Maximizing Overall Ultrasonic Cleaning Effect

Cleaning Chemical selection is extremely important to the overall success of the ultrasonic cleaning process. The selected chemical must be compatible with the base metal being cleaned and have the capability to remove the soils which are present. It must also cavitate well. Most cleaning chemicals can be used satisfactorily with ultrasonics. Some are formulated especially for use with ultrasonics. However, avoid the non-foaming formulations normally used in spray washing applications. Highly wetted formulations are preferred. Many of the new petroleum cleaners, as well as petroleum and terpene based semi-aqueous cleaners, are compatible with ultrasonics. Use of these formulations may require some special equipment considerations, including increased ultrasonic power, to be effective.

Temperature was mentioned earlier as being important to achieving maximum cavitation. The effectiveness of the cleaning chemical is also related to temperature. Although the cavitation effect is maximized in pure water at a temperature of approximately 160°F, optimum cleaning is often seen at higher or lower temperatures because of the effect that temperature has on the cleaning chemical. As a general rule, each chemical will perform best at its recommended process temperature regardless of the temperature effect on the ultrasonics. For example, although the maximum ultrasonic effect is achieved at 160°F, most highly caustic cleaners are used at a temperatures of 180°F to 190°F because the chemical effect is greatly enhanced by the added temperature. Other cleaners may be found to break down and lose their effectiveness if used at temperatures in excess of as low as 140°F. The best practice is to use a chemical at its maximum recommended temperature not exceeding 190°F

Degassing of cleaning solutions is extremely important in achieving satisfactory cleaning results. Fresh solutions or solutions which have cooled must be degassed before proceeding with cleaning. Degassing is done after the chemical is added and is accomplished by operating the ultrasonic energy and raising the solution temperature. The time required for degassing varies considerably, based on tank capacity and solution temperature, and may range from several minutes for a small tank to an hour or more for a large tank. An unheated tank may require several hours to degas. Degassing is complete when small bubbles of gas cannot be seen rising to the surface of the liquid and a pattern of ripples can be seen.

The Ultrasonic Power delivered to the cleaning tank must be adequate to cavitate the entire volume of liquid with the workload in place. Watts per gallon is a unit of measure often used to measure the level of ultrasonic power in a cleaning tank. As tank volume is increased, the number of watts per gallon required to achieve the required performance is reduced. Cleaning parts that are very massive or that have a high ratio of surface to mass may require additional ultrasonic power. Excessive power may cause cavitation erosion or “burning” on soft metal parts. If a wide variety of parts is to be cleaned in a single cleaning system, an ultrasonic power control is recommended to allow the power to be adjusted as required for various cleaning needs. Part Exposure to both the cleaning chemical and ultrasonic energy is important for effective cleaning. Care must be taken to ensure that all areas of the parts being cleaned are flooded with the cleaning liquid. Parts baskets and fixtures must be designed to allow penetration of ultrasonic energy and to position the parts to assure that they are exposed to the ultrasonic energy. It is often necessary to individually rack parts in a specific orientation or rotate them during the cleaning process to thoroughly clean internal passages and blind holes.

Conclusion

Properly utilized, ultrasonic energy can contribute significantly to the speed and effectiveness of many immersion cleaning and rinsing processes. It is especially beneficial in increasing the effectiveness of today’s preferred aqueous cleaning chemistries and, in fact, is necessary in many applications to achieve the desired level of cleanliness. With ultrasonics, aqueous chemistries can often give results surpassing those previously achieved using solvents. Ultrasonics is not a technology of the future — it is very much a technology of today.

Procedure For Starting Fresh water Generator On Ships

Fresh water is an important commodity on board ships, especially on long sea voyages. Hence the procedure for starting the fresh water generator on ships should be familiar to the senior watch-keeping engineer as they need to be started as soon as the ship enters open sea.

As a ship normally sails on long voyages, certainly drinking water is one of the most vital elements required on board. If you are thinking that this should not be a problem since the oceans contains unlimited water, read this article on the effects of drinking sea water and especially imagine the condition in areas such as the Dead Sea. Hence a provision for converting salt water to fresh water exists on ships, and the machine is known as the fresh water generator.

We have learned about the fresh water generator and its working in our previous articles, but it is a different thing to know how and when to start these water generators on a ship.

