification
B01D46/42
PERFORMING OPERATIONS; TRANSPORTING
F16H7/00
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16H7/023
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
A62B11/00
HUMAN NECESSITIES
B01D46/42
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A near ceiling mounted NBC filtration system of collective protection shelters comprising a filter unit, a blower, and an air exchange backup unit [20] (FIG. 5). The air exchange backup unit [20] comprising: a plurality of hinged segments [22a, b, c] serially linked to each other to form a foldable arm. The hinged segments [22a, b, c] are configured for transmission of rotational motion between each other. At least one of the hinged segments comprises at least one stage of a first speed increasing transmission. A first end [24] of the air exchange backup unit is swiveably attached to an electric motor [42] driving a blower [40]. And a second end [26] of the air exchange backup unit carries a detachable hand crank [28]. Manual rotation of the hand crank [28] rotates a shaft of the electric motor [42] at substantially a rated speed of the electric motor. The second end [26] of the air exchange backup unit is firmly attachable to a wall of the protection shelter at a convenient position for manual cranking of the hand crank [28]. The air exchange backup unit [20] is selectively folded up at normal times.
Claims
1. An NBC filtration system comprising: a filter unit; a blower airflow coupled to said filter unit; and an air exchange backup unit mechanically coupled to said blower; wherein said air exchange backup unit comprises a plurality of hinged segments serially linked to each other to form a foldable arm, said hinged segments are configured for transmission of rotational motion between each other, a first end of said air exchange backup unit drives said blower and a second end of said air exchange backup unit carries a detachable hand crank, manual rotation of said hand crank rotates an impeller of said blower, said NBC filtration system is mounted at a near ceiling position and said air exchange backup unit is selectively folded up at normal times.
2. An NBC filtration system as claimed in claim 1, wherein each of said hinged segments is provided with a mechanical drive transmitting rotational motion from one end of said segment to the other end.
3. An NBC filtration system as claimed in claim 1, wherein each link pairing said hinged segments is provided with a rotatable shaft transmitting rotational motion from one segment to the other, said shaft sharing the same axis as the hinge axis.
4. An NBC filtration system as claimed in claim 1, wherein at least one of said hinged segments further comprises at least one stage of a first speed increasing transmission.
5. An NBC filtration system as claimed in claim 4, wherein said first end of said air exchange backup unit is swiveably attached to an electric motor driving said blower, manual rotation of said hand crank rotates a shaft of said electric motor at substantially a rated speed of said electric motor.
6. An NBC filtration system as claimed in claim 1, wherein said second end of said air exchange backup unit is firmly attachable to a wall of the protection shelter at a convenient position for manual cranking of said hand crank.
7. An NBC filtration system as claimed in claim 5, wherein said motor drives said blower through a second speed increasing transmission.
8. An NBC filtration system as claimed in claim 7, wherein said second speed increasing transmission is capable of driving an impeller of said blower at a rotational speed of above 3000 rpm.
9. An NBC filtration system as claimed in claim 5, wherein said electric motor driving said blower is a 4-pole induction motor.
10. An NBC filtration system as claimed in claim 7, wherein said second speed increasing transmission is selected from a group consisting of: a multi groove V belt drive; a toothed belt drive; a roller chain drive; and an inverted tooth chain drive.
11. An NBC filtration system as claimed in claim 10, wherein a pitch size of said roller chain drive or said inverted tooth chain drive is selected between 4 mm and 6 mm.
12. An NBC filtration system as claimed in claim 4, wherein each of said hinged segments comprises one stage of said first speed increasing transmission.
13. An NBC filtration system as claimed in claim 12, wherein said first speed increasing transmission comprises 3 stages of a roller chain drive.
14. An NBC filtration system as claimed in claim 13, wherein a pitch size of said roller chain drive is selected between 6 mm and 10 mm.
15. An NBC filtration system as claimed in claim 5, wherein during operation, said first speed increasing transmission transmit rotational motion to said motor through an unidirectional freewheel fitted to a shaft of said motor.
16. An NBC filtration system as claimed in claim 13, wherein a first intermediate shaft of said first speed increasing transmission defines also a hinge axis between a first segment and a second segment of said air exchange backup unit, and a second intermediate shaft of said first speed increasing transmission defines also a hinge axis between said second segment and a third segment of said air exchange backup unit.
17. An NBC filtration system as claimed in claim 1, wherein said air exchange backup unit comprises four segments, each of said segments is provided with one stage of the first speed increasing transmission providing an overall transmission ratio, sufficient for directly driving the blower.
18. An NBC filtration system as claimed in claim 1, wherein said air exchange backup unit comprises two segments, and a dedicated speed increasing transmission is fitted between the air exchange backup unit and the motor.
