dishwashing and waste disposal chapter 16 (c) 2014 by john wiley & sons, inc

Dishwashing and Waste Disposal

Chapter 16

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

Dishwashing is the process by which dishes, glasses, flatware, and so on are cleaned by using a combination of three things:

Hot water – Sufficient amounts of water, at hot enough temperatures to sanitize. Water amounts, temperatures and lengths of wash and rinse cycles specified by NSF International.

Detergent – Sufficient wetting action to soften water, penetrate food particles and loosen them from dish surfaces.

Motion – Necessary to cover all dish surfaces, with sufficient water volume and velocity to wash and rinse items fully.

Introduction to Dishwashing


In this chapter, you will learn to: Describe sizes, types, and ratings of

dishwashers, and how to evaluate their features. Explain the purpose and functions of booster

heaters. Explain the steps for safely cleaning glassware,

plateware, and flatware. Identify the functions of food disposals and

waste pulpers. Identify the functions and features of specialty

washers.

Learning Objectives


Overall dish volume – What and how much will you be washing? Individual job functions – How and how often are dishes handled before

reaching the dish machine? How much heavy lifting is required? Working conditions – Can you improve on the noise, exposure to heat,

humidity, and chemicals in a typical dish room? Peak hours – A speedy, well organized dish room means you’ll need to

stock less inventory of plates, glasses, etc. Role of guests – Will they clear their own tables? Use a conveyor belt to

send cafeteria trays to the kitchen? Equipment service records – Sure signs the system needs a closer look:

Continued dish machine maintenance problems, breakage, overall inefficiency.

Choosing a Dishwashing System

Analyze warewashing functions for speed and potential cost-savings


Choosing a Dishwashing System5

Getting ‘em clean while controlling costs…

1. Maximize use of sanitation personnel in kitchen.

2. Detergent is expensive! Control its use by prescraping or prewashing.

3. Use enough water, and enough energy to heat it, without wasting either.

4. Run only fully loaded dish racks through the washer.

5. Use proper wetting agent, which promotes faster rinsing, drying and prevents spotting.

6. Laying out dish room efficiently helps reduce breakage.


Design the system with productive workflow, safety, and sanitation in mind

A Dish Room Layout


© J

ohn

Wile

y &

Son

s, I

nc.

High-Temp or Low-Temp?

The low-temp dishwasher washes and rinses at 140ºF, using chemicals instead of super-hot water for sufficient sanitizing. Separate chlorine dispenser for sanitizing function is

installed nearby (on wall or undercounter). The high-temp dishwasher washes at 140º F, rinses at

180º F. Must be installed under a ventilation hood. Rinse water is heated that extra 40º by a booster heater, built in or separate unit.

Many dish machines are field convertible. They can be changed from high-temp to low-temp (or vice versa) with manufacturer’s instructions.

These temperature differences are key


High-Temp or Low-Temp?

HIGH TEMP LOW TEMP

Requires more space: Under ventilation hood, possible separate booster heater

Reduced ventilation requirements; no need to install under hood

Better for items that react to chemicals (made of pewter, aluminum, silver)

Chemicals save money on energy for heating water

Faster drying time Works well for glassware, coffee mugs

Works well for dissolving proteins, food residue

A few dish machine comparisons…


Detergent Use

Cost, environmental concerns drive detergent selection Phosphate-free dish detergents are better for the

environment – but some are convinced they don’t work as well. High phosphate levels in lakes, streams cause excessive

algae growth. Some states don’t allow them in detergents. Check labels for eco-friendly attributes: Are ingredients toxic?

Biodegradable? Fragrance-free? Is packaging minimal and recyclable?

Do not exceed manufacturers’ recommendations for detergent amounts, sanitizing chemicals per load. Too much leaves residue Too little doesn’t clean well enough


Dishwasher Sizes and Ratings

Dish volume – Decide whether you’ll have enough dirty dishes to require mechanical dishwashing. It can always be done by hand.

Available space – Is there room to store dirty dishes and wash them periodically, all at once? Larger machines are run less frequently than smaller ones – but what fits in your dish room?

Do you really need a dish machine?


Types of Dishwashers

Undercounter A small but highly efficient unit that fits on or under a countertop.

Can also fit beneath a dish table with sink for prerinsing.

Some are freestanding.

Uses 3 to 5 gallons of water per wash cycle; each cycle is less than 2:30 in length.

Low-temp or high-temp models available; runs on electricity.


Courtesy of Champion Industries, Huntington, West Virginia.

A variation of the undercounter dish machine. Washes with tap water; final rinse with sanitized water.

Quick-drying option heats water to 212ºF.

Cycle takes about 20 minutes; uses 3 gallons of water.

Conveyor models can clean up to 1000 glasses per hour.


Glasswasher


Co

urte

sy o

f Cha

mpi

on In

dust

ries,

Hun

ting

ton,

Wes

t Vir

gini

a.

Single-Tank Door Style or Stationary Rack

Most widely used model. Efficient and easy to operate.

Washes 35 to 80 dish racks per hour.

Freestanding; often installed with dish tables on either side.

Uses 1.2 gallons of water per wash cycle.

Must be positioned under an exhaust canopy.



Co

urte

sy o

f Cha

mpi

on In

dust

ries,

Hun

ting

ton,

Wes

t Vir

gini

a.


Rack conveyors – Single tank (125-200 racks per hour) and double-tank (250-300 racks per hour)

Water may be heated by electricity, gas or steam People can load/unload; optional automatic features

can help minimize labor costs

Moving Dishwashers


© J

ohn

Wile

y &

So

ns, I

nc.

