Main Article Content
This research aims to develop and produce the steam boiler with high efficiency of the fuel on the Liquefied Petroleum Gas (LPG) for steaming the loaf mushroom for farmers. Design principles for building are based on the increased surface area of heat from the gas generated from the combustion chamber. Small quantity of water is needed in order to produce steam quickly. The chamber is consisted of two parts: 1) a partition walls, and 2) a fire pipe. The tubular structure is made of a tank with capacity of 200 liters and 35 liters of water is supplied into the boiler to produce steam continuously controlled by the valve to prevent reversed steam pressure. From initial test, the boiler produced the steam up to 30 liters within 1 hour with fuel consumption of 2.74 kg per hour and efficiency of 51% with steam absolute pressure of 15 Pa at the cost of steam production 1.50 baht per kg. From the experiment with mushrooms steaming of 500 cubes, it took 3.25 hours. The cubes were incubated approximately one month; they completed the full propagation of mushrooms bags with in that period.