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| Syllabus | |
| 1 | Intro. to the Course |
| 2 | Intro. to Gas and Oil Processing |
| 3 | Gas Processing Methods |
| 4 | Intro. to Water -Hydrolic Cycle |
| 5 | Intro. to Water -Part 2 |
| 6 | Power Generation/ Cogeneration |
| 7 | Electricity Transmission |
| 8 | 8 Missing |
| 9 | 9 Missing |
| 10 | 10Missing |
| 11 | Chemical, Reagents,Tools, Rigging |
| 12 | 12 Missing |
| 13 | Land Use and Reclamation |
| 14 | Instrumentation and Drawings |
| **** Final Exam***** | |
| Resources | |
| Staff E-mail | |
Introduction to Process Technology
Lesson 5
Safety
Topic | Introduction
to Water -Part 2 | Basic Terms
Objectives
- 1. Describe Fire Water Systems
- 2. Describe Potable Water Systems
- 3. Describe Wastewater Treatment Systems
- 4. Describe Water Quality Management
- 5. Basic terms of Maintenance Operations and System Components:
- 6. Basic Math Continued:
- 2. Describe Potable Water Systems
Cranes move materials and products through facilities, on construction sites, and other types of operations.
Examples of cranes are gantry, overhead, crawler locomotive, and derricks. The safe use of a crane depends on several factors. They are:
Site evaluationóevaluating the terrain, what is overhead, what the load bearing capacity of the site is, and what the hazards are in the area.
Operator training Operators must be trained in the operation, limitations, and emergency procedures for the cranes they operate. They should understand the load ratings and how to properly lift loads.
Proper equipment selection for the job, selection of the proper equipment is a factor in operating cranes safely. The crane should be matched to the operation it is to be used in. Review the manufacturer's specifications and recommendations to determine if a crane or derrick can be used in a particular application.
Inspection Inspection of cranes ensures that the equipment is functioning as it is designed to.
Good maintenance Besides repairing the equipment, a crane program should include preventive maintenance. Well-maintained equipment will aid in preventing accidents involving mechanical failure. Modifications can only be made with the manufacturer's approval.
Inspections
The two types of inspections are frequent and periodic. Frequent inspections are the daily preoperational walk-around, the prestart-up check, and the post start-up check. Periodic inspections are performed monthly and annually. The monthly inspection interval varies depending on crane use and site conditions.
Maintenance
Keeping a crane in good operating condition requires preventive maintenance as well as timely repairs. Follow your company's preventive maintenance program. The basis for this program is the manufacturer's recommendations on preventive maintenance.
Overhead lines
All overhead lines are to be considered energized unless the electrical utility owning the line indicates that the line is not energized, and it is visibly grounded and has been appropriately marked.
When operating near power lines, minimum clearance between the lines, and any part of the crane or load must be 10 ft. for voltages of 50 kV or below; or 10 ft. plus 4 inches for each 10 kV over 50 kV. When in transit with no load and boom lowered, the equipment clearance must be at least 4 ft. for 50 kV or below; or 4 ft. plus 4 inches for each 10 kV over 50 kV. Where maintaining the proper clearances by sight is difficult for the operator, a signal man must be present to give timely warnings to the operator for all operations.
Operating rules
For stationary, overhead, or gantry cranes, post the operating rules so the crane operator can see them. Use the manufacturer's operating manual for proper operating procedures.
General safety rules
- Avoid carrying loads over people.
- Don't allow anyone to ride the hook or load during hoisting, lowering, or traveling.
- Don't walk away from the crane with a load suspended.
- Move loads slowly; avoid sudden acceleration or deceleration.
Employee training
For general industry, only designated employees shall be permitted to operate a crane covered by ß1910.179 - .181. Operating and maintenance personnel shall be familiar with the use and care of the fire extinguishers provided.
For construction there are no specific crane training requirements. However, the regulations at 29 CFR 1926.20(b)(4) that the employer shall permit only those employees qualified by training or experience to operate equipment and machinery.
Training tips
Crane operators should be trained before initial assignment and regularly thereafter. They are not the only employees involved in crane operations that should receive training. Include the signal and ground persons, lift directors, and riggers in any training.
Since inspections play a major part in the safe operation of cranes, a mock inspection provides experience in performing an inspection. Develop an inspection checklist for the type of mock inspection to be performed
Where to go for more information
For general industry 29 CFR 1910.179 Overhead and gantry cranes, 1910.180 Crawler, locomotive, and truck cranes, 1910.181 Derricks.
