Volumetric Concrete Mixer
The volumetric concrete mixer is a special design that helps to pour concrete effectively and with efficiency. There are several different benefits to using this type of mixer if you are working on a project that requires concrete or cement. The process that is used through a volumetric mixer adds to proficiency for the process of laying concrete.
Usually, these mixers contain four different bins in them. Each of these will hold a different material that is needed for mixing concrete. This includes cement dust, sand, stone and water. These different elements will then fall into a conveyor that is running through the bins. These are controlled by gates that open and close, allowing whoever is operating the gates to control how much material and mixture goes through the gates.
After the different materials move to create the mix, they are dumped into an auger. At this point, water or any other elements needed are be added to the mixture. This is where all of the mixing of the material occurs. If the mixture is a little off, it can be adjusted at this point. This allows complete control over the levels of mixture that are used before being poured onto the landscape.
The concrete then moves out of the auger and onto the ground. This is where it can be laid out properly and professionally. The benefits of this type of mixing of concrete are many. First, it allows the concrete to be fresh when it is laid. This helps in putting the finishing touches on the concrete. Second, when concrete is mixed through other types of mixing devices, it often comes out hot, making it harder to work properly. Often times, when the concrete is laid while it is hot, it will take a longer time to set in the right place and dry.
Usually, these types of mixers are available in several different sizes. They are best used when attached to a truck. The mixers are available at a smaller size of two yards, or four feet, or a larger size of twelve yards, or twenty-four feet. Depending on the projects that will be done with these mixers, you can control how large or small you will need to have the mixer.
By using volumetric concrete mixers to pour landscapes and roads, it allows for more efficiency. These mixers have been used as a special design to allow companies and individuals to mix and maintain concrete. By using the special process through these types of mixers, it allows for more proficient lying of concrete.
Chemical Cleaning of Oil Refinery Heat Exchangers — The Need for a Joint Effort
One component of the high cost of fouling to oil refineries is the maintenance money spent to clean fouled heat exchangers and the associated lost production while the exchanger is out of service. This presentation will highlight some specific fouling situations in oil refineries which can benefit from chemical cleaning. Cooperative efforts are needed between refinery operators, researchers, and chemical suppliers to develop the proper solvents and to find the optimum procedures to use them for cleaning.
New Chemical Cleaning Agent Developed.
Lanzhou Research Institute of Corrosion Inhibition Technology has successfully developed scale remover GR-943, a new chemical cleaning agent used to clean heat exchangers. The product has passed the appraisal organized by the Science Commission and the Labor Department of Gansu Province
Jiang Shaohua, Director of the research institute, developed acid washing corrosion inhibitor Lan826 in 1984. It replaced the traditional scale removing method of caustic soda boiling and manual scraping. He won the third state invention prize. Thanks to this invention, the annual output value .
Chemical cleaning treatment of textured nickel for the deposition of epitaxial thin films
Coated conductors employing rolling-assisted-biaxially-textured-substrates offer a viable alternative to the BSCCO power-in-tube tapes. These conductors are based on the deposition of biaxially oriented buffer layers and YBCO films on textured nickel alloy substrates. Researchers are becoming increasingly aware that the cleanliness of the nickel surface plays a crucial role in making it conducive to epitaxial film deposition. Several cleaning techniques are currently being explored. In this work we report the results obtained from a simple chemical cleaning procedure based on an aqueous solution of formic acid and hydrogen peroxide. X-ray photoelectron spectroscopy studies were performed to understand the effect of the cleaning treatment on the nickel surface. It was found that the cleaning treatment significantly enhances the ability of the nickel to act as a crystallographic template for the deposition of strontium titanate using a metallorganic decomposition process. These results give promise for the development of scalable cleaning procedures for coated conductor applications.
One-man ultrasonics does more cleaning work
While a two-man labour-intensive system turned out a maximum of 10 units/h, an ultrasonoics cleaning system guarantees at least 15 units/h, and needs only a single operator.
A world leader in the design and manufacture of coin and bill mechanisms for vending machines has speeded cleaning of coin acceptor units with a Kerry CRD ultrasonic clean, rinse and dry system. Having recognised that its manual cleaning process could no longer cope with an increase in the required volume of throughput, the company decided to investigate alternative finishing methods. Speed of response coupled with an on-site demonstration of the process with its improved cleaning quality were deciding factors in clinching the order.
