Steam as a living organism

Why a steam system should not be thought of as individual functional items but as an interdependent ecosystem.

02/13/2014


Steam systems and boilers are an interconnected system of entities that forms a healthy steam and condensate loop. In carrying energy from boiler fuels, each element relies on the other to perform specific tasks to effectively transfer energy liberated from the boiler fuel to the process application.

To assess the application requirements of the steam and condensate system (The Loop) it is important to consider these interconnections and resulting effects. All components in The Loop must be designed and selected properly with the end point of use steam quantity, quality and purity requirements in mind. If not, the components in The Loop could operate correctly but not achieve the required outcome.

The design and selection process should start at the very beginning of The Loop and look at the:

• Quality of the water being supplied to the boiler

• Boiler water treatment chemicals used

• The boilers’ steam generation rate

• Sizing of pipe work, valves and steam traps

• Requirement for positive condensate removal systems

• Condensate pumps

• Quantity and quality of the condensate returned to the boiler feed system

Many applications in a steam system require steam to be used in direct contact with the end product requiring steam of a very high quality and purity to prevent contamination. Some of these applications include hospital sterilization processes. Steam and condensate system design for hospital sterilization processes must consider the high purity condensate requirement. Condensate water quality that is traditionally generated and returned to The Loop does not meet that requirement.

Standard Condensate purity can be limited due to the following reasons:

• Traditional use of a base exchange softener to remove calcium and magnesium salts to prevent scaling in the boiler

• A chemical water treatment plan to prevent corrosion in the boiler

• Carry-over of boiler water into the steam system resulting in higher than acceptable alkalinity, chloride and sulfate levels

• The steam passing through the steam distribution system, picking up contaminants and carrying them to the sterilizer including Pyrogen levels higher than acceptable parameters.

Pyrogens, the resilient remains of dead bacteria, can remain viable after sterilization. They can only be removed in the boiler feed water pre-treatment section of The Loop by either distillation or ultrafiltration typically utilizing a reverse-osmosis plant. To remove these impurities steam must be produced from a source that can be supplied with reverse osmosis water and does not require the use of water treatment chemicals

Clean Steam Generator

A clean steam generator is a stainless steel vessel that is specifically designed to heat high purity feed water to produce steam using plant steam as the motive or fuel source. The stainless steel construction resists the corrosive effects of the reverse osmosis water allowing Pyrogen free water to be used for steam generation and removes the need for a water treatment program to prevent scale formation.

The steam distribution system will also require stainless steel pipe work and valving to prevent contamination of the clean steam as it travels through the distribution pipe work. Regardless of the type of steam system and components used in steam generation the steam and condensate system is a connected loop. The operation of any one component in the loop will affect the conditions experienced within another part of the loop and often in ways that may not seem related.

When attempting to diagnose problems or make changes in the steam and condensate system the potential effect on the entire steam and condensate loop should always be considered.

- Content provided by Spirax Sarco, originally published in Steam News Magazine.

- Edited by Jessica DuBois-Maahs, Associate Content Manager, CFE Media, Plant Engineering, Control Engineering



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2013 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Leaders Under 40 program features outstanding young people who are making a difference in manufacturing. View the 2013 Leaders here.
The new control room: It's got all the bells and whistles - and alarms, too; Remote maintenance; Specifying VFDs
2014 forecast issue: To serve and to manufacture - Veterans will bring skill and discipline to the plant floor if we can find a way to get them there.
2013 Top Plant: Lincoln Electric Company, Cleveland, Ohio
Case Study Database

Case Study Database

Get more exposure for your case study by uploading it to the Plant Engineering case study database, where end-users can identify relevant solutions and explore what the experts are doing to effectively implement a variety of technology and productivity related projects.

These case studies provide examples of how knowledgeable solution providers have used technology, processes and people to create effective and successful implementations in real-world situations. Case studies can be completed by filling out a simple online form where you can outline the project title, abstract, and full story in 1500 words or less; upload photos, videos and a logo.

Click here to visit the Case Study Database and upload your case study.

Bring focus to PLC programming: 5 things to avoid in putting your system together; Managing the DCS upgrade; PLM upgrade: a step-by-step approach
Balancing the bagging triangle; PID tuning improves process efficiency; Standardizing control room HMIs
Commissioning electrical systems in mission critical facilities; Anticipating the Smart Grid; Mitigating arc flash hazards in medium-voltage switchgear; Comparing generator sizing software

Annual Salary Survey

Participate in the 2013 Salary Survey

In a year when manufacturing continued to lead the economic rebound, it makes sense that plant manager bonuses rebounded. Plant Engineering’s annual Salary Survey shows both wages and bonuses rose in 2012 after a retreat the year before.

Average salary across all job titles for plant floor management rose 3.5% to $95,446, and bonus compensation jumped to $15,162, a 4.2% increase from the 2010 level and double the 2011 total, which showed a sharp drop in bonus.

2012 Salary Survey Analysis

2012 Salary Survey Results

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.