INTRODUCTION Floor cleaner is very much useful in cleaning floors in hospitals, houses, auditorium, shops, computer centers etc; it is very simple in construction and easy to operate. Anybody can operate this machine easily. It consist of moisture cotton brush, the brush cleans the floor and dried with aid of small blower. Hence it is very useful in hospitals, houses, etc. The time taken for cleaning is very less and the cost is also very less. Maintenance cost is less. Much type of machines is widely used for this purpose. But they are working under different principles and the cost is also very high. Good well-maintained entrance matting can dramatically reduce the need for cleaning. For public and office buildings about 80 to 90% of the dirt is tracked in from outside. Installing a total of 15 feet of matting consisting of both indoor and outdoor sections will remove about 80% of this. Thus about two-thirds of the dirt can be removed at the entrance
Reasons for cleaning floors The principal reasons for floor cleaning are:
To prevent injuries due to tripping or slipping. Injuries due to slips and trips on level floors are a major cause of accidental injury or death. Bad practice in floor cleaning is itself a major cause of accidents.
To beautify the floor.
To remove stains, dirt, litter and obstructions.
To remove grit and sand which scratch and wear down the surface.
To remove allergens, in particular dust.
To prevent wear to the surface (e.g. by using a floor wax or protective sealant).
To make the environment sanitary (e.g. in kitchens).
To maintain an optimum traction (e.g. for dance floors).
Methods of floor cleaning The treatment needed for different types of floors is very different. For safety it is most important to ensure the floor is not left even slightly wet after cleaning or mopping up. Sawdust is used on some floors to absorb any liquids that fall rather than trying to prevent them being spilt. The sawdust is swept up and replaced each day. This was common in the past in pubs and is still used in some butchers and fishmongers. It used to be common to use tea leaves to collect dirt from carpets and remove odours. Nowadays it is sill quite common to use diatomaceous earth, or in fact any cat litter type material, to remove infestations from floors. There are also a wide variety of floor cleaning machines available today such as floor buffers, automatic floor scrubbers and sweepers, and carpet extractors that can deep clean almost any type of hard floor or carpeted flooring surface in much less time than it would take using a traditional cleaning method.
Wood flooring Wood flooring should be treated completely differently depending on whether it waxed or oiled, or whether it has a polyurethane coating. It is important to determine the type of finish of a wood floor and always treat it the appropriate way, for instance it is difficult to clear wood floor wax from a polyurethane floor. Simple cleaning instructions: 1. Clear the floor of any furnature that's easy to move. 2. Sweep or vacuum all loose dirt and debris. 3. Mop the floor, going along with the grain. If your floors are polyurethaned, dampen a mop with water and a few drops of dishwashing liquid. Be sure to ring out the mop thoroughly before using it on the floor. Run the mop back and forth, going with the grain of the wood in smooth strokes. If your floors are lacquered or shellacked, don‘t use water, which can stain the wood and cause buckling. 4. Buff the floor with a soft cloth to remove any soapy residue. Cloth diapers work well for buffing, because they‘re very soft and absorbent. Tile and stone floors Nowadays many modern kitchens, stairs, and bathrooms have tile flooring that can be cleaned in three simple steps: 1. Dirt or dust should first be removed with a vacuum cleaner or a broom. 2. Have a floor cleaning solution or spray bottle for the appropriate floor. If you are cleaning stone floors (marble, granite, travertine, etc.), make sure the cleaning agent states that it is for stones. An acidic tile cleaning solution can be used on ceramic and porcelain floors 3. After spraying the tile or stone floors in a small area, use a mop to clean and scrub floors.
Reducing the need for cleaning Good well-maintained entrance matting can dramatically reduce the need for cleaning. For public and office buildings about 80 to 90% of the dirt is tracked in from outside. Installing a total of 15 feet of matting consisting of both indoor and outdoor sections will remove about 80% of this. Thus about two-thirds of the dirt can be removed at the entrance.
FLOOR CLEANING MACHINES – TYPES AND USES There are many various types of cleaning machines or equipment on the market today for both commercial and residential use. This is a brief overview of the type, power sources and uses for floor cleaning equipment. For effective cleaning results of any floor or surface, there are four basic and simple principles to follow. 1. Time 2. Agitation 3. Chemical 4. Temperature Using these four simple principles will allow anyone to end up with good cleaning results. Relative to this topic – floor cleaning machines, we will be discussing the second principle; agitation. Most floor cleaning machines and equipment are designed to provide the agitation needed to perform the cleaning procedure. Prior to machines, agitation was accomplished with elbow grease. However, manual agitation is burdensome to the person cleaning and increases labor. The introduction of cleaning machines made the janitor‘s life easier and increased cleaning efficiency while dramatically reducing the labor of the task. The following is an overview of the primary pieces of floor cleaning machines and does not cover each one. But the ones discussed in this article will cover over 90% of all floor cleaning equipment designed to clean hard floors. When we state the cleaning of hard floors; we mean daily or normal cleaning. Although, some of the floor cleaning machines outlined in this article
can also provide periodic or project type cleaning functions as well. We will be covering machines to clean carpeting and specialty cleaning machines in future articles.
