The Principle of Nanofiltration Membrane in Water Treatment

 

What is nanofiltration?

The burst of filtration and filtration-related activity that followed the development of the phase-inversion process for the manufacture of polymeric membranes, in the early 1960s, led to the establishment of three membrane separation processes: reverse osmosis, ultrafiltration and, more recently, microfiltration. These processes took the separation spectrum from the traditional cut point limit of standard filtration of around 0.01 mm (10 μm) to the very finest distinct solids, a few nanometres in size, and enabled the separation of large molecules from solution. The actual size ranges vary somewhat from source to source, but there is general agreement that microfiltration covers the range 10 μm down to 0.1 μm, while ultrafiltration covered 0.1 μm down to 0.005 μm (5 nm) in terms of discrete particles or Molecular Weight Cut-Off (MWCO) figures of 300,000 down to around 300 Daltons for dissolved materials. Reverse osmosis, of course, was designed to retain the very small sodium chloride molecule, which meant passing nothing else but water.

These intended size ranges actually still left a gap in their coverage at the lower end of that for ultrafiltration (at around 100 to 300 Daltons). Membrane development was fairly rapid during the 1970s and 1980s, leading to a “loose RO” membrane process, which was given the name “nanofiltration” at the end of the 1980s.

The key difference between nanofiltration and reverse osmosis is that the latter retains monovalent salts (such as sodium chloride), whereas nanofiltration allows them to pass, and then retains divalent salts such as sodium sulphate. Robert Peterson, in his Foreword to Elsevier's Nanofiltration – principles and applications, describes reverse osmosis (especially in the water treatment business) as the main course, the steak perhaps, of a meal, whereas nanofiltration “is like the wine menu … an opportunity for creativity and exploration”.

UC NF 500 Series-NF Membranes UC NF-500-400

 

The working principle of nanofiltration membrane:

The pore size of the nanofiltration membrane is nanoscale, which can allow water to pass completely, while intercepting or partially intercepting substances with a larger molecular weight than water. For ions, the higher the ion valence, the higher the retention rate of thenanofiltration membrane. In general, nanofiltration membranes allow the passage of monovalent ions and the rejection or majority of divalent or multivalent ions. Heavy metal ions and phosphorus are generally multivalent ions, and nanofiltration membranes have high rejection rates for them. For the difference of organic components such as COD and BOD composed of materials, nanofiltration membranes with different molecular weight rejection ratios can be selected for the concentration treatment of wastewater, and the organic pollutants are trapped in the concentrated solution, so that water and monovalent ions permeate the membrane.

 

Application of nanofiltration membrane:

Industrial applications of nanofiltration are quite common in the food and dairy sector, in chemical processing, in the pulp and paper industry, and in textiles, although the chief application continues to be in the treatment of fresh, process and waste waters.

Nanofiltration membranes are mainly used in softened water treatment, purified water treatment, wastewater purification treatment, and the concentration and separation of valuable components in process material solutions in the field of drinking water and industrial water. At present, nanofiltration membranes in domestic and foreign markets are mainly used in the field of drinking water. Nanofiltration membranes are used to soften water, reduce the concentration of TDS, and remove chromaticity and high molecular weight organics. Nanofiltration membranes have higher water fluxes at lower operating pressures, therefore, in many fields, treatment processes with nanofiltration membranes are more economical in capital and operating costs than reverse osmosis processes.

Ningxia for a Coal Chemical Power Plant workshop

 

NF membranes are also used for the removal of natural organic matter from water, especially tastes, odours and colours, and in the removal of trace herbicides from large water flows. They can also be used for the removal of residual quantities of disinfectants in drinking water.

Food industry applications are quite numerous. In the dairy sector, NF is used to concentrate whey, and permeates from other whey treatments, and in the recycle of clean-in-place solutions. In the processing of sugar, dextrose syrup and thin sugar juice are concentrated by NF, while ion exchange brines are demineralised. NF is used for degumming of solutions in the edible oil processing sector, for continuous cheese production, and in the production of alternative sweeteners.

