Basic Technology for Automatic Gas Burner (For Manufacture Food)

The use of heat energy in industries, especially food manufacturing, has become a basic requirement. In practice heat energy is obtained from Electric Main Power, such as heater, or Utilization of LPG gas. In terms of costs, the use of LPG gas is still more efficient than Electric Heaters, especially for high heat loading.

Elpiji , pronunciation of Indonesian from an English acronym  ; LPG  ( liquified petroleum gas , literally : ” liquefied petroleum gas “), is a mixture of various hydrocarbon elements derived from  natural gas . By increasing the pressure and reducing the temperature, the gas turns liquid. The components are dominated by  propane  (C ₃ H ₈ ) and  butane  (C ₄ H ₁₀ ). LPG also contains small amounts of light hydrocarbons, for example  ethane  (C ₂ H ₆ ) and  pentane(C ₅ H ₁₂ ).

In atmospheric conditions, LPG will be in the form of gas. The volume of LPG in liquid form is smaller than in the form of gas for the same weight. Therefore LPG is marketed in liquid form in pressurized metal tubes. To enable thermal expansion of the liquid they contain, LPG cylinders are not fully filled, only around 80-85% of their capacity. The ratio between the volume of gas when evaporating with gas in a liquid state varies depending on composition, pressure and temperature, but usually around 250: 1.

The pressure at which LPG is liquid, called  its vapor pressure , also varies depending on composition and temperature; for example, it takes a pressure of about 220 kPa (2.2 bar) for pure butane at 20 ° C (68 ° F) to melt, and about 2.2 MPa (22 bar) for pure propane at 55 ° C (131 ° F).

According to its specifications, LPG is divided into three types, namely mixed LPG, propane LPG and butane LPG. The specifications of each LPG are listed in the decision of the Director General of Oil and Gas Number: 25K / 36 / DDJM / 1990. LPG marketed by  Pertamina  is mixed LPG.

The properties of LPG are mainly as follows:

• The liquid and gas are very flammable
•  Gas is non-toxic, colorless and usually smells pungent
•  Gas is sent as pressurized liquid in a tank or cylinder.
•  Liquid can evaporate if released and spread quickly.
•  This gas is heavier than air so that it will occupy a lot of low areas.

One of the risks of using LPG is the occurrence of leaks in tubes or gas installations so that if exposed to a fire can cause a fire. Initially, LPG gas does not smell, but if so, it will be difficult to detect if there is a leak in the gas cylinder. Realizing that Pertamina added mercaptan gas  , which smells distinctive and pierces the nose. This step is very useful for detecting if there is a gas cylinder leak. LPG pressure is quite large (vapor pressure around 120 psig), so that the LPG leak will form gas quickly and change its volume to be bigger.

Here are some uses of Gas Burners in the food industry:

In the Food / Food Manufacture Industry, cooking products ( Cooking, Boilling, Smoking , Frying, Brewing, etc.) products with heating or heating have a huge effect. Temperature and heating time are the main variables. This factor influences product quality. Even in the medium-scale industry, if the control is carried out by humans it will not be optimal and the end result will be

From the observations, there are already many Automatic Gas Burners currently sold in the market, ranging from made in China to German. In the Automatic Gas Burner system there is actually nothing wrong, because it is standardized. This is a matter of Design Machine, when this Burner is grafted into the main machines, sometimes something is forced. For example, some suggested electronic parts are not in a humid area, instead installed there. The effect is the level of break down of the engine is high and some controller parts have a very short life time, the effect is that at the end of the month we are dizzy seeing very high maintenance costs.

Starting from this case, we try to better understand the logic of the Automatic Gas Burner for the purposes of engine maintenance and manufacture, taking into account Safety aspects.

3 main units in the Automatic Gas Burner Perncangan system:

1. Gas supply unit
2. Air supply unit
3. Ignition unit

The three units have an internal and interconnected system, controlled by a burner controller or management burner, which functions as a control center. The Safety System is closely related to these Units:

1. If the air supply unit does not work, the total system must be automatically off

Gas requires oxygen to become a fire. If the air does not supply, the gas will be collected in the room, and will be very dangerous.

2. If the ignition unit does not work, the total system must be automatically off

Same with the first point, if gas and oxygen are not mixed, and at the same time the ingition doesn’t work, then this gas collection will be very dangerous.

3. If there is no fire in a certain time, the system will automatically turn off.

Basic aspects of Safety are the working principle of Automatic Gas Burner, namely; 1) how the system can detect LPG and air supply. 2) Can detect the occurrence of fire / flame automatically.

What is the basic level of efficiency in LPG consumption, namely; 1) The system has a regulator mechanism for the volume of air and gas to get a perfect and efficient mixture. 2) The system is equipped with a temperature sensor, an object of cooking (product / space), so that the burner system automatically runs when needed.

Following is the Basic Automatic Gas Burner Scheme

The product sensor instructs the Burner On system.Explanation of the Scheme:

1. The Air Supply Unit works first, if it’s Ok, then Ignition / ignition is followed, in a short period of time followed by the opening of gas supply.
2. Gas Supply Unit, consisting of:Gas Station, Gas reducer / regulator, Gas / Manometer pressure indicator, Solenoid Gas.

Gas Solenoid : the maximum gas pressure can be up to 500 milli Bar. Gas solenoid is different from wind or water solenoid. For the purposes of Design, this Spare Part is designed with high safety standards, and the electric coil pulling system uses DC Current, so 1 complete selenoid unit with rectifier circuit, if the main input uses AC current. Some selenoid on the market are issued by Weishaupt, Brahma, Rheem, etc.

Gas reducer : To adjust the gas pressure used for the ignition process

4. Air supply unit, consisting of a blower, air volume control valve, air pressure sensor

Blower : In a closed system that does not allow free air supply, the air is forced into the system with a blower.

Air volume control valve: this valve is used to regulate the volume of air entering, so that an ideal mixture occurs between air and gas.

Air Pressure Sensor : This part is to detect whether the air has entered with the appropriate pressure level.

5. Ignition unit, consisting ofElectrode / ignition, Ignition Transformer, Flame Detection, Burner

Electrode / ignition : The fire source (lighter), designed to work for only a few seconds, the characteristics of this ignition must be able to withstand very high temperatures (carbon steel) and in ceramic wrap, because with very high voltage ceramics are used to resist leakage to the body / ground.

Ignition Transformer : More or less like a Step up Transformer, the type we use Weishaupt, W-ZG 01 / V

(230 V / 50-60 Hz / 100 VA)

Flame Detection : There are several types that are on the market. In principle, Flame detection can withstand maximum blower fire temperatures.

Burner : Like a furnace, adapted to the needs, low pressure or high pressure, this burner is carried out by mixing gas and air, and a fire trigger is installed (ignition / electrode)

6. Controler, this unit is the control center of the entire system.All Input Signals such as Sensor products, Flame Detection, Air Pressure Signal, and several other inputs (Timer), are processed to provide the desired output . (according to Design Logic)
7. Based on the actual data in the field, it is better to separate the Controller from the cooking unit(Boiler, Cooker, Breweer, Smoker), to avoid the damp area. So parts that are grafted / installed on the machine are only parts that are moisture resistant.
8. This is just the basic scheme, from this design, it is very possible for further development.For example, fire alley systems, direct use of heat for cooking, or, using other media. Like oil heat transfer.
9. The development of modern technology, making the Automatic Gas Burner unit more compact, simple, and portable. Before using the type unit, make sure it is in accordance with the specifications of your machine, making it easier to maintain and durable.