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PE 4B > Unit 12 Typical Industrial Plant Configurations > Flashcards

Unit 12 Typical Industrial Plant Configurations Flashcards

1
Q

Steam is the principal energy transfer medium that industry depends on for its process applications. It provides energy for process

A

Heating, pressure control, mechanical drives, electrical generation and component separation

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2
Q

Advantages of steam

A

Low toxicity, transportability, high efficiency, high heat capacity and low acquisition and production costs

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3
Q

Most of the heat contained in Steam is in the form of

A

Latent heat

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4
Q

Heat transfer fluid systems (HTF) - hot oil

A

Industrial Systems were a special heat transfer fluid, not water, is circulated by a pump through a fired heat exchanger.

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5
Q

HTF systems may be preferred when the temperature is above

A

175°C

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6
Q

Steam is generated in a boiler by

A

Transferring thermal energy released in a heat generating process, into liquid water. The additional energy carried by the steam is transferred out of the steam by thermal or mechanical action

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7
Q

Generation

3 heat conversion mediums

A

HTF, Compressed Gas, Steam

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8
Q

The efficiency of distribution is affected by

A

Thermal insulation, piping and component separation Technologies

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9
Q

Steam accumulators

A

Allow the additional energy in excess steam to be discharged into a pressure vessel partially filled with water

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10
Q

During system startup, steam traps allow

A

Air in equipment and lines to escape

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11
Q

Examples of end use processes

A

Process heating, mechanical Drive, electrical generation, enabling chemical reactions, fractionation of hydrocarbon components

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12
Q

Two types of processes

A

Physical and chemical

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13
Q

Absorption process

A

Absorbing agents called molecular sieves, are used as a filtering medium. The medium separates on the basis of physical size of molecules being different

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14
Q

Crystallization process

A

A crystalline substance is separated from a non-crystalline one by cooling the solution, and separating the components via a separating process such as filtering or centrifugation.

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15
Q

Dilution

A

Steam is often used to dilute a process gas which can reduce solid buildup on heat exchangers

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16
Q

Distillation/fractionation

A

During distillation, usually in a fractionation tower, compounds are separated into fractions by differential boiling points.

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17
Q

Process of drying or evaporation

A

The vaporization and removal of water or other liquids from a solution

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18
Q

Process quenching

A

Used to cool and thus stop High temperature reaction processes

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19
Q

Solvent extraction

A

Separation process which separates substances by using differences in solubility between compound in complex mixtures

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20
Q

Stripping Towers

A

Steam pulls unwanted contaminants from a process fluid and directs them to waste or back into the process

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21
Q

Thermo-mechanical

A

Direct conversion of thermal energy into mechanical action, which occurs in the final stages in industrial plants

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22
Q

Thermo-mechanical pulping (TMP)

A

Direct conversion of mechanical action into thermal energy

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23
Q

Chemical conversion process

A

Converts one compound into another by chemical reaction. Involves chemical manipulation of molecular size or chemical structure

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24
Q

Molecular size reduction

A

Involves converting a surplus of unsaleable product with a large molecular size into a smaller one that is in demand

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25
Q

Chemical structure adjustment

A

Rearranges the chemical structure of a compound or mixture to create a different product, or to improve performance in the product.

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26
Q

A hot oil system is one that uses

A

Oil as a thermal fluid, in place of steam or water, to transfer heat from a central source to other areas of the plant. Consists of a heat source and piping to distribute the heated oil and return the cooled oil. Heat exchangers transfer the oils heat to other fluids and the pump to create and maintain required circulation

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27
Q

A hot oil system is very much like a hot water heating system, but the difference being that

A

The fluid chosen has a much higher boiling point than water and the Steam runs at a higher temperature. So, heat transfer fluids exhibit a much lower vapour pressure than Steam.

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28
Q

Heat transfer fluids, especially hot oils are widely used in

A

High temperature processes, where low pressures are preferred

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29
Q

HTF vapour is generative at higher temperatures but

A

Exhibits lower pressures

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30
Q

The Vapor phase heat transfer system has even and constant

A

Heating temperature and the temperature difference between Inlet and Outlet of heat can be controlled within a 1-2°C range.

