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Recommended Safety Distance for Siting and Layout of Facilities

Facility layout is one of many document deliverables in a project. Do you know the philosophy to create facility layout? In this post, I want to share a siting and layout approach, as well as recommended safety distance for siting and layout of facilities by Center for Chemical Process Safety (CCPS) of the American Institute of Chemical Engineers (AIChe).

The siting philosophy begin with a review of the material and processing hazards, such as toxicity, flammability, explosivity, reactivity, or a combination of these hazards. Other potential hazards should also be considered since they may be unacceptable to their surrounding community, such as odors, loud noises, or the light from flares.

Once the type of hazards have been identified, their potential off-site and on-site impacts can be addressed. This step includes how the local terrains affects the release scenarios. At the same time, the layout of the process units and associated areas within the facility, such as storage tank areas or flares, should be arranged to reduce risks. The layout of the equipment, including both orientation and distance between them, may affect day-to-day operations. Therefore, it is important to address the balance between reduced or increased distances and the impact on accessibility when evaluating the on-site consequences. Read More

Fail-safe position

Fail-Safe Position Selection of Control Valve

In designing a processing facility, we usually use control valve to manipulates the temperature, pressure, level, or fluid flow rate in process system. The selection of control valve, which is air-to-open or air-to-close, is base on safety consideration. In case of power loss or air failure , control valve should move in safe position (fail-safe).

Fail Position

Fail position is the term used to describe how control valve will react when there is loss of power. I read there are three different fail positions. Read More

Storage Tank Selection

In my recent project, there are at least eight liquid storage tanks we need to design and purchase. Although, the design of storage tank is not part of my work (it is a job of mechanical engineers), but I always wonder how people design the tanks. In this post, I want to share to you the results of my desktop study about liquid storage tank selection. Read More

IP Codes

The IP CodesIngress Protection Rating, sometimes also interpreted as International Protection Rating, classifies and rates the degree of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in mechanical casings and with electrical enclosures.

A two-digit number established by the International Electro Technical Commission, is used to provide an Ingress Protection rating to a piece of electronic equipment or to an enclosure for electronic equipment.

The protection class after EN60529 are indicated by short symbols that consist of the two code letters IP and a code numeral for the amount of the protection.

Example: IP65 (NEMA 4)
The two digits represent different forms of environmental influence:

  •  The first digit represents protection against ingress of solid objects.
  •  The second digit represents protection against ingress of liquids.

The larger the value of each digit, the greater the protection. As an example, a product rated IP54 would be better protected against environmental factors than another similar product rated as IP42.

FactorSedimentationFiltration
Solid size, finex
Solid size, > 150 micronx
Compressible cakesx
Open cakesx
Dry cake requiredx
High filtrate clarityx
Crystal breakage problemsx
Pressure operation
High-temperature operationwill depend on the type of centrifuge usedwill depend on the type of centrifuge used

References:

  1. IP ratings. http://www.mpl.ch/info/IPratings.html
  2. IP code. http://en.wikipedia.org/wiki/IP_Code

Plant Layout Consideration

About a week ago my boss asked me something crucial about Plant Conceptual Design and Layout for our bankable feasibility study of ferronickel project. He asked me if I had explained why we chose this part as smelter plant and not on that part, why the gate should be on the west side of the processing plant, and so on. I just shook my head and grinning. BIG NO! 

My boss was emphasizing the philosophy to make site plan. There are several considerations to make site plan. For example, the processing facilities which are heavy, require high load, and very dynamic, should be positioned at the relatively flat and so on.

I started to think what aspects we need to consider making plant layout. Read More