What is a sulfuric acid dilution & blending system?
Sulfuric acid dilution & blending systems may be referred to as a sulfuric acid in-line-mixing system or an in-line-blending system. Usually these systems dilute 98% or 93% sulfuric acid to lower strengths such as 70%, 50%,30% or lower using city water, RO water, or DI water. Any strength lower than the strong acid can be produced.
What is the most difficult part of the sulfuric acid dilution?
Depending on the final sulfuric acid strength, large amounts of heat are generated during the dilution. When this amount of heat becomes significant, the dilution temperatures can boil the sulfuric acid at atmospheric pressure.
Many companies use very expensive graphite or silicon carbide heat exchangers with the sulfuric acid under pressure requiring special piping materials and insulation to protect the workers from approximately 230° to 250°F temperatures.
Powell has a unique design that allows for much lower temperatures and lower cost materials. Typical temperatures at the product exit is in the range of 95° to 105°F.
What if the sulfuric acid product is in the range of 10% or lower?
In a system where the sulfuric acid product strength is 10% or lower, the sulfuric acid can be diluted with water with no heat exchangers required since the heat of dilution is low.
What piping materials can be used in the Powell system?
Many systems can be constructed using polyethylene fusion welding pipe and fittings. 98% sulfuric acid would typically use PTFE lined pipe and fittings. Other materials can be used depending on the purchasing company’s specification.
What type of instrumentation is utilized for the sulfuric acid system?
Rosemount magnetic flow meters, pressure transmitters, temperature transmitters, Micro Motion mass meters and Masoneilan control valves are used. Other instruments such as Yokogawa transmitters and Fisher control valves can be supplied.
What type of control systems are utilized?
Allen Bradley or Siemens PLC with screen displays are used depending on the location of the equipment. Occasionally, the customer’s DCS is connected directly to the skid mounted system for control. VPN connections to allow Powell’s service technicians to connect to the system via the internet for troubleshooting and programming are supplied.
What exchangers are typically used for heat removal of the sulfuric acid product?
In most cases, a Hastelloy C plate and frame is used for cooling but other materials may be required. Cooling water is usually provided by a cooling tower system. Chilled water from air cooled or water cooled packages can be supplied for special applications.