Pharmaceutical Plant Design

Cooling towers should be sited so that water droplets will not restrict visibility or cause exterior corrosion or ice formation on other parts of the plants, roads, rail or public amenities. Siting should prevent the entrainment into the cooling towers of vapours and dusts from adjacent plants, chimneys, flare stacks, etc.

It is desirable that plant expansion plans should be known when positioning central services plants. They are often centrally placed (but not necessarily together)12  so that site expansion can proceed in all directions, providing the services will not later become part of a hazardous area. Service distribution should run parallel to roadways and not pass through plant areas.12 

Water mains must be buried deeply enough to prevent freezing. Most electric power and telephone cables etc. are run in sand filled trenches.12 Administration buildings should be located on the public or safer side of the security point and close to the main entrance if possible. Canteens, shops for use by employees and medical centers should be located in a safe area, as should workshops and general stores. The last two should be preferably be within easy access of the process units. Direct access should be provided for supply traffic, especially if heavy, which should not pass through process areas. Off-loading of stores and supplies should not interfere with other traffic. Labs and workshops should be central to the plants.

2.5. Effluent

Effluent can be one of the most visible and least desirable of all the effects of a site on the surrounding community if not handled carefully and responsibly. The appropriate regulatory authorities should be consulted at the design stage to ascertain all existing and reasonable foreseeable effluent disposal standards so that design can meet these criteria.

Effluent disposal and treatment should be sited close to areas where the handling of treatment chemicals and the disposal of treated effluents from plant to sewer can be monitored. Incinerators should, where practicable, be sited next to the process supplying the effluent. Solids for dumping should be loaded directly from process to transport. If intermediate storage on site cannot be avoided it should be situated to avoid nuisance to the public and other plants from smell, fire risk, seepage etc.12 

Gaseous effluent should be burnt or discharged at such a height and location so that offensive fumes are not a public nuisance. Flare stacks may need to be on a distant site if the nuisance of thermal radiation and noise from the flame cannot be eliminated by suitable design.

Harmless aqueous plant effluent can be run in open trenches or sewers but obnoxious aqueous effluents must be in an enclosed sewer. Care should be taken in layout in order to avoid flooding of sensitive areas such as pump pits. Liquid effluent must not be allowed to run off plants onto adjacent property, or vice versa. Extra precautions are necessary if the site slopes or contains natural watercourses. Consideration should be given to the problem associated with those flammable effluents, which are immiscible with water.  There is always a possibility of burning liquid entering the effluent system (particularly open trenches) and spreading fire over long distances, unless traps and gullies are installed. The various parts of the plant should be graded so that storm water goes to a specific drain. Storm drainage from underdeveloped areas and from buildings, etc. having no spillable liquids or solids, can go direct to the community sewer providing there is the capacity.

Rain from plant areas should be treated along with aqueous process effluent. When different effluents meet, care must be taken that no undesired reactions take place, e.g. release of toxic fumes. It should be noted that toxic or flammable fumes can easily build up in a drain from relatively small amounts of material and so proper venting should be installed.

2.6. Security

Site security facilities should maintain a secure and stable environment for the planned site activities. In particular, three conditions must be met:

1. Company and employee property must be protected against damage, loss or theft.
2. Unauthorized access to the site must be prevented, to fulfill the company’s legal obligations to protect property and the public to prevent trespassing.
3.  All persons on site, whether staff or visitors, must be accounted for in event of a site emergency.21 

A security fence around the plant is needed though this can exclude some parts of the property, which may be unusable or be left for future developments. An over-long fence is difficult to supervise, particularly at night and in remote areas. Major entry points to the site should be at road accesses and have gatehouses, weighbridges and waiting spaces for trucks. Minor entrances are usually not staffed and need very little space. Access to them can be controlled by magnetic cards etc. in some cases, roads parallel to the fence, lighting of the fence, close-circuit television and armouring (e.g. barbed wire) of fences are employed. Emergency planning may require extra emergency gates.

Security needs to start when construction starts and the construction site must be treated for security purposes as if it were like a fully operational plant. Thus, it is necessary to protect the temporary offices, workshops and fabricating areas, stores buildings, storage areas and vehicle parking.

