Equipment and Services
for the Industrial Gases Industry
PLC Controls UpgradeCold Box RefurbishmentVibration System UpgradeControl RelaysTouchscreen HMI

Plant Upgrades

Control System Rehabilitation

Many air separation plants still in operation today were built 20, 30, or more years ago and are still reliant on much of the original equipment and controls. As a result, reliability suffers and operating efficiency is no longer competitive with newer plants and technologies. In addition, many components, especially in the plant control system, have become obsolete and no longer serviceable with replacement parts.

Solutionwerks has the capability to execute virtually any retrofit project for your plant to improve its performance, increase its capacity, lower its power consumption, reduce labor costs, or improve reliability. Typical retrofits include:

PLC/DCS Control Systems

Most of the older plants in service incorporated either pneumatic controls or single loop electronic controllers with very limited process integration. Pressure and temperature switches drift from their set points and fail with increasing frequency as they age. Plants are forced to operate at fixed and sometimes inefficient rates of production because the controls are just not up to the task of load following. Strip chart recorders break, run out of ink and fail to deliver needed information when problems arise.

All of that can be changed with an upgrade to either a PLC or DCS based control system. The advances in solid state control technology have made it possible to dramatically improve the way these old plants operate. Reliability and efficiency increase substantially and, where needed, the plants can be set up to follow any product demand pattern without operator intervention. Plant start-ups and trouble shooting become much easier and operating data is never more than a few mouse clicks away.

Adsorption Air Pre-purifiers

Cryogenic air separation plants built prior to the mid '80's utilized reversing heat exchangers to remove water and carbon dioxide from the process air stream prior to entering the liquefaction and distillation process. The next generation of plants improved upon that process by incorporating alumina and molecular sieve adsorption systems for removal of the plugging contaminants along with most of the hydrocarbons present in air. These mole sieve front ends, as they're often called, lead to much more reliable and safer operation. Molecular sieve has a high affinity for all but the lightest hydrocarbons thereby greatly reducing the risk of hydrocarbon accumulation in the cryogenic section of the process.

Cooling Water System Upgrade

Many of the old reversing plants also suffer from internal corrosion of the main heat exchanger passages due to air borne corrosive contaminants such as hydrogen sulfide. Those corrosive effects along with the mechanical stresses of constantly switching between high and low pressure services lead to interpass leaks that hurt product purity and reduce production.

While Solutionwerks also offers reversing heat exchanger replacement services, many plant owners have elected to proactively put an end to their corrosion problems by upgrading their plants to mole sieve front ends. The reversing heat exchangers are left intact but taken out of reversing service and the corrosive contaminants are removed from the air stream before they reach the heat exchangers. And plant start-up times are typically cut in half because there is no longer a need to cool down the front and back sections of the plant separately.

Liquid Back-up Systems

What are commonly referred to as "on site" air separation plants serve as a utility to other process facilities. The gases produced, i.e. oxygen, nitrogen, and/or argon, may support a steel mill, copper smelter, chemical plant, electric utility or wastewater treatment facility which cannot function without a continuous supply of gas. The cost of an outage can be very high relative to the cost of the gases being consumed and there is just no room for failure of that gas supply. Well designed liquid and gaseous back-up systems can minimize that risk and provide time for correction of most plant problems that may arise.

In addition, many of the back-up systems at waste treatment plants utilized in-ground water bath vaporizers with copper exchanger coils that are subject to corrosion and failure. These water bath vaporizers must be kept continuously hot and waste a lot of energy when not in service. These problems can be eliminated with the installation of aluminum ambient air vaporizers that draw their vaporization energy from the atmosphere. Corrosion problems are virtually eliminated as well.

These back-up systems can be equipped either with self-contained controls or control packages that are integrated into the plant-wide control systems. With either approach, the systems can be programmed to activate automatically any time there is a loss of primary supply from the gas production plant.

Another popular upgrade of these back-up systems is the incorporation of economizer circuits to capture the boil-off gases from the storage tanks. All cryogenic storage tanks lose a small percentage of their stored products to boil-off since the boiling temperatures of the cryogens are far below ambient temperatures. Without an economizer circuit, these boil-off gases are vented to the atmosphere. An economizer circuit captures and warms these gases and routes them into the pipeline that delivers the gases to the owner's process.

Other Upgrades

Many other plant upgrades are possible ranging from re-rated air or product compressors, process analyzers, corrosion resistant pressure vessels and coolers, refurbished cold boxes, and many others. The possibilities are nearly unlimited.

If you have an interest in improving the operation of your plant in any way, give Solutionwerks a call. We can help you formulate a plan, provide you with either budgetary or firm proposals and do whatever else it takes to help you realize your operating goals.