真空炉为卧式、单室结构，其炉体炉门采用双层水冷，前后开门结构。

由炉体、加热室、真空系统、充气系统、水冷系统、电控及供电系统组成。

 1 、 炉体：本炉整体结构由炉壳、炉门、炉门锁紧机构、炉体支架等组成，炉壳、炉门为双层夹套冷壁结构。炉体部分由炉筒和炉门构成，炉筒和炉门内壁以及外壁材料为 304不锈钢，。炉门采用双层椭圆封头与圆形法兰焊接而成，法兰上装有 O 形密封圈。工件可由下炉门打开装入和取出，中部设置加热室主体及电极和主真空泵的抽气口。

 2 、加热室：加热室圆形加热室，由加热元件、隔热屏、料台组成。加热元件采用高温钼加热，采用特殊设计的陶瓷（95 陶瓷）件绝缘，可最大程度避免由于焊接挥发导致的短路；加热区可单独拆卸，损坏时更换方便。加热电源通过铜软线、铜牌、铜电极与发热元件相连。电路与炉体绝缘性能良好，便于拆卸清理更换。

3、  真空系统：真空系统来实现对炉体的真空泵抽气。在各个阀门和管道都有真空规管座，并在各管路段设置有真空检测装置，便于各段真空测量。

4、 电控系统：

4.1 由触摸屏、可编程序控制器、晶闸管调压器、真空计及记录仪等组成，以实现供电、控制、记录、监视、报警保护功能。

4.2 可编程控制器 PLC 采用西门子系列，控温采用日本导电的控温仪，可精确控制温度。同时，PLC 全面控制设备的运行，根据工艺要求，提供顺序控制信号，同时采集现场的反馈信号，提供转换、连锁、指示及报警信号。除装卸料外，全过程可自动进行，并备有手动操作系统。

4.3 测温为热电偶,用于随机检测炉内温度和炉内温度均匀性。

4.4 真空测量采用真空变送器，多点输出控制，用于过程自动控制和记录。

4.5 设备控制界面采用触摸屏控制系统，通过与 PLC 的通讯，可设定及记录温度、及真空度曲线，便于工艺的制定和查询。并可实时显示设备运行状态。

4.6 具有超温、断水安全保护功能，并有声光报警系统，炉体上设有安全阀装置，有气压、真空度、水压、加热等互锁电路。

4.7 加热电源采用单相可控硅电源，低电压、大电流方式供电。

4.8 控制柜内有风扇冷却系统。

5 5 、水冷系统：真空炉炉体、炉门、真空机组、水冷电极、换热系统需要冷却水。该系统由主供水管分配到各冷却部位，采用闭式水循环系统，冷却管路并配备水压报警系统。进水有分支接到自来水管道上，以备停电时紧急使用。进回水管道均采用不锈钢管道。

6 6 、安全系统：安全系统包括 停水、超温、加热过流、旋片泵、罗茨泵、设备具有自检、故障自诊断、自动保护、防止误操作等功能。并具有声光报警提示和具备相应的联锁、互锁保护。

The vacuum furnace has a horizontal, single-chamber structure. The furnace door adopts double-layer water cooling and has a front and rear door opening structure.

It consists of a furnace body, heating chamber, vacuum system, charging system, water cooling system, electronic control and power supply system.

1. Furnace body: The overall structure of this furnace consists of furnace shell, furnace door, furnace door locking mechanism, furnace body bracket, etc. The furnace shell and furnace door are double-jacketed cold wall structures. The furnace body is composed of a furnace barrel and a furnace door. The inner and outer walls of the furnace barrel and door are made of 304 stainless steel. The furnace door is welded with a double-layer oval head and a circular flange, and the flange is equipped with an O-ring seal. The workpiece can be loaded in and taken out by opening the lower furnace door. The main body of the heating chamber and the exhaust port of the electrode and main vacuum pump are set in the middle.



2. Heating chamber: Heating chamber is a circular heating chamber, which is composed of heating elements, heat shield and material table. The heating element is heated with high-temperature molybdenum and is insulated with specially designed ceramic (95 ceramic) pieces, which can minimize short circuits caused by welding volatilization; the heating area can be disassembled separately, making it easy to replace when damaged. The heating power supply is connected to the heating element through copper flexible wires, copper plates, and copper electrodes. The insulation performance of the circuit and the furnace body is good, making it easy to disassemble, clean and replace.



3. Vacuum system: The vacuum system is used to realize the vacuum pumping of the furnace body. There are vacuum gauge seats in each valve and pipeline, and a vacuum detection device is installed in each pipeline section to facilitate vacuum measurement in each section.



4. Electronic control system:

4.1 It is composed of touch screen, programmable controller, thyristor voltage regulator, vacuum gauge and recorder to realize power supply, control, recording, monitoring, alarm and protection functions.

4.2 The programmable controller PLC adopts Siemens series, and the temperature control adopts Japanese conductive temperature controller, which can accurately control the temperature. At the same time, PLC fully controls the operation of the equipment, provides sequence control signals according to process requirements, and collects on-site feedback signals to provide conversion, interlocking, indication and alarm signals. Except for loading and unloading, the entire process can be carried out automatically and is equipped with a manual operating system.

4.3 The temperature measurement is a thermocouple, which is used to randomly detect the temperature in the furnace and the temperature uniformity in the furnace.

4.4 Vacuum measurement uses a vacuum transmitter with multi-point output control for automatic process control and recording.

4.5 The equipment control interface adopts a touch screen control system. Through communication with the PLC, the temperature and vacuum curve can be set and recorded to facilitate process formulation and inquiry. And can display the equipment operating status in real time.

4.6 It has over-temperature and water-cut safety protection functions, and has an audible and visual alarm system. The furnace body is equipped with a safety valve device and interlocking circuits for air pressure, vacuum, water pressure, heating, etc.

4.7 The heating power supply adopts single-phase thyristor power supply, which is powered by low voltage and high current.

4.8 There is a fan cooling system in the control cabinet.

5 5. Water cooling system: The vacuum furnace body, furnace door, vacuum unit, water-cooled electrode, and heat exchange system require cooling water. The system is distributed to each cooling part by the main water supply pipe, adopts a closed water circulation system, the cooling pipeline is equipped with a water pressure alarm system. The water inlet has a branch connected to the tap water pipe for emergency use in case of power outage. The inlet and return water pipes are all made of stainless steel pipes.

6 6. Safety system: The safety system includes water outage, over-temperature, heating over-current, rotary vane pump, Roots pump. The equipment has functions such as self-test, fault self-diagnosis, automatic protection, and prevention of misoperation. It also has sound and light alarm prompts and corresponding interlocking and interlocking protection.