2.7. Environmental Aspects

As engineers we have a social responsibility to take into account the impact this site will have on the local environment when applying for planning permission, which will have to be sought from the appropriate authorities. A formal environmental impact assessment needs to be carried out. Positive factors such as the creation of jobs and inflow of cash will be strong selling points and will be readily accepted by the local population. Public attention is likely to focus on the effects the site will have on the natural environment, people, amenities, and ecology.

The most immediate impact of the plant will be on the people living around it who may be, or may believe they will be, affected by effluent, smells, noise, traffic congestion, and appearance of the site. The need to contain effluent release within legal limits is obvious. Additionally, effluent of all kinds must be checked for smell, smoke, dust or spray drift, and for visual eye-sores, such as solids stockpiles, drum stores, unwanted or scrap equipment etc. The location of the site main gate and the attendant heavy vehicles and foot traffic should relate to traffic on public roads. Site traffic should not cause congestion or hazards on public roads. Personnel access by foot, cycle, or vehicle should not distant from housing zones in order to minimize large traffic volumes disturbing residents at shift-change times. Heavy goods vehicle loading points, site road and rail lines which can cause noise particularly at night, should be kept away from housing zones. Similarly, areas of very high illumination such as compounds, marshalling yards or elevated plant operating platforms should not be near neighbouring houses.

Although noise suppression begins with the appropriate design of plant and process equipment, the layout can also reduce the amount of noise transmitted across the site boundary by locating noisy items especially those running at night.

Wildlife and the ecological systems have very high tolerances to noise and traffic but are critically affected by effluent. The obvious principal hazards are pollution of watercourses by liquid effluent. Effects on vegetation by fume or dust can be severe and visible immediately around the site but windborne pollution can cause harm a long distance away. Piles of wastes awaiting disposal can give rise to leaching of pollutants into groundwater.22 

Maintaining a pleasing appearance of the site, particularly from outside, is an important factor in preserving good local community relations. Tree-felling and leveling should be kept to a minimum, as apart from cost, they create barren, straight-line appearances which may conflict with natural surroundings. Tasteful colour schemes can help in blending the large buildings into their background. Occasional splashes of colour carefully chosen will break-up large, monotonous slabs and give visual relief and interest.

The works of man have a place in our environment and can be interesting complementary features of landscape so long as they do no seek to dominate both environment and mankind. This is the ultimate challenge associated with our overall design.

3. PRELIMINARY ECONOMIC EVALUATION

The capital needs for an industrial concern fall in three categories:

1. Obtaining capital for the initial establishment of a concern
2. Raising funds necessary to cover operating costs and
3. Changing the financial structure of the going enterprise and securing funds for expansion.

Economy in plant layout is concerned mainly with steelwork, concrete, piping and electric cables.24 Structures, and therefore, deep foundations can be greatly reduced by having most equipment on the ground. Where structures have to be used they should support more than one item. To minimize piling costs, the heaviest equipment should be located over the best load-bearing soil.

Equipment should be located to avoid excessive piping and cable runs. Long runs increase the chance of conduit and insulation; have more fittings and greater energy loss. It must be remembered that economic considerations must not cause the constraints of safety, operation etc. to be overlooked.

4. DEVELOPMENT OF DATA NECESSARY FOR FINAL DESIGN

The development of a complete plant design requires consideration of many different subjects.  There is a common misconception that plant layout consists of shuffling machinery models and templates on a scale floor plan until a nice looking solution evolve. Yes the individual design of individual pieces is very important but what is of paramount importance is the role of costs or profits. Models and templates serve a very useful purpose in visualizing layouts alternatives as well as providing an effective media for selling proposed layouts to executives and other interested personnel. A principal responsibility of the chemical engineer is the design, construction, and operation of chemical plants. Within this responsibility, the engineer must continuously search for additional information to assist in these functions. Such information can be obtained from numerous sources and these can be:

• Intuition based on experience
• Economic optimization
• Critical examination
• Rating
• Mathematical modeling
• Recent publications
• Operation of existing process plants
• Lab and pilot-plant data must be thoroughly studied to achieve the information required.

