A portable stove is a stove specially designed to be portable and lightweight, such as for camping.
Portable stoves can be broadly grouped into two types, based on type of fuel used, because in many respects the fuel dictates the design. The most common type in today's marketplace uses liquid or gas fuel. (Liquid-fuel and gas-fuel stoves are also partly distinct, but they have many similarities.) The simplest and most versatile type, however, remains the solid-fuel stove.
A liquid- or gas-fuel stove has one or two burners, generally similar to the kind used in the large stoves found in kitchens. Fuel passes into the burner from a fuel tank, usually external, but sometimes mounted in the body of the stove. The rate of fuel flow is controlled by a valve.
Stoves differ widely in their size and portability. The smallest models are generally termed backpacking stoves. They are designed for use in backpacking and long-distance cycling, where light weight and small size are paramount considerations. Backpacking stoves consist only of the burner and any related systems, and some (usually crude) devices to support the stove and cooking vessel. The legs are collapsible to minimize the space required. The weight may range from 300 gramss to nearly one kilogram.
Camping stoves are designed for use by people travelling by car, boat, canoe, or on horseback. They are similar in function and ease of use to kitchen stovetops, usually with two burners set into a table-like surface, and often with a folding lid for stowage and wind protection. This increases the weight to at least one kilogram, and sometimes as much as eight kilograms.
A common problem in the use of stoves outdoors is the wind, which often tends to extinguish the flame. Even if it does not do so completely, it may extinguish it on the upwind side, reducing the stove's effectiveness, and cause the hot gas to flow away from the vessel being heated. In camping stoves, the fold-out lid makes an effective wind shield, and some stoves also have protection on the sides.
Backpacking stoves do not include such features. They would interfere with the stove's collapsibility, and many backpackers erect makeshift shields out of materials on hand. However, there are specially designed cylindrical shields that are placed around the burner. In addition to keeping out the wind, they also trap heat that might otherwise escape.
Many camping and backpacking stoves have self-ignition mechanisms so that they can be lit without a match. They use the mechanical work done by the operator in depressing a button to create an electric spark. These devices provide an advantage in windy conditions, because matches blow out easily. Matches are also less convenient to use, and pose a fire hazard if used improperly.
Gas fuel is sold in canisters, typically under sufficient pressure that most of it is actually in liquid form. For backpacking stoves butane or a mixture of propane and isobutane are used. Camping stoves use either these or pure propane, which requires a particularly heavy-walled container.
A variety of liquid fuels are used as well. While gaseous fuels have relatively simple chemical names that transcend language barriers, any discussion of liquid fuels is complicated by regional differences in terminology. (See the External Links for more information about alternative nomenclature.) Broadly, four types of liquid fuel are used:
Most stoves can use either liquid or gas fuel, but not both. Gas-fuel stoves are notably simpler, because the fuel is easier to work with. The gas that flows from the fuel canister is simply ducted into the burner, where it ignites, in the same manner as in kitchen stoves.
Liquid-fuel stoves are more complex. Though the fuel is a liquid at room temperature, it burns better as a vapor. Thus, the stove is designed to bring it into contact with a hot piece of metal before it reaches the burner, so that it can boil there.
This device must be heated before the stove is turned on. Many stoves require the operator to open the fuel valve briefly without igniting the fuel, so that it flows into a small pan. This small quantity of fuel is then lit and allowed to burn down. When the fuel valve is opened again, the fuel vaporizes from the heat of the pan. Some stoves do not have this apparatus, and must be preheated by the application of an external fuel.
Liquid fuel is not stored under pressure, but pressure is needed to force it out of the bottle and into the stove. In many stoves, this pressure is generated by a small hand pump that forces air into the bottle. As the fuel is consumed, the pressure decreases according to Boyle's Law, so the pump must be operated frequently to maintain steady stove operation.
The preheating mechanism makes liquid-fuel stoves larger and heavier than gas-fuel stoves. In addition, many liquid fuels do not burn cleanly. While they leaves less residue than solid fuel, they do produce an oily black film that eventually coats both stove and cooking vessels. When liquid fuel leaks, it soils equipment, making it a fire hazard. The odor of fuel may also attract dangerous wild animals.
Gaseous fuels have many advantages: fuel bottles are widely available in stores;
One disadvantage of gaseous fuel is the impossibility of transferring fuel from one container to another, or of gauging how much fuel remains in a container with any degree of precision. Gaseous-fuel canisters are heavier than liquid-fuel bottles, because it must be stored under greater pressure. When a canister runs out, it becomes hazardous waste. Canisters tend to deteriorate and leak if stored for several years.
A quantity of liquid fuel sufficient to cook a meal, if simply placed in a container and ignited, would burn violently and consume itself in a matter of seconds, and a similar quantity of gas fuel would simply explode. The primary design principle of stoves that use these fuels is to provide a steady flame and prevent the fuel's escape. Solid fuel, however, is more manageable.
A solid-fuel stove may consist of no more than a metal plate to hold the fuel, a set of legs to keep it out of contact with the ground, and some supports for the cooking vessel. This design is highly scalable, and may be used for anything from tiny backpacking stoves to large portable woodstoves.
While admirably simple, solid fuel has many disadvantages. First of all, its burn rate may be controlled only by varying the amount of fuel placed on the fire, while fluid fuels may be controlled precisely with valves. Second, no solid fuel burns completely. It produces considerable amounts of ash and soot, which soil both the stove and the cooking vessels. Some of the chemical energy of the fuel remains locked up in the ash and soot, so solid fuel releases less heat, gram for gram.
Firewood may often be used in solid-fuel stoves, but manufactured fuels are also available. One type is sold in the form of small blocks, on the order of a centimeter in size. Sterno™ is a viscous fluid that is also used in solid-fuel stoves.
Simple stoves are sometimes used in ice houses and large tents, both to provide warmth and for cooking. They burn wood, and have a small flue used to exhaust the smoke. When used in tents, they are used in a larger tent made of fabric that does not burn readily, and are most often used in base camps that move infrequently.
The widespread use of backpacking stoves began with increased awareness of the environmental impact that backpackers had on the areas where they travelled, beginning in the 1950s in parts of Europe and the 1960s in the United States. Prior to their use, the usual practice when backpacking was to build an open fire for cooking from available materials such as fallen branches.
The fire scar left on the ground would remain for two or three years before the vegetation recovered.
The accumulation of fire scars in heavily travelled areas detracted from the pristine appearance that backpackers expected, leading to more widespread use of stoves.
These websites the names of different liquid fuels in different countries:
Liquid-fuel and gas-fuel stoves
The difference between backpacking and camping stoves
Wind protection
Self-lighting mechanisms
Fuel specifics
Differences between liquid-fuel and gas-fuel stoves
Design
Advantages and disadvantages
Solid-fuel stoves
History
Related topics
External links