FLOOR CLEANING MACHINES – COMMERCIAL AND RESIDENTIAL TYPES Types and Uses 1. Single Disc Floor Machines – Commercial & Residential: Electric Plug Powered equipment. These machines operate by a single motor that turns a pad driver installed on the bottom of the machine. Either brushes or floor cleaning pads are installed. It is the brushes or pads that provide the agitation while the motor provides a circular motion. These machines were some of the first on the market and run between 175 to 350 RPM. These same machines were also used to spray buff floors. This versatile machine could be used to
clean
all
hard
floors
(resilient
and
non-resilient)
as
well
as
carpeting.
2. Automatic Scrubbers – Commercial: Battery or Electric Plug Powered, these machines normal run between 110 to 175 RPM. Units
with
slightly
higher
RPM
are
on
the
market.
This equipment combines to include several steps in one operation.
Application of the cleaning solution
The agitation principle utilizing either pads or brushes
Pick up of the cleaning solution This equipment made the life of the janitor even easier because it accomplishes several
steps in one operation and further reduced the labor factor of cleaning floors. To our understanding the very first automatic scrubber was first introduced 1905 by Finnell System, Inc. Finnell is no longer in business but received many patents during its corporate life. These early machines were nothing like today‘s automatic scrubbers. It was made with ¼ inch plate steel, extremely heavy and was somewhat difficult to maneuver and operate mechanically.
Nevertheless, it evolutionized the floor cleaning industry from its first introductio Today‘s machines are state of the art with computerized controls, advanced battery technology, high grade lightweight plastics, etc. They are simple to use and still a labor saver. This versatile machine could be used to clean all hard floors Wet/Dry Vacuums – Commercial & Residential: While this simple and effective machine may not be classified as a cleaning floor machine, it does provide increased efficiency for manual floor cleaning and Single Disc Floor Machines. This equipment picks up cleaning solution from the floor. Speeding up the cleaning operation. These units are normally electric plug powered but there are some available in mechanical operation (no power source required – Aztec‘s Guzzler) and battery power. These units are also great to use in hard to reach and smaller areas being cleaned. This versatile machine
could
be
used
to
clean
all
hard
floors
(resilient
and
non-resilient).
Specialty – Grout Cleaning Machines – Commercial: These units are normally Electric plug powered and the most effective performance units employ a cylinder brush system that allows the brush bristles to get into the grout lines of the floor. These units are used on all types of Non-Resilient tile floors that use grout lines. Specialty – Steam Cleaning Machines – Residential: These units generate steam or hot water to provide the cleaning action to the floors. They are primarily used in the residences and provide principle number 4 – Temperature to clean the floor instead of agitation. They are lightweight, relatively inexpensive and built for the soil levels found in the residential market. This versatile machine that could be used to clean all hard floors.
FLOOR SCRUBBER
Floor scrubber is a floor cleaning device. It can be simple tools such as floor mops and floor brushes, or in a form of walk-behind or ride-on machines to clean larger floor areas by injecting water with cleaning solution, scrubbing, and lifting the residuals off the floor. With the advancement in robotics, autonomous floor-scrubbing robots are available as well. Automatic floor scrubbers Automatic floor scrubbers, also known as auto scrubbers, are a type of floor cleaning machine that are used to scrub a floor clean of light debris, dust, oil, grease or floor marks. These machines have either rotary(disk) or cylindrical scrubbing head and an automated system for dispensing cleaning solution and then vacuuming it up. So, in one pass over the floor, a user can dispense cleaning, scrub it into the floor, then vacuum it all up with an autoscrubber squeegee attachment at the back of the machine. Auto scrubbers have a separate dispensing(solution tank) tank and a collection(recovery tank) tank to keep your clean water from your dirty water and can be categorized into one of two main types: walk behind or riding. Floor Scrubbers are a more hygienic alternative to traditional cleaning methods such as a mop and bucket. Environmentally safe soaps can be used in conjunction with a reduced water system to save on both the amount of chemicals released into the environment as well as the amount of gray water produced. Some floor scrubbers are even capable of cleaning without a water and chemical system at all. Most autoscrubbers can't reach edges, corners, clean under obstructions such as drinking fountains, and can't fit into alcoves. Therefore, mopping is needed to clean areas the autoscrubber can't reach.
