The Physical Laws Relating to Gas. Charles’s Law - Part 3

 This law is named after Jacques Charles (1746–1823), a French physicist who discovered that all

gases increase in volume by the same proportion if heated through the same temperature range, provided

that the pressure remained constant. This proportion is 1/273 of their volume at freezing point

(0◦C or 273K) for each 1K rise above 273K. Therefore, the temperature of a volume of gas would

need to be increased from 0◦C to 273◦C in order to double its volume. (Note: 1K rise = 1◦C rise.) 

Where the pressure remains constant, Charles’s law is expressed as:

                                                           Volume ÷ Temperature = Constant

In simple terms, if the temperature increases, so does the volume. As with Boyle’s law, the formula

can be redefined as:

                                                                   V1 ÷ T1 = V2 ÷ T2

Where V1 = original volume, T1 = original temperature, V2 = final volume and T2 = final temperature.

Practical example If 1 m3 of gas enters a building from outside where the temperature is 2◦C and

passes into a building where the temperature is 21◦C, the gas would increase in volume by:

                                                    V1 ÷ T1 = V2 ÷ T2, so (V1 × T2) ÷ T1 = V2

                                          ∴ 1 × (21 + 273) ÷ (2 + 273) = 1.07 m3, an increase of 7%

The Physical Laws Relating to Gas. Boyle’s Law - Part 2

 

This law is named after Robert Boyle (1627–1691), who discovered the relationship between volume

and pressure of a gas. He found that the absolute pressure of a given mass of gas is inversely

proportional to its volume provided that its temperature remains constant (Absolute pressure =

Atmospheric pressure (1013 mbar + gauge pressure). 

                                                                             So.....

To put it simply, if the absolute pressure (gauge pressure + atmospheric pressure) on a given quantity

of gas decreases, then its volume will increase. So if the absolute pressure is increased four-fold, the

volume would be reduced to one quarter. The formula can be redefined as:

                                                                    P1V1 = P2V2

Where P1 = original pressure, V1 = original volume, P2 = final pressure and V2 = final volume.

Practical example Suppose that the supply pressure to a building is 80 mbar and the total volume

is 1 m3, if the pressure was reduced to 20 mbar the new volume of the gas would be calculated as

follows.

                                                  P1V1 = P2V2, so P1V1 ÷ P2 = V2

                           ∴ (1013 + 80) × 1 ÷ (1013 + 20) = 1.06m3an increase of6%.

Conversely, if the supply pressure is increased to 800 mbar when a new medium pressure regulator

is fitted, supplying the same 1 m3 volume of gas, and also reduced to 20 mbar, there is an interesting

result:

                                                                   P1V1 ÷ P2 = V2

                                ∴ (1013 + 800) × 1 ÷ (1013 + 20) = 1.76m3, an increase of76%

This increase is probably the reason that the gas supplier installed the regulator prior to the meter.

The Physical Laws Relating to Gas. Graham's Law of Diffusion - Part 1

                                                            Graham’s Law of Diffusion

This law is named after Thomas Graham (1805–1869), who discovered that gases will mix with one another quite readily due to the continuous movement of the molecules. However, the rate at which they mix depends on the specific gravity or density of the gases. Graham made a container, consisting of two separate compartments with a small hole in their dividing wall. He placed a different gas in each of the compartments, one having a higher specific gravity than the other. He found that more faster, lighter molecules of the lighter gas passed through the hole rather than the slower, heavier molecules of the heavier gas. After many experiments he discovered that the rates of diffusion, or mixing, varied inversely to the square root of the density of the gas. Thus:

Diffusion rate ∝ 1 ÷

√

Density

Which basically means that a light gas will diffuse twice as fast as a gas four times its density.

 

Thermocouples: What are they?

                                                               Thermocouples

The thermocouple is a vital safety feature for many gas appliances. A thermocouple uses the heat from a flame to produce a millivoltage that controls a gas valve. If the pilot goes out, the thermocouple can no longer send the millivoltage that is required to allow the gas valve to stay open, thus sealing the valve to prevent a dangerous gas leak.