One of the most important pieces of information for the layout engineer is the production volume that his layout will be expected to meet, since the determination of this figure results from the overall study of the product and its marketability.

A formal technique is any logical method that provides definitive information on relationships between item or numerical data, regulatory and contract requirements etc. Before starting layout, this information should be assembled. A first layout is almost certainly based on process flow as intuition drawn on experience indicates that such a layout is basically a good one and that it can be altered successfully to accommodate the requirements of the operation, maintenance, safety etc. Intuition in addition indicates immediately what these principal alterations should be. Hence, formalized methods should be used since the intuitive approach alone misses the less obvious factors thus allowing a potentially good layout becoming a bad one.

4.1. Feasibility Survey

Before any detailed work is done on the design, the technical and the economic factors should be examined. The impetus for developing formal layout methods is being generated by the changing attitude of the society to the process industries and to the consequences of accidents in those industries. The various reactions and physical processed involved must also be accounted for. A preliminary feasibility survey of the market conditions indicates the probable success of the project and also shows what additional information is necessary to make a complete evaluation.

No layout solution can be successful for very long if the information on the production volume is seriously in error. It is essential that only recent information on reliable sources be utilized in establishing the production-volume figure. The data collection phase is difficult to locate chronologically in the various phase of the plant layout.6 It is good practice for the collection of data for plot plats to come early, while data needed for detailed layout may be obtained at a later date.

4.2. Materials and Processes

Certain information about materials and the process of manufacturing is important in developing a layout. Information in a layout problem involving a product already in production may be obtained from records, whereas for a new product this information has to be developed by the layout man.7 The data required about materials and processes are summarized below:

Figure 2. Production Handbook, Second Edition, p.19.7

There are a number of rather refined tools for obtaining most of this information in concise, understandable form. To cite a few examples:

• The parts list – is merely a list of all the components contained in a given finished product. This listing is the basis for a layout solution.

• The routeing – summarizes the operations required to convert a given part from raw materials to finished products. The following minimum information is included in a routeing:

1. Part name and number
2. Part drawing number
3. Operation’s name and number
4. Machine-tool name
5. Tools, jigs, and fixtures
6. Standard time9

• The operation process chart – is defined as “a graphic representation of the points at which materials are introduced into the process, and of the sequence at which materials are introduced into the process, and of the sequence of inspections and all operations except those involved in materials handling. It includes information considered desirable for analysis such as the time required and location.”10

The Production Handbook says that certain basic production data are necessary before the layout process can be undertaken. These items should include:

1. Blueprints of all parts and assemblies in sufficient detail for actual manufacturing
2. Complete parts list, indicating not only parts to be manufactured but all purchased items as well
3. Production routeings, or operation lists for all parts to be manufactured8

The Production Handbook goes on to say this about process planning:

The process engineer studies and analyzes the prints. He will then:

1. Plan the operations necessary to process the rough stock into the finished part
2. Decide on proper sequence for the necessary operations
3. Select machines and equipment required to perform each operation
4. Specify or sketch necessary auxiliary equipment such as tools, jigs, and fixtures
5. Procure production standards, usually in terms of hours per piece, from the time-study records
6. Write up these data as a production routeing or operation list.8

In some cases, process planning may be done by the same department, or even by the same person who works on layout. More on materials of construction is covered in chapter seven.

4.3. Building Data

For any layout proposal, the layout man must obtain complete information on the buildings within which he is going to work. If possible, he should obtain a set of the architect’s drawings. The architect’s drawings should be carefully checked for accuracy, particularly when another concern has occupied the building since he made his drawings. Steam lines and all main utility lines should be shown accurately. Information on sewers, drains, water and compressed air lines should be complete.

In most buildings, columns are spaced at equal intervals,13 but this should also be verified. Although the drawings are to scale, depending upon the drawing scale for a critical dimension has led to difficulties in the past. Locating tall machines on overhead handling equipment depends upon clearances. If a new facility is likely to be a multistory building, information should be obtained on the safe load limitations for the floors. Permanent electrical installations should be noted on the drawings. Where drawings are unavailable, field sketches must be made and converted into engineering drawings.