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31
Q

Vapor systems can be used if higher temperatures and heat transfer rates are required but

A

They are generally more expensive and complex than liquid systems.

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32
Q

Heat transfer fluids will degrade over time in

A

Elevated temperatures and oxidized if in contact with atmospheric air.

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33
Q

Many heat transfer fluids have relatively High

A

Coefficient of thermal expansion

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34
Q

Heat transfer fluids are non corrosive, and any corrosion problems within the system are usually caused by

A

Contaminants such as cleaning fluids left in the system at startup or leakage of process fluid in the system

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35
Q

The operating range between efficient operation and the point at which degradation of the oil occurs

A

20-30°C difference

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36
Q

Although heat transfer fluids have high flash points, the system almost always operates

A

Above the flash point

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37
Q

Liquid thermal systems generally consists of

A

A pump, fired heater, and expansion tank to allow for expansion and contraction of hot oil as it heats up and cools down

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38
Q

Three classes of heaters used in HTF systems

A

Radiant, convection and a combination of the two

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39
Q

Radiant heaters

A

Combustion gases do not flow across tube surfaces. Heat is transferred from the burning fuel to the tubes by radiation from the furnace space. Low efficiency (40-50%)

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40
Q

Convection heaters

A

Combustion gases flow across the tubes, heat is then transferred by conduction through the tube to the hot oil flowing in the tubes. Higher efficiency (75-85%)

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41
Q

Combination radiant and convection heaters

A

Favoured due to their efficiency in larger unit

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42
Q

Updraft fired heater

A

Radiant and convection tube sections

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43
Q

When operating the expansion tank, the tank level should be between _______

The temperature in the tank should be less than _______ to prevent fluid oxidation

A

2/3 and 3/4

60°C

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44
Q

Two pumps are usually installed in a hot oil system;

A

One operating and the other on standby

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45
Q

In order to maintain the standby pump at operating temperature _______

A

The suction valve of the standby pump should be left open all the time to allow a small amount of oil to flow backwards through the pump.

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46
Q

Hot oil pump should be located

A

At a level below the expansion tank to provide necessary static head to avoid possible cavitation in the pump suction

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47
Q

Two pumps used for liquid thermal systems

A

Usually a centrifugal pump, but sometimes gear pumps are used

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48
Q

Petroleum refinery

A

Complex plant that contains several individual process plants. Each plant has a specific function

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49
Q

The overall goal of a refinery

A

The separation of hydrocarbon components in the crude oil and modification to maximize production of high demand products.

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50
Q

Gasoline boils within the range of

A

30 - 300°C

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51
Q

Examples of number 1 oils

A

Gasoline and kerosene

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52
Q

Distillate fuel oil

A

Distillable hydrocarbon liquid mixtures of lower volatility than kerosene. Number 2 oil

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53
Q

Residual fuel oil

A

The material remaining as an evaporated liquid from distillation or cracking processes. Used mainly as boiler fuel and ocean-going ships. Number 6 oil or bunker C

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54
Q

Aviation jet fuel

A

Blended grades of petroleum distillate suitable for use in jet engines. Have high stability, low freezing point and overall High volatility

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55
Q

Petro chemical feedstock

A

Refinery products having low molecular mass and high purity.

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56
Q

Examples of petrochemical feedstocks

A

Ethane, ethylene, propylene, acetylene, butane, butadiene, benzene

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57
Q

Crude petroleum

A

Mixture of hydrocarbon molecules of many different sizes and shapes.

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58
Q

The boiling point of hydrocarbons increase with

A

The number of carbon atoms

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59
Q

The first processing stage in a refinery separates fractions by

A

Boiling point ranges. Separates crude oil into fractions by increasing the boiling point. It is heated to vaporize it, and then the vapour is cooled gradually. As the vapour cools, heavier molecules condense first and are removed. Usually done in fractionating or distillation Towers.

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60
Q

The second stage in the refining process

A

Convert separated fractions into various product streams. Involves additional separation and processes that alter the molecular structure, like Hydrotreating, cracking, forming and alkylation

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61
Q

Once the products are formed,

A

They are further processed to remove undesirable contaminants like sulphur and carbon dioxide. Raw products are then Blended and additives are introduced to produce desired products.