There are probably as many different applications in the whole chemical sector (including petrochemicals and pharmaceuticals) as in the rest of industry put together. Many more are still at the conceptual stage than are in plant use, but NF is a valuable contributor to the totality of the chemicals industry. The production of salt from natural brines uses NF as a purification process, while most chemical processes produce quite vicious wastes, from which valuable chemicals can usually be recovered by processes including NF. The high value of many of the products of the pharmaceutical and biotechnical sectors allows the use of NF in their purification processes.

 

The paper pulp industry uses a very great quantity of water in its production processes, a quantity that the industry is striving to reduce, mainly by “closing the water cycle” – a system in which the purification properties of NF have a major role.

 

How to prevent deviation of conveyor belt

 When your factory is running at full speed, trying to ship a product or fulfill an order, the last thing you want is a conveyor belt running off course. Unfortunately, sometimes even the slightest movement or change on a conveyor can throw the belt off track. Misalignment of idlers or rollers, improper joints, and material accumulation are just some of the reasons that can cause your conveyor belt to deviate from the track. Sometimes, minor collisions with heavy machinery and even weather -- strong winds, frost, and sun exposure -- can interfere with your conveyor belt path.

Potential danger of running off course

If found and corrected in time, the conveyor belt deviation will hardly damage the conveyor. However, other types of damage may occur if it is not detected or corrected. If the conveyor belt continuously hits the frame, it will not only damage the frame, but also may scrape off the conveyor belt layer by layer until it is worn out. Conveyor belt width will also be affected, resulting in a reduction in the amount of material carried.

If the conveyor belt runs badly off course, the material will overflow from the top to the surrounding area, which may lead to safety violations. In rare cases, friction can heat up and the conveyor belt can become a source of fire, causing serious safety problems.

Safety regulations are also a factor

Safety regulations are in place in many parts of the world to regulate these issues. For example, in the United States, the MSHA enacted 30CFR 75.1731, which specifically states that "conveyor belts must be properly aligned to prevent friction between a moving conveyor belt and a frame or component." Failure to comply with these regulations can result in fines and/or disruption of operations.

Temporary repair of conveyor belt

For most factories, a complete overhaul of conveyors is usually not within the budget. Instead, some people resort to temporary repair procedures - such as attaching side rollers to conveyors - which can actually make the problem worse. Idlers mounted on the edge of conveyor belts are not always effective because conveyor belts are better suited for pulling than pushing, so this runs in reverse. Another method of adjusting the conveyor belt is to use friction - oblique idlers relative to the direction in which the belt is running. The third method is to adjust the tension. Usually the conveyor belt is always "away" from the high tension side. If the tension on one side increases, the conveyor belt will move to the other side.

The combination of friction and tension effectively prevents the conveyor belt from running off

Field tests have shown that a combination of friction and tension is the best way to get the Huayue conveyor belt back on track when the racks are not aligned correctly. Many equipment manufacturers provide edge idlers alongside steel return idlers that allow them to rotate or tilt relative to the travel of the conveyor belt. The friction exerted by the idlers on the conveyor belt can turn the latter. The problem with this method is that the edge of the conveyor belt will hit the edge idlers hard, but with little practical effect, and will exert great pressure on the edge of the conveyor belt. This will create greater force in the idlers, which may damage the conveyor belt.

Other manufacturers often offer products called "oscillators" for this purpose, which use a single central bearing inside a gelatin-covered idler (pipe) to cause the conveyor belt to turn. The problem with this design is that in order to generate steering force, the idlers have to be tilted down on the off-course side. This can backfire, as reducing tension can quickly cause the belt to slip into more serious running. Only in applications with minimal tension, where the steering force is much more influential than the tension, does this approach have a chance of providing good results.

In order to avoid applying too much pressure or making the deviation problem worse, the tracker with a "rotating and tilting" design can ensure friction and change the conveyor belt tension distribution. The rotating and tilting mechanism can make the conveyor belt back to the middle of the conveyor, and the efficiency is more than three times higher than other schemes.

The next time you encounter a conveyor that runs sideways or sideways, consider using a "spin and tilt" tracker. This is a very efficient solution that works before off-track problems cause damage or downtime.

Nursing Beds, Are You Really Using the Right One?

