Classes
   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 4

Safety Topic | Introduction to Water-Hydrolic Cycle | Basic Terms

Overview of topic

Chemical exposure may cause or contribute to many serious health effects such as heart ailments, kidney and lung damage, sterility, cancer, burns, and rashes. Some chemicals may also be safety hazards and have the potential to cause fires, explosions, and other serious acc-idents.

Providing protection from chemical hazards is a challenging task because of the range of hazards and operations in which they are used. Potential hazards arising from chemical exposure may occur during:

  • Production operations involving hazardous chemicals.
  • Hazardous substance site survey.
  • Rescue.
  • Spill mitigation.
  • Emergency monitoring.
  • Decontamination

Objectives

1. Describe the Hydrologic Cycle
2. Describe uses of Water in Industry
3. Describe Process Water:
4. Basic terms of Maintenance Operations and System Components
5. Basic Math Continued

Safety Topic

Personal protective equipment (PPE)

Your employer has selected protective clothing by evaluating its performance characteristics against the requirements and limitations imposed by the hazards they face. You will be shown the types of PPE you will be required to use and what jobs or tasks that require use of the PPE.

Inspection of protective equipment

During emergencies is not the right time to discover problems with protective clothing. You need to care for your clothing by following a standard program for inspection, proper storage, and maintenance. This step, plus helping you realize protective clothing/equipment limitations, is the best way to avoid chemical exposure during emergency response.

An effective chemical protective clothing inspection program features five different inspections:

  • ÝWhen equipment is received from the factory or distributor.
  • ÝWhen equipment is selected for a particular chemical operation.
  • ÝAfter use or training and before maintenance.
  • ÝDuring storage.
  • ÝWhen questions arise as to appropriateness of selected equipment or when problems with similar equipment are discovered.

Your employer will tell you who is responsible for each of the above inspections.

Chemical protective clothing will only be effective if it is appropriate for the job and if it is in good condition. Inspect your chemical protective clothing before you use it, and watch for damage during use.

Employee training

OSHA regulations contain specific training requirements for personal protective equipment. At 29 CFR 1910.132(f), the rule says employers must provide training to each employee who is required to use PPE. Each such employee must be trained to know at least the following:

  • ÝWhen PPE is necessary;
  • ÝWhat PPE is necessary;
  • ÝHow to properly put on, take off, adjust, and wear PPE;
  • ÝThe limitations of the PPE; and
  • ÝThe proper care, maintenance, useful life and disposal of the PPE.

There are also requirements for retraining and making sure that workers understand the required training.

Introduction to Water-The Hydrologic Cycle

How the Hydrologic Cycle Works

We never run out of water. After four and a half million years you'd think the water would be all used up! It's not, though, because of one special process: the hydrologic cycle more commonly called "the Water Cycle. This Hydrologic Cycle recycles the earth's valuable water supply.

The water keeps getting reused over and over. Just think, the next glass of water you drink could have been part of a dinosaur's bath in the Mesozoic Era one hundred million years ago. Water in that glass of water could have been a liquid, a solid, and a gas countless times over thanks to the water cycle.

The sun provides energy to power this process. It's energy in the form of light, and heat causes water to EVAPORATE from oceans, rivers, lakes and even puddles.

Warm air currents rising from the earth's surface lift this water vapor up into the atmosphere.

When the air currents reach the cooler layers of the atmosphere, the water vapor condenses around and clings on to fine particles in the air. This step is called CONDENSATION. When enough vapor attaches itself to tiny pieces of dust, pollen or pollutants, it forms a cloud. Clouds do not last forever. Old clouds constantly re-evaporate and new ones form, creating ever-changing patterns in the sky.

As the air gets more and more moist, the droplets that form the clouds grow larger and larger. Eventually they will get so big that the swirling atmospheric winds can no longer hold them up. The droplets then fall from the sky as PRECIPITATION. Precipitation can be in the form of rain, snow, sleet or hail depending on other atmospheric conditions such as temperature.