5. FINAL ECONOMIC EVALUATION

Developing the overall design for a project involves many different design considerations. Failure to include these considerations in the overall design project may, in many instances, alter the entire economic situation so drastically as to make the venture unprofitable.

As mentioned earlier, there is a lot to consider when designing a plant, for example the plant location, layout materials of construction etc. Record keeping and accounting procedures are also vital factors in general design considerations.

As soon as the final process-design stage is completed, it becomes possible to make accurate cost evaluation because detailed equipment specifications and definite plant-facility information are available. Direct price quotation based on detailed specifications can then be obtained from various manufacturers.

6. PROCUREMENT

Things like materials of construction and materials handling may fall under this category. The goal of a plant design is to develop and present a complete plant that can operate on an effective industrial basis. To achieve this goal, the chemical engineer must be able to combine many separate units or pieces of equipment into one smoothly operating plant. It is the material flowing through an industrial enterprise that brings about its success or failure. The material strongly influences the placement of the plant equipment and facilities. In general, materials will influence a plant layout because of:

• Physical properties
• Chemical properties
• Product design
• Product mixing20

6.1. Materials of Construction

As chemical process plants turn to higher temperatures, and flowrates to boost yields and throughputs, selecting materials of construction takes an added importance. Fortunately, a broad range of materials is now available.

The chemical engineer would hardly expect a metallurgist to handle the design and operation of a complex chemical plant. Similarly, the chemical engineer cannot become a materials expert overnight. But a good metallurgist must have a working knowledge of the chemical plant environment. In the same manner, the chemical engineer should also understand something of the materials that make the equipment and process possible.

This chapter provides a working knowledge of some of the major forms and types of materials available, what they offer and how they are specified. With this background the engineer can consult a materials specialist at the beginning of the design, not when the mistakes have already been made.

Metals

Materials of construction may be divided into two categories that being metals and non-metals.

Iron and Steel

Although many materials have greater corrosion resistance than iron and steel, cost aspects favour iron and steel. Because of this they are often used as materials of construction when it is known that some corrosion may occur.

Stainless Steel

There are more than 100 different types of stainless steels. These materials are high chromium or high-nickel chromium alloys of iron containing small amounts of other essential constituents.23 They have excellent corrosion-resistance and heat-resistance properties, therefore for they are the materials of construction most likely to be used.

7. PLANT LOCATION AND ERECTION

Holmes has defined the plant-location problem as “that location, which in consideration of all factors affecting delivered-to-customers cost of the products to be manufactured, will afford the enterprise the greatest advantage to be obtained by virtue of location.”16 

A new business is always faced with the problem of where to locate. Because of the more pressing problems involved in establishing a new business, an organizer of a new business seldom considers sites outside of his own community. A number of conditions can lead to the consideration of the plant-location problem. These include:

• Expansion
• Decentralization and
• Economic factors such as a shift of the market or an inadequate labour supply.

Decentralization of industry is seen to be increasing at a rapid pace. Many of the industrial giants that historically grew in one location have found that decentralization pays off in a number of respects.18 The company benefits by the availability of new sources of labour supply, improved labour relations of a smaller plant, a lower absentee rate and greater interest in their work shown by citizens of small communities. The worker benefits from the lower costs of living in uncongested towns, the elimination of expensive and annoying community etc. General Motors, which are decentralized from coast to coast, are good examples of locating in the concentrated market areas.

7.1. Levels of Location Problems

Two levels of problems must be attacked when considering plant location. They are:

• The selection of the general territory and
• The selection of the community and plant site.

7.1.1. Territory Selection

When making the selection of a general territory, obtaining specific information about a given community can be a waste of time. Territory selection calls for information of a more general nature.18 

7.1.2. Community and Site Selection

Once the general territory for location has been established, it becomes necessary to choose a community and a site. An early decision must be made regarding the size of the community in which the plant is to be located. The alternative choices are:

• City,
• Suburban and
• Country locations.

7.1.2.1. City versus Suburban versus Country

The advent of the automobile has brought new mobility to our working force. With this reason country adventures are made easier. Wide-open space and freedom to expand are the two biggest inducements.

