SIZING AND PLANNING A LAUNDRY Pellerin Milnor Corporation P.O. Box 400, Kenner, LA 70063-400 U.S.A. phone: 504.467.9591 fax: 504.468.3094 www.milnor.com B22SL94011/18323 1 SIZING AND PLANNING A LAUNDRY TABLE OF CONTENTS SECTION 1 BASIC INFORMATION Machine nomenclature Cylinder volume Load factor "G" forces "G" forces Moisture retention Water pressure Estimated peak water flow rates Proper piping size Conversion factors Water hardness How to size a water softener Sizing drain troughs Fuel-Unit of measure Natural gas Calculating natural gas required to heat water Sizing a water heater LP gas Butane No. 2 (diesel) oil No. 6 (bunker) oil Boiler horsepower Steam pressure Sizing a boiler Electricity Motor full load currents charts Electricity Linen cart capacity chart 2 SECTION 2 SPACE ALLOCATION Laundry space allocation SECTION 3 LINEN ARTICLES WEIGHTS Typical linen items and weights Weight of textile rental items SECTION 4 LAUNDRY TASK INFORMATION FORMS Hotel/Motel Prison Nursing Home Hospital XXXXX SECTION 5 SIZING WASHROOM EQUIPMENT Guidelines for sizing wash room equipment Defining the task Hotel/Motel Nursing Home Nursing Home Hospital Prison Prison Division of work Sizing washroom equipment 1-Washer-Extractors 2-Batch washers 3-Automatic batch dryer sizing SECTION 6 FUNDAMENTAL WASH CHEMISTRY Water Washing chemicals Surfactants Alkalies Bleaches Finishing chemicals Antichlor Sours 3 SECTION 6 FUNDAMENTAL WASH CHEMISTRY Fabric softeners Sizing Wash steps Flushes Break Bleach suds Rinsing Temperature Number of rinse baths Dilution Antichlors Sour baths Extraction SECTION 7 CONVERSION TABLES Tables SECTION 8 WATER CHARTS Data Sheets by Model Number SECTION 9 TERMINOLOGY Glossary of textile items used by LSAA 4 BASIC INFORMATION NOMENCLATURE 42044 Washer Extractor First 2 digits (42) = Cylinder Diameter (inches) Last 2 digits (44) = Cylinder Depth (inches) Note: Other American Manufacturers use the same format CYLINDER VOLUME Formula: CDI = Cylinder Diameter in inches Cd = Cylinder depth in inches CDI * CDI * cd = CYLINDER VOLUME ( ft 3 ) 2,200 42" Diameter * 42" Diameter * 44" Depth 3 = 35.28 ft 2,200 LOAD FACTOR Formula: CWGW = Clean Weight of Goods in Washer (lbs) CV= Cylinder Volume (ft3) CWGW = Load Factor CV Example: 42044WP2 Washer Extractor Load Size = 200 lbs 42044WP2 Washer Extractor Cylinder Volume = 35.28 ft3. 200 Pound Load = 5.66 Pounds per Ft 3 . 35.28 Cu Ft 1 Note: 1. A generally accepted load factor (lbs of Linen/ft3 of Cylinder Volume) is between 5.50 to 6.50 lbs. 2. High bulk goods, like the new micro denier fabric for surgical items, require the machine to be under loaded to 65% of its capacity. 3. Dense goods, like walk-on-mats permit the overloading of the machine by 30%. "G" FORCES DEFINITION: A Measure of Extraction's Efficiency to Remove Water. Formula: CRPM=Cylinder Revolutions per minute CD = Cylinder Diameter (Expressed in inches) CRPM *CRPM *CD ="G" FORCES 70,500 Example: 42044 WP2 with 700 RPM Final Extract Speed 42" Cylinder Diameter 700 RPM * 700 RPM * 42" Diameter = 292 "G' s 70,500 Note: 1. The higher the "G" force, the greater the centrifugal force exerted on the goods. 2. One "G" equals 1 times the force of gravity. 3. Other factors which may affect Extraction are: **Final bath temperature **Final bath chemicals **Length of extraction time **Type of goods (towels/sheets) **Ambient air humidity **% of cylinder open area to close area **Size of basket perforations **Type of material (cotton, 50/50) **Thickness of the load **Altitude of installation 2 WATER MOISTURE RETENTION: The amount of water contained in the linens after the final extraction. Expressed as a % of the dry weight of the goods being washed. NOTE: The DIN (German Industrial Norm, the equivalent of our American Standard Association) method adds 5% to the weight of dry textiles to account for the ambient humidity. This method assumes that goods that have been dried will, when allowed to sit on a shelf, absorb 5% of their bone dry weight. MOISTURE RETENTION: Formula: American Norm (Bone dry method) WGAX = Weight of Goods after extraction DWG: Dry weight of goods ((WGAX − DWG) *100) = % Moisture retention DWG Example: 42044 WP2 Washer Extractor 310 lbs = Weight of goods after extraction 200 lbs = dry weight of goods ((310 − 200)*100) = 55% Moisture retention 200 Formula: European Norm (DIN Method) WGAX = Weight of goods after extraction DWG5 = Dry weight of goods plus 5% of its weight ((WGAX − DWG5) *100) = % Moisture retention DWG5 Example: 42044 WP2 Washer Extractor 310 lbs = Weight of goods after extraction 10 lbs = 5% of 200 lbs of Dry Weight ((310 − (200 +10)) *100) = 47.62% Moisture retention (200 +10) 200 lbs = Dry weight of goods 3 WATER PRESSURE: The recommended water pressure is a range of 40 psi to 60 psi. Below 40, the washer extractor has to wait too long to