OPERATIONS & MAINTENANCE

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1 OPERATIONS & MAINTENANCE You are the key to your Indabrator machine s Productivity and Profitability You can t make money on downtime. Since blast cleaning equipment, by its very nature, tends to be self destructive, skilful operation and planned maintenance programs are required to assure maximum productivity of your Indabrator machine. Years of operating and engineering experience have been incorporated in the design of your Indabrator machine and in the development of materials for its construction. However, efficient and trouble free performance, in the long run, depends upon the care and attention given the Indabrator machine by its operating and maintenance personnel. All Indabrator machine machines incorporate these five basic elements: 1. One or more airless Indabrator machine units for hurling the abrasive by centrifugal force in a controlled pattern and duration. 2. A cabinet which contains the abrasive material as it performs its cleaning function. 3. A means of presenting the work to be cleaned to the abrasive action. 4. A system to re circulate and clean the abrasive, removing sand, fines and contaminants from the abrasive mix before returning effective abrasive to the blast wheels. 5. Dust collector to remove all dust and abrasive fines from blast machine to provide an environmentally safe operating atmosphere. The Airless Indabrator machine Wheel The Heart of every blast machine A major revolution in blast cleaning was brought about in 1932 with the introduction of the Wheelabrator airless abrasive blast wheel. Instead of using compressed air to propel abrasive, controlled centrifugal force was utilized with abrasive being thrown from a rapidly rotating wheel upon the work to be cleaned. Each Indabrator machine is fitted with right size and type of wheels and is powered by a motor of a required horsepower to do the job expected. How the Blast Wheel Works Abrasive from an overhead storage hopper is fed to the center of the wheel unit which is rotating at high speed. A cast alloy impeller rotates with the wheel and carries the abrasive to an opening in the stationary control cage form where it is discharged onto the bladed wheels. At this point, the abrasive is picked up by the inner ends of the throwing blades and is rapidly accelerated as it moves to the periphery of the wheel. When the blast wheel is properly adjusted and its elements are in good working condition, the full effect of the blast stream will be attained for maximum efficiency. Some of the more common causes and cures of wheel malfunctions are highlighted on these pages.

2 Control Cage One of the most critical components in the wheel is the control cage. This governs the directions of the blast out of the wheel and onto the work to be cleaned. As little as 10% mis adjustment of the hot spot can reduce cleaning efficiency by 25% or more. In the sketch of a clockwise down blast wheel, the center of the hot spot is located 8 ¾ to the right of the vertical centerline of the wheel. The location of the hot spot is directly controlled by the setting of the leading edge of the control cage opening which in this sketch, is set at 11:00 o clock. Impeller Of equal importance in maintaining the desired blast pattern is the effect of abrasive wear on the impeller. To properly distribute the abrasive over the blade throwing surface, there must be a lead between each impeller segment and its corresponding blade. If the leading edge of any segment of the impeller becomes worn so that it becomes parallel with the blade, the abrasive will cut through the bottom of the blade and could create wear on the steel spacer and blade slots. Not only will the blast pattern be affected but also wheel imbalance will result creating additional serious problems. Wear Affects Efficiency Complaints of longer than normal cleaning cycles, inadequate cleaning and high maintenance costs can usually be traced directly to loss of directional control over the blast pattern. Of course, the blast pattern must be set properly in the first place but it can change for a variety of reasons. Wear on the wheel parts which control the Hot Spot control cage, impeller and blades is the chief cause for changes in this pattern. Inspect them regularly and replace them as soon as excessive wear is detected. Ammeter A Tool to Control Cleaning Efficiency The ammeter on each Indabrator machine wheel motor is an important tool to help you control cleaning efficiency. It is the only way of determining at a glance how much abrasive is being thrown by the wheel. For example, on a typical Indabrator machine, with a 19 ½ diameter by 2 ½ wide wheels using a 15 HP motor on 440 volts approximately 8 amperes would be used without any abrasive flowing into the wheel. Under full load, 20 amps would be used. The abrasive thrown under full amperage would weigh about 375 pounds per minute or about 31 pounds for each abrasive load ampere. If the wheel were operating at 17 amps rather than 20, there would be over 25% reduction in wheel efficiency. When the wheel is operating at less than full amperage (as stamped on the plate above the ammeter) this usually means there is an insufficient amount of abrasive in the machine but it may also indicate poor adjustment of the wheel parts, it is important that the cause of this low amperage be corrected immediately since longer periods of blasting are required under these conditions to produce the desired cleaning results.

