24 



HARDWOOD RECORD 



January 25, 1921 



Engineering in Furniture Factories 



(Continued Jroni iiaye 2") 



hand. This question of the installation of hogs is an individual 

 problem for each plant and can only be intelligently decided by con- 

 sidering all the factors entering into each case. 



48. Another improvement in the handling of refuse is in regard 

 to feeding the excess shavings and sawdust which ordinarily are 

 allowed to collect during the day in a go-called shavings vault. In 

 most plants the contents of the shavings vault must be fed to the 

 furnaces with a shovel, which is not only laborious but prevents the 

 full fuel value being realized. In the design of a power plant for a 

 woodworking factory for which the writer was partly responsible, 

 overhead bins were installed instead of the customary shavings vault. 

 These bins feed by gravity to a short length of screw conveyor dis- 

 charging into the furnace fronts, a separate conveyor being provided 

 for each boiler. The speed of these conveyors could be varied by 

 means of a friction drive, thus allowing the quantity of shavings and 

 sawdust fed to the furnace to be regulated in accordance with the 

 load on the boiler. The tendency of the shavings and sawdust to 

 arch over and thus stop feeding was overcome by a simijle installa- 

 tion of ' ' fingers " on a shaft leading through the lower part of the 

 bin arranged to be tripped periodically by an eccentric and connect- 

 ing rod actuated from the conveyor drive shaft. A small blower was 

 also installed with a branch duct arranged to discharge a current 

 of air just below each outlet into the furnace from the screw con- 

 veyor and thus blow the shavings and sawdust into the furnace in the 

 same manner as they are spouted from the separator. With a fairly 

 constant boiler load the above installation is entirely automatic and 

 it is no longer necessary to burn coal to augment the refuse fuel which 

 at night was previously necessary. 



49. Almost, if not quite, as essential to the .successful and eco- 

 nomical operation of the power plant as the proper selection of the 

 boilers and engines, is the careful consideration given to the aux- 

 iliaries such as pumps, feedwater heater, etc. Also the piping lay- 

 out should be thoughtfully designed, keeping in mind continuity of 

 service and convenient control of all equipment in the plant. Another 

 feature which is not usually found in industrial power plants, par- 

 ticularly the small and medium-sized ones, is a suitable selection of 

 recording gages and instruments for indicating and recording steam 

 pressure, feedwater temperature, quantity of feedwater, electric power 

 generated, and other data having a bearing on proper cost keeping 

 lor the power plant. With the present prices of fuel, oil, and other 

 supplies, it is quite as essential to watch the costs of power production 

 as it is to watch costs in other departments of an industrial institution. 



Fire Protection 



50. In a woodworking establishment the fire hazard is naturally 

 much greater than in a metal-viorking plant, consequently more thaji 

 ordinary care should be exercised in decreasing the fire hazard to a 

 minimum and preventing the spread of fire in case it does start. 

 Buildings should probably not exceed 250 to 300 ft. in length with- 

 out dividing them by suitable fire walls at least 17 in. thick, and 

 extending well above the roof line. Finishing and upholstering de- 

 partments should, if possible, be isolated from the rest of the plant 

 by fire walls, and if they are on upper floors and any great distance 

 from stairways, outside fire escapes should be provided. The build- 

 ing codes in many cities require fire escapes on all buildings exceed- 

 ing certain heights and floor areas. 