The top ten plants of 2006, selected by Factory Management and Maintenance, are all in country locations. The type of manufacturing process may dictate the site selection. For example, a country location is desirable for a plant producing explosives. Some of the general conditions leading to the selection of an appropriate type of community might be listed as follows:

1. Conditions suggesting a city location

• Large skilled labour force required.
• Process heavily dependent upon availability of city utilities.
• Multi-floor building desirable.
• Close contact with suppliers demanded.
• Rapid public transportation available.

2. Conditions suggesting a suburban location

• Semiskilled labour force required.
• Avoidance of heavy city taxes and insurance desired.
• Labour force residing close to plant.
• Plant expansion easier than in the city.
• Community close to, but not in, large population center.

3. Conditions suggesting a country location

• Large site required for either present demands or expansion.
• Lowest property taxes available desired.
• Unskilled labour force required.
• Low wages required to meet competition.
• Morale of working force improved by country location.
• Manufacturing process is dangerous or objectionable.19

With this company a city location will best suit the needs for producing vaccines for DNA. One rule of thumb regarding the size of a site is that it must be at least five times the actual size of the plant itself. This is considered a minimum in order to allow for future expansion, loading platforms, siding, parking facilities, and storage area.19 

7.2. Location Factors

Economists have written a considerable amount of material on the problem of locating industrial plants. A great many factors should be considered if a plant is to be located advantageously. The location factors discussed here must be considered by the majority of industries planning relocation, but should by no means be considered as the only factors of importance. Space limitations prohibit detailed discussion of all the aspects of plant-location problems.

7.2.1. Market

The market i.e., the location of the buyers is a factor to be considered in plant location. Depending upon the product, markets may be concentrated or widely dispersed. When a market is concentrated, the market factor will tend to influence the investigator to locate close to this concentration.18 It is possible to determine the center of a market. This can only be used as a guide for plant location.

7.2.2. Raw Materials

The location of raw materials is influential in the location problem. Some industries by the nature of their raw materials are forced to be located near the sources of their raw materials.

Yaseen suggests that raw materials be treated in three classes.19

1. Pure materials, which are included in the manufacture article without loss of weight.
2.  Weight-losing materials, only a part of whose weight is represented in the weight of the finished article
3. Ubiquities or materials found everywhere.

7.2.3. Transportation

The problem of transportation is of such importance that such a small piece on it is unjustifiable. The movement of materials can consume a very high percentage of the final cost to the customer.  One plant-location analysis done for a specific plant, done by Austin Company, showed that locating the plant as little as much as 250miles from the best location caused lost potential profits of as much as £350,000 per year. This penalty included higher cost of labour, power, and fuel, as well as higher freight cost.

Hoover lists the following transportation medium and suggests particular advantages of each:18

1. Railroads (all classes of traffic)
2. Water carriers (all classes of traffic)
3. Highway vehicles (all classes of traffic)
4. Pipelines (bulk liquid and gases)
5. Aircraft (where speed is essential and where access by surface agencies is especially difficult)
6. Belt, cable, or rail conveyors of various types (short distances)
7. Electric cable (electric energy)
8. Telecommunication (information, commercial negotiations).

As you can see, all of these transport media has its advantages and limitations. In order to select the proper transportation media, the shipper should consider the following:

• Type and extent of materials handling facilities at origin and destination
• The relative costs for the various media
• The urgency of the shipment
• The demand for special services; e.g., refrigeration.

7.2.4. Power

All industries today require electric power of some sort. In addition there are certain industrial processes that require unusually large amounts of electric power, as is the case in DNA vaccine production. Therefore it is desirable to locate the plant where large sources of inexpensive power are available.

In general most companies like to purchase rather than to manufacture their own power. The typical public utility can supply electric power at lower cost than the usual company can produce it. Technical developments lead to constant improvement in power generation and distribution.

7.2.5. Laws and Taxation

International and local laws must be studied when considering various locations. Labour laws, workmen’s compensation insurance laws, and unemployment regulations should be examined.