3 To overcome a flooded wheel condition A flooded wheel condition occurs when an attempt is made to feed more abrasive into the wheel than it is able to handle. This actually results in reduced feed of abrasive onto the blades as indicated by the resulting low amperage shown on the ammeter. Never try to fill the feed spout to full capacity with the abrasive flow. Adjust the abrasive control valve to a position which will provide free flow but retain an air space in the throat of the feed spout. Set feed spout as alone to impeller as possible. Never load wheel above full ampere load rating of motor. Check condition of the impeller and the tension of the motor drive belt. To overcome a starved wheel condition. No wheel can hurl the proper amount of abrasive if the machine is not charged with a sufficient quantity of shot or grit. Add the amount of abrasive required to replenish the supply. It is recommended that abrasive be added regularly in small quantities and at frequent intervals. No more than 10% of the hopper capacity. This insures a well conditioned operating mix. Also inspect the machine for any tramp metal, paper or other objects that could be lodged in the impeller or which could be clogging any screws, screens or feed spouts. Check for possible slippage of the elevator belt. Wheel Housing The blast wheel is enclosed within a housing whose primary function is to serve as a safety guard and abrasive seal around the rapidly rotating wheel. To minimize wear on the housing, a series of Long Lyfe protective liners are installed inside this housing. The latest protective liner kit, which is recommended for all M, R and RLM wheels, consist of only nine places. Labyrinth seals provide an abrasive tight closure between top, side and end liners. The curved top liner minimizes ricochet of abrasive back into the wheel. To Reduce Blast Cleaning Wheel Noise One of the chief sources of noise at the blast machine is the opening where abrasive is fed to the blast wheel. The SoundAbator totally enclosed abrasive control valve, which can be installed on most Indabrator machine machines, is specifically designed to combat noise from this source by sealing the opening to the wheel. It can reduce the noise level of a typical blast wheel, measured three inches from the abrasive feed inlet, by 25 decibels (A scale). The SoundAbator also serves another important function by modulating the volume of abrasive flowing to the blast wheel. The Wheel Tune up Kit Everything needed to restore the blast wheel to peak efficiency is contained in this Indabrator machine Tuneup Kit. A handy single package kit containing all the replacement parts needed for a complete tune up of the blast wheel. Experience has proven that worn wheel components cut blast cleaning machine efficiency drastically. Also, as components wear out, the blast pattern deteriorates. Abrasive that isn t focused on the work is wasted. So is energy as well as production time and labor. What Your Blast Wheel Expects From You

4 By paying prompt attention to danger signals, as indicated by observation and your system of cost control records, you can correct problems before they become costly, and maintain wheel operating efficiency at its highest level. The Abrasive Handling System Every Indabrator machine blast cleaning system contains the following elements: 1. The abrasive elevator. 2. A device to move abrasive from the elevator and provide preliminary screening of the abrasive before it enters the separator this may be by gravity or a screened rotary screw conveyor. 3. An air wash abrasive separator to remove all dust, fines and contaminants from the abrasive. 4. A hopper to collect refuse removed fro the abrasive. 5. An abrasive control device (SoundAbator) to control and meter flow of abrasive to the blast wheel. 6. A means of moving spent abrasive, sand and other contaminants to the elevator. This could be a helicoids screw, shaker conveyor or gravity. A SEPARATOR WORKS LIKE A VACUUM CLEANER Full abrasive curtain means an even flow of air. Distributed abrasive curtain. 1. allows contaminants to remain 2. Causes usable abrasive to be pulled out. The high efficiency CFS separator The role of the abrasive separator in the Indabrator machine operation is to remove sand, scale, abrasive fines and other contaminants from the abrasive operating mix so that only clean abrasive, properly sized, is returned to the blast wheel for reuse. The degree of success of the separator in a large measure determines parts life, abrasive consumption, and the type of finish given the work being blasted, and the speed and quality of cleaning. Although there are two general types of air wash separators used on Indabrator machine machines the gravity and compensating flow (CFS) discussion here will be centered upon the CFS type because of its more general usage and higher efficiency. The CFS separator is designed to utilize compensating flow to present a full length curtain of material to the air washing of abrasive. It is designed so that abrasive not the separator parts. The overhead rotary screen removes any tramp metal from the abrasive. It also spreads out the abrasive across the full length of the separator. Two baffles, as shown on the drawing a fixed sliding baffle and an adjustable swing baffle are utilized. When properly adjusted, the baffles permit only a full width current to be presented to the air currents.