51. As already mentioned, all stair wells and elevator shafts should 

 be enclosed in fireproof towers, and to make fire walls and fireproof 

 towers effective all openings should be fitted with automatic fire 

 doors. It is also well to note that all stairs should be of non- 

 combustible material so they cannot be destroyed in case fire is com- 

 municated to the stair well itself. All sash should be steel and the 

 windows opposite adjacent buildings, where buildings are 30 ft. apart 

 or less, should be glazed with wire glass. It almost goes without 

 saying that a good sprinkler system should be installed throughout 

 the entire plant with plenty of yard hydrants and a good supply of 

 fire hose. All motor-control switches should be enclosed in steel 



boxes so arranged that the box cannot be opened when the switch 

 is closed. This precaution is not only in the interest of fire preven- 

 tion but accident prevention as well. All switches for motors driving 

 spray-booth fans, or for motors in other locations where inflammable 

 gas or dust is prevalent, should be of the remote-control type en- 

 closed in tight steel or iron cases, with a push button near the booth 

 or other machine. Spray-booth fires are a constant source of danger 

 and the method above mentioned of controlling the fan motors is 

 well worth the investment required. Other precautions in either 

 preventing fires or preventing their spreading will apply to certain 

 plants, but the above suggestions will outline the main points to be 

 considered. 



Proper Accommodation for Workers 



52. Under accommodations for workers may be included the light- 

 ing, heating, toilet, and locker-room arrangements of the plant. While 

 some of these features may not be considered as being entirely for 

 the accommodation or comfort of the workers, yet the writer believes 

 they have such a bearing on the morale of the working force that 

 the greatest benefit derived from properly designed equipment as 

 mentioned is through an increased efiiciency on the part of the em- 

 ployees. The day of the dark, poorly heated and ventilated factory 

 building with inadequate and unsanitary toilet facilities is past, for 

 the simple reason, if for no other, that any self-respecting man will 

 not work under such conditions; and if the employer with such a 

 factory does obtain a working force he may be sure that he is getting 

 only the flotsam and jetsam of the laboring class and the result ^vill 

 tie reflected in both the quantity and quality of his product. Bright, 

 cheerful surroundings, comfortably heated and well ventilated, with 

 adequate .sanitary facilities, including a supply of good drinking 

 water, are no longer regarded as an expense by the modern executive 

 liut as an investment which pays large returns in increasing produc- 

 tion and quality of product, decreasing labor turnover and promoting 

 contentment and loyalty among the employees. 



53. The far-too-usual method of providing a drop cord with a 

 bare lamp over each machine or at each workman's bench with a 

 few thrown in for general illumination should not be tolerated in 

 this day and age when good, efficient fixtures may be had at such 

 reasonable cost. While "spotted" fixtures over some machines may 

 be advisable, the writer much prefers good general illumination 

 throughout the entire working space. Where walls and ceilings are 

 painted white with some good industrial enamel, eflieient lighting may 

 be obtained through a proper selection of reflectors or fixtures at 

 a comparatively small cost in power consumption. For the average 

 machine and bench work in a furniture factory an intensity of 

 illumination of 3 foot-candles will be found satisfactory and this 

 intensity may be obtained with the Type C lamps for a power con- 

 sumption of about 1.25 watts per sq. ft. of lighted floor space. Fix- 

 tures or reflectors should be selected to suit the various departments, 

 the selection depending of course upon the kind of work performed. 

 The new enameled steel reflectors, which are made in a variety or 

 styles and designs to suit various conditions will be found very efli- 

 eient and probably as economical in first cost as any type of fixture 

 that can be purchased. Care should be exercised in locating fixtures 

 over machines or benches so that the -direct glare of the lamp will 

 not shine in the workman's- eyes. Where such direct rays of light 

 are unavoidable, opal-glass bulbs should be used. 



54. With regard to heating probably the most ideal system is the 

 hot-blast, for such a system provides adequate ventilation as well 

 as heat and in the summer time may be used to cool the air introduced 

 into the factory by circulating cold water through the heating coils. 

 The hot-blast system has the disadvantage of rather high first cost 

 in comparison to direct radiation, and the ducts for distributing the 

 air are likely to be considerably in the way unless provision for them 

 is made in the building construction. A well-designed direct-radiation 

 system of heating will be found very satisfactory and will probably 

 answer the purpose in most cases. Pipe sizes should be liberal so 

 as to use exhaust steam from the engine without too high a back 