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62
Q

Before entering the separation and chemical reaction processes, crude oil must first be

A

Heated. Initially with a heat exchanger, then a furnace.

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63
Q

After heating, the crude oil enters the

A

Distillation column. The crude separates into liquid and Vapor. Vapor Rises up the column, up the trays, as it bubbles through the barrier “bubble cap”. The liquid filled up the tray and flows into a secondary distillation column “stripper column”.

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64
Q

Stripper column

A

Injects the steam into the fraction to extract Vapor which travels with the stripping steam back into the main column.

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65
Q

Lighter hydrocarbons, which are recovered of the lowest temperatures;

A

Butane and liquid petroleum gases, gasoline blending components, naphtha

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66
Q

Mid temperature range products

A

Jet fuel, kerosene and distillates

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67
Q

Heaviest products

A

Residual fuel oil, recovered at temperatures sometimes over 530°C

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68
Q

Additional stages of processing

A

Hydrotreating, reforming, catalytic cracking and alkylation

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69
Q

Three groups of petrochemical feedstocks

A

Olefins, aromatics, synthesis gas (syngas)

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70
Q

Olefins

A

Doubly bonded carbons. Includes; ethylene, propylene and butadiene. Produced in the cracking process assisted by Steam

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71
Q

Aromatics

A

Includes benzene, Toluene, xylenes. Produced in the reforming process

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72
Q

Synthesis gas (syngas)

A

Mixture of CO and H2. Produced in lean combustion or steam reforming.

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73
Q

Steam generation Powers much of the refinery, so it is generally

A

The first system to start up and the last to shut down.

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74
Q

Most plants operate at least three distinct steam systems;

A

High pressure, medium pressure and low pressure. Systems are interconnected through let down, or pressure reducing stations, which exhaust the high pressure system to the medium system and the medium pressure system to the low pressure system.

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75
Q

High pressure steam system range

Low pressure steam system range

A

4130 - 10 340 Kpa

103 - 415 Kpa

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76
Q

Stripping Steam

A

Steam is injected into sidestream stripping columns to facilitate the movement of light products up the column. Injected steam carries the lighter hydrocarbons out of the stripper column and back into the main fractionating tower.

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77
Q

The most common method of heat tracing flow lines, valves, metres and Recorders is to use

A

Steam

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78
Q

Steam stations

A

Used in Refinery units, so technicians can hook up a steam hose to thaw frozen equipment and lines

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79
Q

Purging equipment with steam

A

Effective method of preparing a Refinery hydrocarbon unit for turn around. Cleans equipment and Towers in preparation for vessel entry.

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80
Q

Canada’s oil sands produce a heavy oil typically referred to as

A

Bitumen. The upgrading process for this oil converts bitumen into a high-quality, Light, low sulphur crude oil.

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81
Q

Bitumen diluted with naptha cut as a mixture is called

A

Dilbit

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82
Q

The first step in the upgrading process of dilbit is to remove

A

The naturally occurring light gas oil component and to recover the diluent naphtha. This is done in the diluent recovery units

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83
Q

Light gas oil stream is sent to

A

Hydro treaters, the diluent naphtha is recycled to the extraction plant and the bottoms of the atmospheric topped bitumen is fed to the vacuum distillation unit with a large amount going directly into the conversion units. The unit removes all remaining light and heavy gas oils, directing the streams to the hydrotreaters.

84
Q

After distillation of naphtha, light gas oil, and heavy gas, oil streams are sent to

A

Their own hydrotreater to remove sulphur and nitrogen by adding hydrogen. The resulting products from each of the separate Hydrotreaters are then combined to produce synthetic crude oil.

85
Q

The residue stream from the atmospheric distillation Tower is further separated into two streams

A

Heavy vacuum gas oil and vacuum residue.

86
Q

The heavy vacuum gas oil is mixed with

A

The heavy gas oil from the atmospheric distillation Tower to undergo hydrotreating.

87
Q

The vacuum residue is

A

Further upgraded either in a hydro converter by adding hydrogen or in a Coker to produce lighter liquid product and by-product Coke.