For constructionóOSHA regulations at 29 CFR 1926, Subpart N Cranes, derricks, hoists, elevators, and conveyors.
Introduction to Water-
part 2
Fire Water
Firewater is water used to extinguish fires.
Sources of fire water
Because it is not used for drinking or industrial processes almost any source is acceptable for firewater.
For example, the Trans Alaska Pipeline Terminal at Valdez (VMT) uses water taken straight from the ocean as firewater. Their system uses massive diesel driven pumps to move the water up the hill for delivery to potential fires.
Ocean going tankers and other ships also use salt water as a fire water source.
Features of Fire Water Systems
1 Systems are typically high pressure and large volume
2 Systems often add foam to the firewater. Water itself is incapable of extinguishing a flammable liquid. The foam floats on the surface of the burning liquid starving it of oxygen and therefore extinguishing the fire. Foam can also secure for extended periods of time against reflash or reignition.
3 Systems use fixed equipment :
A pipes
B monitors (fixed nozzles mounted like a gun)
C foam mixing eductors or positive displacement pumps An eductor uses the principle of water flowing in a pipe to educt or suck foam into the main stream. Eductors are calibrated to induct foam concentrate ratios of .1%, .5% and 1% into hose lines
D high pressure high volume pumps driven by fail-safe drivers (diesel engines) Normally the pumps are powered by an independent prime mover. It is expected that major fires will disable electricity and therefore electric pumps would be a bad choice.
E tanks for both foam and water
F automatic valves often remotely opened; also air breaker valves are designed to prevent firewater from escaping into other water systems
G jockey pumps, keep the pipes fully pressurized during standby. Some depressurization will occur to thermal expansion of the pipes and minor leaks. If the main fire water pumps were used for this purpose they would have a shortened lifespan due to frequent starts.
Potable Water
Potable means water that is drinkable. In order to be drinkable the water must be free of contamination. The best way to avoid contamination is to take the water from a source that is free of contamination. Here are three sources of water and their properties.
- Wells Wells tap into groundwater. The deeper the well, the less likely there will be any contamination. The well must be properly constructed to prevent surface water and or water above the desired aquifer from getting into the desired layer of water. Well water might have minerals in it.
- Watershed Most large water systems take water from the surface. Whenever possible governments will protect the watersheds, which feed these lakes and rivers. When that is not possible, then treatments systems are used to make the water potable. Most of the discussion in this potable water element will be about systems, which treat surface water to make it potable.
- Desalination Desalination is used in some desert areas to produce drinking water from the ocean. It takes tremendous amounts of energy and therefore is very expensive. Desalination is widely used on ships and submarines. The specific process used for desalination is distillation. The salt water is boiled and the vapors condensed.
Potable Water Treatment
The most common treatment methods are Flocculation/sedimentation,
Disinfection, and Filt
ration.
Flocculation/Sedimentation
Flocculation refers to water treatment processes that combine or coagulate small particles into larger particles, which settle out of the water as sediment. Alum and iron salts or synthetic organic polymers (used alone or in combination with metal salts) are generally used to promote coagulation. Settling or sedimentation occurs naturally as flocculated particles settle out of the water.
Disinfection
Disinfection (chlorination/ozonation) Water is often disinfected before it enters the distribution system to ensure that potentially dangerous microbes are killed. Chlorine, chloramines, or chlo- rine dioxide are most often used because they are very effective disinfectants, not only at the treatment plant but also in the pipes that distribute water to homes and businesses.
Ozone is a powerful disinfectant,
Ultraviolet radiation is an effective disinfectant and treatment for relatively clean source waters, but neither ozone nor UV are effective in controlling biological contaminants in the distribution pipes.
Filtration
Many water treatment facilities use filtration to remove particles from the water. Those particles include clays and silts, natural organic matter, precipitates from other treatment processes in the facility, iron and manganese, and microorganisms. Filtration clarifies water and enhances the effectiveness of disinfection.
Activated carbon
Activated carbon is the primary material
used in filtration.
Activated carbon is the generic term used to describe a family of carbonaceous adsorbents with a highly crystalline form and extensively developed internal pore structure.
Activated carbons that are used for the removal of organic compounds from gas or liquid phase systems will gradually become saturated, due to the concentration of contaminants on the surface of the adsorbent. When this occurs the system must be backwashed or otherwise renewed.