Modern floor scrubbers have a pre-sweep option that removes the need to sweep the floor before scrubbing. The pre-sweep brush head is placed in front of the vacuum system to collect dust and debris before it can block the vacuum system. In the past it was important to sweep the floor before scrubbing to remove any debris and dust that could clog the vacuum hose or build up in the vacuum motor, which can decrease performance. If this happens, the vac hose may need to be removed to clear the obstruction and/or the vac motor may need to be blown out with compressed air. Stripping Solution should never be used as it can cause damage to the solution dispensing system, but can still be vacuumed up by the machine without harm. Occasionally, the solution system should be flushed with water mixed with vinegar to remove any soap and calcium deposits that could build in the solution system. After each use, the dispensing(solution) and especially the collection(recovery)tanks should be emptied and rinsed out to prevent dirt build up. Also, the pads/brushes, vac hose, and squeegee should also be rinsed to prevent dirt build up. The vac motor should be run for several minutes afterwards to remove any moisture that could be present in the vac motor to reduce chances of corrosion that could damage the vac motor. Failure do to this maintenance could cause in a loss of vacuum airflow and increase in costly repairs. When storing an autoscrubber, the solution and recovery tanks should be left open to allow ventilation and to prevent odors from building up Before charging battery-powered machines, check to make sure the water in the battery cells is covering the lead plates before charging. If the water level is low enough to expose the plates, Fill the cell with just enough water until the plates are covered. If batteries are discharged, never add water if the electrolyte is visible above the plates. When charging, the battery compartment should be left open for ventilation as hydrogen gases are emitted from the charging process. After charging, check the battery cells again. The water level should be 1/8 below the bottom of the fill well. If the level is low fill until it is 1/8 below the bottom of the fill well. If a battery is overfilled, the water can overflow which can damage the battery and make a mess.
When maintaining deep cycle batteries, distilled water is highly recommended. Never use water with high mineral content. Floor buffers and polishers When floor scrubbing machines became more available to many types of facilities, there was a need to cover a different type of flooring. Floor buffers were invented to scrub and polish the floor with linoleum surface. The machines use rotary brushes with soft material to clean and make the floor shine. For marble and wood floors, floor polishers may be used to apply protective coating to floor. Floor-scrubbing robots With the advancement in technologies used in autonomous robots, floor-scrubbing robots were created by combining the features of automatic floor scrubbers with self-control operations without an operator. Non-residential models such as HydroBot by Intellibot Robotics are suitable for education, retail, healthcare and manufacturing facilities. These commercial floor cleaning machines can clean 10,000-square-foot (930 m2) area in one hour. In the residential applications, floor-scrubbing robots are available using the same principle of operation as in the commercial applications, but with much smaller machines. Scooba by iRobot is an example of such robots.
How to Operate a Floor Scrubber Floor scrubbers clean your floor better, and leave it dryer, than you can do yourself with a mop and bucket. They come in many sizes and styles and can thoroughly clean just about any kind of floor surface. The principle is the same for most models: a water-and-cleaner solution is sprayed onto the floor, scrubbed in with a vibrating or rotating brush, then vacuumed up into an outflow tank. They're especially good for hard tiles like ceramic, as well as linoleum. For home use, you can buy or rent small models about the size of standard vacuum cleaners.
Instructions 1. Sweep the floor thoroughly. If you use your scrubber on a floor that has a lot of loose dirt or dust on it, the scrubber could press the dirt into the lines between tiles or spread it around the floor. 2. Fill your intake tank with very warm water, leaving a few inches at the top. Add in the concentrated cleaner. Don't add the cleaner first, and don't shake or splash it, as you want to avoid stirring up suds. 3. Position the scrubber at the wall furthest from the door. If your scrubber model requires you to pull it backward, start with the machine facing in the corner; if it's a forwardmoving model, start with your back to the corner and the machine facing out into the room. 4. Turn on the various parts of the machine. On most models, the different functions of the scrubber will be controlled by three different switches. Turn on the water pump first, then the vacuum and finally the scrubber. Begin moving the machine in the direction it's supposed to go (forward or backward). Work in slow, steady rows, watching the outflow tank as you go to judge how soon you have to stop and replace the water. 5. Empty the outflow tank as soon as it is full. Refill the intake tank with warm water and cleaning solution. You may have to do this several times depending on the size of the scrubber and the amount of floor you are cleaning
Rotary Floor Cleaning Machines
Along with vacuum cleaners, rotary cleaning machines are the most common machines used by cleaning operatives throughout the industry. They could be accurately described as the workhorses of the industry, given the range of tasks they can be used to perform. Although they may all look similar, the specifications of the different types of machine will dictate their suitability for certain tasks. For instance, machines that rotate at slower speeds are more suitable for scrubbing tasks, whereas the faster machines are more suited to floor polishing procedures.