When I was a ships engineer many years ago, we had evaporators that used steam coils to heat and evaporate the seawater before it was cooled and processed to distilled water. In those days of large water-tube boilers supplying superheated steam to the main turbine, a lot of distilled water was required to make-up the boiler feed water. Today’s motor ships require much less water than the older steamships, but water is still required for drinking and domestic use.

The modern equipment we use for this is examined in the following sections; here we will see the methods and sequence involved in start-up the various components, as well as when it is safe to run the generators. The first section deals with the regulations regarding the safe processing of drinking water from seawater.

·        Regulations Regarding Safe Production of Drinking Water from Seawater

Current marine regulations regarding seawater distillation using a fresh water generator stipulate;

·        The FW generator can only be started when the ship is 12 nautical miles away from the nearest coastline.

·        The engine must be running at full sea speed at start of passage as advised from the bridge.

This will ensure all the main engine temperature and pressure parameters are normal, main engine is on sea speed and not in congested waters and all maneuvering completed

·        Start-Up Procedures

The fresh water generator should be fired up once the above regulations and requisites have been achieved; using the guidelines listed below.

1. Check the jacket cooling water temperature outlet from the main engine - it should be constant

2. Open both the ejector pump suction valve and the overboard discharge valves.

3. Close the vacuum breaker valve

4. Open main sea water feed inlet valve inlet and discharge valves to and from the generator condenser; (the seawater can also be supplied from a stand-by sea water pump; if this is to be used instead, open the pump main inlet and discharge valves and start the pump)

5. Check salinometer (salinity indicator) and distillate pump operation

6. Start the ejector seawater pump and maintain the pressure of 5kg/cm² or higher

7. Check that the vacuum inside the shell is slowly rising as the ejector removes the air from the unit.

8. When the vacuum gauge reading reaches about 17mm of mercury, slowly open the seawater feed to heating tubes.

9. Check the seawater level inside the shell through the sight glass and adjust this water level using the feed inlet valve.

10. Once the heating coils have been covered with seawater; open the jacket water inlet valve slowly to the full open position whilst throttling back the jacket water outlet valve.

11. The effect of the jacket cooling water circulating through the heating tubes causes the shell vacuum to drop, its temperature to rise and feed water level to fall.

12. When all the above is stabilized and running normally; the seawater starts evaporating and steam can be observed rising up through the demister units to be condensed by the condenser coils.

13. Once condensed, the fresh water droplets fall downwards to be collected in the plate collector tray. This can be witnessed through the sight glass

14. When the gauge glass level on the plate collector is more than ¾ full, put the salinity indicator to 'ON' position.

15. Divert the processed water to the bilges or return it to the feed system again till the salinity level comes to the required set value of 5-10 ppm (Parts per million)

16. When the salinity level comes to set value, open the discharge valve of distillate pump to the fresh water tank through the flow meter and start the pump

17. The evaporation rate can be increased by throttling the jacket cooling water return outlet

18. Check for the tank vacuum has stabilized.

19. Observe the following gauge readings on a regular basis;

·        Inlet and outlet temperature of jacket cooling water

·        Condenser sea water inlet and out let temperature

·        Feed water level inside the shell

·        Distillate level

Notes:

·        The salinometer is designed to alarm, automatically shutting the freshwater discharge valve to the storage tank, and dumping the distillate to bilge when maximum salinity is exceeded. It is always best to check the diverter valves are all operating as these can stick due to heat/coating of salts.

·        The distillate level in gauge glass should be monitored and always maintained at half gauge glass level when the distillate pump is running

·        Remember to check the main engine jacket water cooling temperatures once the freshwater generator has settled down.

Generating Drinking Water on Ship - The Magic Machine

How is fresh water generated on a ship? Is it possible to generate drinkable fresh water from sea water?

Yes and for this purpose, a fresh water generator is used on a ship.This article will show the arrangement and working of a normal fresh water generator on a ship.

Introduction

Fresh water is of dire need on a ship. It is used for various purposes such as drinking, for preparing food, in laundry services and in many other day to day activities. In the past, people used to carry tons and tons of fresh water in barrels or in specially made tanks. This was because there were no other sources of fresh water once the ship was in sea, except rain, which was quite unpredictable.

Today in spite of means on board to generate fresh water, ships carry tons and tons of fresh water in segregated fresh water tanks. But there are many other processes in which fresh water is used and as generally the fresh water tanks provided are not sufficient, the need arises to generate fresh water onboard. Fresh water is always in dearth also because it is very difficult to keep a check on the water usage by the crew members and also the usage cannot be avoidable as water is continuously required onboard ship.

