In the treeless zone, the tourist Primus Bumblebee serves as a heat source; it is currently produced in Kazakhstan under the name Dastan. Or the Bee similar to it and their foreign counterpart Febus. However, in the open air, the primus is not able to boil a 5-10 liter capacity.
Tourist gasoline primus Bumblebee, Dastan, Bee, Phoebus, device, design and operation features, causes of failure.
Therefore, to preserve heat and save fuel, it is necessary to cover the stove with a heat shield, such as fiberglass. A piece of fiberglass must be hemmed around the edges and not shake over open dishes.
. After all, if the canister baits and near it a primus flares up or someone lights up, an explosion is possible. That is how our foreign guests burned the pride of Soviet mountaineering the Shelter of the Eleven hotel.
Secondly, you must try not to spend fuel on the evaporation of water during cooking in ordinary dishes. An autoclave is indispensable for this. The third reason for losses is the dissipation of heat into space. The kitchen must be hidden from the wind. A heat shield made of fiberglass will help to keep warm. In difficult winter and mountain hikes, a screen made of stainless steel sheet tape with a width of about 400 mm and a thickness of 0.1-0.15 mm is very convenient. At the bottom of the screen, holes are cut out through which the handles of the stoves are passed and air is sucked in. A steel screen works if a gap of 10-15 mm is maintained between it and the cookware. You can save it by placing small pebbles behind the screen.
The fourth way to save money (the first three were mentioned above) is to reduce the cooking time. No matter how we isolate the stove and dishes from the environment, losses are inevitable: and the more, the higher the temperature of the water in the dishes. Therefore, the longer the heating takes place, the more fuel is wasted. To reduce cooking time, it is necessary to carefully build a heat shield, increase the power of the stove, make the bottom of the dishes wider, and the walls lower. The power of the primus can be increased by drilling a nozzle hole by 0.1-0.2 mm and replacing the double round divider with a flat one similar to the Turus or Ogonyok primus divider. You can put two primuses under one container, a two-head primus is unreliable.
Features of operation of stoves.
If the primus starts to growl, the flame disappears, and the divider is heated (dynamic burning), it is necessary to extinguish the fire and light it again. If at the same time the primus growls again, you need to remove and reinstall the divider. Typically, dynamic combustion is due to loose installation of the divider. When the temperature in the autoclave rises slowly or does not rise at all or the water in the pan boils longer than usual, you do not have to wait until the whole primus refueling burns out. Check the gap between the screen and the dishes, cover the stove with a sheet of polyethylene or polyurethane foam from the wind, move the kitchen to a place protected from the wind, for example, in a tent or in the vestibule between tents installed in tandem.
Generally speaking, working with a primus requires attention and ingenuity. Camp cooking does not forgive negligence and indifference. The primus under the heat shield, especially the paired one, easily overheats, while the safety valve is activated and the primus flashes. The consequences can be very deplorable: overturned pots, burnt tents, scalded and charred tourists. Therefore, the most experienced travelers increase the stiffness of the spring in the valve or put a plug in it. Primus tanks are made with a large margin of safety, cases of their rupture are not known. However, the primus covered by the screen must be in the lid of its case, filled with snow or water for cooling. In this case, you can not be afraid of overheating.
The handles of the pumps in the stoves are made of fusible metal, so if there are two stoves, they need to be turned in different directions, or better yet, replace the handles with homemade ones made of bronze or brass. When using gas burners, note that the plastic and aluminum parts of Campingaz burners under the screen can melt and cause an explosion. Primus burners are more reliable, but even when they overheat, the control knob seals burn out. They can be replaced with rings made of heat-resistant plastic. But best of all, when the burner is connected to the cylinder with a flexible hose. Elementary adapters can be made even in the school technical workshop.
Primus fuel and its kindling.
Subject to all the rules, the fuel consumption on a primus stove does not exceed 35 ml per person for one cooking, 60–70 ml per day. If you extract water from snow, the flow rate increases to 100 ml. These indicators are checked by the author in mountain hikes at heights from 3 to 6 thousand meters. The fuel for the primus is pure (unleaded) gasoline, heptane or other non-toxic combustible liquid with a boiling point of about 80 degrees. Due to the sharp deterioration in the quality of gasoline A-76, A-72. A-66 is not recommended. Do not use petroleum ether that damages the rubber gaskets of pumps.
The reliability of the primus depends largely on the way it is ignited. You can not warm up the primus with gasoline drained through the nozzle. At altitude and in winter, cold gasoline burns poorly, soot clogs the burner. It is better to use dry alcohol or technical (denatured) alcohol. Before igniting, the primus stoves must be installed securely on a level surface, and plywood should be placed under them, otherwise the snow will melt and the stoves will tip over.
Some causes of failure of primuses in work.
The most common cause of primus failure is nozzle clogging. If after warming up the primus does not light up (you can not hear the hiss of escaping vapors), try to clean the nozzle by turning the key several times in different directions. If at the same time the primus does not hiss, check if it is inflated. When the pump does not help, you have to cool the stove, unscrew the nipple and clean it and the head from above (do not damage the needle!). Use the first guitar string or thin spring wire. Sometimes a sharp blow to the fitting helps with the valve open, not pressed.
Cleaning the shut-off valve helps with a zero-sandpaper, but you will have to completely disassemble the head, destroying the stuffing box seal. You can restore the seal with an asbestos cord. In stoves where gas supply is blocked by a ball valve (type Bumblebee-4), the wire will not help. You have to unscrew the head, remove the strainer and release the burnt ball with a needle or awl. By the way, so that the valve does not stick, after turning off the primus, it is useful to blow off the head with gasoline vapor, turning the key in different directions. When the valve is cleaned, the head is replaced.
However, after this, its seal may be broken and, when fired from under the thread, a flame will appear, or pressure will begin to drop after several minutes of burning. You can try to restore the seal by tightening the thread. To do this, it’s good to have a regular 20 mm wrench in the repair kit. A sealing ring specially cut from soft aluminum will also help restore the seal. It is useful to add an aspect modifier to the fuel, this reduces the failure rate.
Based on materials from the book Camping Food.