News Column

Patent Application Titled "Fan Array Vibration Control System and Method" Published Online

May 1, 2014



By a News Reporter-Staff News Editor at Politics & Government Week -- According to news reporting originating from Washington, D.C., by VerticalNews journalists, a patent application by the inventor Hopkins, Lawrence G. (Happy Valley, OR), filed on October 8, 2012, was made available online on April 17, 2014.

The assignee for this patent application is Huntair, Inc.

Reporters obtained the following quote from the background information supplied by the inventors: "Embodiments generally relate to a system and method of controlling a fan array, and, more particularly, to a system and method of minimizing vibrations within a fan array.

"Enclosed structures, such as occupied buildings and factories, for example, generally include a heating, ventilating, and air conditioning (HVAC) system for conditioning ventilated and/or recirculated air in the structure. A typical HVAC system includes a supply air flow path and a return and/or exhaust air flow path. The supply air flow path receives air, for example outside or ambient air, re-circulated air, or outside or ambient air mixed with re-circulated air, and channels and distributes the air into the enclosed structure. The air is conditioned by the HVAC system to provide a desired temperature and humidity of supply air discharged into the enclosed structure. The exhaust air flow path discharges air back to the environment outside the structure, or ambient air conditions outside the structure.

"Air-handling systems (also referred to as 'air handlers') have traditionally been used to condition buildings or rooms (hereinafter referred to as 'structures'). An air-handling system includes components designed to operate together in order to condition air as part of a primary system for ventilation of structures. The air-handling system may include cooling coils, heating coils, filters, humidifiers, fans, sound attenuators, controls, and other devices functioning to meet the needs of the structures.

"Some air-handling systems include an array of fan units. Each fan unit includes a fan operatively connected to a motor, which drives the fan. During operation, each fan unit produces a certain amount of residual vibration. Residual vibration is the amount of vibration present in an operating system after standard balancing procedures are completed, and the fan unit is certified for use.

"Vibration energy from fan units within an array, mounted to a common structure, such as a frame, is additive at certain points of operation. The additive effect of fan vibration increases when one or more fans are in-phase with one another. Generally, each fan has a certain amount of residual imbalance due to a mass located at a position that is not at the center of rotation. If the mass center of rotation is not coincident with the physical center of rotation, the assembly will not be balanced. When fans are commonly oriented such that their mass centers are at the same radial positions relative to one another, the fans are in-phase. In general, when the mass centers of fans of a fan array are in-phase with one another, the fan array generates a maximum vibration, which may then be transmitted to the support structure of the air-handling system, and ultimately to a structure, such as a floor or roof, that supports the air-handling system. The additive vibrational energy may produce undesirable vibration in a building. Conversely, when the mass centers are 180 degrees out-of-phase relative to one another, the amount of force due to operation of the fans is minimal."

In addition to obtaining background information on this patent application, VerticalNews editors also obtained the inventor's summary information for this patent application: "Certain embodiments of the present disclosure provide a fan array vibration control system that may include a fan array having a plurality of fans, and a control unit operatively connected to the plurality of fans. The control unit is configured to operate the plurality of fans and detect a phase relationship among the plurality of fans. The control unit is configured to reduce the phase relationship among the plurality of fans in order to reduce vibrations within the fan array.

"The system may also include at least one phase sensor operatively connected to one or both of the fan array and the plurality of fans. The control unit may be configured to be in communication with the at least one phase sensor. The control unit may also configured to detect the phase relationship among the plurality of fans through the at least one phase sensor. The at least one phase sensor may include a plurality of mass-location sensors configured to be proximate to the plurality of fans. Each of the plurality of mass-location sensors may be configured to detect a location of a mass concentration of each of the plurality of fans. Each of the plurality of mass-location sensors may include one or more of a tachometer, a magnetic sensor, an optical detector, or a camera.

"At least one phase sensor may include at least one vibration sensor configured to be proximate to one or both of the fan array or the plurality of fans. The vibration sensor(s) may be configured to detect vibrations generated by one or both of the fan array or the plurality of fans. The control unit may be configured to adjust the phase relationship among the plurality of fans based on the vibrations detected by the at least one vibration sensor. The vibration sensor(s) may include a plurality of vibration sensors configured to be proximate to the plurality of fans. Alternatively, a single vibration sensor may be configured to be proximate to the fan array. The single vibration sensor may be configured to detect vibrations generated by the fan array. The vibration sensor(s) may include one or more of an accelerometer, a velocity transducer, or a proximity pickup.

"The plurality of fans may be operatively connected to a plurality of motors. The control unit may be configured to detect the phase relationship among the plurality of fans through a slip of each of the plurality of motors.

"The plurality of fans may include first and second fans. The control unit may be configured to reduce the phase relationship between the first and second fans by maintaining the first fan in a fully out-of-phase relationship with the second fan throughout operation of the fan array.

"The plurality of fans may include at least three fans. The control unit may be configured to reduce the phase relationship between the at least three fans by reducing a likelihood of (or preventing) the at least three fans from being in-phase with one another throughout operation of the fan array.

"Certain embodiments of the present disclosure provide a method of controlling vibrations within a fan array having a plurality of fans. The method may include operating the plurality of fans of the fan array with a control unit, monitoring a phase relationship among the plurality of fans with the control unit, reducing the phase relationship among the plurality of fans with the control unit, and controlling vibrations within the fan array through the reducing operation.

"Certain embodiments of the present disclosure provide a fan array vibration control system that may include a control unit configured to be operatively connected to a plurality of fans. The control unit is configured to operate the plurality of fans and detect a phase relationship among the plurality of fans. The control unit is further configured to reduce the phase relationship among the plurality of fans in order to reduce vibrations within the fan array.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 illustrates a transverse interior view of an air handling system 10, according to an embodiment.

"FIG. 2 illustrates a side perspective view of a column of chambers and corresponding fan units, according to an embodiment.

"FIG. 3 illustrates a simplified view of a fan array, according to an embodiment.

"FIG. 4 illustrates a simplified view of a fan array, according to an embodiment.

"FIG. 5 illustrates a simplified view of a fan array, according to an embodiment.

"FIG. 6 illustrates a block diagram of a fan array control system, according to an embodiment.

"FIG. 7 illustrates a simplified view of a fan array having two fans, according to an embodiment.

"FIG. 8 illustrates a simplified view of a fan array with two fans out-of-phase with one another, according to an embodiment.

"FIG. 9 illustrates a graph of simplified vibration waves for two fans when fully out-of-phase with one another, according to an embodiment.

"FIG. 10 illustrates a simplified view of a fan array with two fans out-of-phase with one another, according to an embodiment.

"FIG. 11 illustrates a block diagram of a fan array vibration control system, according to an embodiment.

"FIG. 12 illustrates a simplified block diagram of a control block of a control unit, according to an embodiment.

"FIG. 13 illustrates a simplified view of a fan array vibration control system, according to an embodiment.

"FIG. 14 illustrates a flow chart of a method of operating a fan array, according to an embodiment."

For more information, see this patent application: Hopkins, Lawrence G. Fan Array Vibration Control System and Method. Filed October 8, 2012 and posted April 17, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=4031&p=81&f=G&l=50&d=PG01&S1=20140410.PD.&OS=PD/20140410&RS=PD/20140410

Keywords for this news article include: Huntair Inc.

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Source: Politics & Government Week