88
Q

The lighter liquid product from the hydro converter or Coker

A

Further separated into naphtha, light gas oil, and heavy gas oil by distillation. The final products from the upgrading facility are synthetic crude oils and Coke

89
Q

Fluid cokers.

A

Thermal conversion units that crack long-chain bitumen molecules into more valuable short-chain molecules - heavy gas oil, light gas oil, and naphtha.

90
Q

Hydrotreater units

A

Operate at high pressure to treat the product and remove sulphur, nitrogen, and other impurities.

91
Q

Bitumen is found in

A

Geological formations mixed with sand, called oil sands. Bitumen is so heavy and viscous that it will not flow without first being heated.

92
Q

Two common methods of extracting and descending heavy crude bitumen

A

Steam assisted gravity drainage (SAGD) and cyclic steam stimulation (CSS)

93
Q

When the bitumen is found too deep for the economical application of surface mining,

A

SAGD and CSS are used

94
Q

SAGD and CSS work by

A

Reducing the viscosity of the bitumen, so it can flow to the surface.

95
Q

SAGD

Because once through steam generators (OTSG) generate wet Steam,

A

Separators are installed in the steam lines to dry the steam to nearly 100% dry and saturated. The saturated steam is piped to a number of wellheads through injection Wells. Vertical section of underground piping maybe around 500m in length

96
Q

SAGD

Once in the oil sands formation, the injection well piping continues

A

For another 700 to 1000m. Horizontal piping is slotted along its length, to distribute steam evenly.

97
Q

SAGD

When the injected steam condenses,

A

It gives off its latent heat to the surrounding bitumen. The high temperature steam reduces the bitumen viscosity, allowing it to flow. The steam mixes with the bitumen to form an emulsion, which is extracted through Wells drilled adjacent to, and about 5m below, the injection wells. (Producer wells)

98
Q

Emulsion

A

Mixture of oil, water, and gas

99
Q

CSS and SAGD

Similarities and differences

A

Both use OTSG to supply high temperature, high pressure steam for injection into oil sand formations. Both heat the bitumen to allow it to flow to the surface.

SAGD is a continuous recovery process, whereas CSS takes place in the stages or Cycles

100
Q

CSS

first stage (injection stage)

A

High pressure and temperature wet steam, around 320°C, is injected into vertical wellbores

101
Q

CSS

second stage (soaking stage)

A

Steam is allowed to soak through the oil sands, melting the bitumen

102
Q

CSS

Production stage

A

Steam is shut off and the resulting bitumen and water emulsion is brought to the surface through the same wellbore

103
Q

CSS

The cycle is repeated

A

Many times, upwards of 15 Cycles on each well, until the reservoir bitumen is depleted. Each cycle of this process can take from 4 months to two years

104
Q

CSS is not used for

A

Shallow reservoirs, because they do not have a thick shale cap which is needed to contain the high injected steam pressure.

105
Q

CSS is superior to SAGD at extracting bitumen when ________

A

Oil sand reservoirs are deeper

106
Q

In both SAGD and CSS, the emulsion returning from the producer Wellhead contains

A

Water, bitumen, and sand.

107
Q

Oil dewatering

Emulsion returning from the Wellhead

A

May be around 160-170°C. Some of the heat is used to preheat boiler feed water, using heat exchangers. Emulsion is now cooled to 115°C and enters a knockout vessel, in the first step to the emulsion separation.

108
Q

Oil dewatering

Knockout vessel

A

Separates the free water from the remaining bitumen and emulsion, with a special demulsifier chemical.

109
Q

Oil dewatering

The bitumen that leaves the knockout vessel

A

Is diluted and less viscous, by adding diluent. After dilution, the bitumen is called dilbit.

110
Q

Oil dewatering

Dilbit

A

Flows to a Treater vessel, where electrostatic grids help remove water. Final sales dilbit has less than 0.5% water and relative density of 0.95. Stored in large tanks, pumps then transport the sales dilbit to an upgrader facility through a pipeline

111
Q

Water de-oiling

Produced water

A

Water that leaves the free water knockout vessel and combines with the water from the treater vessel

112
Q

Water de-oiling

Produced water flows to

A

Large settling tanks (skim tanks), where Oil floats to the surface and is recaptured. The produced water then flows to a induced gas flotation (IGF) vessel. Natural gas is blown through the produced water, forming an oil froth and further cleaning the water.