Fresh water is generated on ship by a fresh water generator, also known as evaporator. The process by which fresh water is generated is known as distillation process. Sea water is converted into fresh water by evaporating and condensing the sea water. Evaporation of the sea water is either done by boiling or by flash process. This process enables the reduction of 32,000 parts per million in sea water to 1 to 2 parts in fresh water. Fresh water generators can be tube type or plate type.

 Single stage fresh water generator

A fresh water generator consists of mainly two parts. A condenser and an evaporator. The boiling process is done either by a heating coil or by using the high temperature main engine jacket water. In some FWGs, heating is also done by superheated steam. Generally water is boiled at 100 degree Celsius, but in freshwater generator it is done at around 60-70 degree Celsius. For this purpose, educators or air ejectors are use. Eductors reduces the chamber’s pressure to such a point that water starts boiling at a temperature of 60-70 degrees Celsius. A flow meter is used to regulate the flow of sea water into the generator. The freshwater generated in the condenser is later collected by a distillate pump. A salinometer is used to check the salinity in the fresh water generated.

Working of the FWG

The hot jacket water from the diesel engine is passed through the evaporator’s heated nest. The sea water enters the evaporator through the flow meter and due to the low pressure of the chamber; it boils and gets converted to steam. Generally the feed of the seawater is kept half the stated quantity to facilitate adequate boiling of sea water. The steam then passes through a steam separator, in which the water particles in the steam are separated and collected.

The steam then enters the condenser, where it cools down to form fresh water. It is then removed from the condenser with the help of a distillate pump. The remainder sea water particles or the brine which gets collected at the bottom is drawn out with the help of an ejector pump.

Flash process- Increasing the efficiency

A liquid which is already having sensible amount of heat when introduced in a pressurized chamber, immediately gets converted to steam, i.e. in a flash, without the boiling process. Thus the phenomena can be used to acquire higher level of efficiency by controlling the exact pressure and temperature of the water, which will lead to higher energy efficiency.

Chemical Cleaning Facts - All Those Chemicals Don't Do That Much Harm, Do They?

Do you want to know the cleaning facts that are not widely publicised? If you’ve ever read the ingredients on the labels of your household cleaners, you’d know that they contain a number of different chemicals. You’re also probably aware that these chemicals have a distinct smell or odour. This article is intended to tell you what you probably don’t know. All the cleaning facts in this article have a direct affect on you and it should be your right to know them.

Our cleaning facts research states that there are over 75,000 chemicals licensed for commercial use in today’s world, with about 2000 new synthetic chemicals licensed each year. A large number of these chemicals are suspected carcinogens or are thought to cause a number of health problems. It may surprise you to know that only 600 of these chemicals have been adequately tested. Commercial cleaning product companies are under no legal obligation to research how their products might harm human health. What’s more, only 1% of toxins are required to be listed on the product label. This is because companies classify their ingredients as ‘trade secrets’. -Lorie Dwornick, researcher, educator and activist, 2002

Want more cleaning facts? According to the Federal Environmental Protection Agency, chemical levels in the home are up to 70 times higher than outside. It has been proven that air quality inside the average American household is 2 to 5 times more contaminated than the outside air. This is due largely to the chemicals found in commercial products such as cosmetics and cleaning products. In 1985, research by the EPA concluded that chemicals in household cleaners are about 3 times more likely to cause cancer than any other air pollutant. Did you know that in the early 1900’s, only 1 in every 8,000 Americans developed cancer. This ratio has dropped to 1 in every 3 today!

Our cleaning facts research has also alerted us to the dangers concerning our children. Over a million Americans are treated for exposure to household cleaning products. The majority of these are children under the age of 12. When you take into account the weight difference between that of a child and that of an adult, the amount of air, food and water consumed by a child is far greater than that of an adult. This means that they are exposed more to pollutants than adults. A child’s immune system is also less developed and their developing cells are more easily damaged. Pollutants in the air tend to be more concentrated towards ground level. Children breathe air which contains more pollutants simply because of their height. They also tend to spend more time playing on the floor and in contact with cleaning product residues. Those chemicals which are tested are only tested for adults. Children are not considered. Does this sound worrying? What affect is our chemical lifestyle having on our children’s health?

