Gas, Steam, and Water Chapter 6 (c) 2014 by John Wiley & Sons, Inc.

Gas, Steam, and Water

Chapter 6

(c) 2014 by John Wiley & Sons, Inc.

In this chapter, you will learn to:

Describe the uses of gas and steam in foodservice. Identify the basics of how gas and steam equipment

work. Identify energy-saving use and maintenance tips. Identify water quality problems and how to deal with

them. Identify the basic foodservice plumbing requirements. Identify the basics of installing and maintaining a

drainage system. Explain hot-water needs, and how water heaters work.

Learning Objectives


Understanding Energy Use

Terminology:

Air shutter adjusts primary air coming into burner

As the burners burn, the flames also use secondary air, the air around them

When air and gas are mixed, the speed at which the flame shoots through them is called the burning speed

You may encounter incomplete combustion, when the fuel doesn’t burn fully

Yellow flames create carbon soot, making cleanup harder and clogging orifices

The ideal is flame stability, a clear blue ring of flames with a firm center cone

Gas flows from the orifice in the form of a jet

The jet causes a rush of air (called primary air)

The primary air flows into the burner tube (sometimes called a mixer tube)


Types of Burners

Pipe BurnerThis is a pipe

(usually cast iron) with two or more

rows of ports drilled along its length. Found in ovens, griddles, broilers

Slotted BurnerA type of pipe

burner; pipe can be straight or circular.

Ports all aim in same direction to form a single large flame

Flame Retention

BurnerHighly efficient

slotted burner with additional ports

drilled into the pipe.

Ring BurnerWidely used on range

tops, steam tables, boilers. Standard has

1 or 2 rows of ports arranged in a circle. Made of cast iron;

comes in many sizes

Gas burners come in several shapes and sizes


Types of Burners

Radiant (Infrared) Burner

A set of porous ceramic plates with about 200 holes per square inch on its surface. Super-hot

and good for broilers.

Rangetop Power BurnerPremixes gas and air

in proportion to produce high heat

and efficiency.

Infrared Jet Impingement Burner

The IR jet premixes gas and air in separate

chamber. Flames impinge (hit hard) on

pan surface. Uses less gas than conventional

burners

Gas burners come in several shapes and sizes


Pilot Lights and Thermostats

New technology replaces gas pilot light with electronic spark ignition. Reduces gas consumption, as pilot is not continuously lit.

Standard gas pilot light, located near main burners of appliance, should be about ¾-inch high.

Pilot light safety feature: thermoelectric control. When a junction of two metal wires (the thermocouple) is heated by the pilot flame, a very low electric voltage is generated – just enough to fire an electromagnetic gas valve and hold it in an open position.


Pilot Lights and Thermostats

The thermostat is the control used on most gas-fired equipment to maintain the desired burner temperature Most common type is a knob or dial called a

throttling control or modulating control. Some types of cooking appliances, such as deep-fat

fryers, require quick heat recovery in less than 2 minutes. In these cases, a snap-action thermostat is used, which opens fully to permit maximum heating until the desired temperature is reached. Then, it shuts off just as quickly.


Maintaining Gas-Powered Equipment

Perform routine checks

Monthly Tasks

Weekly Tasks

When a new

piece is added

Clean burner parts and orifices; check

primary blower speeds; vacuum-

clean entire blower system.

Clean & adjust air

inputs/pilot lights;

calibrate thermostats; check burner

valves, balance exhaust,

make-up air

Professional test of main gas line to

ensure your hot line has

sufficient pressure

Routine checks and/or

maintenance weekly and

monthly. Document

what you’ve done


Steam Energy

Steam is water vapor. Steam molecules carry large quantities of heat, and they return to their original form (condense) when they come into contact with a cooler surface. The steam-jacketed kettle is a large "bowl within a bowl" used for

making sauces, soups, and stocks. Between the two bowls is an area about 2” wide into which steam is pumped, for high but uniform cooking temperatures.

A steamer is an oven-like appliance with an insulated door. Used for any cooking or thawing process that would benefit from adding moisture. Convection steamers contain a fan that circulates the warm,

moist air for quicker, more even cooking. Steam tables, often seen in cafeterias or on serving lines,

hold food above a reservoir of hot water to keep it warm Bain-marie is a hot-water bath in which a container of more

delicate foods (sauces, gravies) is immersed to stay warm.(c) 2014 by John Wiley & Sons, Inc.

Steam Energy

Steam systems and appliances work in one of three ways: Steam generators use electricity to heat water and make their

own steam. Small generators, called boilers, are located under or near the steam equipment.

Heat exchangers take steam already made from one source, circulate it through a series of coils to clean it, and use it to heat another source. Steam from a building's heating system could, for example, be captured by a heat exchanger and “recycled” to heat hot-water tanks.

Steam injectors shoot pressurized steam directly into an appliance to produce heat. This is the least efficient method, as a one-time use. Condensation is drained away, not reheated and reused.


Your Water Supply

Safe, plentiful water is often taken for granted in foodservice – which is ironic when you consider what a truly scarce resource it is.

