Low Silhouette Tray Deaerators
Transcription
Low Silhouette Tray Deaerators
Roth Roth Low Low Silhouette Silhouette TRAY DEAERATORS Boiler Boiler Feedwater Feedwater Heater Heater Capacities Capacities to to 50,000 50,000 lb/hr lb/hr Model RDTV-150-5-1-2 vertical tray type deaerator The Roth Solution: Preheated, deaerated conditioned water reduces operating cost. Roth deaerators are assembled with Roth pumps requiring only one- or two-foot NPSH operating at 1750 rpm Roth Pump Company 1 . 888 . 444 . ROTH Reduce costs and improve system efficiency by preheating and deaerating boiler feedwater Roth tray type deaerators condition feedwater to 0% CO2 and only .005 cc/l of oxygen Why deaerate boiler feedwater? Choosing the right deaerator There are many advantages to deaerating water prior to boiler input, but they all boil down to reduced cost operation. • Water is heated during deaeration to near the temperature of the boiler water, thus minimizing the risk of thermal shock damage to a high-value boiler system. Roth tray type deaerators are generally considered the superior choice for most applications. These units use stainless steel for all internal surfaces which come in contact with undeaerated water. • The deaerating process removes noncondensable gases (oxygen and carbon dioxide) which tend to act as insulators inhibiting the transfer of heat within the boiler. • Removal of oxygen and carbon dioxide reduces corrosion within the boiler and piping, extending the life expectancy of the system and reducing maintenance cost. • Higher temperature feedwater reduces the chance of pressure drop within the boiler which can occur when cold water is added. • Recycling of steam from vents and flash steam from traps that would otherwise be vented to the atmosphere can result in appreciable energy savings. • Mechanical deaeration by a feedwater deaerator can cut the amount of chemical consumables used for water conditioning for a continuing operating cost saving. Residence time for undeaerated water inside a tray type deaerator is longer, providing more efficient deaeration, particularly where wide load swings occur. A large diameter hinged door affords easy access to internal trays and spray tubes for maintenance and replacement. Although tray type deaerators require a larger initial investment, the benefits in efficiency and reduced cost of maintenance tend to pay for themselves quickly. Pump selection Roth deaerators use low NPSH pumps. Most pumps selected require only one foot NPSH operating at 1750 rpm. By using these pumps, the overall height of the unit can be lowered. This can save on construction cost. Roth Deaerator Specifications Control and piping configurations will vary depending upon job specifications and conditions. Dimensions are subject to change without notice. Consult factory for certified dimensions. Legend for drawings 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. Model * = # of pumps RDTV150-5-1-* Capacity Lb/h (kg/h) Boiler hp (kW) 5,000 (2,268) 145 (1,422) 10,000 (4,536) 290 (2,844) 15,000 (6,804) 435 (4,267) 20,000 (9,072) 580 (5,686) 25,000 (11,340) 725 (7,107) 30,000 (13,608) 870 (8,529) 35,000 (15,876) 1,015 (9,950) 40,000 (18,144) 1,160 (11,372) 45,000 (20,412) 1,305 (12,793) 50,000 (22,680) 1,450 (14,214) Storage gallons (l) 100 (378) 200 (757) 300 (1,135) 400 (1,514) 500 (1,893) 600 (2,271) 700 (2,650) 800 (3,028) 900 (3,407) 1,000 (3,785) A. Overall length 66 (168) 66 (168) 66 (168) 84 (213) 84 (213) 84 (213) 96 (244) 96 (244) 96 (244) 96 (244) B. Overall width 54 (137) 54 (137) 54 (137) 72 (183) 72 (183) 72 (183) 84 (213) 84 (213) 84 (213) 84 (213) C. Overall height 83 (211) 99 (251) 113 (287) 108 (274) 116 (295) 124 (315) 125 (318) 131 (333) 141 (358) 147 (373) D. Tank diameter 42 (107) 42 (107) 42 (107) 60 (152) 60 (152) 60 (152) 72 (183) 72 (183) 72 (183) 72 (183) E. Overflow trap 2 NPT 2 NPT 2 NPT 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 20 (51) 20 (51) 20 (51) 24 (61) 24 (61) 24 (61) 24 (61) 24 (61) 24 (61) 24 (61) 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 6”, 150 lb flange 6”, 150 lb flange 6”, 150 lb flange 6”, 150 lb flange Dimensions in (cm) except as noted F. Tray access door dia. G. Pump suction RDTVRDTV150-10-2-* 150-15-3-* RDTVRDTV150-20-4-* 150-25-5-* RDTV150-30-6-* Make-up water control High level control Low level control Vacuum breaker Temperature gauge Pressure gauge 1½” NPT vent 1” NPT chemical port 1” NPT drain 1” NPT sample port 1” NPT additional port Gauge glass RDTVRDTV150-35-7-* 150-40-8-* RDTVRDTV150-45-9-* 150-50-10-* H. Pump bypass I. Hi-temp condensate return 2 NPT 2 NPT 2 NPT 2 NPT 2 NPT 2 NPT 3 NPT 3 NPT 3 NPT 3 NPT 2”, 150 lb flange 2”, 150 lb flange 2”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange J. Steam connection 4”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 6”, 150 lb flange 6”, 150 lb flange 6”, 150 lb flange 8”, 150 lb flange 8”, 150 lb flange 8”, 150 lb flange 8”, 150 lb flange K. Water connection 2”, 150 lb flange 2”, 150 lb flange 2”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 3”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 4”, 150 lb flange 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) 4 (10) L. Base height Sample Specification—Roth Deaerator DEAERATOR: A. The deaerator shall be a Roth style “RDTV” deaerator which guarantees oxygen removal to 0.005 cc/l (7 ppb) or less and carbon dioxide removal to a zero measurable level in the effluent throughout all load conditions between 0% and 100% of rated capacity. The deaeration process will take place in a 5-15 psig steam environment that will heat the water to 228250°F requiring a pressurized vessel. The deaerator shall be manufactured in strict accordance with the ASME Section VIII, Div. 1 code and bear the ASME stamp for a maximum working pressure of 50 psig at 300ºF. An atmospheric deaerator is not acceptable. A