The chemical industry claims that very low levels of exposure to these chemicals are safe, yet there have been no exposure studies completed for the large majority of these chemicals. There is also limited information as to how these chemicals interact with each other. According to the EPA, combined chemicals are far more dangerous. Did you know that mixing Ammonia with bleach results in a toxic gas extremely lethal to humans? If you also check the ingredients of many household cleaners you will find that they often contain both ammonia and bleach.

If you remember any of these cleaning facts, remember this. Petrochemical cleaning products are absorbed easily through our skin. The chemicals travel through our blood stream and are stored in our fatty tissues. Over time, the build up of these toxic chemicals causes many health problems, including cancer and Alzheimer’s disease. All this can be avoided with the use of ‘green’ products which contain no toxic chemicals and are much safer for the environment. You should also be aware that all the chemicals that you wash down your drains will inevitably end up in our rivers. The water in our rivers is put through a water treatment plant where it is mixed with even more toxic chemicals. It is then returned to us in our taps. Everything that we do to the environment we also do to ourselves!

5 interesting cleaning facts

Cleaning Fact 1: Cold water will inhibit the spread of bacteria and germs. Hot water only encourages the growth of nasty organisms.

Cleaning Fact 2: Antibacterial soaps are really not necessary in the home and may do more harm than good.

Cleaning Fact 3: Commercial dish washing detergents often leave chemical residues on your dishes that accumulate each time you wash them. Those chemicals are absorbed into your food.

Cleaning Fact 4: If a chemical kills half of a group of test animals it is labeled toxic. If the lab animals survives after being exposed to an amount greater than that listed it is labeled non-toxic. These tests are not specific to humans and do not consider long term exposure. (Lab animals often include mice which have a stronger immune system than humans.)

Cleaning Fact 5: Women who work at home are at a 54% greater risk of developing cancer than women who work away from home. A 15 year study concluded that this is a direct result of the chemicals in household products.

Check out for more information on Chemical cleaning.

The Significance of an Air Cooler

One of the most prominent reasons for using an air cooler is the fact that it tends to bring a huge drop in the temperature within areas that are hot or warm for instance. These have been used since quite a long period of time now and are excellent for combatting heat always. Often compared a lot with air conditioners, people sometimes may even think that they are the same thing but in reality, they are entirely different from one another. These coolers are easy to purchase and are being used in countless homes in the world these days due to the fact that they provide high end cooling at all times.
A Huge Decrease in Electricity Bills
A prominent thing to note about these coolers is the fact that they consume a very less amount of power in comparison with air conditioners, which are known for devouring massive amounts of power – resulting in decreased electricity bills. With these coolers, power bills can be cut down by a long shot and it can stay that way forever, allowing people to save a lot more money than they ever have been able to. Since these coolers are undoubtedly very beneficial, acquiring them immediately has been highly recommended for everyone.
Massive Variety to Choose From
There are many different types of an air cooler and these are all unique in their own way. Individuals can choose the one which they want, depending on their preferences in general. However, different types always tend to have different prices and this is something that all people should be aware of. Before buying, the quality is these coolers is also another thing that must be checked for sure as ensuring that tends to make them last for a long period of time. This is due to the fact that high quality coolers are undoubtedly much more durable than the low quality ones.
High End Cooling
Another thing which makes these coolers different from any other cooling device or equipment is the fact that it enables people to acquire individual cooling. This means that a person can achieve individual cooling, which is only and precisely for a single person only, without having to face any issues in the matter. Other cooling devices, most particularly air conditioners, do not provide this exclusive benefit. Instead, they offer overall cooling and this is something which has become rather common. Individual cooling is the best way for people to combat heat in summer for as long as they want.
Affordable Price Range
On the other hand, the air cooler is a highly efficient device that can be easily found within the market at affordable prices. This not only allows people to stay away from the heat at all times in the summer months, but it also allows them to save a massive amount of money in both the short as well as the long run. With air conditioners and other devices being costly, this proves to be rather cost efficient and something that will most definitely leave people feeling satisfied in the matter of feeling cool and rather relaxed in the hot months of summer.
Easy to Install & Use
The installation of these coolers is another thing which people must not worry about because it is exceptionally easy to follow and maintain in the future. Due to their easy installation, which also takes very little time, these coolers have become the best way for cooling down places as well to achieve individual cooling in the hot months of summer. Mostly, the installation is taken care of by the company through which people purchase these coolers in the first place. However, the installation process being easy and swift surely does provide individuals with a high level of convenience.

Air Cooler – Why is it Important?