Once the precipitation reaches the ground, several things can happen to it.

Re-evaporation, as in the mist rising off hot roads after a summer shower.

Run-off that goes into streams and rivers.

INFILTRATION. Once in the ground, the water can join the earth's GROUNDWATER supply. This is one of the world's largest storehouses of water. The water could also be absorbed from the ground by the roots of plants.

TRANSPIRATION. Water given off through the pores of plants and animals joins the atmosphere as a vapor.

EVAPORATION, CONDENSATION, PRECIPITATION, RUN-OFF, INFILTRATION, and TRANSPIRATION. Each time a molecule of water goes through the cycle it is cleaned, or purified, so it can be used again.

Now look at slide 4-2. Look at the relative quantities of water storage. Compare the amount of water present in each area. Compare the amount of water stored in lakes to groundwater and the amount of water in the atmosphere.

 

 

Uses of Water in Industry

Here is a list of Industrial Water Uses.

  • Cooling                          Open and closed systems, heat exchanger, cooling towers
  • Energy production          hydropower, fuel cells, steam
  • Energy transfer               hydraulic systems, heat transfer via piping,
  • Feedstock                      medicine, pulp, food, cement, desalination plants
  • Fire Fighting                   fixed, foam, mobile
  • Food                             Cooking, freezing
  • Heating                          Primary as direct steam like in a radiator in a house, secondary would be heat exchanger in a process plant
  • Hydraulic                       jets ships steering in tight spaces, placer mining
  • Hydrocutting                  water and sand mixture used to cut metal, bricks, and concrete without making any sparks, heated water for cutting wax
  • Irrigation                        flood, sprinkler, and drip irrigation
  • Life Support                  Cruise ships, municipal systems
  • Materials processing      Facilitates mixing, floating, flocculation, wetting of grinding stones,
  • Solvent                          salt, used with detergent,
  • Salt production              in desert areas flood a saline soil and let it evaporate, desalination
  • Transportation               as in coal slurry, pulp slurry, in the case of copper mine waste slurry gold and silver are dissolved in the slurry and it is therefore subject                                      to further processing
  • Washing                        mining, equipment washing, papermaking machines are constantly washed for example some rollers are under a constant drip
  • Water Flood of oil field reservoirs

Process Water

Process water is that water used in the actual processing of materials to produce an end product. Two types of process water would be feedstock water and washing water.

Water as a feedstock

For example the addition of water to salty soil and its subsequent evaporation would be a process use of water.

Water is also used as a feedstock in the making of cement. Cement is a good example of the importance of some of waters properties. For example, the water must be clean and the correct temperature or the cement will be unacceptable.

Waters evaporative properties form the basis for some of these processes. The water is mixed with other feedstocks and then ultimately evaporated to form the final product.

One industry where water is used as a feedstock without evaporation is irrigation.

Boiler Feedwater

Water is also used as a feedstock in the operation of boilers which supply high pressure steam to turbines for the production of electricity. This boiler water must be treated continuously to make sure it is suitable to the purpose

Treatment prevents corrosion problems in boiler systems and improves energy efficiency, economics of operation and safety.

Corrosive reactions in boiler systems are affected by many parameters, such as oxygen content, water pH, temperature, pressure, water flow velocity and the formation of certain types of salts and scales.

A micro thin film of scale as small as .001" can cause large losses in heat transfer efficiency.

Boiler water treatment chemicals are designed to protect the boiler from corrosion, hardness scale deposits, oxygen induced corrosion, pH variations, etc.

Dissolved oxygen is handled by first mechanically removing most of the dissolved oxygen and then chemically scavenging the remainder. The mechanical degasification is typically carried out with vacuum degasifiers

Removal of the last traces of oxygen is accomplished by treating the water with a reducing agent that serves as an oxygen scavenger. Hydrazine and sulfite are often used for this purpose.

Water Quality

The water quality is crucial in many processes. Below is a list of some of the properties required.