More Options for Conveyor Machines

Side loader – Saves space in corner installations. Curved unloader – Pushes clean racks off conveyor. Condenser – Dries moist air exhausted from dish

machine. In some cases, may replace need for exhaust hood. Increases height requirements.

Blower-dryer – Electric or steam-heated blower dries dishes faster, but increases length and height of unit and adds exhaust requirements.

Cowls – Add ventilation capability at each end of dish machine, but also add length.



Circular Dishwashers

Exterior portion of conveyor is curved, minimizing need for employees at both ends of the machine.

Three “types” based on rack capacity per hour: Type 1 (180 racks); Type 2 (387 racks); Type 3 (480 racks).

Requires use of curved dish tables in some spots. Depending on size, has 1, 2 or 3 water tanks.


Co

urte

sy o

f Cha

mpi

on In

dust

ries,

Hun

ting

ton,

Wes

t Vir

gini

a.


Flight-Type Conveyor Dishwashers Also called rackless conveyors or belt conveyors. A large, long dish machine for use in settings of 600 to 800

meals per hour. Moving conveyor has plastic-tipped pegs to hold dishes.

Special racks for glassware, flatware fit onto pegs. Manufacturers offer a variety of water- and energy-saving

options.


© J

oh

n W

iley

& S

on

s, I

nc.

Booster Heaters

Most dish machines today have built-in booster heaters. Separate unit can be standalone or installed undercounter. This small water tank raises final rinse cycle water

temperature to 180ºF for sanitizing. Energy use depends on amount and temperature of

incoming water supply. Gas and electric models available – select yours depending

on local utility costs. Newest models use infrared heating. Steam-heated boosters are found in large facilities where

steam is created for other reasons. Even the largest booster heater will pay for itself within a

few years through utility cost savings.


Dishwasher Maintenance

Don’t program shorter cycles or use less detergent or sanitizing chemicals to try to save money.

Leave dish machines door open when not in use. On machines with curtains, clean and hang them up to dry at end of day.

Dish machines have same mineral buildup problems as other equipment that uses water. Remove mineral scales regularly.

Remove and inspect spray nozzles to clear clogs. Clear scrap screens daily. Inspect water lines, water pump shafts for leaks. Check water temperatures, water pressure.


Care and Cleaning of Dishes

Keeping glassware breakage to a minimum: Don’t use glasses still hot from being washed. Place dirty glasses directly into dish racks; don’t stack them

elsewhere. Use flatware baskets in bus tubs; don’t stack flatware in glasses. Don’t scoop ice out of an ice bin with a glass. Use the scoop! Instruct servers not to pick up multiple glasses at a time in one hand.

Protecting plateware: Store plates level with or below the plating area. When workers have

to reach up, more dishes get dropped. Don’t use one dish to scrape food off another. Pre-rinsing dishes in very hot water can cause stains, discoloration. Teach servers not to overload trays, bus tubs. Air-dry plates when possible. Don’t stack plates more than 12" high; cover if stored for more than

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

Care and Cleaning of Dishes

Keeping flatware looking good:

Presoak (no more than 30 minutes) before sending into dish machine.

Makes it easier to remove food particles in wash cycle. Minimizes contact with acidic foods that can corrode.

Don’t use steel wool or scouring pads on flatware. Pack loosely into flatware baskets. Consider a flatware washer, which cleans and sanitizes in 90

seconds. Keep flatware out of garbage disposal and trash cans. Wetting agent in rinse cycle will help minimize spotting; in hard-

water areas, a water softener may also be needed. Consider use of a cutlery polisher or, for silver plate, a

burnisher to maintain shiny finish and remove spots.


Waste Disposal Options

A pot sink A (low-flow) spray nozzle or faucet with flexible hose A food waste disposer – if your city allows it

Continuous feed shreds waste whenever it is turned on Batch feed handles a specific amount at a time Sized by horsepower or number of meals served Rotor size is as important as horsepower Automatic reversal function is handy in case of jams Read the instructions to prevent serious (and preventable)

accidents Scrap basket and/or vinyl guard is important for sink drain;

prevents bones, jewelry, flatware from ending up in disposer

The Pre-Rinse Station


Waste Disposal Options

Waste pulper is preferred alternative to food disposer when building is on septic tank instead of sewer system

Also used in addition to disposers in busy kitchens Paper, Styrofoam, plastic, aluminum foil – it shreds them all. Uses much less water than disposals Chops solid waste into a slurry, then squeezes out the water to

reduce waste to 15% of its original size Can be composted if incoming waste was completely

biodegradable Deodorant, sanitizers can be added to reduce odor Downsides: Machines are expensive, noisy; pulping reduces

size of waste but not its weight. Some items (glass, cloth, etc.) can’t be pulped.

Scrap collector is a perforated pot that sits in sink, straining scraps as water circulates through it. Uses only 2 gallons of water per hour.

Waste Pulpers and Collectors


Washing Pots and Pans

Mechanical pot/pan washer – similar to dish machine but adapted for large pots and pans, sheet pans, etc.

Can save up to 75% on labor costs and 50% on detergent and water.

Takes 4 to 15 minutes per cycle Undercounter models available to save space Requires scrapping area for pre-rinsing and scraping,

and sufficient landing space Power sink – Three-compartment sink with built-in water

heater, water circulation, and high-pressure spray capability Water jets or whirlpool-style circulation options Some units can retrofit onto regular pot sink Requires presoak, rinsing area and sanitizing sink


dishwashing and waste disposal chapter 16 (c) 2014 by john wiley & sons, inc

Documents