fill. Above 60, there is the possibility of water hammer. Air operated water valves, on MILNOR large (standard) and small (optional) machines, have a closing adjustment which helps to minimize the water hammer problem ESTIMATED PEAK WATER FLOW RATES: In multiple machine installation, the maximum flow rate will occur when all inlet valves open simultaneously. But using this criteria would result in over design and costly installation. Therefore, we use the following rule of thumb: 1. The flow rate required by the largest machine in the installation, OR 2. The flow rate equivalent to one third of all machines filling simultaneously. We recommend the use of whichever results in the largest flow rate of the two options. The ideal flow rate will allow a machine to reach rinse level, which is usually the highest level, in approximately 60 seconds. Filling in less than 60 seconds may result in water hammer, particularly in the long runs of pipe. EXAMPLE: A laundry with 4 washer extractors, each requiring 40 gallons for the rinse level. The total number of gallons if all machines filled simultaneously would be: 40 gallons X 4 machines = 160 gallons Applying rule #1: 40 gallons = flow of largest machine Applying rule #2 160 gallons ÷ 3=53 gallons Therefore, we would choose 53 gallons since it is the larger of the two values (40 gallons and 53 gallons). PROPER PIPE SIZE: For multiple washer extractor installations, each water line should be sized according to the following rules: 1. A size larger than the largest water inlet valve in the installation, OR 2. A size larger than the one third of the total area of all the water valves connected to the line. We recommend the use of whichever results in the largest flow rate. CONVERSION FACTORS: 1 gallon of water = 8.33 lbs in weight 4 1 cubic foot of water = 7.48 gallons 1 cubic foot of water = 62.425 lbs in weight WATER HARDNESS HOW IT'S MEASURED: Grains of hardness OR parts per million Degree Hardness Grains per US Gallon Parts per Million Soft Less than 1.00 Less than 17.1 Slightly hard 1.0 to 3.5 17.1 to 60 Moderately hard 3.5 to 7.0 60 to 120 Hard 7.0 to 10.5 120 to 180 Very hard 10.5 and over 180 and over NOTE: What we call hardness is really calcium and magnesium salts in water. These minerals may result in deposit build-up on heat transfer surfaces and pipes thereby reducing efficiency. A softener is recommended when the degree of hardness exceeds 3.00 grains because chemical costs increase disproportionately as the water becomes harder. SIZING A WATER SOFTENER: 1. Determine the hardness of the water supply. In most cases the municipal water works will be glad to provide the information. Water softener companies will do free analysis. Call them for a sample bottle. 2. Compute the amount of water required per day, the peak water flow rate (see estimated peak water flow rate") and the grain hardness that must be removed from the calculated amount of water. 3. A softener must be chosen with a capacity (gallons/regeneration) and a peak flow rate equal to or greater than the one required for the laundry. Ideally the regenerating capacity (number of grains of hardness removed in a given period of time) should permit the softener to be regenerated once every day. If the regenerating capacity of the softener is not sufficient and requires more than one regeneration per day, then a dual softener should be used. 4. The salt requirement may be calculated using the formula below. FORMULA: THG = Total hardness in grains (THG ÷ 1000) x 0.50 = lbs of salt 5 SIZING DRAIN TROUGHS: 1. Determine the maximum amount of water to be dumped at one time. This is usually at the rinse operation which normally is the highest water level. 2. Divide the total number of gallons by 7.48 to obtain the number of ft3 required to hold the given amount of water. 3. Starting with a width of 14" and an initial depth of 12", find the length necessary to obtain the required ft3 to hold the amount of water being dumped. 4. The bottom of the trough should be sloped toward the drain, at 0.25 of an inch per linear foot. If the slope is too steep, the slope can be reduced to no less than 0.12 of an inch per linear foot. 5. The drain trough should be empty by the time the next large amount of water is dumped. The trough's drain must be sized properly to accomplish this. EXAMPLE: 175 gallons are being dumped at one time. The width of the drain trough is 1.167 ft (14") The initial depth of the trough is 1.0 ft (12") The trough's drain is 4" diameter pipe 175 Gallons 3 = 23.40 ft 3 7.48 Gallons per ft 3 23.40 Ft 3 = 20 ft 1.0 * 1.167 @0.25" slope, the end of the trough would be 17" deep @0.12" slope, the end of the trough would be 14.50" deep 6 FUEL UNIT OF MEASUREMENT: British Thermal Unit (Btu)- Amount of heat required to raise one pound of water one degree Fahrenheit.