  One-third of a person's life is spent in bed, among the many pieces of furniture, there is no furniture as long as the bed and the relationship between people, are so close. In today's emphasis on people-oriented everywhere, the "bed", a carrier of a happy life, its comfort or not is pivotal. For people with mobility problems, the role of the bed is even more unusual for people with functional disabilities who need to be in bed. They need a bed with special functions, we call it a "nursing bed". So, nursing beds, are you using the right one?

Sickbeds & Nursing Beds

 

In the early days, the function of nursing beds was relatively single, but as the standard of living improved, the aging population proliferated, people's needs for different ways of care, and the pursuit of quality of care, nursing bed manufacturers found business opportunities, and multifunctional nursing beds were born to meet the different needs of individuals.

 

MAIN FUNCTION

Whether it is an elderly person with insufficient home care capacity or a patient who has difficulty turning, sitting up, standing up, and moving to a wheelchair, their daily life requires not only the care of family members and caregivers in many ways, but also some other activities of life, and the function of the nursing bed is to make the patient more comfortable and safer and then reduce the difficulty of care.

 

Back Lifting

The back-raising function helps the elderly to sit up, and after sitting up, it is easy to carry out activities such as eating, feeding, meeting guests, and getting out of bed.

 

Knee Lift

The knee lift function facilitates care of the user's lower body, promotes blood circulation, prevents joint stiffness, etc.

 

Back and knee linkage

The back and knee linkage function can prevent the user from slipping and causing falls and pressure sores, which is also a function that most of the nursing beds on the market have.

 

Height lift

The height lift function can help the elderly to lower the height of the bed when getting out of bed to prevent falls. It also facilitates the transfer of the bed and chair and standing up, helping the caregiver to use the correct nursing posture, and also increases the space under the bed for the use of medical equipment, making it easy to clean and maintain.

 

Nursing bed classification

Electric Nursing Beds

The name of the electric nursing bed sounds advanced, then the price is also relatively high, electric nursing bed for long-term bedridden elderly people with mobility problems is more suitable. It can help the user to turn over, and automatically clean up the urine and stool, because the user can adjust themselves, so it can also have a benefit to the user's physical and mental rehabilitation, the user will not feel that what they do need the help of others. It also reduces the burden for the escort and helps to take better care of the elderly.

 

Manual nursing bed

Manual nursing beds are suitable for short-term messengers and can be chosen by users with low needs. Although the price is relatively low, they are not as convenient to use as electric nursing beds, and the burden on the escort is relatively heavy. Manual nursing beds are also divided into single and double shaking, which are selected according to the user's own needs.

 

Living design

Compared to hospital beds, the living design of nursing beds is more comprehensive, safer, and more comfortable with the same functions, which can improve the user experience and effectively reduce the workload of family members and caregivers, so that users like it and caregivers and family members like it more, so that caring for bedridden users is no longer a "chore".

  

Care beds change lives

The "bed-centered" creation of bedroom warmth is proposed after people's housing conditions are getting better and better, and the quality of life is more and more important, and the home care bed is designed to improve the comfort and safety of the private space of people with functional disabilities, convenience, beauty, practicality will also improve the physical and mental health and self-esteem of patients, so that dysfunction is no longer a burden. 

Choosing the Right Hospital Bed

INQUIRE Wheelchairs

Application of Velcorin

  Velcorin, also known as dimethyl dicarbonate, is a preservative approved by the Ministry of Health and complies with the Food Sanitation Law of the People's Republic of China and the Food Additive Sanitation Management Measures. The molecular formula is C4H6O5, and the relative molecular mass is 134.09. The boiling point is 172°C, at room temperature, it is a slightly astringent colorless liquid, usually used in beverage cans.

DMDC has a broad-spectrum antibacterial effect. Its main target microorganisms are yeasts (including Saccharomyces cerevisiae, Zygosaccharomyces ruckerii, Rhodotorula, Candida, Pichia, Toluobacillus, Torula, Endosporium, Klerkia, Hansenula, etc.). It also has a disinfecting effect on many other bacteria (such as Acetobacter pasteurianus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, various lactobacilli, Pediococcus beer). DMDC has also been shown to kill E. coli 0157:H7. The antibacterial effect of DMDC is the result of inactivating enzymes in microorganisms - mainly through the reaction with imidazoles and amino groups of proteins, thereby destroying microorganisms. The unreacted DMDC residue is rapidly decomposed into methanol and carbon dioxide. The activity of DMDC depends on its hydrolysis rate. DMDC undergoes hydrolysis in contact with water, and the rate of hydrolysis depends on the temperature of the beverage or wine. Complete hydrolysis takes 4 hours at 10°C (50°F) and 2 hours at 20°C (68°F), i.e. complete hydrolysis after dispensing.