The Principles of Rotary Cleaning Therefore, it is crucial that the correct machine is chosen to carry out any given task efficiently. The most common varieties of machine used have a single rotating head, onto which can be attached brushes, pads, bonnet mops, sanding discs and scarifying assemblies (more on these later). The head itself is driven by an electric motor or, in the case of non-electric versions, propane and petrol. The power is transmitted to the rotating head in one of the following ways: Direct drive – where the motor is situated directly above the head with the power being transmitted by means of a gear box. Belt drive - where the motor is situated off centre or the rear of the rotating head with the head itself being driven by a drive belt. The Range of Tasks Performed Scrubbing Impacted soil deposits can be removed from hard floors by scrubbing, which requires the use of a suitable cleaning solution in conjunction with the machine. Brushes or a suitably graded abrasive pad can be used to dislodge the soil once it has been softened by the cleaning solution. Burnishing The tips of a rotary brush or the surface of an abrasive pad will scratch and cut at the floor surface to create a smooth surface with a gloss finish. If this process is used on a floor that has had polish applied, it will lead to the removal of the surface layer of polish to achieve the same results. Spray Cleaning Again, like scrubbing, the machine is used in conjunction with a cleaning solution. It differs from scrubbing in that a buffable detergent is used and it is applied using a trigger spray or pump up bottle spray in the form of a fine mist, which, when subjected the action of the
machine, will leave a gloss film on the surface of the floor. This process can be used to maintain unpolished floors or to maintain the appearance of floor treated with polish. Buffing A soft grade abrasive pad is used to create a gloss finish on the floor. If a floor has been recently treated with wax, emulsion or seal finish, buffing will enhance the appearance of the floor by generating heat on the surface which will harden waxes and resins present in the newly laid polish. Spray Burnishing In essence, this is very similar to spray cleaning but the term is applied to the maintenance procedures required of floors where a buffable polish has been applied and the abrasive pad will remove soil along with the surface layer of polish to leave a glossy finish. Waxes and resins present in the product applied form part of the eventual finish, further enhancing the appearance of the floor. Scarifying This is the most aggressive way of removing impacted soil from a surface. A scarifying attachment is fitted to the machine that incorporates a series of sharp cutting tools that will remove soil deposits by means of a chisel like action. Light Sanding This can be done with the use of abrasive mesh discs used in conjunction with a slow speed machine. They can be used to lightly sand an uneven or damaged surface or strip back multiple layers of polish that cannot be removed by conventional stripping. Bonnet Mopping A cleaning process for carpets or hard floors using a standard speed rotary machine fitted with the appropriate bonnet mop. Each surface has its own particular technique and involves a surface-specific bonnet mop.
Carpet
A carpet bonnet is manufactured from a mixture of polyester and viscose and is an extremely effective cleaning technique. For best results the carpet should first be vacuum cleaned and pre- sprayed to tackle any heavy soiling. A solution of the appropriate detergent is used to pre-soak the bonnet mop which is then wrung out before being used to ―buff‖ the carpet. Hard Floors
With hard floor bonnet cleaning the rotary machine should have a centre feed facility and be fitted with a solution tank A hard floors bonnet is manufactured from a mixture of nylon and high tensile nylon which ensures that it is hard wearing and the mop does not hold too much water. To distinguish it from carpet bonnets the hard surface bonnet generally contains easily identified coloured fleck, and has a mesh centre to allow water to feed through to the bonnet. The cleaning technique here is different to carpets. The bonnet is put onto the drive board in a dry state, and dampened by feeding water through from the solution tank. Only sufficient cleaning solution should be fed to the bonnet, and as the bonnet dries out more solution can be fed through. If done correctly the floor should be air dried in two or three minutes.
Types of Machine As previously stated, although the machines may look similar, they do perform a number of separate tasks, depending on their individual properties. In this section we will look at the various types of machines available. Single Brush Machines Single brush machines have, as the name implies, a single rotating drive pulley driven, powered by an electric motor. The drive pulley itself can be driven via a belt linking it to the rotor of the motor or through a gearbox. All machines apart from the Ultra High Speed machines are designed to be used in conjunction with drive brushes, abrasive pads and a wide range of other accessories and assemblies. Ultra High Speed machines, due to their speed configuration tend to be fitted with a fixed drive board which is not removed after use. The working width of these machines can vary from 28 to 60 cm and the speed at which it is driven falls into one of the following categories: • Slow or Standard Speed
120 – 250 rpm
• High Speed
260 – 360 rpm
• Super Speed
370 – 490 rpm
• Ultra High Speed
500 – 2000+ rpm
As a general rule, machines in the Standard, High and Super Speed categories, will tend to be swing machines which are operated in a side to side motion. They will have a head weight on the floor of anything between 20 to 45 kilos, depending on working diameter, size and weight of motor and general construction of the machine. The machines operate on the principal that at a point of equilibrium or in a horizontal position to the floor the machine will ‗hover‘ in the same spot. By gently raising the handle the machine will move to the right, and by gently lowering the handle the machine will move to the left. It is a combination of this slight upward and downward movement on the handle that allows the machine to swing in a side to side action.