113
Q

Water de-oiling

The last step

A

Uses oil removal filters (ORF’s), which are filled with Walnut shells and naturally attract oil. Water leaving the ORF’s contains less than 25ppm oil

114
Q

De-oiled produced water

A

Contains dissolved scale forming compounds, like bicarbonate and silica. These impurities must be removed.

115
Q

The de-oiled produced water is softened using

A

Hot or warm lime precipitation softener. Soda Ash will be added if the permanent hardness is present in the influent

116
Q

The softener effluent is filtered and then further softened by

A

Ion exchangers. Typically, weak acid cation exchangers (WAC) are used opposed to Strong acid cation exchangers (SAC).

117
Q

WAC are more efficient ion exchangers than

A

SAC. Also cost less to regenerate.

118
Q

Both WAC and SAC

A

convert hardness to highly soluble sodium compounds, which will not precipitate as scale in boilers.

Results in 0 ppm hardness and less than 50ppm dissolved silica.

119
Q

SOR

A

Steam to oil ratio. Barrels of steam consumed per barrel of oil produced. Ranges from 1.5 to 3. If SOR becomes too high, the plant is uneconomical.

120
Q

Predominant constituent of natural gas

A

Methane, with 95% volume.

121
Q

The production gas from Wells passes through

6

A

Compression, separation, absorption, dehydration, stabilization, and recompression

122
Q

Absorption

A

The process where the hydrogen sulfide and carbon dioxide, acid gases, are absorbed by a solution of amine

Often monoethanolamine (MEA)

123
Q

Dehydration

A

Additional absorption process that removes water through contact with a glycol mixture

124
Q

Stabilization

A

Involves the flashing off of gases removed in the separation processes at low pressure from the liquid hydrocarbons.

125
Q

Recompression is needed to

A

Increase the pressure of the gases from the stabilization process to a pressure suitable for sales gas or for the plant boiler fuel gas.

126
Q

Cryogenic removal process

A

Uses an expansion turbine (turboexpander). Gas stream flows through an expansion valve, lowering its pressure. The lowered pressure causes the gas to expand and cool to below the dew point for the gas to be removed.

127
Q

Cryogenic removal is most often used when

A

CO2 concentrations are high (50%). Mechanical energy from the gas expansion is converted to electrical energy in an attached generator

128
Q

Sulfur removal using the Claus process

A

Requires a rich H2S gas stream. Burns 1/3 of the H2S in a furnace to produce SO2. SO2 reacts with remaining H2S in a catalytic process to produce water and Elemental sulphur. Recovers 95 to 97% of the sulfur

129
Q

Gas treating

Dehydration

A

Uses glycol based absorption units

130
Q

Gas treating

Hydrocarbon recovery

A

Uses a cryogenic turbo expander followed by a fractionating process. Leads the cooled liquids through separate distillation columns

131
Q

Gas treating

Nitrogen

A

Removed by cryogenic distillation

132
Q

Gas treating

Helium

A

Removed similar to nitrogen removal

133
Q

Liquefaction of natural gas produces

A

A liquefied natural gas (LNG). typically 90% methane.

134
Q

Sawn Timber that is not sold when newly cut, is required to be

A

Air or kiln-dried to prevent deformation of the wood through uneven natural drying

135
Q

Drying and lowering the moisture of wood

A

Increases the woods value due to its Dimensions becoming stabilized, it’s increased strength, and mass lowered. Reducing Transportation costs

136
Q

Air drying

A

Stacking the sawn Timber in piles in the open or under open sheds, exposed to a good flow of air

137
Q

Kiln drying

A

Accelerates the drying process and permits greater temperature and humidity control. Can be completed within one week to one month

138
Q

2 most common kilns

A

Batch and Progressive type

139
Q

Kiln drying of sawn Timber accounts ___ of the total energy consumed in the sawmilling process

A

70-90%

140
Q

2 types of kiln configurations to deliver Heat

A

Indirect heated Kilns and direct heated Kilns

141
Q

Indirect heated Kilns

A

The most common.

