The advantages of external vacuum heat treatment furnace are.

1. simple structure, convenient construction, or with the original ordinary heat treatment resistance furnace transformation;.

2. The vacuum chamber is smaller in size, with less discharge, and there are almost no other parts that need to be deflated in the furnace chamber except for the workpiece, thus less deflation (no insulation board structure, etc.), and it is easy to achieve high Vacuum.

3、Since the electric heating element is externally heated, there is no vacuum discharge problem.

4、Furnace is no longer mechanically operated, simple operation, fewer failures, easy maintenance.

5, high-temperature vacuum furnace of the workpiece and the furnace lining does not contact, there is no possibility of chemical action at high temperatures; compared with the endothermic vacuum furnace, due to the simple structure, the load is equivalent, the cost is only 112 ~ 1/3 of the endothermic vacuum furnace; from the maintenance, service life and reliability assessment, more practical. 

However, thermal vacuum heat treatment furnace has some defects.

1. Low heat transfer efficiency of the furnace chamber, the workpiece heating rate is slow.

2. Furnace chamber material, furnace temperature is generally maintained in the range of 1000-1000C below;

3, the furnace chamber can be partially exposed to the atmosphere, although you can set the heat insulation screen, but the heat loss is still very large.

4、The heat capacity and thermal inertia of the furnace chamber are large and difficult to control.

Modern vacuum heat treatment furnace can be oil-cooled and pressurised air-cooled at the same time, the equipment is equipped with air-cooled system with excellent performance, good gas quenching effect, and is equipped with oil heater and strong stirring device can be realised hot oil quenching. Air-cooled oil quenching vacuum heat treatment furnace in use can be very convenient to set the cooling and cooling time, and can achieve a variety of applicability of pressurised air-cooling, inflatable oil (or gas) stirring or static oil cooling. As the quenching oil in the cooling chamber is in a vacuum state, after quenching in oil, the workpiece oil level without pressure, will produce a sharp rise in the phenomenon, so it must be before or after the oil injection of the workpiece in the oil filled with high-purity ammonia, reduce the vacuum in the cold chamber, pressurised vacuum quenching oil. Cold indoor nitrogen charger, can also improve the cooling capacity of the vacuum quenching oil, so that the workpiece to achieve pressure quenching hardness, and more importantly, filled with nitrogen to inhibit vacuum quenching of a large number of volatile oil in the hot oil to reduce the air-cooled indoor concentration of oil mist (gas), to protect the oil-cooled quenching safety. It also reduces the loss of vacuum oil and the pollution of the furnace.

Multi-chamber continuous vacuum heat treatment furnace One day is composed of feeding room, preheating room, high-temperature studio, cooling room, discharging room, intermediate gate valve, vacuum system, workpiece conveying system, water-cooling system, electric control system and other parts. The unique modular design allows users to easily build up different production lines such as five or eight chambers. The new vacuum furnace is a further application and extension of induction melting technology. The vacuum furnace body adopts square box structure, which is practical and beautiful, and also can effectively reduce the docking between the charge car and the furnace roller shaft. Vacuum Furnace The vacuum system adopts digital composite vacuum gauge, measuring high vacuum with ionisation gauge and low vacuum with resistance gauge. Preheating room and high temperature studio heating system has the advantages of good insulation effect and energy saving. In addition, the vacuum furnace also has a new type of pneumatic gate valve, workpiece car conveying system and automatic control system, intelligent temperature control and flexible. In short, the superior performance of the vacuum furnace has been recognised by the industry. Multi-chamber continuous vacuum heat treatment furnace with induction melting technology has equally strong vacuum melting capability in the fields of metal material brazing, vacuum sintering, vacuum heat treatment, etc., which can realise large-volume assembly line production.