With Ultra High Speed machines, these are known as divided weight machines and tend to be operated in a straight line method. In order to facilitate these higher speeds the rear wheels will be in contact with the floor when in use and possibly the machine will also have a front or central castor wheel to give further ease of mobility. Ultra High Speed machines usually have a pad pressure of between 3 to 9 kilos, depending on the diameter and speed of the machine. This is why they are particularly effective in polishing or burnishing hard floor surfaces, but cannot be used for more aggressive cleaning methods such as scrubbing or stripping.
COMPONENTS REQUIRED 1. A.C Motor 2. Pulley 3. Brushes 4. Belt 5. Cleaning liquid 6. Water 7. Battery
COMPONENTS DESCRIPTION PULLEY A pulley is a wheel on an axle that is designed to support movement and change of direction of a cable or belt along its circumference. Pulleys are used in a variety of ways to lift loads, apply forces, and to transmit power. In nautical contexts, the assembly of wheel, axle, and supporting shell is referred to as a "block." A pulley is also called a sheave or drum and may have a groove between two flanges around its circumference. The drive element of a pulley system can be a rope, cable, belt, or chain that runs over the pulley inside the groove. Hero of Alexandria identified the pulley as one of six simple machines used to lift weights. Pulleys are assembled to form a block and tackle in order to provide mechanical advantage to apply large forces. Pulleys are also assembled as part of belt and chain drives in order to transmit power from one rotating shaft to another.
Block and tackle
Various ways of rigging a tackle. A set of pulleys assembled so that they rotate independently on the same axle form a block. Two blocks with a rope attached to one of the blocks and threaded through the two sets of pulleys form a block and tackle. A block and tackle is assembled so one block is attached to fixed mounting point and the other is attached to the moving load. The mechanical advantage of the block and tackle is equal to the number of parts of the rope that support the moving block.
Rope and pulley systems
A hoist using the compound pulley system yielding an advantage of 4. The single fixed pulley is installed on the hoist (device). The two movable pulleys (joined together) are attached to the hook. One end of the rope is attached to the crane frame, another to the winch. A rope and pulley system -- that is, a block and tackle -- is characterised by the use of a single continuous rope to transmit a tension force around one or more pulleys to lift or move a load—the rope may be a light line or a strong cable. This system is included in the list of simple machines identified by Renaissance scientists. If the rope and pulley system does not dissipate or store energy, then its mechanical advantage is the number of parts of the rope that act on the load. This can be shown as follows.
Consider the set of pulleys that form the moving block and the parts of the rope that support this block. If there are p of these parts of the rope supporting the load W, then a force balance on the moving block shows that the tension in each of the parts of the rope must be W/p. This means the input force on the rope is T=W/p. Thus, the block and tackle reduces the input force by the factor p.
A gun tackle has a single pulley in both the fixed and moving blocks with two rope parts supporting the load W.
Separation of the pulleys in the gun tackle show the force balance that results in a rope tension of W/2.
A double tackle has two pulleys in both the fixed and moving blocks with four rope parts supporting the load W.
Separation of the pulleys in the double tackle show the force balance that results in a rope tension of W/4. How it works The simplest theory of operation for a pulley system assumes that the pulleys and lines are weightless, and that there is no energy loss due to friction. It is also assumed that the lines do not stretch. In equilibrium, the forces on the moving block must sum to zero. In addition the tension in the rope must be the same for each of its parts. This means that the two parts of the rope supporting the moving block must each support half the load.
Fixed pulley
The load F on the moving pulley is balanced by the tension in two parts of the rope supporting the pulley.
Movable pulley
Diagram 2: A movable pulley lifting the load W is supported by two rope parts with tension W/2. These are different types of pulley systems: Fixed: A fixed pulley has an axle mounted in bearings attached to a supporting structure. A fixed pulley changes the direction of the force on a rope or belt that moves along its circumference. Mechanical advantage is gained by combining a fixed pulley with a movable pulley or another fixed pulley of a different diameter. Movable: A movable pulley has an axle in a movable block. A single movable pulley is supported by two parts of the same rope and has a mechanical advantage of two. Compound: A combination of fixed and a movable pulleys forms a block and tackle. A block and tackle can have several pulleys mounted on the fixed and moving axles, further increasing the mechanical advantage.
