Tag Archives: humidity measurement

Sugar Production and Relative Humidity

The sugar market worldwide

Sugar is one of the most important raw materials traded on the worldwide markets.

Top 5 sugar producing companies

1. Suedzucker AG,

2. Cosan SA Industria & Comercio

3. British Sugar PLC

4. Tereos Internacional SA

5. Mitr Phol Sugar Corp.

In the 18th century only a few countries were producing sugar. However, these days over 100 nations process different base materials into sucrose. Remarkably India, China, Brazil & the European Union alone deliver 50% of the global demand.

Sugar Facts:

– Worldwide 170 million tons of raw sugar were produced in 2011/2012

– Brazil, India, China & EU are the most important sugar producing nations

– With an annual consumption of more than 24 million tons India, is the world’s largest market for raw sugar

Raw materials & processing

In temperate regions such as West, Central & Eastern Europe, the United States, China and Japan raw sugar is produced from sugar beet. However in the tropics and subtropics sugar is extracted from sugar cane.

800px-cut_sugarcane

Sugar cane & Sugar Beet

Processing

The processing of these two raw materials only differs in the first few steps. The main goal is to extract the juice, containing the sugar,  as efficiently as possible.

Extracting the sugar

Sugar cane is cut into small pieces during the harvest. It is then put through an industrial press to squeeze out the sweet sap.
Sugar beet has to be processed in extraction towers, where the plants release their sugar during a hot water treatment at 70°C.

Evaporation

After filtering the juice the water is extracted by passing through different stages of evaporators until only a thick syrup is left consisting of around 70% sugar.

Crystallisation

The syrup is then boiled until sugar crystals are formed. These crystals are then cleaned through centrifugation. To further improve purity this process is repeated twice.

Cooling & drying

Now the sugar has to be dried. One option is in large scale drum dryers at a temperature of 60°C. after drying, the sugar is cooled down on fluidized-bed coolers before heading to the warehouse or packed for shipping.

Trommel2_400_219_01

Inside a drum dryer.

Storage & logistics

Sugar belongs to the group of hygroscopic goods with an extremely low water content – below 1.5%. Basically sugar is a robust material but vulnerable to high humidity and temperature changes.
Generally it is recommended to store and transport sugar at a temperature of 20-25°C and 25-60% relative humidity.

By taking a closer look at the adsorption curve of sugar it is easy to see that over a long range of relative humidity the product quality is not affected. But as soon as the humidity level rises to 75% sugar starts to clump and above 80% relative humidity even dissolves .

Storage

Immediately after production the refined sugar is stored in humidity controlled sugar terminals or ventilated silos connected to dehumidifiers.

6.2.4. Sugar Terminal 5086

Sugar in a storage terminal

Logistics

Large quantities are trans-ported in silo trucks or train wagons. When sent by ship sugar is packed in double-walled bags made of natural fibre and plastic. If sealed like this, temperature is the crucial parameter which can affect the quality of the sugar. Due to big differences in temperature water vapour left inside the bags may cause clumping and even liquefaction.
The finer the sugar, the higher the risk of clumping.

Caking-dark-brown-sugar

Sugar clumping

Why the need to measure humidity?

As seen above, temperature and humidity measurements are crucial parameters in the sugar industry. Due to its hygroscopic behavior sugar can resist small changes in humidity, and slight temperature variations are not a major problem. But as soon as relative humidity rises above 80% or temperature changes significantly, the product can be destroyed as it clumps or even turns liquid.
During the process of evaporation, crystallisation, drying and cooling temperature and humidity play a huge role.

Philip Robinson                                                                                                        Rotronic UK

 

Meteorology: Numerical Weather Prediction

The Calculation of Weather Data

What is the weather going to be like tomorrow?

For a long time, people have tried to predict weather conditions using the hydrologic climate cycle.

In the early 1920`s scientists were able to compile a six-hour forecast. Back then it took six weeks to calculate by hand the weather data collected at two points in Europe and create a useful illustrative model.

