The heat preservation of autoclack body is mainly aimed at conduction and radiation heat transfer, which requires the selection of economical and efficient heat preservation materials. Mineral wool or rock wool is generally used as the insulation layer, and polished aluminum plate or galvanized plate as the protection layer. However, many enterprises do not achieve the expected effect of heat preservation, which has some defects.
1.Insufficient insulation layer thickness
According to relevant national specifications, the insulation layer thickness of autoclavie should not be less than 120mm, but in fact, very few enterprises achieve it.Insulation layer thickness is insufficient, in addition to reduce the heat preservation effect, and exposed the disadvantages of kettle body reinforcing ring if body reinforcing ring without package within the insulation layer and protective layer, not only body reinforcing ring in the form of conduction heat transfer in heat dissipation, and, when it rains, the rainwater infiltration of thermal insulation layer, thereby reducing the heat preservation effect, at the same time, the rain wet body reinforcing ring, and increased the heat of phase change heat transfer.The scientific practice is to use two layers of 60mm mineral wool or rock wool to block the conduction and heat transfer.The interlacing of mineral wool or rock wool is superimposed to block the convective heat transfer of the interstice in the heat preservation material;Polished aluminum plate or galvanized plate is used as the protective layer to block the radiant heat transfer of the kettle body (note that the darker the color of the protective layer and the lower the reflective effect, the lower its ability to block the radiant heat transfer);The construction shall ensure that the reinforcement circle of the kettle body is all wrapped in the protective layer. The polished aluminum plate or galvanized plate shall be folded and overlapped, and it shall be noted that the upper plate must be pressed against the lower plate when the upper plate is overlapped, so as to prevent rain water from pouring in and block the phase transition heat transfer.
2.Insulation material defect
In order to reduce costs, some enterprises often choose calcium silicate insulation block or aerated concrete waste block masonry kettle insulation layer, and ignore the waterproof insulation layer.Although calcium silicate insulation block or aerated concrete waste block has a good heat preservation and insulation effect, but the specific construction method is difficult to ensure the insulation effect of the insulation layer, and the insulation mortar used in the construction of heat preservation will also reduce the effect of heat preservation.If the above method has been adopted, the surface layer of the insulation material should be practically done to avoid the insulation layer cracking and falling off;Take effective rain prevention measures (such as building awnings) to make up for the lack of material selection.
3.Insulation process defect
Generally, the following defects exist in the heat preservation process: to facilitate the construction, the supports and hooks are welded randomly on the kettle body;The insulation layer cannot be effectively waterproof;The cauldron door is not insulated.According to the specification, welding other objects on the kettle body is strictly prohibited. Except for safety factors, any welding parts are on the heat dissipation surface of the kettle body.Therefore, the method of welding bracket and hook should be abandoned in the construction of heat preservation. Meanwhile, all parts should be insulated as much as possible.
4.The kettle body (or kettle head) is not rainproof
Many enterprises tend to set autoclave outdoors. However, although the autoclave body is well insulated, the valves and joints of the pipes are difficult to be insulated, especially the head of the autoclave. This part becomes the main part of heat loss of the autoclave.Therefore, we should try to make the kettle body rainproof, at least for the kettle head rainproof.
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Post time: Jul-01-2020