Diagram 3: The gun tackle "rove to advantage" has the rope attached to the moving pulley. The tension in the rope is W/3 yielding an advantage of three.
Diagram 3a: The Luff tackle adds a fixed pulley "rove to disadvantage." The tension in the rope remains W/3 yielding an advantage of three. The mechanical advantage of the gun tackle can be increased by interchanging the fixed and moving blocks so the rope is attached to the moving block and the rope is pulled in the direction of the lifted load. In this case the block and tackle is said to be "rove to advantage Free body diagrams The mechanical advantage of a pulley system can be analyzed using free body diagrams which balance the tension force in the rope with the force of gravity on the load. In an ideal system, the massless and frictionless pulleys do not dissipate energy and allow for a change of direction of a rope that does not stretch or wear. In this case, a force balance on a free body that includes the load, W, and n supporting sections of a rope with tension T, yields:
The ratio of the load to the input tension force is the mechanical advantage MA of the pulley system
Thus, the mechanical advantage of the system is equal to the number of sections of rope supporting the load. Belt and pulley systems
Flat belt on a belt pulley
Belt and pulley system
A belt and pulley system is characterised by two or more pulleys in common to a belt. This allows for mechanical power, torque, and speed to be transmitted across axles. If the pulleys are of differing diameters, a mechanical advantage is realised.
A belt drive is analogous to that of a chain drive, however a belt sheave may be smooth (devoid of discrete interlocking members as would be found on a chain sprocket, spur gear, or timing belt) so that the mechanical advantage is approximately given by the ratio of the pitch diameter of the sheaves only, not fixed exactly by the ratio of teeth as with gears and sprockets. In the case of a drum-style pulley, without a groove or flanges, the pulley often is slightly convex to keep the flat belt centred. It is sometimes referred to as a crowned pulley. Though once widely used on factory line shafts, this type of pulley is still found driving the rotating brush in upright vacuum cleaners, in belt sanders and bandsaws. Agricultural tractors built up to the early 1950s generally had a belt pulley for a flat belt (which is what Belt Pulley magazine was named after). It has been replaced by other mechanisms with more flexibility in methods of use, such as power take-off and hydraulics.
A.C. MOTOR An electric motor is used for the conversion of electrical energy into mechanical energy. This conversion of electrical power to mechanical energy takes place in the rotating part of the motor. A D.C. Motor is called as Conduction motor, but an A.C. Motor is called as Induction Motor. Induction Motor Design Principle We all know that an electric motor is used for the conversion of electrical energy into mechanical energy. This mechanical energy may be used for the pumping of liquid from one place to other by using pumps or even to blow air by blowers or ceiling fans. The conversion of electrical power to mechanical energy takes place in the rotating part of the motor. In D.C. Motors, the electric power is conducted directly to the armature (the rotating part) through brushes & commutator. Thus we can say a D.C. Motor as a conduction motor. But in case of an A.C. Motor, the rotor does not receive electric power by conduction, but by Induction. Thus they are called as induction motors. This can be compared with the secondary winding of a transformer. These induction motors are also called as rotating transformers. Of all motors, it is generally a 3-phase or a poly-phase induction motor is used in a larger extent in many industries
The Direction of rotation of an Electric motor is given by Fleming's Left Hand rule: o
It shows the relation between the direction of "thrust" on a conductor carrying a "current" in a "magnetic field".
o
Keep the Thumb, Index finger & the Middle finger of the left hand at right angles to each other.The First finger or the index finger indicates the direction of the Field.
o
The seCond finger or the middle finger represents the direction of the Current.
o
The THumb represents the direction of the THrust or the direction of motion of the conductor.
Also other important Law is the Faraday's Law Of Electro Magnetic Induction.There are 3 important rules/laws of electro magnetic induction.They are as follows: 1. An EMF is induced in a coil whenever the flux through the coil changes with time. 2. The magnitude of induced EMF is directly proportional to the rate of change of flux. 3. The direction of the EMF is such as to oppose the change in flux.
Why Does A Rotor Rotate?
If a 3-phase supply is fed to the stator windings of a 3-phase motor, a magnetic flux of constant magnitude, rotating at synchronous speed is set up. At this point, the rotor is stationary. The rotating magnetic flux passes through the air gap between the stator & rotor and sweeps past the stationary rotor conductors. This rotating flux, as it sweeps, cuts the rotor conductors, thus causing an e.m.f to be induced in the rotor conductors. As per the Faraday‘s law of electromagnetic induction, it is this relative motion between the rotating magnetic flux and the stationary rotor conductors, which induces an e.m.f on the rotor conductors. Since the rotor conductors are shorted and form a closed circuit, the induced e.m.f produces a rotor current whose direction is given by Lenz‘s Law, is such as to oppose the cause producing it. In this case, the cause which produces the rotor current is the relative motion between the rotating magnetic flux and the stationary rotor conductors. Thus to reduce the relative speed, the rotor starts to rotate in the same direction as that of the rotating flux on the stator windings, trying to catch it up. The frequency of the induced e.m.f is same as the supply frequency.