An air cooler is an important device that is used for cooling down surroundings in places that have a warm or hot climate in general. These have been used since quite a long period of time now and are excellent for combatting heat on a day to day basis. Often compared a lot with air conditioners, people sometimes may even think that they are the same thing but in reality, they are entirely different from one another. These coolers are easy to purchase and are being used in countless homes in the world these days due to the fact that they provide high end cooling at all times.
Provision of Individual Cooling
One thing that makes the air cooler different from any other cooling device or equipment is the fact that it enables people to acquire individual cooling. This means that a person can achieve individual cooling, which is only and precisely for a single person only, without having to face any issues in the matter. Other cooling devices, most particularly air conditioners, do not provide this exclusive benefit. Instead, they offer overall cooling and this is something which has become rather common. Individual cooling is the best way for people to combat heat in summer for as long as they want.
Cost Effective
On the other hand, the air cooler is a highly efficient device that can be easily found within the market at affordable prices. This not only allows people to stay away from the heat at all times in the summer months, but it also allows them to save a massive amount of money in both the short as well as the long run. With air conditioners and other devices being costly, this proves to be rather cost efficient and something that will most definitely leave people feeling satisfied in the matter of stay cool in summers.
Wide Range of Types
There are many different types of an air cooler and these are all unique in their own way. Individuals can choose the one which they want, depending on their preferences in general. However, different types always tend to have different prices and this is something that all people should be aware of. Before buying, the quality is these coolers is also another thing that must be checked for sure as ensuring that tends to make them last for a long period of time. This is due to the fact that high quality coolers are undoubtedly much more durable than the low quality ones.
Swift Installation
The installation of the air cooler is another thing which people must not worry about because it is exceptionally easy to follow and maintain in the future. Due to their easy installation, which also takes very little time, these coolers have become the best way for cooling down places as well to achieve individual cooling in the hot months of summer. Mostly, the installation is taken care of by the company through which people purchase these coolers in the first place. However, the installation process being easy and swift surely does provide individuals with a high level of convenience.
Reduced Power Bills
Another very prominent thing to note about these coolers is the fact that they consume a very less amount of power in comparison with air conditioners, which are known for devouring massive amounts of power – resulting in increased electricity bills in both the short and the long run. With these coolers, power bills can be cut down by a long shot and it can stay that way forever, allowing people to save a lot more money than they ever have been able to. Since these coolers are undoubtedly very beneficial, acquiring them immediately has been highly recommended for everyone.

Chemical Cleaning - Methods and Applications

Chemical cleaning is a method relevant in freeing walls and surfaces of various equipment, heat exchangers, pipelines, vessels and kettles from unwanted residues and bacterial contaminants. It is also essential in water purification, treatment, disinfection and conditioning. With varying methods to its name, several industries benefit from the procedure.

The most important facets of chemical cleaning gear on providing environment-friendly alternatives to consumers. No matter where it is applied, the aim is to primarily free the surface from contaminants. Below are the different methods listed under this cleaning process.

Chlorine dioxide method

Biofilms and legionella are two of the most common microbes that reside in water. Biofilms are residences or havens for organisms that contaminate products in water solutions. Legionnaires disease is caused by legionella or a Gram negative bacterium.

With the aid of chlorine dioxide, the biofilm or legionella may be removed from the water system. It is a favored technique because it has the capacity to prevent future formation of contaminants plus it can also be used in both hot and cold water systems. Chlorine is proven to have a safer solubility in water and has the capability to destroy THM precursors. It also increases coagulation while it destroys phenols. It is not hazardous to health and does not have any distinct smell.

Ultraviolet radiation

Another proven chemical cleaning process for water disinfection is the ultraviolet or UV radiation. Aside from water, it may also disinfect air and solid surfaces contaminated by microbes. Its capacity to disinfect was reported since biology and light waves were introduced in the fields of science research.

Ultraviolet radiation has several advantages. It is considered safe because there is no need to monitor any dangerous chemicals thus the results of disinfection are quickly attained. Any household or business establishment does not need to spend a lot since the initial system and operating costs are very minimal. It does not change the taste and smell of water as well plus they are easily installed and maintained.

Ozone purification

Ozone is one  molecule that contains three atoms of oxygen and is naturally produced by a series of chemical reactions. It may come from the ultraviolet rays of the sun as well as from waterfalls and thunderstorms. It is also a chemical cleaning process used in wide areas of water treatment and purification. It is used in potable water treatments and in the broader municipal wastewater sites. It is also being widely recognized in several industries.