The CRD450 removes dirt, debris and sticky residues from plastic electro-mechanical coin acceptor units, including copper wire wound components.
Failure to adequately clean the mechanisms would result in them malfunctioning in the field.
Whereas the company’s previous two-man labour-intensive system turned out a maximum of 10 units per hour, the CRD machine guarantees at least 15, needs only a single operator and finishes each component to a uniform level of cleanliness.
Coin acceptor units first undergo an aqueous ultrasonic clean before passing through a mains water rinse and finally a warm-air dry.
* Cleaning trials - following the integration of Kerry Ultrasonics into Guyson International in 2004, Kerry CRD systems are now available from Guyson, who offer free cleaning trials with no obligation to buy.
Ultrasonics clean up effectively for plating
Ultrasonic clean and rinse systems effectively remove polishing compounds before electro-plating from items as diverse as door furniture: handles to motorcycle components.
Guyson International - who acquired Kerry Ultrasonics early in 2004, is now providing manufacturing, sales, support and service from its extensive 10,000m2 facility in Skipton in the North of England, for the Kerry Pulsatron UCR (ultrasonic clean and rinse) systems. Pulsatron UCR systems effectively remove polishing compounds before electro-plating from items as diverse as door furniture: handles, plates, letterboxes and locks, light fixtures, bathroom fittings, auto and motorcycle components to intricate electronic and audio components, where any contamination remaining on the product would result in poor adhesion and lifting of the plate. With all aqueous wash tanks a detergent additive is essential to ensure effective removal of contaminants.
To avoid potential staining of the cleaned parts by detergent residues adhering to the surface subsequent water rinsing is critically important.
The UCR two-tank system incorporates both ultrasonic cleaning and immersion/spray rinsing to overcome this problem leaving parts completely residue free and ready for processing.
The latest Kerry UCR systems have been designed to achieve optimum cleaning results.
Ultrasonic transducers bonded to the tank base provide high performance and reliability together with uniform distribution of the ultrasonic energy.
The frequency is tuned to the individual tank/transducer combination and then optimised under normal usage conditions with frequency sweep and fully automatic tuning.
Pulsatron UCR tanks allow the user to pre-set exact cleaning times and temperatures, ensuring consistent levels of cleanliness from batch to batch and providing an affordable way to improve cleaning quality.
All functions are controlled by a simple four-button membrane keypad.
An LCD panel displays the temperature and time set by the user, the time elapsed since the start of the cleaning process, and the status of the power supply, heater and ultrasonics.
Each unit works within operating temperatures from 20 to 80 deg C which can be set in 1-degree increments, allowing the optimum temperature to be selected for a particular combination of component material, cleaning solution and contaminant.
Sonics time may be set in the range 0.1 up to 99.9 minutes in 0.1 min increments, or to constant when sonics may be switched on and off manually.
Automatic safety devices include non-operation of sonics if solution temperature is more than 10 deg C above set temperature, and low-level protection to prevent heater burn-out if solution level drops.
Advice given on solvent cleaning legislation
Advice is given on coping with legislation and solvent cleaning and how it affects the industrial user by Stowlin Croftshaw, reported here by Derek Carpenter.
For anyone dealing with solvents over the past 15 years it will have seemed a period of uncertainty and change. For most people, manufacturing finished or semi-finished parts inevitably involved solvent cleaning using a vapour degreaser. For the UK at least this was the tried and tested method that could provide consistent results.
During the 1980s you could probably have split users product choice equally into the 1.1.1.
Trichloroethane or Trichloroethylene camps.
Then came concerns for the environment.
In particular ozone depletion and its potential damage to our stratosphere.
Since 1.1.1.
Trichloroethane had the greater ozone depletion potential and an atmospheric lifetime beyond 5 years it was phased out.
No absolute science existed at the time but a precautionary principle and the alternative availability of Trichloroethylene seemed to provide a necessary response to an uncertain dilemma.
I’m often asked: ‘was it for politics or science?’ I believe the science was never validated if it ever existed.
As the years have passed the precautionary principle has ‘ruled’ and resulted in major debate about the solvent legislation that has followed.
No-one would wish to argue against responsible protection of environment, operators and the community around us.
It is of course reasonable to expect a full scientific argument to exist prior to regulation and this cannot always be assumed.
