Most crematories consist of a rectangular chamber with a hinged door and either a flat or arched roof and a fiber lined flue. Resco supplies refractory for the combustion chamber and associated hearth or base. The designs vary by manufacturer, but the concept is always similar. The primary differences in design are related to the capacity, intended crematory purpose, and burner systems for introduction of fuel. Corrosion and spalling of the refractory hearth are the principal cause of refractory repairs and vary greatly from unit to unit.
Pacocast 28 LI is the standard for economical crematory repairs. It is a low iron, conventional refractory castable with Resco’s unique pyrohyllite grain providing superior thermal shock resistance and low thermal expansion over a wide temperature range. Pacocast 28 LI is adequate for service up to 2800 F which should be sufficient for this furnace application – in most cases. Castables require a well-defined water content and mixing time if proper physical properties in service are to be achieved. Most crematory units do not have great capability for a controlled heat-up with fixed temperature holds. Resco encourages taking sufficient time for heat-up of a new or repaired hearth and can provide guidelines for these scenarios. Steam spalling is the most frequent source of damage both during dry-out and due to absorbed fluids. All refractory castables use a special cement which should not be mixed or handled in equipment which has standard Portland cement residue. It will cause flash setting and prevent proper installation.
Most crematories do not have any means of high-end control nor control after ignition of remains. Temperature spikes are common and are probably the second leading cause of refractory damage.
Pacocast 28 LI has proven to be reliable for full hearth replacement and repairs greater than 1” with proper surface preparation. Resco can once again provide guidelines for various scenarios. Veneer repairs of less than 1” are never recommended as they do not have any reasonable longevity in service.
Resco recognizes that a slow and thorough cure and dry out of conventional castable is not always possible. Resco’s Quikturn technology is useful in these instances because it is more forgiving of “early” dry-out and allows a more liberal ramp up in temperature during dry-out. These two factors make it attractive for crematories that are not capable of engaging in proper dry-out procedures of newly installed castable refractories. The Quikturn family of products starts at 3000 F service limits making it more versatile for higher temperature crematory furnaces or those which see elevated temperature spikes above 2800 F for any period.
For these reasons it may be worthwhile to upgrade material to offer additional insurance against less than ideal treatment of the refractory hearth for a crematory. The technology driving the Quikturn family of products is a premium option beyond Pacocast 28 LI.
Crematory Hearth Options:
1) Pacocast 28 LI
a. Recognized Industry Standard
b. Good to 2800 F
2) Quikturn 45 PC
a. Good to 3000 F
3) Quikturn 60 PC
a. Good to 3100 F
4) Quikturn 32-70 PC
a. Good to 3200 F
In the West we have successfully used Pyrocast 3000C/EZ Cubed 60M/Vibrocast 60 in creamatory hearths. The Quikturns are a good idea to promote for rapid heat-ups. Most customers casting a hearth need a stiff material so that can cast a lip in the front and sides to retain the body fats/fluids from leaking out the door.
Pacocast 28LI Coarse a good material to offer in roof/arches.
Patriot -Super Duty brick is used in the sidewalls with LW 26 in upper regions. Ladlelock 3000 Trowel or Trowleze is mortaring to use with the Patriot and LW 26. We also have used 22 Caulk to patch any cracks in linings instead of total repair.
Resco also offers a full line of refractory brick and mortar products for the walls and roof. The crematory equipment manufacturer can provide a Bill of Material with grades of brick, specific sizes and quantities of each.
Whether relining or patching your crematory Resco has the knowledge and products necessary for proper repairs.