VAC AERO’s uses the Honeywell HC900 process controller integrated with the Honeywell Experion HS software running on a Windows 7-based PC to provide Supervisory Control and Data Acquisition (SCADA). The Honeywell HC900 controller can connect remote users to the system, link multiple furnaces together, or to other operating systems in a facility. The VAC AERO control system is programmable, logic based and comprised of proven hardware components, suitably hardened for an "industrial shop" environment. The software has been optimised to cover all normal operating and alarm conditions. VAC AERO’s design philosophy is to simplify control by using the program capabilities to perform as many functions as possible, thereby reducing operator dependence. The software is optimised to control the machine functions and furnace temperature and to cover all normal operations, maintenance alerts and alarm conditions.
When problems arise, especially those related to safety, we want to know that we have isolated the root cause and instituted corrective action measures so as to avoid their reoccurrence. Worker safety and the safe operation of heat-treat equipment is both MANDATORY and NON-NEGOTIABLE, especially when operating and maintaining vacuum equipment where dangers of asphyxiation, electrocution and explosion are as real as they are with any other type of thermal processing equipment. “It won’t happen to me” is not a phrase that belongs in the heat-treat shop and provides a false sense of security to all involved. There is no substitute for understanding the inherent dangers, taking the necessary steps and placing the right safeguards in place to prevent accidents from happening. Safety and safety issues are a serious matter and should be treated as such by all individuals within the company.
A number of companies I’ve visited who conduct vacuum brazing operations have asked for assistance in understanding how to properly use a torch-brazing (flame braze) process to repair some of the assemblies that did not fully braze during their vacuum brazing operations. The components were such that they did not want to send the entire assembly back through the vacuum brazing furnace, but merely needed to fix a small portion of the assembly where it did not fully braze. So let’s take a brief look at torch-brazing to see what it is, and how it can be used by brazing shops today to meet some of their production-repair needs. Figure 1 shows a typical example of a torch-brazing setup, in which a small region of a metal assembly is being heated for application of some brazing filler metal (BFM) so that the entire assembly does not need to be heated.
Steels used for tools and dies differ from most other steels in several aspects. First, they are used in the manufacture of other products by a variety of forming processes. Second, tools and dies are generally used at a higher hardness than most other steel products; 58 to 68 Rockwell C is a typical range. Dies for plastic molding or hot working are usually used at a lower hardness, typically from 30 to 55 Rockwell C. These high hardness values are required to resist anticipated service stresses and to provide wear resistance. However, the steels must also be tough enough to accommodate service stresses and strains without cracking. Premature failure caused by cracking must be avoided, or at least minimized, to maintain minimum manufacturing costs. Unexpected tool and die failure can shut down a manufacturing line and disrupt production scheduling.
When designing or operating a vacuum system, it is critical to understand the function of the vacuum pumps. We will review the most common types of vacuum pumps, their principles of operation, and where in the system they are used. In the coming months we will focus on each of these pumps in more detail. Vacuum pumps are categorized by their operating pressure range and as such are classified as: primary pumps. booster pumps or secondary pumps. Within each pressure range are several different pump types, each employing a different technology, and each with some unique advantages in regard to pressure capacity, flow rate, cost, and maintenance requirements. Regardless of their design, the basic principle of operation is the same. The vacuum pump functions by removing the molecules of air and other gases from the vacuum chamber (or from the outlet side of a higher vacuum pump if connected in series).
Constructed of the finest materials and craftsmanship, VAC AERO’s high performance vacuum furnaces are operator friendly and designed to minimize maintenance and downtime to deliver outstanding quality and value to commercial and in-house heat treaters alike. VAC AERO’s vacuum furnaces are designed for rapid heating rates to very uniform temperatures at high vacuum levels and can be customized to suit unique applications such as high pressure gas quenching, high temperature heat treating, ultra-clean processing and more. VAC AERO’s high efficiency hot zones are designed for easy maintenance and reduced energy consumption. Our external quench system allows for easy maintenance of the heat exchanger and quench motor. A high efficiency blower and motor combine fast cycle times and quenching speeds to provide uniform gas distribution and superior cooling performance from processing temperatures at pressures of up to 10 bar.