Municipal Potable Water System
Municipal Potable Water System is a municipal water treatment plant that is used for the removal of taste and odor.
Water is pumped from the river into a flotation unit, which is used for the removal of suspended solids such as algae and particulate material. Dissolved air is injected under pressure into the basin through special nozzles. This creates microbubbles, which become attached to the suspended solids causing them to float. The result is a layer of suspended solids on the surface of the water, which is removed using a mechanical skimmer.
Ozone is produced on site by passing high tension high frequency electrical discharges through air in specially designed equipment. Ozone is injected into the water to provide a powerful bactericidal action and to break down the natural compounds that are the cause of bad taste and odor.
The water then enters a rapid gravity charcoal filter to adsorb the compounds resulting from the ozone treatment. Following adsorption the water is chlorinated to disinfect it.
Potable Water Contaminants and sources of contamination
Hydrogen sulfide
Sulfur-reducing bacteria, which use sulfur as an energy source, are the primary producers of large quantities of hydrogen sulfide. These bacteria chemically change natural sulfates in water to hydrogen sulfide. Sulfur-reducing bacteria live in oxygen-deficient environments such as deep wells, plumbing systems, water softeners and water heaters. These bacteria usually flourish on the hot water side of a water distribution system.
Hydrogen sulfide gas also occurs naturally in some groundwater. It is formed from decomposing underground deposits of organic matter such as decaying plant material. It is found in deep or shallow wells and also can enter surface water through springs, although it quickly escapes to the atmosphere. Hydrogen sulfide often is present in wells drilled in shale or sandstone, or near coal or peat deposits or oil fields.
Performing a shock chlorination procedure may reduce, but does not eliminate, the sulfide producing bacteria. This process involves placing a strong chlorine bleach solution into the well. Taps then are opened to draw chlorinated water into all parts of the plumbing system. The chlorinated water is left in the system for several hours or overnight and then flushed out.
Wastewater Treatment
Wastewater
Wastewater is water discharged after it has been used.
Wastewater Sources
Industry-Almost every industry uses water. This water can not be simply dumped back into the river or lake as was the practice in the past. Federal state and local agencies strictly regulate the discharge of water back to the environment.
Normally a water discharge permit is required. The permit describes how the water is to be discharged, allowed concentrations of bacteria and byproducts, temperature, turbidity, and many other parameters.
Domestic -Household water typically finds its way to a municipal wastewater treatment plant. These plants are designed to clean, disinfect and discharge the water back to the environment. We will discuss a municipal treatment plant in some detail later.
Agricultural- Two sources of agricultural wastewater are field runoff and the runoff from concentrated feeding operations. Field runoff contains fertilizer and pesticide residue. Feedlots produce tremendous amounts of manure that must be treated.
Water Pollutants
The major types of water pollutants can be subdivided into six different categories:
1 Nutrient Pollution Organic nutrients from feedlots, sewage and some industries such as paper mills and meat-packing plants. Inorganic nutrients including nitrogen, phosphorus, iron, sulfur, sodium, and potassium.
2 Infectious Agents from untreated sewage, animal wastes, and meat-packing plants.
3 Toxic Organic Wastes from compounds such as Chlorinated Hydrocarbons, Organophosphates and Carbamates.
4 Toxic Inorganic Wastes such as Mercury, Nitrates and Nitrites, Salts, and Chlorine.
5 Sediments resulting from timber cutting, agriculture, mining, and road construction.
6 Thermal Pollution typically generated by power production facilities.
Wastewater Treatment
Here is a description of a typical wastewater plant. A series of biological treatment systems separate the solids (organic and inorganic) from the liquids. The remaining liquid is then treated separately to reduce the bacterial pollutants and to render it suitable.
There are three types of treatment. Below is an introductory description followed by a very detailed description.
Primary Treatment - milliscreen technology is used to remove inorganic debris like rags, plastic, tin cans and grit from the flow. This is then washed and bined for landfill disposal. Sludge is removed from the settling tanks and anaerobically (without oxygen) decomposed and eventually burned, used as fertilizer or disposed of in a landfill.
Secondary Treatment - conversion of biodegradable organic material through biological decay using aerobic (with oxygen) bacteria. Bacteria use the organic material as a food source, converting it into carbon dioxide and water via cellular respiration. Secondary treatment removes approximately 95% of the biodegradable organic material.