Today, supercomputers are used to predict the weather for a period of several weeks. The complex modelling programs require several million data points for parameters such as temperature, humidity, pressure, vertical & horizontal wind velocity with time stamps and absolute coordinates. To create a correlation between the data and the environment, scientists “slice” the atmosphere virtually into smaller horizontal & vertical parts – this process is called discretization. It is more useful to compute the chronological change of the parameters using this model.

Meteorological events that are too “small” such as a single thunderhead, layer clouds or smaller turbulences will be parameterised through variables. This parameterisation is a science of its own that aims to reduce uncertainties as best as possible.

754334main_GOES-7Jun2013-0831EDT
Every forecast calculation starts with the current weather conditions. The quality of this input is crucial for the accuracy of the final forecast. Meteorologists link the forecast of yesterday’s weather with the actual measured parameters. Only large data centres are capable of computing this data assimilation. The overall result is a best possible calculation basis to predict the weather for the next day. If this groundwork is flawed the forecast may be incorrect, for example it could report rain at the wrong location.

Today’s meteorological mathematicians also take parameters into account that change extremely slowly compared to the other factors. Growth and the reduction of polar ice, or the temperature of the oceans are summarised as boundary values

After a model is run using all the available data, meteorologists’ process and customize reports for a wide range of target groups such as public authorities, flight control centres, energy producers, industries and many more, including the issue of specific warnings.

Facts & figures:

17.8 cm is the diameter of the largest hailstone ever recorded.

Sukkur City in Pakistan is one of the most humid places in the world with 30 °C dew point & a felt air temperature of 65 °C.

A study showed that a small thunderstorm system holds more than 10 million tons of water.

No two weather patterns are completely alike.

Some weather models assimilates data obtained from more than 25,000 weather stations.

Why The need to Measure Humidity?

As described above, the daily weather fore-cast relies on the precise measurement of weather parameters. The science of numerical weather prediction aims to describe the daily hydro-logic cycle in numbers – humidity plays an important role in this – data errors will multiply during calculations.

Humidity values influence weather calculations e.g. through the water vapor balance equation – this formula expresses the influence of humidity through rain & condensation, and vice-versa.

Incorrect measurement or incomplete humidity data directly leads to wrong predictions of a huge number of weather phenomena; this can include the condensation altitude of clouds, locations of hyetal regions, fog layers and storms.

In 1999, incorrect data sent by a weather station in Nova Scotia, Canada led to an incorrect forecast for Hurricane Lothar two days before it hit Central Europe. Authorities were insufficiently prepared to alert people in time.

hurricane-ivan_200_600x450
What is the Rotronic Solution?

Rotronic products are used in weather stations around the globe. They provide temperature & humidity data continuously with high accuracy even in demanding environments.

Rotronic manufactures a range of meteorological probes and weather shields to meet the standards required by meteorological organizations.

Philip Robinson

Rotronic UK

Humidity Control & Pharmaceutical Tablet Coating

Tablet coating in general

Pharmaceutical tablet coating involves the application of a coating composition to a moving bed of tablets with the use of heated air to facilitate the evaporation of the solvent. Several different types of coating are typically used.

Tablet Coating
Tablet Coating Machine
  • Sugar-coated tablets are coated with a coloured or an uncoloured sugar layer. The coating is water soluble and quickly dissolves after swallowing. The sugar-coating protects the encapsulated drug from the environment and provides a barrier to objectionable tablet taste or odour.
  • Film-coated tablets are compressed tablets coated with a thin layer of a polymer that forms a skin-like film. This is usually coloured and has the advantage over sugar coatings  that it is more durable, less bulky, and works faster at the desired location in the gastrointestinal tract.
  • Enteric-coated tablets have delayed release properties. They are designed to pass unchanged through the stomach to the intestines, where the tablets disintegrate and allow the drug to dissolve and start its effect. Enteric coatings are used when the drug substance itself would be destroyed by gastric acid or is irritating to the gastric mucosa.

Facts & figures:

Aspirin is one of the most used drugs in the world – approximately 35,000 metric tonnes are produced annually, enough to make over 100 billion aspirin tablets.

Americans consume 80% of the world`s supply of painkillers — more than 110 tons of pure, addictive opiates every year.

How can accurate measurements help?

