CHAPTER XI.Scrubbing Systems.
Vacuum cleaning systems in which appliances for scrubbing are provided in addition to the usual appliances for the removal of the dust and other materials in a dry state have been introduced by a few manufacturers, none of which has come into general use.
The usual method employed is to provide an ordinary corn scrubbing brush which has a connection to the water supply of the building, with control valves in the tool handle for regulating the flow of water to the brush. Soap is applied either in the form of soap powder sprinkled on the floor, in a liquid state fed into the water supply by means of a sight-feed oil cup or soft soap in a plastic state fed into the water supply by means of a compression grease cup.
In any case, the water is run onto the floor mixed with the soap and the floor scrubbed by manipulating the corn brush, in the same manner that an ordinary corn scrubbing brush without attachments would be used.
After the dirt has been loosened from the floor, the floor may be rinsed by the application of more water. The water is then drawn up from the floor by the suction of the cleaning machine, and passes through the hose and piping system to the separator and vacuum producer. To effectively remove the water a rubber-faced tool is usually employed. In one system this rubber face is arranged to permit the corn brush to be fitted over same when scrubbing is being done, and the brush must be removed from the tool before the water can be drawn up from the floor. Other manufacturers provide a double-faced tool having the brush on the opposite side of the tool from the rubber-faced slot. By reversing the tool, scrubbing and mopping can be accomplished without the removal of the corn brush from the tool, which is more convenient for the operator.
With either of the above forms of scrubbing tools it is necessary or desirable to cut off the suction to the mopping attachment when using the corn brush, and it is also necessary to cut off the water supply to the brush when using the mopping attachment. One system, introduced several years ago, conducted the water to the brush and away from the rubber-faced mopping appliance through the same hose. This arrangement requires the use of a special three-way hose cock, which had to be manipulated frequently during the scrubbing operation, requiring the time of another person in addition to the operator, or else greatly delaying the scrubbing process by requiring the operator to constantly pass back and forth between the hose cock and the scrubbing tool. This method of supplying water also requires the use of a removable corn brush attached over the rubber mopping device.
Other forms of scrubbing appliances are provided with separate hose for the water supply and suction and with valves in the handles for controlling the suction and water supply. These valves to be efficient and quick in action are generally made self-closing, otherwise they will be short-lived, as explained inChapter V. When springs are used to close the valves, the hand and wrist will be quickly fatigued, as stated inChapter V.
With either of the above systems all of the scrubbing, that is, the agitation of the brush, has to be performed by the operator, as in the case of the ordinary scrubbing brush. However, the combination tool is much heavier and clumsier than the ordinary scrubbing brush, and the only advantage obtained by using this heavy and clumsy appliance is the ability to supply water without carrying it in buckets, also the removal of the dirty water after scrubbing. These appliances cannot be termed mechanical scrubbers, nor can they be classed with scrubbing machines with motor-driven brushes, such as have been recently introduced.
A real mechanical scrubbing device for use with a vacuum cleaning system was manufactured by Foster & Glidden, of Buffalo, N. Y., but was never placed on the market, although at least one is in commercial operation to-day. This machine isprovided with a turbine motor operated by the air current passing through the machine. This turbine revolves a pair of scrubbing brushes turning in opposite directions. Water is fed through a separate hose, and an auxiliary air inlet is opened when the suction under the brushes is closed, in order to supply the necessary air to keep the turbine running. Mr. Foster states that he has experienced no trouble in operating this machine on from 8 in. to 12 in. of vacuum, being able to scrub and remove the dirt and water with one operation. The speed with which the work was done depended on the condition of the floor, the usual rate, as given by Mr. Foster, being from 10 to 12 yds. per minute.
Mr. Foster also states that he has not pushed the introduction of this scrubber, as he considers it so far ahead of the times as to require the education of the public in the use of the hose and ordinary vacuum cleaning tools before users would be capable of successfully operating this type of scrubber.
The author considers this condition to be lamentable if true, for until some such appliance is in commercial use scrubbing attachments to a vacuum cleaning system can never compete with the mechanical scrubbing machines now on the market, and are little if any better than the old method of scrub-brush, mop and pail, and certainly not as rapid in operation.
When the vacuum cleaning systems combine scrubbing with dry cleaning, the separator and vacuum producer must provide for the removal of water as well as air. A few manufacturers have attempted this, among which are the makers of the Rotrex system, described inChapter IX, in which the water is passed through the pump and into the sewer under sufficient pressure to overcome the friction in the exhaust pipe through which the expelled air passes after leaving the separator. This may be sufficient to force the trap seals of the plumbing system, and, if used, the discharge connection should be made to the sewer outside the main running trap, close to the fresh air inlet. As large articles cannot be allowed to pass through the pump, a screen is necessary on the inlet side of the vacuum producer, but this may give trouble, due to the clogging with litter.
The Atwood Vacuum Cleaner Company uses a wet tank on the suction side of the vacuum producer into which the dirt and water are discharged, the air being separated and passed to the vacuum producer. When this tank becomes partly filled it is necessary to shut down the plant and empty the contents of the tank by gravity into the sewer.
This method overcomes the objections to clogged screens and forced trap seals, and all litter is discharged direct to the sewer, together with a quantity of water which is presumably sufficient to flush the litter through the sewer. The last named system is still open to two objections; first, it is not automatic, and, if neglected, the tank will fill with water and force same into the vacuum producer. With the Root type of vacuum pump this will do little harm unless a large quantity of floating litter should pass into the pump. Second, the system may be operated with dry renovators exclusively for a considerable portion of the time, in which case the contents of the separator may become of such a consistency as will not readily flush through the sewer, and stoppage of the same may occur.
Another separator of this type has recently been patented by E. B. Dunn, the originator of the Dunn Locke, in which the mud and the water are automatically discharged alternately from one of two separators, as described inChapter VIII.
Such a separator, in which sufficient water is automatically introduced to dilute the dirt and which will automatically empty when sufficiently filled, when so constructed that it will operate continuously, is considered to be the ideal separator for use with a combined cleaning and scrubbing system. Until the mechanical scrubber and an automatically operated separator are commercially introduced the author does not consider that the use of scrubbing attachments, in connection with the vacuum cleaning system, is advisable.