In the end of course we must ensure all legal obligations in law are met to protect our business and show our due diligence.
The trends driven by the European parliament looks set to continue to provide challenges.
With a stated intention to test and approve 30 - 100,000 chemical products their own study prepares the UK for a loss of GBP 3.42 billion a year! (see leaflet ‘your business is under threat’ - BCDTA).
The fear remains that no budget exists to ensure a diligent scientific approach.
Inevitably our options to achieve chemical cleaning will reduce.
The precautionary principle may yet be held as the final word for legislation.
I hope it never becomes a substitute for hard science.
Coming up to date the majority of solvent users with a vapour degreasing system will be using Trichloroethylene.
Others may have chosen Methylene Chloride or Perchloroethylene as the other alternative chlorinated group.
Beyond chlorinated solvents the fastest growing alternative comes from n-Propyl Bromide technology.
All are direct replacements for vapour degreasing.
At the onset we must understand one constant thread of solvent legislation.
These are regarded as useless.
In time a typical solvent user will be 1 to 3 tonnes per annum.
That is your immediate challenge.
Trichloroethylene faces the most immediate issues.
Why?
Because the legislation is in place and you now need to respond to the legal obligations outlined.
Two potential areas of solvent legislation that you should be aware of are: * The environmental protection Act - 1990.
* Integrated Pollution Prevention and Control (IPPC) - 1999.
However, my intention is to focus on two other vital areas: 1 - Reclassification of Trichloroethylene by the European Union in June 2001.
2 - The solvent emissions directive (1999/13/EC).
Each has a serious impact on a users continuing ability to use Trichloroethylene.
Oddly, reclassification has been better understood whilst the Solvent Emissions Directive appears to have caused confusion.
One constant of both is that Trichloroethylene must now be considered as carcinogenic under coshh with an obligation to seek its elimination.
In general your choice of product classifications are: * R45 - May cause cancer.
* R40 - Limited evidence of carcinogenic effects.
* R20 - Harmful by inhalation.
Our solvent choices fall into the following categories: * R45 - Trichloroethylene.
* R40 - Methylene Chloride and Perchloroethylene.
* R20 - n-Propyl Bromide.
Debates about the rights and wrongs of classifications can be contentious.
A risk phrase should be created where the potential risk might arise in ‘Normal working circumstances’.
At times it may appear that a hazard, albeit highly unlikely, has unfairly been issued a risk phrase.
In the end we are required to deal with the established rule of law.
Given the pressures on Trichloroethylene we should now be seeing some impact on its reduced use if the spirit of legislation is being upheld.
Looking at Western Europe back in 1996 101,000 tonnes were in use.
By 2000 figures dropped to 74,000 tonnes and thereafter in 2001 to 63,000 tonnes.
(a decline in 6 years of 53%).
Figures for 2002 are likely 47,250 tonnes with a realistic prediction for 2007 being below 10,000.
( a 90% reduction over 11 years!).
The impact of legislation is clear.
The outcome brings product users back to assessing a suitable alternative.
This must always be measured by performance benefits but science is a guide to safety.
Most toxicological studies to consider safety profiles are performed on exposure to rats or mice.
These are important.
No singular study should ever make another void.
Risk assessment involves collecting as much data as possible to produce the best judgement.
One valuable comparative study by Dr Mark Stelljes, Ph.D.
acts as one very useful aid.
As a world renowned toxicologist with SLR International Corp (Concord CA) who specialises in risk assessment and management he concluded a human in vitro bioassay study of commonly used cleaning solvents.
It is considered that this study marks the first time 1.1.1.
Trichloroethane, Trichloroethylene, Methylene Chloride, Perchloroethylene and EnSolv (stabilised n-Propyl Bromide) have been selected to an identical set of tests on human cells.
It assists on judgement of the relative human toxicity of these solvents.
* Most toxic were Trichloroethylene and Perchloroethylene.
* Least toxic were EnSolv and Methylene Chloride.
(see full study in technical file of ‘Surface World’ Issue of July/August 2001).
* The real issue of the moment is the Solvent Emissions Directive (SED) - if you are a user of Trichloroethylene, Methylene Chloride or Perchloroethylene in excess of 1 tonne per annum or a brominated solvent in excess of 2 tonnes per annum you have obligations under this directive.
1 tonne represents the following litres: * Trichloroethylene - 685.
* Methylene Chloride - 752.