142
Q

Pelletizing

A

Compresses biomass (sawdust), into a pellet which can then be used as a solid fuel.

143
Q

Plywood

A

Flat panel built of sheets of veneer, fused together by a bonding agent under heat and pressure to create a panel

144
Q

Medium density fiberboard (MDF) has replaced particle board for a number of reasons;
3

A

Improved Machining and mechanical characteristics, smoother appearance, smaller particles

145
Q

A pulp Mill is normally used to

A

Reduce wood to pulp fibre for the production of paper or other products

146
Q

Pulp

A

The cellulosic material used for commercial purposes

147
Q

Wood is composed of

A

50% cellulose and 30% lignin, as well as sugars and organic compounds

148
Q

Pulp may be prepared from wood by _______ or ________

A

A Mechanical or chemical process

149
Q

Pulp mechanical process

A

Wood is shredded with a grinder made from sandstone, or stone made of blocks of silicon carbide. Cheapest method, less equipment is needed compared to chemical processing.

150
Q

Pulp chemical process

A

Freeze the cellulose material in the wood by treating it with reagents which dissolve the lignin. Lignin interferes with bonding in the cellulose fibres needed for increased strength in paper

151
Q

Pulp chemical process advantages

A

Resulting product is more refined and has greater strength than ground would.

152
Q

Pulp Chemical processes use

A

Sulfite and sulfate

153
Q

Sulfate process can

A

Pulp any kind of wood

154
Q

Digester

A

Filled with chips and cooking liquor (white liquor). Mixture of sodium sulfide and sodium hydroxide. Heated with steam to 175°C for 6 hours

155
Q

Black liquor

A

The liquid leaving the digester and blow tank after the cooking operation is finished. Must be put through a recovery process to restore its properties before reuse in the digester

156
Q

Green liquor colour is a result of

A

Iron impurities

157
Q

High pressure steam is mainly used to

A

Power turbines

158
Q

Medium pressure steam is used in

A

The process to heat, cook, and mix Liquors and stock

159
Q

Low pressure steam used for

A

Heating and process applications

160
Q

Thermal water/Steam cycle in a pulp mill

A

Generation - steam turbogenerators, wood waste boilers, recovery boilers

Distribution - condensing turbines, pressure reducing stations

End-use process - Dryers, digesters, evaporators

Recovery-reuse - condensers

161
Q

Common combustion method with firing black liquor

A

Black liquor is fired on a vertically inclined trajectory, so the black liquor dries and starts to combust in suspension, prior to falling and accumulating in the furnace. The burning pile of fuel is called char bed

162
Q

2 preventable causes of black liquor recovery furnace explosions

A

Fuel explosions and smelt water explosions

163
Q

___________ increases the efficiency of the overall operation of a sawmill

A

Adding cogeneration facilities to convert extra waste into electricity for sale to utilities

164
Q

The largest volume of non-coal solid-fuel is

A

Wood or wood waste and bark from the paper or Lumber industry

165
Q

Hog fuel contains ____ moisture

A

45-55%

166
Q

Four ways wood waste is burned in a furnace

A

Dutch ovens, Cyclone furnaces, boilers with underfeed Stoker’s, fluidized bed combustors

167
Q

Gasification

A

Partial combustion of the biomass in a low-oxygen environment, leading to the release of a gaseous product, called producer gas or syngas, which has CO as a major constituent

168
Q

Pyrolysis

A

Partial combustion is stopped at a lower temperature (450-600°C), resulting in the creation of a liquid Bio-Oil, as well as a gaseous and solid product

169
Q

Anaerobic digestion or biomethanization

A

Process which takes place in most biological material that is decomposing and is favoured by warm, wet and airless conditions. The resulting gas, which is mostly methane and carbon dioxide, is known as biogas

170
Q

Equipment used with steam in the production of sugar

A

Boilers, evaporators, clarifiers, crystallizer, and steam turbine/generator

171
Q

Co-firing

A

Process of adding a percentage of biomass to the fuel mix in a solid fuel fired power plant

