Global Journal of Researches in Engineering, J: General Engineering, Volume 1 9 Issue 2

sensor is located in the end left position. In this position electric heater is connected to the network, and the temperature in the camera rises. In this case the disk begins to displace to the side indicated by pointer, also, at a specific temperature, concerning the button of end key K 1 tearing up contact between its contacts. But turning off electric heater in this case does not occur since. The contact pairs of the end normally locked keys K 2 and to K 3 remain locked and the temperature in the camera continues to rise. In this case the disk as before continues to move to the side, indicated with pointer, compressing the spring, on which is located the key K 1 . With further increase in the temperature in the camera the disk reaches the button of key K 2 and it tears up its contacts. In this case nourishment the coils of starter will be opened, and proceeds turning off electric heater from the phase, is torn up also contact between the contacts of key K 3 . The temperature in the camera begins to fall after this. With the reverse wobble at first are locked the contacts of key K 2 , but this does not lead to the starting of starter, since the contacts of key K 3 are thus far still extended. And only after the decrease of temperature to value dT, disk releases the button of key K 1 , including starter. The cycle is repeated after this. Thus the position of key K 2 determines the upper temperature of cycle, and the position of key K 1 lower. © 2019 Global Journals Global Journal of Researches in Engineering ersion I 33 Year 2019 must be ~ 85-90 0 Cand 65-70 0 C respectively. The readiness of wood is determined on the difference between the dry and moist thermometer, which must be 29-30 0 C. In this case the relative humidity of lumber will be within the limits 6-8 percent. With reaching of this temperature they turn off camera. For the more rapid cooling of wood it is possible to open slightly the door of camera. With the reaching in the camera of the temperature ~35-40 0 Cthe wood can be unloaded. The cameras examined do not require the interference of operator in entire cycle of their work independent of the initial humidity of the loaded wood. The only parameter, which in the end of the drying cycle is subject to control from the side of operator, this is difference boundary by the indications of dry and moist thermometers. With the drying of the freshlyn-saw down softwood the expenditure of electric power per one cubic meter of the loaded wood composes ~ 700-800 kWchas, while with the drying of solid rocks~ 900-1000 kWchas. For turning off of temperature control system from the power source in the case of exceeding in the camera of the temperature of higher than the assigned limits (emergency) serves blocking. For its work as the sensor are used separate temperature -sensitive element, the same, as in the temperature control system, it shown in Fig. 21. 1 K Wooden bushing Bolt №1 Disk F i g. 19: Schematic of blanking sensor. In the sensor is used the normally locked key K 1 . With the aid of the nut on the bolt № 1 the position of key is established so that the wear and tear of blocking would occur at a maximum permissible temperature in the camera. Heat of vaporization of water with the atmospheric pressure is 2260 kJ/kg (540) kcal/kg. But if we calculate the quantity of water, which is contained in the wood and the quantity of energy, expended for its evaporation, then even taking into account the ideal heat insulation of camera, specific expenditure occurs 1.5 - 2 times more. This connected with the fact that for the elongation of entire cycle of drying into the camera is sucked atmospheric air, which is then, being heated to the operating temperature of camera, it is ejected outside. It is essential to decrease these unproductive losses possible in the condensing chamber, whose diagram is depicted in Fig. 22. ( ) Volume XIxX Issue II V J Cameras for the Drying of the Wood