* Perchloroethylene - 617 * 2 tonnes of n-Propyl Bromide (EnSolv) is 1504 litres.
Falling below these figures would provide the benefit of being exempt from this legislation.
To assist a simple understanding we need to consider some essential questions and answers.
Q - Is this a UK directive?
A - No.
This legislation must be adopted by all European Union countries.
Delays will result in infringement penalties.
All must keep in mind the principle of this legislation.
‘The aim is to prevent or reduce the direct or indirect effects of volatile organic compounds (VOC’s) into the environment, mainly into air and the potential risks to human health.’ In essence protection of workplace, environment and the local community is sought.
Q - Who interprets the legal obligations under SED?
A - The Secretary of State for the Department for Environment, Food and Rural Affairs (DEFRA) determines England and Wales whilst the Scottish Environmental Protection Agency (SEPA) offer advice for Scotland.
Q - Who is affected/exempted?
A - If you use more than 1 tonne per annum of chlorinated solvents or more than 2 tonnes per annum of brominated solvents you have obligations under SED.
If you achieve product levels below these you are exempt under this legislation.
Q - How long can I continue to use Trike?
A - Trike is not banned for use.
However if you currently use in excess of 1 tonne per annum (685 litres) you must seek substitution in the ’shortest possible time’.
Q - Can improvements to machinery extend my use of Trike?
A - Only if it places you below 1 tonne per annum and no safer alternative exists.
Machinery is not the issue.
Product volume is.
Q - What if I cannot afford an alternative?
A - This is not accepted as a reason to delay.
A period of transition is built in from 1999 to allow companies to plan the necessary change.
Given that it is possible to find an alternative a more appropriate question would be ‘why is it necessary to delay?’ Q - What is expected of me?
A - Strong advice has been given by DEFRA to determine any obligations under SED and thereafter to create a substitution or reduced emissions plan which will be viewed by the regulator.
It is necessary to set your target with a timescale to achieve it.
This information will become a public record and will form the basis of future permits to continue using your cleaning system.
Q - What obligations exist for Perchloroethylene and Methylene Chloride?
A - No obligation to substitute exists.
However to achieve permit status the following emission standards will need to be achieved: * Perchloroethylene - 3 parts per million.
* Methylene Chloride - 6 parts per million.
* n-Propyl Bromide would be 14 parts per million.
Q - Is there a final deadline to achieve the emissions target?
A - Yes.
The absolute deadline is 31st October 2007.
Q - What happens if I change my existing equipment or substantially change my process?
A - Under these circumstances you would need to comply with SED with immediate effect.
You should take specialist advice before considering changes to avoid any difficulties.
Q - Can I delay, awaiting DEFRA guidance?
A - Do not be misled by misinformation.
Some suppliers promote this idea but guidance is available.
A recent guidance document can be viewed on: www.defra.gov.uk/environment/airquality/lapc/default.htm Statutory Instruments already exist to allow prosecution if a willful abuse is considered to exist.
It makes sense to seek compliance.
Never forget that this legislation dates back to 1999.
Ample time to prepare for adoption.
If you are a Trike user not affected by SED remember you are still required to seek a safer alternative under reclassification regulations.
From a 2003 poll of UK companies it was found that the following five primary objectives were commonly sought: * Safe working environment - 90%.
* Reduced solvent emissions - 78%.
* Reduced solvent use - 73%.
* Quality of product - 70%.
* Regard for the environment - 64%.
These are commendable objectives.
With so much legislation to consider always seek the advice of a specialist supplier who offers full technical support.
Legislation is often felt to be burdensome but the spirit of intention is good.
Working in line with it will bring benefits to your business, not least from the reduced level of product you will need to use to achieve good performance without compromising safety.
The EnSolv roadshow was first established as an educational forum in 2002.
Due to renewed popular demand it is now returning in 2005 to update on all aspects of solvent degreasing.
Independent chemical suppliers and equipment manufacturers will contribute their added assessments.
A half day forum will travel to UK cities.
No cost to attendees exists and a complimentary buffet lunch is provided.
Experience suggests interest will be high.
Health, safety and environment officers and production managers will find this forum of value, joining companies with similar issues.
UK’s MOD approves cleaning fluid
Following trials with a variety of products, a cleaning fluid has gained the UK’s MOD Defence Standard number 08-121 (NES 844) for the cleaning and preparation of surfaces prior to bonding.