Environmental control is the practice of managing the temperature, humidity, air circulation, ventilation and air pressure of a given space. Within certain types of pharmaceutical manufacturing processes, precise environmental control can help limit inefficiencies and potential problems.

Pharmaceutical tablet coating is one such application. Inefficiencies during the coating process may result in contamination and tablet impurity in the form of tablet-to-tablet colour variation, surface pitting from over-wetting, twinning due to spray drying, cracking or peeling. Most of these problems can be overcome by better control of the environment within the process. Over-wetting, for example, occurs when the coating hits the still wet tablet surface and the surrounding air does not dry it quickly enough. Another example involves spray drying, when the coating hits the tablet surface after the moisture has been removed resulting in poor adhesion of the coating.

In the case of incorrect cooling and drying of the sugar solution, a rough, translucent and uneven coating may be produced.

Since the required environment for a perfect coating strongly depends on the composition of the tablets, many pharmaceutical manufacturers have scientists who perform experiments to determine the ideal coating procedure including temperature and humidity levels. Once these specific requirements are determined, the set-points can be configured at the controller to enable the precision tablet-coating machines to work at optimal performance.

spoonfull of medicines
A spoonful of perfectly coated tablets!

Tablet Coating Benefits-Summary

  • covers the unpleasant taste, odour and colour
  • provides physical and chemical protection for the medicine (light, moisture and air)
  • controls the release of a drug (enteric coating)
  • improves the appearance of tablets
  • easier to swallow the tablets
  • assists and facilitate the identification of a drug
Dr. Jeremy Wingate
Rotronic UK

Humidity measurement in Paint Spray Booths

Paint booths in general

Spray painting has existed since the late 1800’s. The technique was developed in a bid to accelerate painting times compared to brush painting. Spray painting is a method of painting where paint is atomised onto a surface via a spray gun. The paint is mixed together with a solvent or water (called a carrier) so that it can be applied correctly.

Cars, aircraft, boats and other such equipment is often spray painted in a spray paint booth.

A spray booth is an enclosed room, designed for spray painting. Depending on the requirements, the booth may be equipped with filtered air to avoid getting dust in the room and an exhaust air system to clear the fumes of any evaporating solvents used during the spray painting process.

Regulations, such as the Occupational Safety & Health Administration from the United States department of Labor have a criteria for design and construction of spray booths state that a spray booth is: a power-ventilated structure provided to enclose or accommodate a spraying operation to confine and limit the escape of spray, vapour and residue, and to safely conduct or direct them to an exhaust system.

Spray paint booths regulate relative humidity, temperature, airflow and pressure to ensure a quality coating and a perfect curing.

Certain paints contain flammable solvents which release flammable fumes: in this case explosion-proof components are required for all measuring equipment that come in contact with the fumes.

Paint dry and cure times
Paint dry and cure times

Why do we need to monitor and measure in Paint Spray Booths

In order for paint to dry correctly within the paint booths, the relative humidity and temperature levels should be within the following conditions:

 – 65 to 75%rh
 – 20 to 24°C

Based upon the intake air, there may be a requirement to either dry or humidify the air in order to reach the desired values. From the temperature side, exactly the same thing: the air might need to be cooled or heated depending on the outside temperature.

Additionally, paint booths might have a  separate monitoring system inside the booths in which the different elements are painted. In order to ensure that the paint is  applied correctly to the element to be painted, it is important to ensure that the surface temperature of the element is not too close to the dew point level in the booth.

If the surface temperature of the element to be painted is close to the dew point temperature, then there will be risks of condensation forming on the surface of the element. If this were to happen, the coating will not be optimal and the drying and curing phase will not be completed properly and the results could be catastrophic.

 

Rotronic have recently launched a totally new range ATEX (Intrinsically Safe and Explosion Proof) instruments. Paint spray booths typically require ATEX certified instruments.

More details here.

Rotronic ATEX range
Rotronic ATEX range

 

A look at the Beer Brewing Process – Just in time for the Rotronic 2014 International Sales Meeting

Beer brewing in general

There is no exact date, as to when the first beer was brewed but already at the beginning of the fifth millennium BC, people in southern Mesopotamia, in a region known as Sumer (modern Iraq), were brewing beer.