Cogging Of Induction Motors
Sometimes, when the supply voltage is low, the squirrel cage induction motor refuses to start. This happens when the number of stator teeth and the number of the rotor teeth is equal, thus causing a magnetic locking between the stator and the rotor. This phenomenon is other-wise called as teeth-locking or Magnetic locking. This problem can be overcome by having the number of rotor slots prime to the stator slots.
Plugging of Motor The Induction motor can be stopped immediately by just interchanging any two of the stator leads. When an induction motor is rotating at a high speed, during emergency if situation arises that the motor has to be stopped immediately, can be done by interchanging any 2 leads of the stator supply. By doing this, it reverses the direction of the revolving flux, which produces a torque in the reverse direction, thus causing a breaking effect on the rotor. This breaking period is called the ―Plugging‖ period.
Analogy with the Mechanical Clutch
The Rotor Cu loss = Slip * Rotor Input This is evident by considering the working of mechanical clutch, used in automobiles. By visualizing the figure pf plate clutch, it is evident that the torque on the drive shaft must be equal to the torque on the driven shaft. Further, it should be emphasized that the these two torques are the one and the same, because the torque is caused by the friction between the two plates. Let $1 and $2 be the angular velocities on these two shafts assuming the plate clutch is slipping. Then input = T*ω1 Output= T* ω 2 But ω 2 = ω 1*(1-s) So output = T* ω 1*(1-s) Loss = T* ω 1 – T* ω 2 Loss = T* ω 1 – T ω 1*(1-s) Loss = s * T ω 1 Thus Loss = slip * input.
Advantages & Disadvantages Advantages of A.C. Induction Motors: 1. It has a simple design, low initial cost, rugged construction almost unbreakable 2. The operation is very simple with almost very less maintenance as there are no brushes. 3. The efficiency of these motors is very high, as there are no frictional losses, with reasonably good power factor.
4. The control gear for the starting purpose of these motors is minimum and thus simple and reliable operation.
Disadvantages of A.C. Induction Motors: 1. The speed control of these motors is not easy without some loss in efficiency. 2. As the load on the motor increases, the speed decreases. 3. The starting torque is inferior when compared to D.C. Motors.
BATTERY Battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery (or "voltaic pile") in 1800 by Alessandro Volta and especially since the technically improved Daniel cell in 1836, batteries have become a common power source for many household and industrial applications. The Lead Acid battery is made up of plates, lead, and lead oxide (various other elements are used to change density, hardness, porosity, etc.) with a 35% sulfuric acid and 65% water solution. This solution is called electrolyte, which causes a chemical reaction that produce electrons. When you test a battery with a hydrometer, you are measuring the amount of sulfuric acid in the electrolyte. If your reading is low, that means the chemistry that makes electrons is lacking. So where did the sulfur go? It is resting on the battery plates and when you recharge the battery, the sulfur returns to the electrolyte. Basically there are two types of lead acid batteries (along with 3 sub categories);The two main types are Starting (cranking), and Deep Cycle (marine/golf cart). The starting battery (SLI starting lights ignition) is designed to deliver quick bursts of energy (such as starting engines) and therefore has a greater plate count. The plates are thinner and have somewhat different material composition. The deep cycle battery has less instant energy, but greater long-term energy delivery. Deep cycle batteries have thicker plates and can survive a number of discharge cycles. Starting batteries should not be used for deep cycle applications because the thinner plates are more prone to warping and pitting when discharged. Dual Purpose Battery is a compromise between the two types of batteries, though it is better to be more specific if possible.