Fast Dry Precision Cleaner (DSI 1000FD) has been awarded a DEFSTAN number as approved for use within the armed forces in the UK. Following a search and trials with a variety of products, Fast Dry Precision Cleaner (DSI 1000FD) was awarded the MOD Defence Standard number 08-121 (NES 844) for ‘Acoustic Cladding Treatment Using Epoxide Adhesive Systems’ - essentially the cleaning and preparation of surfaces prior to bonding (MOD is UK’s Ministry of Defence - Ed). Fast Dry Precision Cleaner (DSI 1000FD) was chosen due to its excellent degreasing performance, fast drying capabilities and good safety profile.
The fact it is not a chlorinated, aromatic or paraffin-based cleaner was very much in its favour due to the enclosed working conditions.
Based on the same best-selling Citrus chemistry as our High Performance Degreaser (DSI 1000), Fast Dry Precision Cleaner (DSI 1000FD) is designed for the degreasing and precision cleaning of engineering and electrical components, including printed circuit boards.
It has a high dielectric strength of 30,000V and removes soils such as oils, greases and cutting fluids.
It is ideally suited to the pre-treatment of surfaces prior to bonding or coating as the fast drying formulation leaves no surface residue and contains no ozone depleting chlorinated solvents.
As part of a complete, industry proven cleaning solution, the De.Solv.It range from Mykal can offer excellent degreasing performance, approved at the highest levels of industry, without compromising on User and Environmental safety.
Shotblaster can be integrated with sawing/drilling
Especially developed for the surface treatment of beams and plates, a roller conveyor shotblast system can also be combined with a sawing and/or drilling system.
Voortman Automatisering has recently extended its delivery programme with a roller conveyor shotblast system, especially developed for surface treatment of beams and plates. At this moment Voortman has delivered shotblasting machines in several European countries. The VSB1500 shotblaster can be delivered with roller conveyors, liftable cross transports or complete tailor-made solutions.
The shot blaster can also be combined with a sawing and/or drilling system, enabling a fully automated production system for the pre-fabrication of steel constructions.
Advantages of such an automated system in comparison with stand-alone installed machines are for example the substantial increase of production capacity and the production speed.
At the same time less operators are necessary.
The result is that the production costs are reduced substantially.
‘Magic’ weld cleaning is more eco-friendly
Thermo-chemical stainless steel cleaning method removes only the oxide layers generated by heat treatment or HAZ, so that the optical surface smoothness is fully preserved.
The heat treatment of stainless steels (in particular when welding) creates troublesome oxide layers which have to be removed. In addition to mechanical processes such as grinding, brushing, shot-blasting, chemical processes with aggressive pickling pastes have traditionally been used. The ISOjet III’s thermo-chemical method is faster, less hazardous and more ecological.
The ISOjet III stainless steel cleaning apparatus, manufactured by ISO in Switzerland, operates on the thermo-chemical principle.
In contrast to other cleaning processes and thanks to the wand and the electrolytes, specially selected for this process - only the oxide layers generated by the heat treatment are removed.
This guarantees that the optical surface smoothness is fully preserved.
The cleaned work piece merely has to be rinsed with clean water.
The passive layer required for the corrosion resistance of the steel is preserved by the ISOJET III method (corrosion tests as per DIN 50921).
No subsequent passivation is needed, and one step in the operation can be omitted.
The Isojet III is attached to a 230V or 110V electrical supply with an adjustable constant current.
The electrolyte is supplied simply by dipping the wand into the fluid.
ISO prefer this method to intregrated fluid pumps and feeds because of the high maintenance cost and failure rate such systems demand.
Once the wand is dipped in the electrolyte and the current for cleaning is chosen the wand can be moved over the discoloured weld at a rate of up to 2m/min, leaving a clean surface on both grained and polished stainless steel.
* Magic printing is no conjuring trick - ISO also offer a ‘Magic Printing’ function.
This refers to the electro-chemical etching of chrome nickel materials.
Company logos, codes, names or other data can be applied without any problem, creating a permanent and corrosion- resistant effect.
‘Magic Printing’ is simplicity itself to use.
Set the unit voltage to ‘ETCH’, place the stencil on the work piece, moisten the printing felt and the film with the special etching electrolyte, pass the electrode over two or three times, and the printing operation is complete.