Beer, like other commodities such as wheat and other grains, was used as a currency. A clay tablet, dating from 6’000 BC contains one of the oldest known beer recipes.

Beer Map
Beer consumption throughout the world

The basic ingredients of beer are: water; a starch source: which is able to be fermented; yeast: to produce the fermentation; a flavouring such as hops. Yeast is the microorganism that is responsible for fermentation. Specifically Saccharomyces cerevisiae is the species of yeast that is used for brewing.

Facts & figures:
Beer is the third most popular beverage in the world, coming in directly behind tea and water.
American beer is made mostly from rice. This was invented to give American beer a lighter taste and tap into the market of women buyers.
In the UK 28 million pints of beer are consumed every day, which equates to 100 litres per head each year.
Belgium has over 400 different beer brands.
Cenosillicaphobia is the fear of an empty glass.

There are several steps in the brewing process, which include malting, milling, mashing, lautering, boiling, whirl-pooling, fermenting, conditioning, and filtering.

Step by step brewing:
  • Malting: germination of cereal grains. The sprouted cereal is then kiln dried at around 55°C. Milling: grinding of the malted cereal.
  • Mashing: the cereals are mixed with water and then heated.
  • Lautering: separation of the mash: the liquid (wort) is separated
    from the residual grains.
  • Boiling: the wort is boiled to ensure sterility and then hops are added for flavour!
  • Whirl-pooling: the wort is sent into a whirlpool, removing the dense particles using centrifugal force.
  • Fermenting: yeast is added to the wort: conversion of the carbohydrates to alcohols and carbon dioxide – the chemical conversion of sugars into ethanol!
  • Conditioning: the tank is cooled and the yeast and proteins separate from the beer. This conditioning period is also a maturing period.
  • Filtering: the beer is filtered: stabilising the flavour.
  • Packaging: the beer is packed then to the customers
Example brewing process
Example brewing process
Why the need to measure the carbon dioxide?

Carbon dioxide Carbon dioxide (CO2) is a naturally occurring chemical compound. It is a gas at standard temperature and pressure.

We inhale oxygen and exhale carbon dioxide. The carbon dioxide level in exhaled air is rather constant: around 3,8%. When carbon dioxide is exhaled it will quickly be mixed with the surrounding air even indoors and provided that the ventilation is good, the concentration will be reduced to harmless levels. Indoor carbon dioxide levels usually vary between 400 and 1’200 ppm (parts per million). Outdoor carbon dioxide levels are usually 350 – 450 ppm.

Beer brewing process: Heavily industrialised or contaminated areas may periodically have a higher concentration of CO2. Carbon dioxide is released during the beer brewing process and as you will see below, CO2 is toxic for living organisms. In brewery environments where process generated carbon dioxide is widely present, the maximum permitted carbon dioxide concentration according to most standards is as high as 5’000 ppm (5%) during an 8 hour working period.

Beer storage: Most beer leaves the brewery carbonated: beer and carbon dioxide are sealed in a container under pressure. It can be carbonated during fermentation but it can also be carbonated in the bottle. In this case the beer is allowed to ferment completely. It is left unfiltered which leaves active yeast suspended in it. A small amount of sugar is then added at bottling time. The yeast begins to act on the sugar: CO2 is released and absorbed by the beer.

Beer can also be force carbonated, in which case it is allowed to fully ferment. Then CO2 is pumped into a sealed container with the beer and absorbed by the liquid. In this case, a tank of carbon dioxide will also be required. Undetected leaks in a gas system is a costly waste and a safety risk to personnel. While small leaks are inherent in any gas system, those of significant size raise the level of economic and safety risk.

How does CO2 affect the human body?

Due to the health risks associated with carbon dioxide exposure, there are regulations and laws in place to avoid exposure! The US National Institute for Occupational Safety and Health (NIOSH) states that carbon dioxide concentrations exceeding 4% are immediately dangerous to life and health.

In indoor spaces occupied by people: concentrations higher than 1’000 ppm will cause  discomfort in more than 20% of occupants. At 2’000 ppm, the majority of occupants will feel a significant degree of discomfort and many will develop nausea and headaches.

