Hobs - Did you know?

The hob is used for boiling, frying, steaming, simmering and braising. It primarily works by the conduction of heat from the flame through the pan surface. A certain amount of radiant heat is also generated. A large volume of primary air is provided so that the pan can be located as close as possible to the burner head and so gain the heat from the flame. The flame should not be allowed to lick up the side of the pan as heat will be wasted. 

The hotplate is usually a solid steel flat plate or ceramic surface, on which the pan sits, or it can take the form of a griddle, which is used for dry-frying foods such as eggs etc. The flame is located beneath the metal and heats it to the desired temperature.

The heat setting of a hob or hotplate often has a grading, such as simmer, medium and high. The flame does not adjust to the heat requirements of the food being cooked and if set too high, the contents of the pan may boil over or burn. Some appliances have thermostatically controlled burners. They work using a contact sensor that is filled with a volatile fluid that, when heated, expands forcing the gas valve to close down to a by-pass rate. With freestanding cookers all control taps and the oven thermostat are located on a pipe, named the float rail, which is located behind the control knob fascia. During any maintenance work all these gas connections should be sprayed with leak detection fluid to ensure they are gas tight. The gas burners used with the associated parts of the cooker are generally unprotected, in terms of flame failure. This means that should the flame go out, gas is allowed to discharge freely into the room. The oven will be found to have a flame failure device fitted, usually of the liquid vapor type, which will shut down the main flow of gas but will still allow a discharge through the by-pass. Cookers supplied by LPG are controlled and all control taps generally require the operation of a thermo-electric FSD before gas is allowed to flow freely. 

The Oven - Did you know?

The oven is used for warming, roasting and baking. It works by surrounding the food with hot convection currents. The oven temperature is adjusted by a thermostat that varies the amount of heat surrounding the food to be cooked. The grading ranges from a simmer or economy setting of around 100◦C through to gas mark 9, which generates temperatures of around 245◦C. Most domestic ovens found in the UK work by natural convection currents. The burner located at the rear of the base creates a circulation of hot gases that eventually discharge from the rear of the oven by means of a flue. Owing to the relatively slow circulatory motion, temperature zones invariable develop in the oven, with the hottest region at the top. In another design of oven, the gas burner is located outside the food compartment and hot air is allowed to enter via various ports, so producing a more even spread of heat temperature throughout the oven. This design is often used with an additional fan to give improved efficiency.

                                                                Built-in Oven and Hob

                                                                Freestanding Cooker

The Grill - did you know

The grill is used for toasting, grilling or browning previously cooked food. It works

by directing radiant heat that has been produced on the surface of a red-hot fret,

mesh or gauze surface, on to the food. There are two designs of grill.

First, those referred to as conventional grills, as they have been around the longest.

The grill consists of a pressed steel burner, fed via an injector at one end and located

beneath an expanded metal fret. The flames, on leaving the burner, heat the metal fret

and cause it to glow red-hot. The combustion products rise by convection through

holes in the canopy top. The biggest problem with this design is the problem of

uneven cooking, a result of the burner failing to heat the whole surface of the fret

uniformly.

In the second design of grill, known as a surface combustion grill, the injector feeds gas

into the primary air intake, this entails some 80–90% of that required for combustion.

The mixed gas and air now travels to the centre of a sealed chamber, which has a fine

metal mesh burner surface where the ignition probe is located and where combustion

takes place, the air/gas mixture clings to its face, producing an evenly heated radiant

surface across the entire burner.

Deep Fryers - Did you know

 Deep fryers:

These are appliances that hold a quantity of oil or fat in which food such as chips, fish and doughnuts are cooked. There are two different designs - one that has a flat bottom with the oil heated directly from below and a second type has oil that is heated at a location above the base so maintaining a cool zone below the flame in which old food particles can sink without carbonizing and spoiling the flavor of the food load. There are two methods of heating the oil using this design of fryer. In the first method there is what is known as a V-shaped fryer, with the lower V section below the burner. The second method requires the gas flame to be fired directly into tubes that pass through the mass of the oil. With the flat bottom fryer it is essential that, before each frying all old particles are strained from the oil. The heat input can vary between 8 kW and 40 kW depending on the size of fryer.

Grill and Salamanders - Did you know

Grill and Salamanders

Under-fired or flare grills give a heat source below the food, operating up to 30 kW. The grill consists of a burner firing upwards on to a bed of refractory ceramic or pumice material. The food is placed on a series of bars. As the hot fat from the food drops, it is burnt off in the form of an ‘uncontrolled’ flame, giving the meat a characteristic appearance and flavor. 