19. An NBC filtration system as claimed in claim 18, wherein said air exchange backup unit is provided with a first speed increasing ratio while said dedicated speed increasing transmission provides an additional second speed increasing ratio calculated to provide the overall required speed increasing ratio.
20. A method of introducing fresh air into a protection shelter during an event of a power failure comprising the steps of: a. Providing a near ceiling mounted NBC filtration system comprising: a filter unit; a blower driven by an electric motor; an air exchange backup unit having a first end swiveably attached to said electric motor; and a detachable hand crank selectively fitted to a second end of said air exchange backup unit; said air exchange backup unit comprising a plurality of hinged segments serially linked to each other to form a foldable arm, said hinged segments are configured for transmission of rotational motion between each other; b. expanding said air exchange backup unit in an event of a power failure; c. attaching said second end of said air exchange backup unit to a wall of a protection shelter at a convenient position for manual cranking of said hand crank; d. attaching said detachable hand crank to said second end of said air exchange backup unit; and e. cranking said hand crank while said power failure continues.
21. The method as claimed in claim 20, further comprising the steps of: f. stopping the cranking operation when electric power is revived; g. detaching said detachable hand crank from said second end of said air exchange backup unit; h. Detaching the second end of the air exchange backup unit from the wall of the protection shelter; and i. folding up said air exchange backup unit.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The invention and a way it may be carried out in practice, will be understood with reference to the following illustrative figures, by way of non-limiting example only, in which like reference numerals identify like elements, and in which:
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
[0033]
[0034]
DETAILED DESCRIPTION OF EMBODIMENTS
[0035] Several terms relating to the present invention will be defined prior to describing the invention in detail. It should be noted that the following definitions are used throughout this application.
[0036] For the purpose of the present invention, directional terms such as “top”, “bottom”, “below”, “above”, “left”, “right”, “horizontal”, “vertical”, “upper”, “lower”, “up”, “down”, etc. are merely used for convenience in describing the various implementations of the present invention. The assemblies demonstrating the present invention may be oriented in various ways.
[0037] For the purpose of the present invention, the term “plurality” refers to two or more than two.
[0038] For the purpose of the present invention, the term “hinged element” refers to an element provided with at least one hinge or having at least one hinge point enabling swivel of the element about the hinge point.
[0039] For the purpose of the present invention, the term “segment” refers to one of the parts into which an assembly is separates or is divided.
[0040] For the purpose of the present invention, the term “air exchange backup unit” refers to a device, energized by human power, configured for introducing fresh air into a protection shelter during an event of electric power failure.
[0041] For the purpose of the present invention, the term “foldable” refers to a structure that can be folded down into a small space when it is not being used.
[0042] For the purpose of the present invention, the term “inverted tooth chain” or “silent chain” refers to a type of drive chain with teeth formed on its links to engage with standard or modified gear wheels.
[0043] For the purpose of the present invention, the term “pitch” refers to the distance between successive corresponding physical occurrences, such as rollers in a roller chain.
[0044] The term “NBC” is used throughout this text as a general abbreviate for all kinds of hazardous agents including any one of Nuclear, Biological, Chemical and Radiological threats or any combination thereof. Such combinations may include for instance: NBC, CBRN, CBR, BC, B and C.
[0045] With reference to the figures, according to one embodiment of the invention, there is shown in
[0046] According to an embodiment, the blower 40 is normally driven by an electric motor 42 as long as electric power is available. The air exchange backup unit 20 may be mechanically coupled to the blower 40 directly, or through the electric motor 42 as will be explained herein below. The air exchange backup unit comprises a plurality of hinged segments, here shown by a way of example with three segments 22(a, b and c) serially linked to each other. The linked hinged segments forming a foldable arm, shown partially folded in
[0047] With reference to
[0048] A second end 26 of the air exchange backup unit 20 carries a detachable hand crank 28. Rotation of the hand crank 28 at normal manual operation of about 40 rpm, rotates the shaft 44 of the electric motor 42 at substantially a rated speed of the electric motor. The second end 26 of the air exchange backup unit 20 is firmly attachable for instance by a dedicated fixed bracket 60 to a wall of the protection shelter at a convenient position for manual cranking of the hand crank. The air exchange backup unit 20 may selectively be folded up at normal times as shown in
[0049] With reference to
[0050] As mentioned in the background, in real installations the NBC filtration system is fitted at different locations and different heights. The different locations are enforced by variations in position of the intake pipe between building constructions. The embodiments of the present invention solves this difficulty by simple adaptation of the air exchange backup unit 20 folding arm construction to any installation position. It should be noted that although shown vertically oriented in
[0051] As mentioned above, during operation of the air exchange backup unit 20, in an event of power failure, rotational motion is transmitted from the hand crank 28 through the hinged segments 22 to the electric motor 42. The way of transmittal of the rotational motion will be explained with reference to
[0052] In addition to the above mechanical drive, transmitting rotational motion from one end of the segment to the other end, the hinged segments 22 are configured for transmission of rotational motion between each other. This is shown with more clarity in
[0053]
[0054] With reference to
[0055] With reference to
[0056] With reference to
[0057] In more detail, yet with reference to
[0058] The third sprocket 92 rotates a forth sprocket 94 preferably smaller than the third sprocket 92, via a second drive chain 96. The third sprocket 92, second drive chain 96 and fourth sprocket 94 are forming together the second stage 72b of the first speed increasing transmission of air exchange backup unit 20. The fourth sprocket 94 is mounted on one end of a second intermediate shaft 98 defining also a hinge axis between the second segment 22b and the third segment 22c of the foldable arm constituting the air exchange backup unit 20. A fifth sprocket 102 is mounted on the other end of the second intermediate shaft 98, thus accepting the same rotational speed as the fourth sprocket 94.