Some of the aspects of industrial operations regulated by law are hours of work, minimum wages, minimum ages etc. One reads constantly about the excessive taxes paid by industrial concerns. Of course taxes should be considered, in selecting a site but Greenhut says, “tax incentives are at best a relatively unimportant secondary factor of location. Given the governing factor, the tax incentive may induce a specific location within the area defined by the basic factor. If the location offering tax incentives is not within the area set by the governing factor, it is simply not considered.”17 (p.39)

8. STARTUP AND TRIAL RUNS

When a definite decision to proceed with the construction of as plant is made there is usually an immediate demand for a quick plant start up. Timing therefore is particularly important in plant construction. Long delays may be encountered in the fabrication of the major pieces of equipment, and deliveries often lag far behind the date of ordering. These factors must be taken into consideration when developing the final plans and may warrant the use Project Evaluation Review Technique (PERT) or the Critical Path Method. The chemical engineer should work closely with the construction personnel during the final stages of construction and purchasing designs. In this way, the design sequence can be arranged to make certain the important factors that might delay construction are given priority. Construction of the plant may be started long before the final design is fully completed. Correct design sequence is then essential in order to avoid construction delays.

During construction of the plant, the chemical engineer should visit the plant site to assist in the interpretation of the plans and learn methods for improving future designs. The engineer should also be available during the initial startup of the plant and the early phase of operation. Thus, by close network between design, construction, and operations personnel, the final plant can develop from the drawing board stage to an operating unit that can function both efficiently and effectively.

9. PRODUCTION

This section is devoted to the rate of production output and how it is utilized in layout planning and a brief orientation of the procedures used in the sales department to determine market demand. The layout man will seldom, if ever, find himself in a position where he personally must analyze the market demand, but he should have an inkling of an idea about the problems involved in obtaining market data. Market research and predicting future trends in business require specialized knowledge and ability. Generally the layout engineer must bas his proposals completely on the best estimates of the market demand by specialists in these fields. The orientation of this chapter is not intended to make a market researcher out of the reader, but rather to provide a sufficient background to provide him with sufficient background to have some understanding of the limitations of market-research data.

9.1. Importance of Sales Planning

The most critical single piece of information needed for effective plant layout and design is the planned rate of production.14 the reasons for sales planning are numerous, but the plant layout man is interested primarily in the demand for product and its variability, which in turn can be converted into planned rate for production. It must be noted that the demand for the product and production rate may not necessarily be the same. Production planning must take scrap and quality rejects into account, so that it is generally larger than demand rate.14 

Why is the rate of production so important? This information is essential as it guide experts to determine the size of the plant to be designed. It will determine the general layout type i.e., process layout or production-line layout. It will influence the type of equipment that is to be obtained i.e., special-purpose or general-purpose equipment. It will influence the size of the work force. It will influence the type of sales effort needed to sell the DNA vaccines. It will influence the type of distribution channels to be utilized. It will influence the caliber of the work force required i.e., skilled labour or unskilled labour. It will determine the flexibility required of the materials-handling system.15 The list of reasons why valid production output information is so important could go on and on, but I hope that the point has already been made. Data concerning it are critical for plant layout and must be obtained by the best procedures available.

9.2. Market Research

How does the sales department go about gathering information about the market? The basic tool of the market researcher is the market survey. The novice is apt to consider a market survey as a few questions hastily jotted down and posed to friends and neighbours. This is not the case if accurate information is to be obtained on a particular topic. Effective market research requires considerable knowledge about the DNA vaccines and specialized ability in the analysis of the results of a survey.

Plant design requires that market research provide a reliable estimate of sales volume, cover foreign as well as domestic sales, and indicate the current price structure and the trend of prices projected over three or five years.15 In recent years, technological changes have taken place so rapidly that obsolescence of a product design must be given serious thought in plant design.

10. CONCLUSION

As a result of all the research done, a plant layout has been produced taking everything discussed into consideration.