Horizontally fired grills use surface combustion plaques between 3 kW and 12 kW and are often accompanied by a rotisserie to cook food. The fat from the food can drop to be collected in a container at the base. Over-fired grills or salamanders have the heat source above the food and operate between 5 kW and 16 kW. They can also be used for toasting. This type of grill often has a grooved solid aluminum branding plate on to which the food is placed. This plate allows the hot fat to drain away but at the same time assists in cooking the food on both sides due to absorbed heat that is held in the aluminum plate.

Salamander

Grill

Cooking with LPG

 In a country where loadshedding has become a daily reality, South Africans are forced to find new ways to adapt to life without electricity.

As with most challenges in life, we always work towards improving and solving the problem but in South Africa loadshedding is only getting worse by the year. At the time this blogpost is written, loadshedding has been a daily constant for almost 3 weeks and stages have been alternating between stage 3 to 6.

The timing of loadshedding usually falls during the hours when a person wants to bath or cook meals. Its become a challenge to live and just do basic things such as cook a meal, wash washing and also impacts businesses.

Luckily, we are not entirely dependent on electricity. With Eskom's continued failure at providing the country with electricity, energy sources such as solar power and LPG gas are slowly making their way into the spotlight and into people's homes.

Our business is focused on promoting the use of LP gas which is the perfect energy source to use in conjunction with solar power. Installing a solar power system can be quite costly whereas LPG is easily accessible, affordable and portable giving you a lot more versatility than solar or electricity.

Cooking with LPG has many benefits. 

Here are some of the reasons why you should consider making the switch:

• Your cooking time is faster: When it comes to gas stoves, there's no need to first wait for your stove plates to heat up like electricity. Your stove plates reach the desired temperature instantly meaning you can cook your meals faster.
• Better temperature control: Any baker will know that temperature control is extremely important when baking, the same applies to cooking. When you change the temperature on an electric stove, it usually takes some time for the oven or stove plate to adjust accordingly. With a gas stove the temperate adjustment is almost immediate and remains constant.
• Cooking with LPG is the most eco-friendly solution: LPG is a clean-burning fuel and emits very low carbon emissions making it a better option than electricity and even wood.
• It is cost effective:  Because gas stoves reach their temperatures faster and the heat remains at a constant temperature, you are able to cook meals much faster. Spending less time cooking means you use less energy than you would with an electric stove which means your gas lasts longer and you save on the electricity expense.
• Gas cooking is versatile:  As mentioned, LPG is an easily accessible and portable energy source. The sizes of gas canisters and cylinders vary meaning that you are spoiled for choice when it comes to cooking with gas. You can use gas in your home or outdoors at a braai. Are you going camping or hiking? There are cooking solutions for these activities as well. 

Cooking safely with LP gas:

When we were young and electricity was the main source of energy in every home and business, we were educated on how to use electricity safely. Now that we are considering other options of energy sources within our home, it is important to educate ourselves on their safety hazards.

Dangers of CO (Carbon Monoxide) and the Effects of CO in the Air

                             Carbon Monoxide

What is Carbon Monoxide?..

Carbon monoxide, or “CO,” is an odourless, colourless gas that can kill you. CO in the environment can have a devastating effect on human health. For most of us it would be the most dangerous gas we might ever experience. It is often referred to as the ‘hidden gas’ because it is very hard to detect. However, the effects of CO are quite dramatic and in high concentrations it will kill within a few minutes.

When we breathe, our lungs absorb oxygen. However, CO is absorbed more readily into the blood stream than oxygen and when our haemoglobin, or red blood cells, become saturated with CO, no oxygen can be absorbed. One of the functions of oxygen is to remove waste matter from our tissues, so without oxygen our blood rapidly become poisoned. 

What percentage of CO can be harmful and what percentage can kill us?

CO in air  -  0.01%

Saturation of CO in blood  - 0–15%

Effects of CO in adults - Slight headache after 2–3 hours  

 

CO in air  -  0.15% - 0.3%

Saturation of CO in blood - 50–55%- 55-65%

Effects of CO in adults - Severe headache, nausea, and dizziness within 10 minutes; increased breathing and convulsions, leading to collapse, possible death after 15 minutes.

Yellow flames coming out from gas appliances is a sign that your appliance isn't burning correctly and efficiently. Thus, its important to keep your appliance in good health by servicing it regularly.