  1.     It must be free of air
  2.     It must be free of dissolved substances such as chlorine or salts
  3.     It must be free of suspended solids. Turbidity of a fluid sample is a measure of how "clear" or "cloudy" the sample is, the degree of cloudiness being a     function of the concentration of suspended solids in the liquid.
  4.     It must be free of hydrocarbons
  5.     It must free of minerals
  6.     pH must be controlled to a specific value conducive to corrosion resistance. This does not necessarily mean a pH of 7.
  7.     Oxygen content should be low to prevent corrosion

Water Analysis

A major expense of industries that use water as a feedstock is storage, testing and transport.

Many types of electronic sensors are used on process water to detect unwanted conditions. These systems often apply a corrective chemical to the water to achieve the desired condition. Sampling systems require their own pumps, piping and controls. The application of corrective chemicals is usually done with a positive displacement pump because this is the easiest way to control the dose.

Here is a simple description of an analyzer for boiler water. See slide 4-3 for a photo of an analyzer rack. From the various tapping points in the boiler, the samples are piped to the analyzer "wet rack" for initial cooling, then de-pressurization and possible filtration. Steam samples are much better off when cooled quite close to the tapping point.

After filtration the sample is sent through the actual sensors which produce an electrical voltage equal to the value of the material being sampled for.

Basic Terms of Maintenance, Operations and System Components

  • Analyzer In industry an integrated system designed to determine the makeup of an industrial product such as feed or waste water. The analyzers output can be a simple indicator or a control output designed to add chemicals or energy to bring the water to a desired condition.
  • Anhydrous Refers to compounds having no water in their composition.
  • Aquifer A rock formation or basin containing water.
  • Artesian an aquifer or water bearing zone where the piezometric surface (pressure level) is above ground surface.
  • Biosphere That part of the Earth which contains living things.
  • Boiler device for generating steam.
  • Dissolved oxygen oxygen which is dissolved or merged into water. The presence of oxygen in water will enhance corrosion and cause the build up of boiler scale that inhibits heat transfer
  • Evaporate Drying out; also refers to the dry product.
  • Feedstock A primary input component of a process industry
  • Flocculation A chemical process involving addition of a coagulant to assist in the removal of turbidity in water
  • Hydraulic A system which uses a liquid as opposed to pneumatic which uses air or electric which uses electricity
  • Hydrocutter a device designed for cutting metal, stone and concrete constructions by a water jet with abrasive. Major parts include an abrasive container, a water source, a high pressure pump, a high-pressure hose and a nozzle (in a form of a gun).
  • Jet Device for spraying water, also the water spray itself.
  • Leaching A chemical process for the extraction of valuable minerals from ore; also, a natural process by which ground waters dissolve minerals, thus leaving the rock with a smaller proportion of some of the minerals than it contained originally.
  • Meteoric water Surface water that sinks into cracks and fissures. Oxide Any chemical combination with oxygen.
  • NTU A measure of water turbidity.Also known as National Turbidity Units
  • Oxidize To combine with oxygen.
  • pH pH is a unit of measure which describes the degree of acidity or alkalinity of a solution. It is measured on a scale of 0 to 14. The term pH is derived from "p", the mathematical symbol of the negative logarithm, and "H", the chemical symbol of Hydrogen. The formal definition of pH is the negative logarithm of the Hydrogen ion activity.
  • Scale Scale is the result when dissolved minerals and salts precipitate out of the water that they are dissolved in. The particles which come out of solution are the same ones that cause the water to be "HARD".
  • Solvent A substance in which another substance is dissolved, forming a solution. For example water is a solvent of oxygen
  • Turbidity a measure of how "clear" or "cloudy" the sample is, the degree of cloudiness being a function of the concentration of suspended solids in the liquid.
  • Water table The underground level at which the ground is saturated with water. The level at which water will stand in an excavation.

Task/Quiz

Go to the basic math link and study pages 20 thru 30. Lesson 4 Quiz will contain questions on this material.