General Maintenance Services

Comprehensive Maintenance Solutions for Cement, Power, Processing, Pulp and Paper and Other Industrial Plants

At Corrosion Monitoring Services (CMS), we specialize in industrial plant maintenance, offering expert services for biomass energy, cement, chemical processing, pulp and paper and other types of industrial plants. CMS’s maintenance solutions ensure your plant is back up and running smoothly on schedule. From detailed inspections to critical repairs, including corrosion and erosion control, our expert mobile teams cover all your inspection and maintenance needs.

In fact, when CMS inspectors spot a problem, they are often able to repair it on the spot, saving customers time and money. That has included everything from identifying/welding corroded areas in ducts to finding/patching holes in stacks with steel plate and much more. Most of our general maintenance services are covered below, but we also welcome new projects, so please request a quote on any unique challenges that you might be facing.

Thorough Inspection and Repair

Heat Exchangers: We inspect, clean, and repair heat exchangers to ensure efficient heat transfer and prevent fouling.
Flue Gas Ducts and Stacks: Our team provides regular inspections, cleaning and repair of flue gas ducts and stacks to avoid blockages, patch holes, and help ensure compliance with emission standards.
Fuel Handling Systems: We inspect and repair fuel handling systems, including conveyors and hoppers, for biomass and cement plants.
Pulp and Paper Processing Equipment: CMS inspects and repairs pulp and paper equipment, including digesters, washers, screens, and dryers, to optimize performance.

Corrosion and Erosion Inspection and Repair

Pitting and Cracking: Our specialists address corrosion and erosion issues, such as pitting and cracking in critical components and dust collectors.
Fouling, Corrosion, and Erosion: We inspect, identify and repair fouling, corrosion, and erosion problems in plant equipment to ensure integrity and performance.
Erosion Damage: We inspect and repair erosion damage in high-wear areas, such as tubular air heaters, fans, and ducting (where fly ash is abundant), to prevent further deterioration and ensure durability.

Mechanical Repairs and Replacements

Welding Repairs: Our skilled welders perform high-quality welding repairs to restore the integrity of damaged components.
Pumps and Valves: CMS provides pump and valve maintenance, including inspections, repairs, and replacements.
Bearings and Seals: We replace worn bearings and seals in rotating equipment to ensure smooth operation.
Dryers, Conveyors, and Silos: Our team repairs and replaces components in pulp and paper dryers and cement plant conveyors. We have even removed solidified concrete from silos.

Environmental Compliance

Emission Control Systems: CMS inspects, cleans, and repairs emission control systems such as scrubbers, electrostatic precipitators, and filters. In addition, CMS inspects and repairs stacks (e.g. overlay support collars etc.), gas conditioning towers, and other areas of your plant where compliance is critical.
Waste Handling Systems: We maintain systems for handling and disposing of industrial waste and byproducts, such as baghouses, hoppers, ash doors, etc., and are able to supply replacement parts when needed.

Structural Repairs and Maintenance

Structural Repairs: Although CMS has made a wide variety of structural repairs over many years, it does not perform structural engineering. We work with your staff or contractor as required.
Catwalks, Ladders, and Handrails: CMS inspects and repairs catwalks, ladders, and handrails to ensure safety and compliance.
Manways: We inspect, repair, fabricate, and install manways for safe access and secure sealing. CMS also fabricates and installs manways to meet your needs.
Pad Eyes and Ladder Rungs: CMS custom-fabricates and installs ladder rungs and multi-directional pad eyes.

Duct and Fan Inspection and Repairs

Duct Systems: CMS inspects ductwork to ensure optimal airflow and prevent blockages. We repair damaged sections for enhanced system efficiency.
Expansion Joints: CMS inspects, repairs and replace expansion joints on a regular basis. CMS can also supply expansion joint materials. Please see more details here
Fans: We perform detailed inspections and work with industry partners to repair industrial fans, including balancing, lubrication, and replacing worn or damaged blades and bearings. CMS also inspects and repairs fan housings.

Bag House Inspection and Repairs

Filter Bags: CMS inspects and replaces bag house filter bags to ensure effective dust collection and compliance with emission standards.
Cages and Framework: We inspect and repair bag house cages, including cage bullets, as well as framework to maintain structural stability and functionality.
Cleaning Systems: Our team can maintains and repairs bag house cleaning systems, including pulse-jet mechanisms and shaker systems, to ensure efficient dust removal.

Operational Readiness Checks

Training and Safety Drills: We provide staff training and conduct safety drills to prepare for emergency situations.
High-angle Inspection Experts: CMS's inspectors are trained in confined-space safety and high angle inspection. We also offer safety teams when needed by facilities, often staffed by experienced first responders.
Detailed Reporting: Our detailed reports provide information that can be used plan yearly maintenance activities as well as long term planning.

Regular maintenance activities, including thorough inspections and timely repairs, are vital for the safe, efficient, and reliable operation in cement, coal, processing, power, pulp and paper, and other types of industrial plants. Corrosion Monitoring Services ensures proper planning and execution of these activities, minimizing downtime and preventing unplanned outages. Trust CMS for expert industrial maintenance services and keep your plants running at their best.

Click here for more information of for a quote.

Black Liquor Evaporator

Evaporator performance can be negatively impacted by various mechanisms such as fouling, surface corrosion, stress from thermal cycling, or tube damage from vibration.

Leaking evaporator tubes allow cross contamination. In order to minimize this impact, a simple temporary solution is to plug both ends of the tube and remove it from service.

The number of tubes removed from service effectively reduces the thermal capacity of the heat exchanger. When reduced efficiency is detected in one or more of the evaporators, the overall system performance is impacted, resulting in one or both of the following outcomes:

Reduced Black Liquor Production
Increased Steam Consumption

Figure 1 - A typical position of black liquor evaporators in the overall process. Black Liquor Evaporators take Weak Black Liquor (typically 15% solids) and condense to 70-80% solids based on evaporator design. This process provides Heavy Black Liquor as fuel to the Recovery Boiler. Black Liquor Evaporators also reduce the waste water stream by recycling it to the process.

Because the recovery process is critical to the efficient operation of the overall system, proactive maintenance is a requirement.

If the quality or quantity of Heavy Black Liquor production is reduced, then the boiler may not have sufficient fuel to maintain steam production without a supplemental fuel source. Additionally, the production of White Liquor to the digester will either be reduced or made up with consumption of additional chemicals. When evaporator steam consumption is increased, the overall system steam availability is reduced. This reduction in performance may impact power generation, if the facility produces power, and reduce steam to other processes.

CMS Evaporator Inspection Services

CMS has over 30 years of experience inspecting and repairing heat exchangers in wide variety of industrial operations, including plants in the Pulp & Paper Industry. CMS’ expertise includes process analysis, inspections and customized repair of heat exchangers that can be a valuable cost effective component of your maintenance strategy.

It is becoming increasingly difficult for the Paper Industry to maintain profitable and competitive operating margins due to environmental and energy demands. Recognizing and identifying the existing operating conditions and the appropriate maintenance techniques are critical steps in any effort to minimize energy consumption and maximize quality production.

One difficult area to assess in evaporators is the external corrosion damage that can occur near the top from trapped non-condensable gasses, or other corrosion elements near the bottom of the evaporator. This issue may be overcome through the application of the proper test equipment to evaluate the total wall thickness.

Figure 2 - Black Liquor Evaporators are often arranged as Multiple Effect Evaporator (MEE) Systems. Weak black liquor enters in the last stage, and the steam enters in the first stage. As the Black Liquor flows through the system, water is removed by evaporation to drive the next evaporator stage. The solids content of the liquor is increased through each stage. Each evaporator effect stage is a separate heat exchanger that operates at increasing vacuum as the stages progress.
The most popular configuration for these MEE heat exchangers is the shell in tube configuration.

A regularly scheduled inspection routine can:

Locate damaged tubes
Identify tube sheet damage
Apply methods to return damaged tubes to service
Replace tube sheets or repair tube sheet damage
Removed damaged tubes from service
Install full length replacement tubes
Install full length or partial tube liners
Can improve operating efficiency
Locate tube corrosion, erosion, or cracking
Assess damage and provide a recovery plan

Visual Inspections

Often, a visual inspection is the first step in identifying damaged tubes. This is performed from the top and bottom tube sheets. Using an external light or other equipment, the inside walls of the tube can be inspected over about the first 18 inches of the tube.

This inspection technique is sufficient at times, since damage is predominantly near the tube sheet interface. As damaged tubes are identified, these tubes may require no further inspection at this point.

Repair Ready

Using an external light or other equipment, the inside walls of the tube can be inspected over about the first 18 inches of the tube. Some tubes can be identified as damaged from visual inspection.

Both methods are a quick way to temporarily improve efficiency and can add up to measurable energy cost savings, while allowing time to plan for a more permanent solution.

As with all CMS inspections, a detailed report is provided that includes a tubesheet map, documenting damaged tubes as well as any necessary repairs.

Pressure Testing

Once the visual inspection is complete, a pressure test can be performed. This is conducted by having access to both the top and bottom tube sheets. A pressurized airline is placed at one tube end. A pressure indication allows the inspector to detect the presence of a leak. Anything less than a specified pressure is considered a tube failure.

During this test, a CMS inspector pressurizes each tube and records any drop in tube pressure and the associated time. The speed of the pressure change is an indication of severity of the air leakage. If a leak is detected, it may be possible to pinpoint the location by using the more advanced Acoustic Pulse Reflectometry Inspection System (APRIS) tube test to determine the location and damage mechanism (hole, crack, or obstruction). Knowing the location of the leak may provide a clue in determination of the failure mechanism and provide guidance in the repair technique selection.

Repair Ready

Where failures are identified within 12 inches of the tubesheet, CMS inspectors can install airtight sleeves to capture the failure behind the sleeve and keep the tube in service. In other cases, the tube can be removed from service by installing mechanical plugs. Both methods are a quick way to temporarily improve efficiency and can add up to measurable energy cost savings, while allowing time to plan for a more permanent solution.

As with all CMS inspections, a detailed report is provided that includes a tubesheet map, documenting damaged tubes as well as any necessary repairs.

APRIS Inspections

Using portable acoustic pulse reflectometry equipment (APRIS), CMS inspectors direct one-dimensional acoustic waves at tubular systems to detect defects in along the contours of the tube inner diameter.

If the pulse encounters a discontinuity in cross section, a reflection is created. The shape of the reflection enables inspectors to define the damage mechanism, which they then verify using a borescope. CMS APRIS inspections are able to accurately identify the exact location, type, and size of tube defects, without impacting outage schedules.

Acoustic Pulse Reflectometry - APR

Our APRIS inspection reports are translated into a tubesheet map that indicates the pattern of damage detected. In addition to the tubesheet map, sample plots from the APRIS are provided to illustrate the information used. The combination of this information enables the customer to plan tube repairs and replacements for improved operational efficiency and cost savings. For more information on Acoustic Pulse Reflectometry technology, you can visit the Talcyon APRIS website.

CMS Evaporator Repair Services

A number of repair solutions can be applied based on the findings of CMS Inspectors and the client's input. CMS will work with site representatives to provide the data and options for development of the best approach for repairs. The repair process in most cases will have different options based on site objectives.

Whether you are looking for a quick fix to bridge the gap between outages/maintenance intervals or a more permanent solution, turn to Corrosion Monitoring Services to solve your problems before they turn into performance issues.

As the inspection process is completed, a tube sheet map is generated to document the findings.

There are several primary repair solutions:

Install partial or full length tube sleeves
Full tube replacement
Plug leaking or damaged tubes detected by the testing
Repair or replace tube sheet
Correct vibration issues that are detected by tube damage assessment

Sleeves

Locating damaged areas that have not yet failed is critical to determining the right repair approach. If the tube damage is located near the tube sheet, CMS may be able to install a sleeve on the inner diameter of the tube to capture the tube failure or crack. This process places a liner section of tube inside a fully cleaned parent tube.

The sleeve has a 360° seal towards the bottom of the liner tube and is then rolled into the tube sheet plate. Depending on inspection results, this process is often recommended to be applied proactively to increase the service life of evaporator tubes. In some cases, where a tube has severed completely from a tube sheet plate, CMS can install a sleeve and return these tubes to service. Installing tube sleeves is ideal for repairing damaged tubes and extending the service life of evaporator tubes. A critical step when installing partial or full length sleeves is that the parent tube must be clean to establish metal to metal contact for sealing and for heat transfer.

Plugs

While plugging evaporator tubes is often seen as the simplest solution, it should be evaluated for overall thermal performance based on the number of tubes out of service. Once a tube is plugged, it no longer adds to the evaporator performance, the total surface area is reduced and pressure drop across the bundle will increase if enough tubes are taken out of service.

CMS has been able to remove plugs and repair the damage and return these tubes to service. This cost effective repair method can restore significant operational gains and extend the service life.

Full Tube Replacement

As a complete repair option, tubes can be replaced or full length liners installed.

For more information on how CMS can evaluate and repair your evaporator damage, ask to speak to one of our engineers at (800) 637-6592 or contact us at inforeq@cmsinc.us Our proprietary tools and analyses techniques can help you avoid unexpected downtime and expenses.