• The process units have been arranged to give a smooth flow from production to the storage area, however to avoid excessive loading/ unloading bays around the site, the single tank farm will contain both raw materials and products. It is typical on a plant to separate process units by 30m, but as the oxidation and cleavage areas are both potentially dangerous, they are separated by a greater margin, as shown.
• The offices and main labs are the areas which will employ the greatest number of personnel, and so as a safety precaution they are placed as far away from the main hazard areas as possible, as well as being located close to the exit points. Hence the bulk of employees can be evacuated very quickly in the event of an emergency.
• A smaller control room is located adjacent to the plant for periods of prolonged plant based activities, therefore avoiding long treks for operators between the plant and the main control room. A plant based lab is also located here for routine operator sampling.
• The utilities area is required to be located close to the process units, as the distillation and vaccine recovery section will be using the majority of the utilities generated. It is economic to use pipes to have them located closer together.
• For safety the site boundary is some distance away from the hazardous and tank storage areas, thus reducing the likelihood of damage to the public in the event of safety systems failure.
• There is a single loading/ unloading zone to reduce the need for heavy vehicles from being traveling across the site which might be hazardous. An adequate turning circle has been provided to ensure that vehicles do not travel a long distance to exit the plant. A driver waiting distance is also provided close to the loading bay to stop drivers from wandering into danger zones.
• There is a second exit point, which is desirable in the event of an evacuation or as a point for entry for fire fighters.
• The fire station is located relatively close to the hazardous are, enabling rapid response times in the event of an emergency.

11. REFERENCES

1. Mecklenburgh, J.C. (ed.), Plant layout. Leonard Hill/I.Chem. E, 1973.
2. Eugene Richman, “Trends in Plant Layout and Design”, Journal of Industrial Engineering, Vol. VII, No.1 (January-February, 1956), p. 29.
3. Kern, R., ‘Plant Layout’, Chem Engng, 12 parts, 1977-78: Specifications are key to successful plant design’, 4 July, 123, 1977.
4. William Grant Ireson & Eugene L. Grant, Ed., Handbook of Industrial Engineering and Management, p.547.
5. Shubin, John A., and Huxley Madeheim. Plant layout. Englewood Cliffs, N.J. : prentice- Hall, 1951.
6. Pemberton, A.  W., Plant Layout and Materials Handling. Macmillan, London, 1974.
7. Mackenzie, G., ‘The time and resources aspects of project management in the construction of chemical plants’, Chem. Engr, lond. 209, CE118, June 1967.
8. Production Handbook, Second Edition, edited by Gordon B. Carson, p.19.7. Copyright 1950 The Ronald Press Company.
9. Mallick, Randolph W., and Armand T. Gaudreau. Plant Layout – Planning and Practice. New York: John Wiley & Sons, 1951.
10. American society of Mechanical Engineers, Operations and Flow Process Charts, Standard No. 101.
11. Townroe, P., Planning Industrial Location. Leonard-Hill, London 1976.
12. Balemans, A. W M., et al., ‘Check-list. Guidelines for the safe design of process plants’, in Buschmann, C. H., (ed.), Loss Prevention and Safety Promotion in the Process Industries. Elsevier Scientific Publishing Co., Amsterdam, 1974.
13. Tunkel, S. J. ‘Barricade design criteria’, Chemical Engineering Progress, 50, Sept. 1983.
14. Boyd, Harper W., and Ralph Westfall. Marketing Research: Text and Cases. Homewood, Illinois: Richard D. Irwin, Inc., 1956.
15. Emphasizes the analytical aspects of market research. Phillips, Charles F., and Delbert J. Duncan. Marketing: Principles and Methods (3rd ed.). Homewood, Illinois: Richard D. Irwin. Inc., 1956.
16. W. G. Holmes, Plant Location, p. 3.
17. Greenhut, Melvin L. plant Location in Theory and in Practise. Chapel Hill, N.C.: University of North Carolina Press, 1956.
18. Hoover, Edgar M. The location of Economic Activity. New York: McGraw-Hill Book Company, 1948.
19. Yaseen, Leonard C. Plant Location. New York: American Research Council, 1956.
20. Bolz, Harold A., and George E. Hagemann, eds. Materials Handling Handbook, New York: Ronald Press, 1958.
21. Maclean, W.C., ‘Construction site selection – a US viewpoint’, June 1977.
22. Herzet, G. L., ‘Construction site selection – a European viewpoint’, Hydrocarbon processing, 116, June 1977.
23. Degerbeck, J., Corrosion of stainless Steel in Sea Water, Chem. Proc. Eng.
24. Kern. R., ‘How to arrange the plot plan for process plant’, Chem. Engng, May 8, 191, 1978.