Document zbjQDpGoLB445DD2OQaGJqmxg

American Society of Heating and Ventilating Engineers Guide, 1930 machines in the minimum laundry is primarily to provide a break down service. Washing machines require repairs oftener than any other machines in the laundry and they are indispensable to the operation of the plant. Water, Steam and Power Requirements The minimum water, steam and power requirements are about 100 gal. of cold water, 80 gal. of hot water, 30 lb. of steam and 1 k.w. of electricity per 100 lb. of clothes (diy). The average laundry may exceed these as much as ,50 per cent and small laundries may exceed this by as much as 100 per cent. The instantaneous demands for steam and water are much higher than the average demands. Due to the heavy instantaneous demands, espe cially in a small laundry, it is well to supply the laundry from the main boiler plant, where these drafts will be least felt. If an individual boiler is installed for the laundry, or for other reason the load curve must be flattened out, the use of larger tanks to obtain Table X. Average Steam, Water, and Power Requirements of Washing Machines Size or Washer Dry Clothing per Co. Ft. or Cylinder Capacity, Lb. Hot Water per Hour, Gallons Hot Water Tank Storage, Gallons Size op Hot and Cold Water Connections, In. Size op Steam Connections. In. Electric Demand, Hp. Small....... ....... .... Medium.............. Large.................. High Duty. ,, . 2 2 2 4 150 100 l'A Vi 2 200 150 2 i 4 300 200 2 i 6 600 400 2(2) m 8 more storage capacity is necessary. Tanks double the sizes given in Table 1, are,frequently required. In estimating the hot water demand the laundry trays ordinarily may be neglected. The hot and cold water connections to washers are from I34 in. to 2 in., depending on size, with 34 in. to 1 in. steam connections, without returns. The use of oily exhaust steam in washers is objectionable. With alter nating current machines an allowance of 100 per cent must be made for reversing. Ironers usually have steam-heated rolls, and steam pressures of from 70 lb. to 90 lb. are desirable. Occasionally, with light-work, a pressure of 50 lb. will suffice. Each roll of an average sized ironer should have a J-in. or 1-in. steam connection, with a 34-in. or ,34'in. trap. The electric motors for ironers are from 34 to 2 hp., according to size. Electrically heated irons require from 500 to 1,000 watts, according to size. < Tumbler Dryers are rated on diameter and length of cylinder. Each ' has a small fan, which must have its outlet connected to an outside vent, as it discharges hot, damp air and considerable lint and refuse. . The average machine requires about 600 lb. of steam per hour, and takes an electric motor of from 3 to 6 hp. The usual steam connection is from 1 to 134 in. with a 34-in. return- 388 Chapter 22--Piping and Equipment for Laundry, Kitchen and Hospital Service Extractors require from 2 to 5 hp. motors. Other Laundry Equipment, steam and return services, average as follows: Unit Supply In. Return In. V* A H A AA l .% Average water services are as follows: Unit Soap tank.------ ---Starch cooker-----Laundry trap------ Hot Water Ik. 14 14 H Importance of Soft Water Soft water, the softer the better, is a necessity if a clean, white wash is to result. With hard water the soap forms insoluble compounds with calcium, magnesium and iron which cling to the washed fibres and after they have been through the flatwork ironer the spots turn various colors. In addition to this, more soap is required with hard waters than with soft; the excess depending upon the amount of hardness present. Before any lather is formed the soap must neutralize the hardness of the water. One pound of average soap will soften (bring to point of producing lather) 167 gal. of water when the hardness is 20 parts per million, but only 40 gal: when the hardness is 100 parts per million. Seventeen parts per million is equivalent to one grain of hardness, by weight, per gallon. Equipment Arrangement For efficient operation the arrangement of equipment must be given careful study so that it will fit in with the natural sequence of operations from receipt to delivery. Any backward movements of material that might involve possible contact of washed materials with unwashed ma terial must be guarded against. Whenever possible the laundry should be in a separate building. The ceilings of the building should be high and the rooms well ventilated by large windows and adequate roof ventilators. Ventilating fans will frequently be required. All operations except receiving, mending, storing and delivering should be carried on in one room. EQUIPMENT FOR KITCHENS The equipment covered herein includes the equipment found in the ordinary institution or hotel kitchen. Nearly all of this equipment can be obtained for gas or for steam. For small kitchens where steam is not 389