Each year when it comes time to prepare for a boiler outage, concerns about downtime and potential damage are common. At Valmet we understand these concerns, and have developed our Wash-X service to make your boiler cleaning process easier and efficient. Below are three reasons why using Wash-X will change the way you view the boiler cleaning process.
1) Limited Downtime: The timespan of the boiler cleaning process all depends on how long it takes for the smelt bed to cool down. Typical smelt bed cooling times can be anywhere from 15-35 hours. By using the Wash-X process the smelt bed cooling time can be reduced greatly to 4-6 hours. This reduced time is accomplished by simultaneously washing the floor with the rest of the boiler using low pressure water sprays and mixing devices installed on the furnace floor.
2) Reduced Risk of Damage: During the boiler cleaning process there is always the risk of damage due to large falling deposits and from mechanical cleaning. The Wash-X process works with water being sprayed to the flood as soon as safe bed temperatures have been reached. Then eductors are inserted to start floor washing in parallel with superheater washing. By using hot water, faster washing occurs and it also is used to dissolve large ash deposits which fall to the floor. The wash pool that forms also creates a barrier that protects the floor from large deposits which may fall off the wall during the cleaning process. When the water is drained at the end the remaining deposits can easily be cleaned out, avoiding the need for mechanical cleaning that can cause damage to boiler floor.
3) Unique and Effective: Our Wash-X recovery boiler floor washing service is unique in its ability to wash the floor simultaneously with the rest of the boiler while using low pressure water sprays and mixing devices. The ability to limit downtime and reduce potential damage is unmatched in the industry. With successful jobs completed in North America, the Wash-X service will save a huge amount of time and money for companies who need their recovery boiler systems cleaned.
Valmet has over 40 years of experience providing full service in the boiler chemical cleaning industry. Our boiler cleaning services including Smelt-X and Wash-X will save companies time and money and have your boiler operating at full strength much faster than any other process on the market. For more information about our services and to arrange an in person meeting to discuss how our Wash-X service can work for you, please contact Mike Ward.
When it comes to cleaning and emptying chemical recovery boilers, Valmet has the services required to do it swiftly and safely. If the recovery boiler cleaning process starts too quickly, the water being used in the washing process may cause an explosion when it comes into contact with the molten smelt. In the past, this potential threat has been avoided by waiting 15-35 hours to make sure the smelt bed is frozen and safe to clean. To speed up and improve this procedure, Valmet has developed the Smelt-X and Wash-X processes which change the way recovery boiler cleaning is executed.
The Smelt-X process has been specifically designed to alleviate the recovery boiler cleaning process. The bottom section of the recovery boiler furnace is heated during load reduction so that the whole smelt bed becomes molten, and the smelt is extracted from the floor to the dissolving tank using air-operated ejectors. Our custom designed ejectors for each furnace arrangement are made to extend from spouts to lowest point in floor for max extraction. This custom design is unique in the industry, and can’t be matched by our competitors. Our typical extraction time is 1-3 hours and smelt does not touch spouts during the extraction process. The Smelt-X process also allows for chemicals in the smelt bed to be recovered and the amount of strongly alkaline waste water is minimized resulting in savings in both make-up and neutralization chemicals. Due to these features, Smelt-X can be carried out safely in the middle of the operation cycle as well, and the operation can continue with the same spouts without any additional risk of spout failures during the rest of the cycle.
Other benefits include:
- faster cooling – boiler bank and superheater washing can begin sooner
- recovery of chemicals in the smelt bed
- minimisation of wash water volume and alkalinity
- savings in makeup chemicals for black liquor
- savings in neutralization chemicals in waste water plant
- faster floor cleaning for inspection and repairs
- safer floor cleaning – reduced need for mechanical cleaning and/or high pressure washing
- shorter mill shutdown – increase in pulp production
Valmet has also developed a washing service for recovery boilers called Wash-X in which the floor is washed simultaneously with the rest of the boiler using low pressure water sprays and mixing devices installed on the furnace floor. Once the super heaters are clean, the mixing devices are removed and floor is emptied of wash water using smelt ejectors.
The typical Wash-X arrangement for mixing devices and wash water sprays:
- 1 or 2 mixing devices in each spout (operated with pressurized air)
- 8 – 18 primary air port sp rays connected to feedwater or warm water system (depending on floor size)
- black liquor sprays (at least) in front wall (not shown here) spraying warm wash water
The Smelt-X and Wash-X services will save a huge amount of time for companies who need their recovery boiler systems cleaned. Our process will do no damage to your boiler and have you back operating at full strength much faster than any other process on the market. Please contact Mike Ward to arrange an in person meeting to discuss how our Smelt-X and Wash-X services can work for you.