172
Q

Co-firing process is typically used to reduce

A

The potential environmental impacts associated with the combustion of fossil fuels. Works best with a large Coal Fueled utilities, that have Material Handling capabilities on site

173
Q

Three possible setups for co-firing

A

Direct, indirect and parallel

174
Q

Direct co-firing

A

Biomass and coal are fed into a boiler with shared or separate burners

175
Q

Indirect co-firing

A

Solid biomass is converted into a fuel gas, burned together with Coal

176
Q

Parallel co-firing

A

Biomass burned in a separate boiler and steam is supplied to the coal fired power plant

177
Q

Advantage of biomass co-firing

A

electric efficiency is higher than dedicated biomass combustion plants

178
Q

Ambient temperature food processing

A

Prepares freshly harvested or slaughtered food for;

Processing, altering size, mixing ingredients, separating components

179
Q

Elevated temperature food processing

A

Converts raw materials, plant or animal based, into edible and inedible components using steam or hot water

180
Q

Reduced temperature food processing (preservation)

A

Involves methods to prolong the safe storage time frame of food

181
Q

The initial stage of ambient temperature processing is

A

Surface treatment. Involves cleaning, sorting, grading and peeling if the surface requires removal

182
Q

Culinary Steam

A

Steam used for direct injection into products

183
Q

Reducing the temperature of food slows the

A

Biochemical and microbiological changes that would otherwise take place during storage

184
Q

By bringing the internal temperature to _____ most foods have both an increased shelf life and increased perception of freshness

A

8°C and -1°C

185
Q

Freezing

A

When the product is reduced below its freezing point and a portion of the water undergoes a change in state to form ice crystals

186
Q

As food is Frozen,

A

Ice crystals form within its Matrix. At lower temperatures, the unfrozen material becomes more concentrated and forms a glass, which encompasses the ice crystals, preventing growth

187
Q

Equipment used for chilling and freezing

A

Mechanical refrigerators, Heat exchangers, cryogenic systems

188
Q

Cryogenic chillers and freezers

A

Use solid and liquid carbon dioxide, or liquid nitrogen, as a chilling medium placed in the chilling chamber

189
Q

Minerals

A

Metals in their natural state combined with Rock and other nonmetallic components of the Earth

190
Q

Native ores

A

Contain Metals in the freeform

191
Q

Sulfide and arsenide ores

A

Contain Metals in combination with sulphur or arsenic

192
Q

Oxide ores

A

Contain Metals combined with oxygen or oxygen based salts, such as carbonates or nitrates

193
Q

Carbonate ores

A

Contain Metals in contact with the carbonate ion

194
Q

The first step in all metallurgical processing is

The second step is

A

Mining The Ore

Preparing the raw materials for metal extraction. Focuses on concentrating or enriching the ore to remove non-metallic elements

195
Q

Crushing

A

Reduces Rock size to smaller pieces

196
Q

Hydraulic washing

A

Form of classifier which separates components of the mineral ore

197
Q

Froth flotation

A

Common in the concentration of metallic sulfides. Separates based on differences in surface properties

198
Q

Magnetic separation

A

Separate magnetic ores from the non-magnetic ores with an electromagnet

199
Q

Ore leaching

A

Chemical reaction which washes the ore with a solvent solution to dissolve the metal

200
Q

Metal ores are the most abundant in their __________ forms

A

Oxide, sulfide, and carbonate

201
Q

Two methods for converting concentrated ores into their oxide forms

A

Calcination and roasting

202
Q

Calcination

A

Heats the concentrated ore in an oxygen depleted atmosphere at a temperature below the melting point of the ore. Used for carbonates and hydrates

203
Q

Roasting

A

Heats the concentrated ore in the presence of excess air and other metals. Used for sulfide ores

204
Q

Smelting

A

Involves heating The Ore with a reducing agent

205
Q

Electrolysis

A

Electric current is passed through the molten oxide or chloride of the metal. Pure metal is deposited at the cathode

206
Q

The conversion of iron oxide to iron is the most

A

Significant reaction in metal processing

PE 4B (8 decks)

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