Thomas Johann Seebeck accidentally discovered the Thermocouple in 1821. He experimentally determined that a voltage exists between the two ends of a conductor when the conductor's ends are at different temperatures. His work showed that this voltage is proportional to the temperature difference. His discovery soon became the basis of the thermocouple, which today is one of the most popular and cost effective temperature sensors.

Gas Regulators - what are they and how do they work?

 What is a gas regulator?

A gas regulator, also known as a gas pressure regulator, is a mechanical device used with a gas cylinder. It’s designed to slow down the compressed gas rushing out of a cylinder and release it in a controlled and steady stream to the appliance it’s connected to.

Which one is right for you?

There are all kinds of gas regulators available. Choosing the correct one for your installation or appliance is extremely important. First we have to understand why we need one and if it should be used indoors or outdoors.

This is your common low pressure regulator with a gauge. This is used on cooking appliances and heating appliances. This is attached to a 9 Kg bottle and will be connected to the appliance.  

This is a low pressure bullnose regulator. This one is ideal for outdoors installations and should be mounted against a wall. This regulator is for bigger sized cylinders like the 19 Kg or 48 Kg.

 

Green Living with LPG.

The world is moving towards a greener future with businesses and every day civilians becoming more self-aware of their carbon footprint.

These days people are opting for more environmentally friendly alternatives in their daily practices. Single-use plastics are being phased out for reusable alternatives, plant-based foods are becoming more popular by the day and alternative energy sources are being seen more frequently.

LPG is Liquified Petroleum Gas, also referred to as LP Gas or propane. It is a mixture of natural gas and propane. It is a portable, clean and efficient energy source that has many applications and is readily available world-wide. 

It's carbon footprint is 50% less lower than coal and produces virtually no particulate matter or soot when burned making it a clean-burning energy source. LPG is the perfect back-up fuel to use in conjunction with other eco-friendly alternatives such as solar power.

LPG can make daily life more convenient in the following ways:

- Gas Heaters used to heat your home and office.

- Gas Geysers used to heat water instantly.

- Gas Braais provide a stable heat when braaiing with very little cleaning afterwards.

- Gas stoves & hobs used for indoor cooking.

- Gas fireplaces used for indoor and outdoor heating.

LPG is even used to fuel vehicles. A simple, inexpensive conversion can be done so that your car can run on Autogas, making your vehicle duel-fuel. Your car will be able to alternate between using Autogas and petrol or diesel.

Once again, Autogas is a more eco-friendly vehicle fuel as it produces 96% less carbon emissions than diesel and 68% less than petrol.

With increasing electricity prices in South Africa and more load-shedding being implemented every year, #LPG is a great alternative fuel to use at home.

(Gas Dryers) Did you know?

 

Have you heard about gas dryers?

According to Energy Star, a government-backed program that helps consumers learn about energy-efficient homes and products, your tumble dryer (or clothes dryer) is most likely the most energy-hungry appliance in your home even more than your refrigerator. 

If you’re shopping for a new dryer, now is a great opportunity to learn about ways to save energy. 

Gas dryers heat up much more quickly and generate more heat which in turn dries clothes faster. An electric dryer takes longer to reach its hottest point and doesn’t get as hot, so it uses electricity for a longer duration because it takes longer to tumble the clothes dry. If you want to save money on electricity, a gas dryer is well worth the consideration.

We break-down the pro's and con's of the gas dryer.

Pros:

• More energy efficient than electric dryers. 
• Dries a load of laundry more quickly.
• Uses a standard electrical outlet.

Cons: 

• Requires a gas hook-up.
• Must be placed near a vent that goes outside the home.
• Often more expensive than a comparable electric dryer.

Importance of  a Service:

Both of these types of dryers (electric or gas) pose safety hazards that can be mitigated with proper installation, maintenance and usage. It’s worth noting that the safety concerns about gas and electric dryers apply to pretty much any major home appliance. It is recommended to have your gas appliances and installations serviced regularly to ensure that they use gas efficiently.

Designs:

                                       

LG Ultra Large Capacity
Gas Dryer
with Sensor Dry Technology

Need more convincing? Watch the video below.