How CO2 affects the body
How CO2 affects the body

Case study: The lake Nyos
The lake Nyos is a crater lake situated in Cameroon. In 1986, a pocket of magma from under the lake, leaked a large amount of CO2 into the air. The result was suffocation of around 1’700 people and 3’500 livestock!

As we take beer brewing seriously we will be sure to test a number of varieties with our colleagues from the world over at the Rotronic 2014 International Sales meeting in Grindelwald next week!

Dr Jeremy Wingate
Rotronic UK

New training course dates! – Temperature and Humidity Measurement and Calibration Training.

Following the continued success of our training courses we have several new dates for October this year!

These courses are aimed at providing excellent theoretical and practical knowledge useful both for those new to the field or those looking to expand their knowledge.

Details and booking information can be found via the below links.

7th – 8th October 2014 :: Two Day Temperature Measurement and Calibration

9th October 2014 :: One Day Humidity Measurement and Calibration

Courses will be hosted by our partner Benrhos Limited in Wales and delivered by Dave Ayres (Benrhos) and Jeremy Wingate (Rotronic).

These excellent value courses are open to a maximum of 8 delegates ensuring course content can be targeted specifically to your needs.

Details and booking information can be found via the below links.

7th – 8th October 2014 :: Two Day Temperature Measurement and Calibration

9th October 2014 :: One Day Humidity Measurement and Calibration

Key areas covered include;
  • Knowledge that is not available from other sources.
  • Terminology and units.
  • Fundamentals of each parameter.
  • Best practice measurement.
  • Calibration methodologies.
  • How to interpret results and spot common errors.
  • Measurement uncertainty.
  • How to use uncertainty budgets and benefit from them.
  • Common instrument types and their advantages/disadvantages.

Any queries please do not hesitate to contact us.

Dr Jeremy Wingate
Rotronic UK

BlogShot – Inexpensive Compact Logger

Rotronic is pleased to announce the introduction of its smallest ever temperature and humidity logger. The HL-1D measures only 90 x 60 x 23 mm, is well specified with good accuracy, durable and has high ingress protection against dust and water (IP67). HW4-Lite validated software for programming, data download and analysis is included. The logger is available now at a competitive, inexpensive price.

Hygrolog HL-1D
Hygrolog HL-1D

The Rotronic HL-1D logger is very suitable for monitoring and recording conditions for a wide range of applications across all industries, in commerce and for research organisations. The compact logger is particularly suitable for monitoring high value products of all types during transportation to ensure that quality is maintained.

The significant features of the HL-1D inexpensive logger include:

•  High measurement accuracy of 3 %rh and 0.3 °C
•  Slim, compact and durable. High ingress protection rating of IP67
•  Clear LC display with configurable visual alarms
•  Large data recording capacity:  32,000 data points
•  Ranges:  -20…70 °C, 0…100 %rh. Logging interval from 30 s
•  Min / Max / Average statistical function on logger display
•  Package includes HW4-Lite validated PC software with data analysis
•  Three year battery life (with five minute logging interval)
•  FDA 21CFR Part 11 / GAMP5 conformity
•  Temperature only logger available (product code TL-1D)

HL-1D / TL-1D Logger Technical Datasheet – click here

Contact us now for logger pricing and additional information

Tel: 01293 571000  Email: instruments@rotronic.co.uk  Web: www.rotronic.co.uk

Critical monitoring of wind turbines

The future is very encouraging for wind power. The technology is growing exponentially due to the current power crisis and the ongoing discussions about nuclear power plants. Wind turbines are becoming more efficient and are able to produce increased electricity capacity given the same  factors.

Picture2
Worldwide installed wind power per year in MW. (Source GWEC)

Converting wind power into electrical power:

A wind turbine converts the kinetic energy of wind into rotational mechanical energy. This energy is directly converted, by a generator, into electrical energy. Large wind turbines as shown in the picture, typically have a generator installed on top of the tower. Commonly, there is also a gear box to adapt the speed. Various sensors for wind speed, humidity and temperature measurement are placed inside and outside to monitor the climate. A controller unit analyses the data and adjusts the yaw and pitch drives to the correct positions. See the schematic below.