In most waste water treatment facilities secondary treatment is the terminal event. Effluent (water to be discharged into aquatic system) is then treated with chlorine or ozone to destroy pathogenic (disease causing) bacteria prior to discharge.
Tertiary Treatment - removal of chemicals that are not biodegradable. Tertiary treatment is extremely expensive and rarely used.
In the PRIMARY stage of treatment, solids are allowed to settle and are removed from the water. Here's how it works: as sewage enters a plant for treatment, it flows through a screen. The screen removes large floating objects such as rags and sticks that may clog pumps and small pipes. After the sewage has been screened it passes into what is called a grit chamber where sand, grit, cinders and small stones are allowed to settle to the bottom.
The unwanted grit or gravel from this process is usually disposed of by filling land near a treatment plant. With screening completed and the grit removed, the sewage still contains dissolved organic matter along with suspended solids.
In a sedimentation tank the suspended solids will gradually sink to the bottom, forming sludge. Then, the sludge is mechanically removed from sedimentation tanks. The heavier solids sink to the bottom while floating solids, such as fat and grease, accumulate on the surface. A system of scrapers on the tank floor move the settled solids to a sludge hopper, from where they are pumped to the sludge digesters.
At the same time water sprays move the floating solids to a skimmer and this too is fed to the digesters. At this stage about 60 per cent of the suspended solid matter in the wastewater has been removed.
The SECONDARY stage of treatment removes up to 95% of the organic matter by making use of the bacteria in it. Two techniques are used in this stage: trickling filters and the activated sludge process.
A trickling filter is a bed of stones from 3-6 feet deep through which sewage passes. Bacteria gather and multiply on these stones until they can consume most of the organic matter in the sewage. The cleaner water trickles out through pipes in the bottom of the filter, then flows to another sedimentation tank to remove the bacteria. To complete the process, the water gets chlorinated for disinfection purposes.
The other technique which is being used more today is the activated sludge process. After the sewage leaves the settling tank in the primary stage, it is pumped to an aeration tank where it is mixed with air and sludge loaded with bacteria. It is allowed to remain here for several hours. During this time, the bacteria break down the organic matter. The sludge can be reused by returning it to the aeration tank and mixing it with new sewage and an ample amount of air.
Meanwhile, the sewage flows from the aeration tank to another sedimentation tank to remove the bacteria. The final step, as with the first technique, is the addition of chlorine.
TERTIARY treatment uses chemicals to remove specific compounds such as phosphates. This allows the water to be in better condition before it is put back into the water cycle system.
Tertiary treatment, in the form of sand filters may also be used. Filtration of the secondary clarifier effluent has a polishing effect, which means that additional removals of suspended solids, biochemical oxygen demand, and phosphorus are achieved. The higher removal efficiency increases the quality of the water.
Most wastewater plants do not employ tertiary treatment due to cost and feasibility.
Industrial Wastewater Treatment Plant
While municipal treatment is somewhat consistent, industrial wastewater treatment can be very unique. This is because industrial plants produce highly concentrated waste streams which require special treatment. Slide 5-6, Industrial Wastewater Treatment Plant, illustrates an industrial plants wastewater treatment. This specific plant is a timber treatment facility. The treatment plant removes creosote and pesticides from the water.
A storage tank is used to smooth the flow.
The water is chemically dosed to adjust the pH.
Also, ferric sulphate is added to form a precipitate with suspended solids.
In the air flotation tank the water is flocculated by the addition of polyelectrolyte
The water is then pumped through two sand filters and two activated carbon filters
To ensure compliance, the water is sampled and analyzed after the first activated carbon filter.
The second activated carbon filter acts as a backup in case something gets past the first filter.
Water Quality Management
Water Quality Management :Water quality management is a broad based effort by federal, state and agencies to manage the water resources of the nation.
Every user of water and especially industrial users have an obligation to the community in general to protect the water. The consequences of pollution are far ranging and long lasting. Contamination of underground aquifers is especially troubling because of the long term implications.
Because pollution must be controlled over both time and space the federal government has initiated programs to manage water quality.
Who is responsible for drinking water quality?
The Safe Drinking Water Act gives the Environmental Protection Agency (EPA) the responsibility for setting national drinking water standards that protect the health of the 250 million people who get their water from public sourses.
National Pollutant Discharge Elimination System (NPDES)
The purpose of the National Pollutant Discharge Elimination System (NPDES) Program is to protect human health and the environment.