Salt water makes up 97% of all water on

earth

More than ½ % of what remains

worldwide is diverted for human use

2% percent is inaccessible,

frozen in remote ice caps and

glaciers


Your Water Supply

EPA estimates that Americans use 100 gallons of water a day. EPA’s Water Alliances for Voluntary Efficiency program (WAVE) for hotels, restaurants, businesses began in 1990s, with water conservation goal of up to 30% Many water mains and pipes are more than 100 years old, long neglected, and reaching the end of their useful life

Desalination being explored as an option for increasing water supply:

Multistage flash distillation removes contaminants from seawater by boiling it, then condensing (distilling) the steam. In reverse osmosis (RO), highly pressurized seawater is pumped through a semi-permeable membrane that allows only the freshwater molecules to flow through.


Water Quality Factors

EPA implements drinking water safety standards, regulations through the Safe Drinking Water Act. Concerns include:

Arsenic occurs naturally in some groundwater and is also a residue of mining and industry. At low doses, linked to cancer and diabetes; at high doses, it is poisonous.

Pathogens are bacteria that can cause gastrointestinal illnesses: Escherichia coli (E. coli O157:H7), cryptosporidium, and Yersinia enterocolitica, etc. Farm waste runoff and sewage discharge can accidentally contaminate food or water systems.

MTBE is a fuel additive designed to reduce air pollution. When spilled or leaked from storage tanks, it can contaminate water and cause liver, digestive, and nervous system disorders.


Water Quality Factors

Perchlorate is used in making fireworks, weapons, and rocket fuel. It interferes with thyroid function in humans.

Trihalomethanes (THMs) are among the most common groundwater contaminants. They form when chlorine reacts with organic material such as fallen leaves. THMs may contribute to miscarriage risks and bladder cancer.

Ammonium perchlorate is an additive the National Aeronautics and Space Administration (NASA) and the Defense Department used for rocket fuel and munitions. For disposal, perchlorate often was dissolved in water and poured on the ground because defense officials did not consider low levels hazardous to humans.


Buying and Using Water

Water is purchased in much the same way as electricity. A meter measures the amount of water that enters the water system, either in cubic feet or in hundreds of gallons

Typical home water pressure is 50 to 100 psi. An upfeed system uses excess pressure to move water through a building’s pipes. Components of typical upfeed system are Water meter. The device that records water consumption Service pipe. Main supply line between meter and building. Fixture branch. A pipe that carries water to a single fixture. It can

be vertical or horizontal and carry hot or cold water. Riser. A vertical pipe that extends 20 or more feet, and carries

hot or cold water. Fixtures. Devices (faucets, toilets, sinks) through which water is

used.



Upfeed system components (continued):

Pipes. The tubes fitted together to provide system for water to travel through. They can be copper, brass, galvanized steel, or plastic. (Building codes determine what materials are acceptable for different uses.) Copper is most expensive, but considered easy and

economical to work on. Plastic pipes are allowed only for limited, special uses. The

most common is made of polyvinyl chloride (PVC). It is inexpensive, corrosion resistant, durable.

Fittings. The joints of the pipe system fit onto the ends of pipes, allowing them to make turns and to connect to each other and to appliances or fixtures.



Upfeed system components (continued):

Valves. Valves control water flow, and are made of brass, copper, or cast iron. Use of the correct valve minimizes plumbing problems. Gate valves are used to vary water flow and allow water to go in either direction. Check valves allow water to flow only one way. They are marked with an arrow indicating the direction of flow. Safety valves are spring-loaded, operated by temperature or water pressure, to relieve excess pressure if they sense a buildup.


Water Conservation

Turn off continuous flow feature of drain trays

New commercial dish machines are designed to work with water usage

well below 1 gallon per rack

Thaw food and presoak utensils in tubs or basins of water, not running

water

Boilerless steamers use least water of all steamer types

Adjust ice-making equipment to make and dispense less ice when

less is needed

Repair leaky toilets and faucets

Install aerators, spring-loaded valves, electronic sensors, or

timers on all faucets.

Replace worn-out fixtures with water-saving ones

Apply water conservation stickers on mirrors to remind

both employees and customers to turn off taps.

Kitchen & Service Areas Restrooms


The How & Why of Hard Water

Hard water is unavoidable in some areas, but causes scaling,

soap scum. It can discolor dishes, clog equipment or make

it run less efficiently.

Caused by calcium carbonate, a natural mineral suspended in tap water; it builds up in appliances that use water. It is annoying but

not a health risk.

Avoid scale buildup with regular maintenance. Get expert help if necessary to test and treat hard

water.


Basic Water Heating Guidelines

Hot-Water Heating

The average foodservice establishment uses roughly 5 gallons of hot water per guest. Less is needed in quick-service, with disposable utensils and

plastic ware To determine correct size of water heater needed, multiply the

five-gallons-per-guest average by the maximum number of guests you would serve at a peak mealtime

Water must, by health ordinance, reach certain temperatures for certain foodservice needs: restrooms (110-120 degrees F.); pot sinks (120-140 degrees F.); dish machines (140-160 degrees F.); final dish rinse (160 degrees F.)


Hot-Water Heating

Types of Water Heaters

Self-contained storage heater

Heats and holds water up to 180°F,

delivers on demand. Most common water

heater type.

Tankless water heater

Circulating tank water

heater

Heats water immediately, only on demand. No tank is

needed.

Heats water up to 180°F, passed

immediately to a separate tank

Heat pump water heater (HPWH)

Uses “waste heat” recovered from other

appliances to heat water.


Gas, Steam, and Water Chapter 6 (c) 2014 by John Wiley & Sons, Inc.

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Transcript of Gas, Steam, and Water Chapter 6 (c) 2014 by John Wiley & Sons, Inc.