Wind Turbine
Schematic of Wind Turbine Systems

The formula for wind power density:

W   = d x A2 x V3 x C  where :

d: defines the density of the air. Typically it’s 1.225 Kg/m3 This is a value which can vary depending on air pressure, temperature and humidity.

A2: defines the diameter of the turbine blades. This value is quite effective with its squared relationship. The larger a wind turbine is the more energy can be harnessed.

V3: defines the velocity of the wind. The wind speed is the most effective value with its cubed relationship.

In reality, the wind is never the same speed and a wind turbine is only efficient at certain wind speeds. Usually 10 mph (16 km/h) or greater is most effective. At high wind speed the wind turbine can break. The efficiency is therefore held to a constant of around 10 mph.

C: defines the constant which is normally 0.5 for metric
values. This is actually a  combination of two or more constants depending on the specific variables and the  system of units that is used.

 Why measure the local climate?

To forecast the power of the wind over a few hours or days is not an easy task.

Picture3
Off shore wind farms

Wind farms can extend over miles of land or offshore areas where the climate and the wind speed can vary substantially, especially in hilly areas. Positioning towers only slightly to the left or right can make a significant difference because the wind velocity can be increased due to the topography. Therefore, wind mapping has to be performed in order to determine if a location is  correct for the wind farm. Such wind maps are usually done with Doppler radars which are equipped with stationary temperature and humidity sensors. These sensors improve the overall accuracy.

Once wind mapping has been carried out over different seasons, wind turbine positions can be determined. Each turbine will be equipped with sensors for wind direction and speed, temperature and humidity. Using all these parameters, the turbine characteristics plus  the weather forecast, a power  prediction can be made using complex mathematics.

The final power value will be calculated in “watts” which will be supplied into power grids, (see schematic on the right).  Electricity for many houses or factories can be powered by the green energy.

Picture4
Not ideal energy generating conditions!

Why measure inside a wind turbine?

Wind farms are normally installed in areas with harsh environments where strong winds are common. Salty air, high humidity and condensation are daily issues for wind turbines.

Normal ventilation is not sufficient to ensure continuous operation. The inside climate has to be monitored and dehumidified by desiccant to protect the electrical components against short circuits and the  machinery against corrosion. These measurements are required to ensure continuous operation and reduce maintenance costs.

What solutions can Rotronic offer?

Rotronic offers sensors with  exceptional accuracy and a wide range of products for meteorological applications and for monitoring  internal conditions.

Low sensor drift and long-term stability are perfect in   wind energy applications where reduced maintenance reduces operational costs.

The wide range of networking possibilities including RS-485, USB, LAN and  probe extension cables up to 100 m allows measurements in remote or hard to reach places. Validated Rotronic HW4 software makes it easy to analyse the data or it can be exported into MS Excel for  reporting and further processing.

The ability to calibrate  accurately using humidity standards and portable generators on site ensures continued sensor performance!

Comments or queries? Please do get in touch!

 

BlogShot – Rotronic High Precision, Fast Response Sensors for Temperature & Humidity Monitoring in Data Centres

There has been a rapid increase in large stand-alone data centres housing computer systems, hosting cloud computing servers and supporting telecommunications equipment, they are crucial for company IT operations around the world. Data centres must be extremely reliable and secure; many are wholly remote facilities.

Air conditioning is essential to maintain temperature and humidity levels within tight defined tolerances, thus ensuring the longest possible service life of the installed hardware.

Precise temperature and humidity measurement with fast reacting sensors is an absolute requirement. This increases energy efficiency whilst reducing energy costs. Additionally, data centre managers need to be alerted to even a small change in temperature and humidity levels. A separate monitoring system with networked alarms using fast reacting temperature and humidity sensors is installed.

Rotronic ‘standard’ HC2-S interchangeable temperature and humidity sensors are regularly specified for monitoring & controlling conditions in data centres due to their high precision and fast response with long-term stability. Used with a HygroFlex5 measurement transmitter analogue (scalable) or digital outputs are available exactly as required for interface with control systems. The loop can be validated electrically in minutes saving a significant amount of time. Probes can be exchanged rapidly when service work or periodic calibration checks are required.

Contact Rotronic for full product information

Tel: 01293 571000  Email:  instruments@rotronic.co.uk