The Clean Water Act requires that all point sources discharging pollutants into waters of the United States must obtain an NPDES permit. By point sources, EPA means discrete conveyances such as pipes or man made ditches. Although individual homes that are connected to a municipal system or that do not have a surface discharge do not need permits, facilities must obtain permits if their discharges go directly to surface waters.
Some pollutants that may threaten public health and the nation's waters are:
human wastes
ground-up food from sink disposals,
laundry and bath waters,
toxic chemicals,oil and grease,
metals, and
pesticides.
An NPDES permit will generally specify an acceptable level of a pollutant or pollutant parameter in a discharge (for example, a certain level of bacteria).
The permittee may choose which technologies to use to achieve that level. Some permits, however, do contain certain generic 'best management practices' (such as installing a screen over the pipe to keep debris out of the waterway). NPDES permits make sure that a State's mandatory standards for clean water and the federal minimums are being met.
Monitoring
Why monitor?
Monitoring can be conducted for many purposes. Five major purposes are to:
1. characterize waters and identify changes or trends in water quality over time;
2. identify specific existing or emerging water quality problems;
3. gather information to design specific pollution prevention or remediation programs
4. determine whether program goals -- such as compliance with pollution regulations or implementation of effective pollution control actions are being met; and
5. respond to emergencies, such as spills and floods.
Some types of monitoring activities meet several of these purposes at once; others are specifically designed for one reason.
Who monitors?
The responsibility to monitor water quality rests with many different agencies.
State pollution control agencies and Indian tribes have key monitoring responsibilities and conduct vigorous monitoring programs. They receive pollution control and environmental management grants from the U.S. Environmental Protection Agency (USEPA) that help them establish and maintain monitoring programs and report the results of monitoring activities to the USEPA.
Interstate commissions, like states and tribes, may also receive grants and maintain monitoring programs.
Many local governments, such as city and county environmental offices, also conduct water quality monitoring. The USEPA helps administer grants for water quality monitoring and provides technical guidance on how to monitor and how to report monitoring results. Some of USEPA's technical monitoring guidance documents are provided through this homepage.
The USEPA also conducts some limited monitoring of its own. Its Environmental Monitoring and Assessment Program (EMAP), managed by the Office of Research and Development, is designed to provide status and trends information on statistically selected waters representing a variety of ecosystems.
Basic Terms of Maintenance, Operations and System Components
Aerobic with oxygen
Air breaker valve A special valve designed to totally isolate fire water from potable water when they share a common source
Anaerobically without oxygen
Biodegradable Capable of being decomposed by biological agents, especially bacteria
Check valve a valve which only allows fluid to flow in one direction
Chlorine A highly irritating element, capable of combining with nearly all other elements, used widely to purify water and serve as a disinfectant
Disinfectant An agent, such as heat, radiation, or a chemical, that destroys, neutralizes, or inhibits the growth of disease-carrying microorganisms
Eductor A device used to mix fire foam into flowing water using the vacuum produced as the main stream flows past the foam inlet nozzle.
Effluent A discharge of liquid waste
Filtration The removal of microscopic particles by passing a liquid through a filtering medium
Flocculation/sedimentation processes that combine or coagulate small particles into larger particles, which settle out of the water as sediment
Gpm Gallons per minute
Industrial wastewater Water derived from industrial sources or processes
Milliscreen A super fine mesh screen
Ozone a highly reactive oxidizing agent used to deodorize air, purify water, and treat industrial wastes
Pathogen An agent that causes disease, especially a living microorganism such as a bacterium or fungus
Potable water Water of high quality intended for drinking, cooking, and cleaning. This grade of water would conform to the drinking water quality
Precipitate A solid or separated from a solution
Reflash or reignition the reignition of a burning liqud or gas which has been extiguished. Caused by hot metal or small fires hidden in hard to locate parts of equipment that was involved in a fire and not readily accessable to fire foam
Sludge Semisolid material precipitated by sewage treatment
Ultraviolet radiation Light produced by the sun or artificailly in the ultraviolet spectrum. A powerful disinfectant
Wastewater Water that has been previously used by a municipality, industry or agriculture and has suffered a loss of quality as a result. Wastewater is generally 98 to 99 percent water and one to two percent waste
Water reclamation A treatment process or processes to produce reclaimed water.
Task/ Quiz
Go to the basic math link and study pages 31 thru 37. Lesson 5 Quiz will contain quertions on this material.
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