Wet Cell (flooded), Gel Cell, and Absorbed Glass Mat (AGM) are various versions of the lead acid battery. The Wet cell comes in two styles; Serviceable and Maintenance free. Both are filled with electrolyte and are basicly the same. I prefer one that I can add water to and check the specific gravity of the electrolyte with a hydrometer. The Gel Cell and the AGM batteries are specialty batteries that typically cost twice as much as a premium wet cell. However they store very well and do not tend to sulfate or degrade as easily as wet cell. There is little chance of a hydrogen gas explosion or corrosion when using these batteries; these are the safest lead acid batteries you can use. Gel Cell and some AGM batteries may require a special charging rate. If you want the best,most versatile type, consideration should be given to the AGM battery for applications such as Marine, RV, Solar, Audio, Power Sports and Stand-By Power just to name a few. If you don't use or operate your equipment daily, AGM batteries will hold their charge better that other types. If you must depend on top-notch battery performance, spend the extra money. Gel Cell batteries still are being sold but AGM batteries are replacing them in most applications. There is a some common confusion regarding AGM batteries because different manufactures call them by different names; some of the more common names are "sealed regulated valve", "dry cell", "non spillable", and "Valve Regulated Lead Acid" batteries. In most cases AGM batteries will give greater life span and greater cycle life than a wet cell battery. SPECIAL NOTE about Gel Batteries: It is very common for individuals to use the term GEL CELL when referring to sealed, maintenance free batteries, much like one would use Kleenex when referring to facial tissue or "Xerox machine" when referring to a copy machine. Be very careful when specifying a battery charger, many times we are told by customer they are requiring a charger for a Gel Cell battery and in fact the battery is not a Gel Cell.
AGM: The Absorbed Glass Matt construction allows the electrolyte to be suspended in close proximity with the plates active material. In theory, this enhances both the discharge and recharge efficiency. Common manufacturer applications include high performance engine starting, power sports, deep cycle, solar and storage battery. The larger AGM batteries we sell are typically good deep cycle batteries and they deliver their best life performance if recharged before allowed to drop below the 50% discharge rate. The Scorpion motorcycle batteries we
carry are a nice upgrade from your stock flooded battery, and the Odyssey branded batteries are fantastic for holding their static charge over long periods of non use. When Deep Cycle AGM batteries are discharged to a rate of no less than 60% the cycle life will be 300 plus cycles.
GEL: The Gel Cell is similar to the AGM style because the electrolyte is suspended, but different because technically the AGM battery is still considered to be a wet cell. The electrolyte in a Gel Cell has a silica additive that causes it to set up or stiffen. The recharge voltage on this type of cell is lower than the other styles of lead acid battery. This is probably the most sensitive cell in terms of adverse reactions to over-voltage charging. Gel Batteries are best used in VERY DEEP cycle application and may last a bit longer in hot weather applications. If the incorrect battery charger is used on a Gel Cell battery poor performance.
BLOCK DIAGRAM
WORKING PRINCIPLE The cleaning liquid is mixed in proper proportion and it is poured into the reservoir through the top way. The cleaning liquid is poured until the tanks are filled. Actuating the lever opens the valve. Cleaning liquid from the tank spills on the brush. After the required amount is delivered, the lever is released and the machine is switched ON. The brush gets drive from motor through pulleys and belts. The brush applies pressure on the floor, when the adjuster rod is unscrewed and the handle is moved in the required direction to clean the sufficient area. Again the lever is operated to supply cleaning liquid whenever required.
This process is
repeated, so floor is cleaned well. The cotton brush prevents the damages on the mosaic, marble floors and gives smooth surface finish and shining.
ADVANTAGES
Manual effort is reduced.
Operating time is less.
Cleaning and polishing can be done at same time.
It consumes less cleaning liquid.
Power consumption is less.
Design is very simple.
Easy fabrication.
It occupies less floor area.
Net weight is less.
Maintenance cost less.
Easy control of cleaning solution supply.
It can be used in various floors.
Smoother operation.
By further modification the drive or movement can be made automatic.
APPLICATIONS
Domestic purpose
Hospitals
Computer centers
Auditoriums
Cultural centers
Schools
Colleges
Large scale industries
Medium scale industries
Theatres
Educational institutions
CONCLUSION Thus in our project we have designed the Automatic floor cleaning machine with the help of A.C Motor and belt transmission. The machine is designed in order to enable easy operation and to reduce the effort of human beings. Even chidren and aged people can handle this machine, no critical operations is needed in this machine. The ultimate need of this project is satisfied and with the help of this machine we can clean the floor easily.
BIBLIOGRAPHY 1. Woodbank Communications Ltd. (n.d.). (2005). State of Charge (SOC) Determination. Retrieved from http://www.mpoweruk.com/soc.htm
2. North Arizona Wind & Sun. (n.d.). (2009). Deep Cycle Battery FAQ. Retrieved from http://www.windsun.com/Batteries/Battery_FAQ.htm
3. http://www.medicaljobsireland.ie/tag/hospital-hygiene-audit-results/ 4. http://www.hmi.ie/Documents/february_2009/cover_story_hygiene_report %20hm_Feb_09_p12.pdf 5. http://www.mrsainfection.org/mrsa-in-ireland.php 6. http://www.wsh.nhs.uk/InfectionControl/MRSA.htm Chen & Schelin:
