Seismic isolation devices for the safety of industrial machines

Seismic Isolation devices are equipment’s used for preventing the transmission of vibration to the structure caused due to the earthquake. This is a method adopted to separate the building/ machine from the ground by installing seismic isolation devices to prevent the transmission of the vibration and to maintain the safety of the building. So, by installing seismic isolators one can dampen the vibration of the seismic force, thus protecting the structure/ building from any impact. The foundation of the seismic isolation device is placed at the base of the structure/building all to protect them from seismic vibration.

The primary purpose of installing these Seismic Isolation devices on to an equipment machine or structure is to separate them from the floor of the building in order to reduce the transmitted severe seismic movement. It basically acts as an ideal countermeasure for protecting the equipment/instrument/structure from any damage.  In a seismic application where vibration isolation of the mechanical equipment is required, these kinds of equipment’s are still required for proper isolation. However, in these installations, the lateral & vertical movement of the equipment should be minimized to ensure the equipment remains in place during a seismic event.

When Seismic forces are exerted on a building/structure during an earthquake, the forces act horizontally upon the structure and the adjoining equipment’s like the piping, cable trays, duct work, and other building systems within the structure. Holding down the equipment during this phase can only be achieved by either attaching a mechanical snubbing device in conjunction with “standard” spring isolators or use spring isolators with in-built snubbing devices. Typical for piping, trays, and other suspended equipment are designed for the gravity, or vertical, loads but it does not take into account the horizontal loading caused by earthquakes. For this seismic restraint is used to resist the horizontal forces and to keep the systems in place and secure. The main purpose of seismic bracing is to minimize the damage and loss of life caused due to the earthquake.

To understand more about seismic isolation devices, we have listed down various benefits of seismic isolators and they are as follows.

Improved Safety- If you install a seismic isolator, you will be assured of least or no damage to the interior equipment as well as the building. Further this will ensure prevention of disasters like loss of workers life in that building. 

Stability in functionality:

Even after a severe earthquake, the functionality of the building will not be disrupted and will have a stabile functionality.

Security of Property:

With seismic Isolation device you need not worry of repair or rebuilding or replacing of damaged structure or equipment’s. the property shall be well secured with installation of seismic mounts and seismic spring isolators.

Cost effective- Seismic Isolation will reduce the cost of damage and cost incurred due to the short life span of the machine due to the earthquake. So, there would be practically no damage or rather minimum cost incurred for repairs in such scenarios.

 

Wire Rope Isolators are durable and can withstand extreme environments.

Vibration is undesirable in domains like engineered systems and habitable spaces, and methods have been developed to prevent the transfer of vibration to such systems. One of the ways to mitigate those vibrations is by “active vibration isolation” by employing electric power, sensors, actuators, and control systems. The other way is to use “passive vibration isolation” with techniques such as rubber pads or mechanical springs or wire rope isolators.

Wire Rope Isolators are durable and can withstand extreme environments. They are utilized in a variety of industrial and military devices. While such isolators are intended to protect the mounted item from shock and vibrations occurring along all three spatial dimensions or axes, as a practical matter the configuration of the isolators results in substantially greater stiffness and damping effect along one axis. Accordingly, a choice must be made as to the type of vibration of primary concern, with a response along the other axes being severely compromised.

The wire rope isolators have stainless steel cable and aluminum retaining bars, which provides excellent vibration isolation. The isolators are corrosion resistant, which makes them environmentally stable and high-performance in a variety of applications. The wire rope mounts are unaffected by harsh environmental conditions and temperatures, oils, abrasives, mycosis, humidity, ozone, grease, chemicals, nuclear radiation, ozone, dust and erosion of organic solvent. The compact wire rope isolator is smaller than a traditional wire rope and can absorb shock and vibration in small spaces. Single point mounting offers flexibility for integration into existing products. With versatile mounting options, crimping patterns, and size variation, wire rope shock absorber products can help your systems meet all requirements for industrial, defense, and commercial uses. Both compact wire rope isolators and wire rope isolators can be used on galley components where motors and fans produce vibrations onto surrounding structures.

A wire rope vibration isolator includes a coil of wire rope having a predetermined number of individual consecutive coils, a first crimp bar, and a second crimp bar. Each of the crimp bars is rectangular in shape and has a pair of opposing side surfaces. A series of lateral holes extending from one side surface to the other side surface of each of the bars is provided so that the predetermined number of individual consecutive coils may be threaded through the series of lateral holes of each of the bars. In this manner, when a crimping force is applied to each of the two crimp bars at a point where each of the individual coils passes through a respective bar, the coils are thereby secured in a fixed position relative to one another while remaining elastically deformable. A spring-like quality is thus imparted to the coil of wire rope so that the first crimp bar and the second crimp bar may move relative to each other to dissipate vibrational energy. This elastic support is for heavy-duty machinery such as generators and vibration isolation for delicate applications such as precision instruments, transportation of missiles and satellites, processors, communication units, protection for navigation and launching systems as well as large scale construction. The working temperature for wire rope isolators is -75°C-+175°C, up to +370°C and each wire rope isolator comes with softened non-linear stiffness. The performance of a wire rope isolator is dependent on its inherent elasticity and damping. The elastic spring function is created by the flexing of the cable that is wound and clamped into a loop. The damping function is the result of friction between the individual wires as the rope flexes. The exceptional advantages are:

  • Combined isolation of shock and vibration
  • High inherent damping
  • Very wide temperature range
  • Long product lifetime with no maintenance
  • Excellent resistance to chemicals, seawater, ozone, radioactivity, and UV light
  • Infinite customization possibilities
  • Quick and inexpensive prototyping

Below are the few applications of wire rope isolator technologies:

  • Pump, Generator & Compressor Isolation
  • Shipping Cases, Skids & Containers
  • Chemical Processing Equipment
  • Carts, Transporters & Gurneys
  • Chimneys, Scrubbers & Vessels
  • Power Plant Piping Suspension
  • Over-the-road Transport
  • Navigation Equipment
  • Transportable Shelters
  • Electronic Cabinets
  • Seismic Isolation

There are manufacturers out there offering a variety of wire rope isolators. Select a company who is specialized in the same and opt for wire rope isolators that best fits the applicational requirement. Consult with the specialist to help you with the selection of the wire rope isolators.

How to minimize the impact of vibration on buildings & machines caused by a seismic force?

Seismic force is an outcome of the energy caused due to the tectonic movement of the earth’s crust. The outburst of the energy and its corresponding effects have tremendous impact on the structural stability of buildings in the vicinity, causing threat to human lives. However, to minimize the impact and reduce the transmission of the energy to the structure and its internal parts, scientific techniques are adopted to provide structural safety and to control the internal forces and displacement within limits. One of the most common method adopted for protecting the structures from the effects of earthquakes is using a seismic isolation device to damp the seismic energy.

Seismic isolators are equipment’s that provide adequate resistance to the vibrations caused by the seismic force. This ensure effective isolation of vibration and protection to the structure exposed to such destructions. Installing seismic base isolators will help dissipate the energy and restrict the transfer of vibrations from source to structures. Seismic isolation is a technique used to reduce the impact of earthquake on structure and their components. The device protects the structure from any sort of damage caused due to the critical event.

By installing seismic base isolator, they effectively help decouple the supporting structure from mounting structure and protect the base of the building and ensures stability and sturdiness. Offering a significant structural protection, seismic isolators are considered as a much better protection device as it isolates the vibrating source and dissipates the energy internally. The seismic isolators and energy dissipating devices are seen as an effective solution. They dampen the undesired seismic energy under the ground of the structure and reduce the effects of lateral loads on the above surface.  Not just that, Isolators as we all know amend the dynamic characteristics of the structural system by distributing the mass within structure.  Currently, the isolation industry offers two types of seismic isolators namely the seismic spring isolators and seismic mounts. Both the seismic isolators are installed in a structure to offer stability and desired strength.

Depending on the location, seismic isolators are generally categorised under either externally mounted seismic isolators and internally mounted seismic isolators. While the external type seismic mounts are installed outside the structural location and provide isolation externally through foundation of structure, the internal type of seismic mounts is an energy dissipating mechanism that facilitates internal stability through effective isolation. We all know that preventing a natural disaster like earthquake is not in our hands. However, eliminating the potential damage by taking precautionary measures by installing equipment’s like seismic isolators will sure help reduce or limit the impact of such disaster. Consult a specialist or seismic isolator manufacturers in your area and accordingly install seismic devices that best fit your requirement.

 

How does HVAC spring isolators help reduce the transmission of noise and vibration to the adjoining structure?

Vibration isolation is nothing but a process of isolating equipment’s and machine from the source of vibrations. Undesirable vibration and noise arising from industrial machines will require spring isolators, especially for HVAC equipment’s to prevent the transfer of vibration to adjoining systems, or a building structure or suspended mechanical equipment. Suspended hangers or hanging spring isolators are equipment’s that can reduce structure-borne noise and vibration in HVAC applications. Available in a wide variety like spring vibration isolation hanger and rubber hanger, make for the best suspend isolation equipment such as fans, air conditioners, distribution pipes and ducts.seismic spring mounts

HVAC spring Isolators are designed to provide maximum isolation to suspended equipment and piping system. The spring isolators facilitate high deflection and consists of color-coded spring element, a noise isolation pad, assembled into a welded hanger bracket to offer maximum isolation. Further, to assure stability and maximum isolation the spring element has a minimum lateral spring stiffness of 1.0 times the rated vertical stiffness. Not just that the spring hangers also help support misalignment in the equipment in case of any.

Generally, hanging spring isolators are recommended for isolation of suspended equipment’s especially in cases where inaudible frequency vibration, are at its peak. Suspended mechanical equipment such as exhaust fan plumbing pipes, fans, cabinet fans, and piping and ductwork in close proximity to mechanical equipment typical use spring isolator hangers for solving vibration and noise transmission issues.

The spring isolators HVAC are isolation equipment’s that work on the same principle as other spring vibration isolator. Designed to provide effective isolation and desired spring deflection, makes for an ideal isolator for suspended machines. Based on the load capacity and deflection required one can select the right kind of spring isolator for HVAC system. When it comes to machines like fans, spring isolators provide the best vibration damping solution with similar load and deflection. On the on the hand for equipment’s like heavy chillers which are mounted on the floor, spring vibration hangers with floor mounting techniques are used. Heavy spring hangers are used along with the metallic brackets to suspend the heavy chiller tanks and to accordingly support the other points. At times to meet the applications load and deflection requirement, additional springs are used in a spring isolator.

There are manufacturers out there offering a variety of spring isolator for HVAC. Select a company who is specialized in the same and opt for spring vibration isolators that best fits the applicational requirement. Consult with the specialist to help you with the selection of the spring vibration isolation hangers for your application based on the load capacity and deflection requirement. You will be clearly guided with the right dimensions and space availability along with the load and deflection requirements to make the right choice if you approach a professional vibration isolator manufacturer. So, whether you require spring isolators for chiller, fan or the complete HVAC system, you can find a wide range of options to suite your need.