5 Ventilation and Environmental Protection Since the blasting action removes sand, scale, rust, etc. from work and reduces the material removed to varying degrees of fineness, an adequate and properly operating dust collector system is necessary for efficient operation of the blast equipment. The predetermined flow of air from each of the vent points on the Indabrator machine machine must exist for proper operation of the machine. Although the failure to maintain this flow will soon become obvious through a reduction in cleaning efficiency and dusting at the machine, a periodic check on air volumes will preclude the possibility of an unobserved gradual degradation of operation. The dust collector is also the air source for the abrasive separator. The condition and efficiency of the dust collector have an important influence on separator efficiency. When proper ventilation is being experienced at each venting point, static pressure readings (with a manometer) should be taken in each of the vent pipes and these readings recorded as standards for future comparison. Should any future readings show material change in static pressures, it indicates an upset in the condition of air flow, the cause of which should be investigated immediately. Your Indabrator machine is probably ventilated by either a Indabrator machine (Shaker type) or ultra jet (Pulse type) fabric filters. These are simple yet highly efficient dust collectors and when properly sized will provide adequate ventilation for the Indabrator machine. Listed in the box below are a number of maintenance procedures which should be followed regularly to insure continuing ventilation to the Indabrator machine. The Indabrator machine Cartridge Filter System The Indabrator machine Cartridge Filter is a continuous, automatic pulse type Dust Collector. Dust particles are effectively captured on the outer surfaces of the cellulose non woven fabric cartridges. This construction and the highly efficient filter medium combines features of compact design with ease of servicing. A simple cam locking device is utilized for installation and removal of cartridge filters. The unique venture system sends a periodic metered jet of high pressure air down the inside of the cartridges, halting the in flow of air and expelling the collected dust from the outer surfaces. Dustube Fabric Filter The Indabrator machine Dustube Collector is a simple dependable air cleaner employing cloth filter tubes. Dust laden air entering the collector first strikes a baffle plate. The sudden change in velocity and direction causes heavier particles to drop into the hopper leaving only the finest floating dust particles to reach the tubes. To remove build up dust from the inside of the tubes, they are shaken when limp. Ultra Jet Pulse Type Collector The Indabrator machine Ultra Jet is a continuous automatic pulse type fabric dust collector. Its specially designed baffle plates opposite the air inlet deflect incoming dust laden air around the surfaces of all filter bags. To remove collected dust, a metered jet of high pressure air is released through the jet pump cleaning

6 system. This inflates the filter tube, halting in flow of air through the tube and expects dust from the outer surface of the cloth. Importance of Abrasive The final element of blast cleaning is the abrasive itself. Three important factors should be considered to evaluate the performance of the abrasive: 1. The amount of cleaning the abrasive will do in a given length of time. 2. The quality of the cleaning. 3. The cost of performing a given amount of work. This performance is determined by abrasive breakdown characteristics, the abrasive size distribution in the blast machine and the abrasive hardness. Abrasive breakdown rate affects the shape of the abrasive in the operating mix, and therefore the maintenance on the blast equipment. Abrasive size distribution is also influenced by the breakdown rate. The smallest size abrasive possible should be selected for each job. The size of the abrasive selected, however, is not the factor influencing consumption. Rather, it is the size at which the abrasive is removed fro the machine. Abrasive hardness is the third major consideration in arriving at proper product selection. The harder, tougher and more resistant the abrasive, the more useful energy it will impart to the cleaning task. When possible, use a low breakdown and high hardness product, characteristics found in Indabrator machine Steel Abrasive, for lowest maintenance costs and maximum cleaning efficiency. Controlling the Cost of Blast Cleaning A Indabrator machine blast cleaning operation involves the discharge of millions of abrasive pellets per hour. Any loss of abrasive out of the machine means increased operating costs because of the cost of abrasive and maintenance on equipment outside the blast chamber. The real indication of the efficiency of the Indabrator machine operation is the blasting cost per wheel hour. Since the basis of any cost record involves the compilation of abrasive added, parts replaced, maintenance labor, accurate records of these items should be maintained. The wheel hour meter on your machine will provide the record of the number of hours the machine was actually blasting. Since blast cleaning equipment is by nature self destructive, the accurate control and determination of operating costs is of particular importance. The better the maintenance practices and the more thorough the knowledge of the operating cost picture, the larger the dividends. Poor maintenance practices an be a very serious problem because operating costs can rise rapidly if efficiency of the Indabrator machine is not kept at peak condition. Routine inspections of all components on a regular schedule are recommended to prevent unnecessary breakdown and costly repairs.

7 Preventive Maintenance Cost Reduction through an Adequate Program of Preventative Maintenance The best way to lick costly maintenance and repair costs is to nip them in the bud before the little acorn (accent on ache ) branches out into a mighty oak. Preventive maintenance of Indabrator machine equipment is a major factor in any cost reduction program. Assignment of Responsibility Once the desirability of setting up a plan is determined, careful thought must be given to its organization. This can be very simple or quite involved depending upon the number of Indabrator machines involved and the production requirements. Trained Operators Operators of Indabrator machine machines should be capable, intelligent men who take pride in their work and machine. They should be able to detect problems when cleaning quality falls off or time for cleaning is longer than usual. The operator is the first line of defense in any maintenance program. Check Sheets are Desirable Without accurate operating information, it is impossible to determine abnormal performance. A check sheet has proven helpful to a great many of our customers in recording this information. We will be glad to assist you in formulating an acceptable check sheet. Spare Parts Inventory A well planned program means little unless adequate spare parts are available when needed. The spare parts stock control system can be very involved or entail. Merely a regular examination of the part available to determine reordering dates. The important point is to maintain a stock adequate to take care of regular replacements. Call Upon Indabrator If you are interested in setting up a preventive maintenance program, our field sales or service engineer will be glad to assist you. He can be of invaluable assistance to you in setting up a workable inspection program, in advising you as to an adequate parts and abrasive inventory, in recommending desirable controls and record forms, and provide training programs for you. Take care, Indabrator Service Team