Machinery enclosures

Engineering controls constitute a wide range of options full machinery enclosures, mufflers, sound blanirets or curtains, dampeners, and particularly important accaxling to OSHA s Hauter, routine maintenance on noisy equipmoiL She said engineering control solutions often can come in under 100. 

Machinery enclosures Walls of acoustic enclosures should consist of heavy but flexible panels lined internally with sound-absorbing material. Adequate ventilation, demountability of the enclosure for repairs, and arrangements for operating and/or observing the machine to be provided. If hot gas fans are acoustically enclosed, the surface of the fan casing should additionally be heat-insulated. For information on design and performance of enclosures for noise control see VDI2711. 

Roiaiing elecirical machines. Classificaiion ol degrees of protection provided by enclosures for rotating machinery 4691/1985 BS 4999-105/1988 ... 

Once the information on the industrial processes and space requirements, the indoor climate requirements for workers, machinery, and products, and a lot for the factory have been obtained, then the architectural design of the industrial enclosure can be accomplished, A complete factory or industrial building may consist of several enclosures where industrial processes are run. One heating and ventilation plant may service several enclosures, or there may be a separate system for each enclosure. 

Oscarson, G. L. and R. L. Kolar, Enclosure Protection for Large A-C Motors, Electric Machinery Co., Div. Dresser-Rand Co. 

The first of these can he reduced hy suitable siting of the plantroom, anti-vihration mounting and possible enclosure of the machinery Air flow noise is a function of velocity and smooth flow. High-velocity ducts usually need some acoustic treatment. 

Self-levelling polyurethane sealants are used to seal horizontal movement joints and construction joints in a variety of materials subject to light traffic such as concrete pavements (Figure 4.4), access roads, yards, parking areas, between rails and metal enclosures and around equipment and machinery. 

Li Ytmwang, Ge Shirong Zhu Hua. 2009. Design and Manufacture of Flame-proof Enclosure of Coal Mine Rescue Robot. Coal Mine Machinery 30(2) 104-106. 

HPDs do not block out sound completely, but they give some protection by reducing the amount of sound reaching the ear. At the same time, workers can hear speech and important machinery sounds. HPDs come in four types enclosures, earmuffs, canal caps, and earplugs. 

Ver, Istvan L., and Leo L. Beranek, eds. Noise and Vibration Control En neering Principles and AppUcor tions. 2d ed. Hoboken, N.J. John Wiley Sons, 2006. Details sound absorption, passive silencers, enclosures, vibration isolation and damping, machinery and heating, ventilation, and air-conditioning (HVAC) noise control, and active noise suppression. 

Noisy machinery is sometimes placed inside a small containment building or acoustic enclosure. Acoustic enclosures may be either of the close fitting or walk-in (large) type. The use of acoustic enclosures is generally not a preferred solution to noise problems because they create a confined space and have the potential for a buildup of a flammable or explosive cloud should the equipment leak. Also, the containment structure is likely to make maintenance and inspection more difficult (a confined space entry will be required), and it will increase the size of the equipment s footprint. 

Electric motors Motors with low speeds are preferable. Big motors to be water-cooled rather than air-cooled. Direct drive by four-pole or variable-speed motors. Choose motor types with low noise emission. Fan blading to have irregular pitch. If necessary, motor enclosure to be provided with special silenced ventilation. Internal combustion engines (e.g., for driving quarry machinery) Exhaust noise can be reduced by using amply dimensioned absorption and reflection silencers. Enclosure of the engine with ventilation system equipped with inlet and outlet silencers and ducts lined with sound-absorbing material (see Funke, 1977). 

Noisy machines should be accommodated in different rooms from quieter ones. Special acoustic enclosures for machinery with particularly high noise emission levels. 

In a practical sense, enclosure designs often require some accommodation. For ease of maintenance, enclosures can be constmcted to rise upward and away from the machinery by overhead cranes. Access openings can be provided by tunnels lined with acoustically absorbent material (in effect, mnfflers). Access for controls can be designed with hinged covers that lift easily, or the controls can be relocated. Some enclosure panels can be lifted automatically at the correct point in the machine cycle to provide access. Ducts can be provided with small ventilating fans to prodnce a controlled cooling airstream and, if combined with filters, can allow a controlled environment for some operations. 

Extreme situations may require heat exchangers or air conditioning of enclosures. Also, consider locating the entire control system in a separate room adjacent to the controlled machinery. 

Elecric shock as a result of direct contact, means that a person makes contact with part of the circuit which is intended to be live. The only form of protection against direct contact is to prevent such contact in the first place. This can be achieved by following the same principles of risk assessment and machinery safeguarding discussed earlier, namely to provide fixed guards, enclosures or insulation. However, if access is foreseeable, then permit-to-work systems should be operated. It should be remembered that intrinsic safety is an absolute priority in removing the risk of shock injury. This can be achieved by reducing the system voltage in areas of likely contact to such an extent that it cannot result in an electric shock. 

Since the SSR must be able to clone its core elements, its enclosure, and its scaffolding elements, it is absolutely necessary for the SSR to have a fabrication function. This function is the ability to fabricate exact copies of all parts, components, and assemblies that exist inside a mature SSR or on its enclosure. In other words the fabrication function must be able to fabricate all machinery inside the SSR, including fabrication machinery. Since all the elements that reside inside the SSR must be copied (cloned) and various types of information and software elements also reside inside the mature SSR, the fabrication function must also have the ability to accurately copy information and software. 

The SSR must have a power distribution network (e.g., an electrical distribution network) that must reach each of the SSR s machinery. The design of the layout and geometry of the power network must consider the variable geometry of the SSR enclosure, scaffolding, and interior space and structure. Particular consideration must be made for the zones affected by growth and shape changes. 

The SSR must be able to fabricate the necessary machinery and enclosures for energy generation, as specified above. 

The SSR must be able to fabricate machinery and enclosures to control and host a very wide set of processes (e.g., material extraction, energy generation, possible chemical reaction processes, electrolytic processes, and PCB etching chemical processes). 

Figure 13.1 Using an enclosure to Isolate workers from the machinery.

A barrier guard is a safety device designed to protect machine operators from hazard points on the machinery or equipment. Some example barrier guard types include enclosures, gates, fences, and interlocks. 

A safety guard is a device, barrier, or enclosure that prevents accidental contact with an item, such as a control switch. The guard typically prevents accidental operation of machinery, weapons, and so on. 

Interlocked barrier guard An enclosure attached to the machinery or equipment frame and interlocked with the power switch so that the operating cycle cannot be started unless the guard is in its proper position. 

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