Often, non-alcoholic beverages can go bad easily. Fruit juices, sugars, thickeners and other ingredients are ideal media for food spoilage bacteria such as yeast, molds and fermenting bacteria. Once the deterioration occurs, not only the product is damaged, but also the brand image of the product is destroyed, and the health of consumers may also be threatened.

During beverage production, microorganisms are present everywhere, such as in the surrounding air, on production equipment, and even in the beverage itself. As a beverage manufacturer, you have to choose the right method to sterilize your beverages, in addition to aseptic cold canning, pasteurizing hot canning and adding traditional preservatives, Velcorin is also an excellent tool for microbial control during the filling process choose. The application of Velcorin can produce stable beverages with pure taste based on the traditional filling process. Even at low concentrations, Velcorin can effectively kill harmful microorganisms in beverages.

There are many advantages to using Velcorin, and more and more beverage manufacturers are using Velcorin because it kills typical beverage spoilage bacteria even at very low concentrations. Once added to the beverage, Velcorin is rapidly and completely hydrolyzed to trace amounts of carbon dioxide and methanol.

Because of the fully hydrolyzed properties of Velcorin, Velcorin will not affect the taste, smell and color of beverages, ensuring the pure and freshness of beverages. Velcorin can be used in carbonated drinks, carbonated or still juice drinks, tea drinks, isobaric drinks and many other beverages. Velcorin is compatible with glass, metal and plastics such as PET or PVC beverage packaging.

In Europe, the United States and some other countries around the world, Velcorin is permitted to be used in many different beverages. Some important international organizations in the world, such as the Scientific Food Association of the European Union, the Food and Drug Administration of the United States, and the Joint Expert Committee on Food Additives of the World Health Organization, have proved that Velcorin is very safe to add to beverages. And Velcorin has passed the following certifications: ISO9001:2000, ISO14001

Chongqing Hesheng Longgang Technology Co., Ltd.supply Benzophenone,  Velcorin. Welcome browse our website and contact us.

A Guide for Choosing the Type of Elevator You Need

Construction projects require a great amount of detail and can take months or years to complete. An important part of the construction process is ensuring you choose the right structure design and materials.For example spc floor, vinyl flooring, manhole cover, thread bar, aluminum building materials, plywood, vanities and so on. You must consider the foundation and various natural elements before incorporating certain additional items into the building.

 

When building multi-story buildings, you should think about how people are going to access each floor. Stairs are a natural choice, but it is also wise to install an elevator because it’s faster, more convenient, and it considers people with disabilities and mobility limitations.

 

What is an Elevator?

An elevator is a platform that could either be open or closed and is used for lifting or lowering both people and goods to upper and lower floors. In the past, it was not mandatory for story buildings to have elevators. As a result, some real estate investors avoided installing elevators because they were expensive to install and maintain.

 

How the Law has Influenced the use of Elevators

It was not until the Americans with Disabilities Act was introduced in 1990 that elevators become common. The legislation forbids any form of discrimination against people with disabilities. The law also requires all two or three-story buildings to be fitted with elevators. This makes it more convenient for people living with disabilities to easily access multiple floors.

How Elevators Work

Elevators haven’t changed much since the 1800s. Elevators still maintain their original purpose of transporting people across floors. The Otis Safety System is used in most elevator types and has been since the 1850s.

 

Control systems have been altered for modern elevators in ways that improve on speed and safety. In most cases, elevators will apply the use of counterweight and 40% of the maximum rated load to balance the car.

 

The main purpose of the counterweight is to reduce the weight to be lifted by the motor and to keep the entire elevator in control with the cables intact. In order to ensure durability and strength, the car elevator is made from steel. The pulley used by the hoist cable is held in place by a spanned side-to-side elevator shaft. This spun is controlled by a set of steel beams that are placed above the elevator car.

 

Modern elevator cars also have additional technology installed in them. Some have phones that allow the occupant to call for help in the event of an emergency. Others are fitted with a trap door located at the ceiling that make escape possible in emergency situations.

 

Elevators are designed and fitted into a building according to the building’s population capacity and duties to be performed. For example, there are some buildings that will have large elevators to transport cargo to different floors. Hospitals have elevators that open on both sides to allow easy entry and movement of emergency patients.

Elevator Types

In the past, most elevators had to be controlled through a centralized machine room. Today, there are some elevators that don’t need a machine room because they have an inbuilt safety mechanism. There are four main types of elevators: hydraulic, traction, machine-room-less, and vacuum.

1. Geared and Gearless Traction Elevator

Geared and Gearless Traction elevators can be separated into three different categories:

 

Traction Elevator

This elevator has ropes that pass over a wheel attached to an electric motor located above the shaft. The main function of the ropes is to raise and lower the elevator car. It can be used for both mid and high-rise applications and can travel much faster than hydraulic elevators.

 

Like other elevator types, this system uses a counterweight, which eliminates the weight of the occupants and the car so that the motor has an easier job moving the elevator load.

 

Geared Traction Elevator

The geared elevator is made up of a motor that has a gearbox attached to it. The main function of the gears is to power the wheel that moves the ropes. This type of elevator can travel up to speeds of up to 500 feet per minute. The maximum distance it can travel is 250 feet.

 

Gearless Traction Elevator

Gearless elevators don’t have a gear for speed regulation. This explains why they can move as fast as 2,000 feet per minute and can also travel a maximum of 2,000 feet. They are the best option for skyscrapers.

2. Hydraulic Elevator

Hydraulic elevators are normally given support by a bottom-placed piston. The purpose is to push the elevator car up while an electric motor forces hydraulic fluid down the piston. When it’s time for the elevator to come down, the valve releases the hydraulic fluid from the piston. This type of elevator is mostly used in 2 to 8 story buildings and can only travel at a maximum speed of 200 ft per minute. Below is a further breakdown of hydraulic elevators:

 

Roped Hydraulic Elevator

This type applies the use of both ropes and a piston to enhance the motion of the elevator car. The maximum distance it can travel is about 60 feet.

 

Conventional Hydraulic Elevator

Designed with an elevator pit, it comes with a sheave that extends beneath the floor of the pit. As the elevator begins to drop, the pit supports a retracting piston. In some configurations, a conventional hydraulic elevator may require a shallower hole below the pit that accepts a collapsing telescoping piston when the elevator drops. The approximate distance it can travel is 60 feet.

3. Machine-Room-Less (MRL) Elevator

Most elevators are designed with a machine room located above the elevator shaft. This type of elevator has a machine fitted in the override space, and it can only be accessed through the top of the elevator car whenever maintenance is required. This type of elevator can only travel a distance of 250 feet with speeds of up to 500 feet per minute.

 

MRL elevators are gaining popularity with mid-rise buildings because they conserve energy and require less room during construction.

Before your install an elevator in your multi-story building, you must know the building’s dynamics. Is it a residential or commercial building? You should also know how much the elevator needed for your structure will cost. Even though elevators can be an expensive investment, the convenience and ease of use is often an intriguing reason to add one to your next structure.

What Is A Solar Panel?

  Solar energy begins with the sun. Solar panels (also known as "PV panels") are used to convert light from the sun, which is composed of particles of energy called "photons", into electricity that can be used to power electrical loads.

 

Solar panels can be used for a wide variety of applications including remote power systems for cabins, telecommunications equipment, remote sensing, and of course for the production of electricity by residential and commercial solar electric systems.

 

On this page, we will discuss the history, technology, and benefits of solar panels. We will learn how solar panels work,  how they are made, how they create electricity, and where you can buy solar panels.

 

A Short History of Solar Panels

The development of solar energy goes back more than 100 years. In the early days, solar energy was used primarily for the production of steam which could then be used to drive machinery. But it wasn't until the discovery of the "photovoltaic effect" by Edmond Becquerel that would allow the conversion of sunlight solar electric energy. Becquerel's discovery then led to the invention in 1893 by Charles Fritts of the first genuine solar cell which was formed by coating sheets of selenium with a thin layer of gold. And from this humble beginning would arise the device we know today as the solar panel.