[0059] The fifth sprocket 102 rotates a last sprocket 104 preferably smaller than the fifth sprocket 102, via a third drive chain 106. The fifth sprocket 102, third drive chain 106 and last sprocket 104 are forming together the third stage 72c of the first speed increasing transmission of air exchange backup unit 20.
[0060] The last sprocket 104 is fitted to a first end 107 of the motor shaft 44 through an unidirectional freewheel also known as freewheel clutch or freewheel bearing. The unidirectional freewheel permits rotation of the motor shaft 44 by the air exchange backup unit 20, but prevents rotation of the first speed increasing transmission elements by freewheeling when the motor is electrically energized. It will be understood that different types of unidirectional or clutch mechanisms can be used alternately, for instance a ratchet mechanism or a wound spring mechanism as known in the art.
[0061] Yet with reference to
[0062] The second speed increasing transmission 74 driving the blower 40 is capable of driving the impeller 76 of the blower at a rotational speed of above 3000 rpm using a motor 42 of the known 4-pole induction type. To minimize transmission losses, the second speed increasing transmission 74 may be a low friction, efficient drive system selected between some options including: a multi-groove V belt drive, toothed belt drive, a roller chain drive or an inverted tooth chain drive also known as silent chain. Due to the high speed and low torque of this second speed increasing transmission, if a roller chain drive or a silent chain drive is utilized, than the pitch size is selected between 3 mm and 6 mm. It will be understood that other transmission types can be used such as direct gear drive, single or multiple V belt drive, flat belt drive and ladder chain drive.
[0063] With reference to
[0064] With reference to
[0065] The present invention seeks protection regarding the device as described above, as well as the method steps taken to accomplish the desired result of introducing fresh air into the protection shelter during an event of a power failure, using a near ceiling mounted NBC filtration system and an air exchange backup unit of a foldable arm structure.
[0066] Accordingly and with reference to
a. Providing a near ceiling mounted NBC filtration system comprising: a filter unit; a blower driven by an electric motor; an air exchange backup unit having a first end swiveably attached to the electric motor; and a detachable hand crank selectively fitted to a second end of the air exchange backup unit. The air exchange backup unit comprising a plurality of hinged segments serially linked to each other to form a foldable arm. The hinged segments are configured for transmission of rotational motion between each other.
b. Expanding the air exchange backup unit in an event of a power failure. Indicated as activities 120 and 122 of the flowchart of
c. Attaching the second end of the air exchange backup unit to a wall of a protection shelter at a convenient position for manual cranking of the hand crank. Indicated as activity 124 of the flowchart.
d. Attaching the detachable hand crank to the second end of the air exchange backup unit. Indicated as activity 126 of the flowchart.
e. Cranking the hand crank while said power failure continues. Indicated as activity 128 and decision 130 of the flowchart.
The method may further include the steps of:
f. Stopping the cranking operation when electric power is revived. Indicated as activity 132 of the flowchart.
g. Detaching the detachable hand crank from the second end of the air exchange backup unit. Indicated as activity 134 of the flowchart.
h. Detaching the second end of the air exchange backup unit from the wall of the protection shelter. Indicated as activity 136 of the flowchart.
i. Folding up the air exchange backup unit. Indicated as activity 138 of the flowchart.
[0067] It will be understood that while activities 120 to 128 of the flowchart are required to start manual operation of the air exchange backup unit, the following activities 132 to 138 are optional or may be carried out at a later time or by a dedicated maintenance person that may further check the system before bringing it back to the folded state.
[0068] It will be appreciated that the specific embodiments of the present invention described above and illustrated in the accompanying drawings are set forth merely for purposes of example. Other variations, modifications, and applications of the present invention will readily occur to those skilled in the art. It is therefore clarified that all such variations are considered within the scope and spirit of the invention. Accordingly, the protection sought herein is as set forth in the claims below.