 

Russel Ohl, an American inventor on the payroll of Bell Laboratories, patented the world's first silicon solar cell in 1941. Ohl's invention led to the production of the first solar panel in 1954 by the same company. Solar panels found their first mainstream use in space satellites. For most people, the first solar panel in their life was probably embedded in their new calculator - circa the 1970s!

 

Today, solar panels and complete solar panel systems are used to power a wide variety of applications. Yes, solar panels in the form of solar cells are still being used in calculators. However, they are also being used to provide solar power to entire homes and commercial buildings, such as Google's headquarters in California.

 

How Do Solar Panels Work?

Solar panels collect clean renewable energy in the form of sunlight and convert that light into electricity which can then be used to provide power for electrical loads. Solar panels are comprised of several individual solar cells which are themselves composed of layers of silicon, phosphorous (which provides the negative charge), and boron (which provides the positive charge). Solar panels absorb the photons and in doing so initiate an electric current. The resulting energy generated from photons striking the surface of the solar panel allows electrons to be knocked out of their atomic orbits and released into the electric field generated by the solar cells which then pull these free electrons into a directional current. This entire process is known as the Photovoltaic Effect. An average home has more than enough roof area for the necessary number of solar panels to produce enough solar electricrity to supply all of its power needs excess electricity generated goes onto the main power grid, paying off in electricity use at night.

 

In a well-balanced grid-connected configuration, a solar array generates power during the day that is then used in the home at night. Net metering programs allow solar generator owners to get paid if their system produces more power than what is needed in the home. In off-grid solar applications, a battery bank, charge controller, and in most cases, an inverter are necessary components. The solar array sends direct current (DC) electricity through the charge controller to the battery bank. The power is then drawn from the battery bank to the inverter, which converts the DC current into alternating current (AC) that can be used for non-DC appliances. Assisted by an inverter, solar panel arrays can be sized to meet the most demanding electrical load requirements. The AC current can be used to power loads in homes or commercial buildings, recreational vehicles and boats, remote cabins, cottages, or homes, remote traffic controls, telecommunications equipment, oil and gas flow monitoring, RTU, SCADA, and much more.

 

The Benefits of Solar Panels

Using solar panels is a very practical way to produce electricity for many applications. The obvious would have to be off-grid living. Living off-grid means living in a location that is not serviced by the main electric utility grid. Remote homes and cabins benefit nicely from solar power systems. No longer is it necessary to pay huge fees for the installation of electric utility poles and cabling from the nearest main grid access point. A solar electric system is potentially less expensive and can provide power for upwards of three decades if properly maintained.

 

Besides the fact that solar panels make it possible to live off-grid, perhaps the greatest benefit that you would enjoy from the use of solar power is that it is both a clean and a renewable source of energy. With the advent of global climate change, it has become more important that we do whatever we can to reduce the pressure on our atmosphere from the emission of greenhouse gases. Solar panels have no moving parts and require little maintenance. They are ruggedly built and last for decades when porperly maintained.

 

Last, but not least, of the benefits of solar panels and solar power is that, once a system has paid for its initial installation costs, the electricity it produces for the remainder of the system's lifespan, which could be as much as 15-20 years depending on the quality of the system, is absolutely free! For grid-tie solar power system owners, the benefits begin from the moment the system comes online, potentially eliminating monthy electric bills or, and this is the best part, actually earning the system's owner additional income from the electric company. How? If you use less power than your solar electric system produces, that excess power can be sold, sometimes at a premium, to your electric utility company!

 

There are many other applications and benefits of using solar panels to generate your electricity needs - too many to list here. But as you browse our website, you'll gain a good general knowledge of just how versatile and convenient solar power can be.

 

How Much Do Solar Panels Cost?

Prices for solar panels has decreased substantially in the last couple of years. This is great because, combined with the 30$ federal solar Investment Tax Credit and other applicable incentives, NOW is the best time ever to invest in a solar power system. And, consider this: a solar power system costs about the same as a mid-sized car!

 

Where can I buy solar panels?

Well, right here on this website, of course!

 

OuShang is one of the top solar panel china manufacturers and has been engaged in the research and development, production and sales of solar panel products for many years.The factory is located in hebei province, china, covering an area of 50,000 square meters.