minimum of 1/16” corrosion allowance shall be added to the ASME calculated material thickness for heads and shell and will be noted on the ASME data report (form U-1). The deaerator is to be of the vertical design with a vessel of _____” diameter x _____” high setting less than 18” from the floor. B. The deaerator is to be of the tray type design. Spray type deaerators are not acceptable. Flow of steam shall be such that the steam entering the heater first comes in contact with the hottest water which is leaving the last row of trays and then proceeds upward through the tray stack in a counter-flow fashion. The water to be deaerated will enter the vessel through a stainless steel spray tube. The spray tube will disperse water into a 304L stainless steel box that is sealed so that escaping gasses can not come in contact with the vessel walls. The gases escape through a 304L vent condenser pipe on top of the tray box that extends out the top of the vessel. The spray tube directs the water into sections of a 304L stainless steel vent welded on top of the tray box. The water falls downward from the vent condenser and spreads over the stainless steel trays and, after deaeration, falls into the storage area. The stainless steel (304L) trays will be removable through a minimum 20” dia. hinged tray access door. Each tray shall weigh no more than 30 lbs. for easy handling and inspection and shall be of welded construction. Rivets are not acceptable. The deaerator will be designed so that undeaerated water will only come into contact with stainless steel components. C. The tray type deaerator is to be fully trimmed by the manufacturer including the following items: 1. Low Level Control: An external float type control is to be supplied to monitor a low level condition. A low level shall ring an alarm bell and light a red light on the control panel notifying the operator. The control shall also shut off the deaerator pumps protecting them from harm. 2. High Level Control: An external float type control is to be supplied to monitor a high level condition. A high level shall ring an alarm bell and light a red light on the control panel notifying the operator. The high level control shall be activated before the water reaches the overflow level. 3. Overflow Trap: A mechanical self-contained external float type overflow trap shall be supplied to overflow the water in the storage area before flooding the deaerator. The overflow trap body is to be constructed of cast iron. Inside the body, a stainless steel ball float automatically operates a double-seated brass valve. The cast iron body is to be bolted together in order to take apart for inspection/maintenance of the valve assembly. A butterfly valve is to be supplied between the deaerator and the trap for inspection without having to shut down the deaerator. 4. Make-up Water Assembly: An electric water level controller and make-up water valve is to be supplied to monitor the level of water storage in the deaerator and add make-up water when necessary for continued operation. The level to activate the water valve shall be field adjustable to match desirable operating conditions. The water valve shall be suitable for operation with a pressure differential of up to 150 psi. The valve shall default to a closed position when deenergized and be a modulating or slow closing valve in order to reduce or eliminate water hammer. The valve shall be factory piped with a 3-valve bypass assembly and strainer. 5. Pressure Reducing Valve: A self-contained pilot operated valve shall be supplied when necessary to reduce the available steam pressure to the operating pressure of the deaerator (5-15 psig). The valve is to be shipped loose for field installation. Relief valve(s) acceptable for ASME service shall also be supplied. The relieving capacity of the valves shall be greater than the maximum capacity of the pressure reducing valve and set to relieve at 50 psig. 6. Vacuum Breaker: A vacuum breaker is to be supplied to release any vacuum in the deaerator during operation. 7. Vent Valve: A manual valve shall be supplied to vent the deaerator. The valve is to have the ability to be field adjustable with a 1/8” drilled orifice to avoid complete shut off capability. 8. Drain Valve: A gate valve is to be supplied and sized the same diameter as the drain connection and be supplied by the manufacturer. 9. Misc. Gauges: A pressure and temperature gauge shall be supplied and installed by the manufacturer. The gauges shall be sized suitable for the operation and design range of the deaerator and follow any ASME or local codes and requirements. A gauge glass shall be supplied and installed to cover the water level range from low level to overflow level. The gauge glass shall be protected from getting hit by outside objects and be so mounted to protect from getting broken. 10. Pump Suction: The pump suction shall be sized based on a velocity 3 ft/sec of twice the deaerator capacity. A separate gate valve, strainer, and flexible connector shall be supplied for each pump. Roth Tray Type Deaerators Roth tray type deaerators remove CO2 from feedwater completely and reduce oxygen to .005 cc/l. Available with capacities up to 50,000 pounds per hour, Roth tray type deaerators come completely packaged with all standard accessories and trim. Internal surfaces which come in contact with undeaerated water are stainless steel. Undeaerated water and corrosive gases never come in contact with the deaerator shell. A complete line of boiler feed pumps and control panel packages is available. Custom engineered systems and larger than standard units are also available. Consult the factory. Non-condensable gases (O2, CO 2) Deaerated water Condensate return & water make-up Steam Roth Deaerator Pumps Roth pioneering— The Roy E. Roth Company has been a pioneer in the industry for over 45 years by developing NPSH data on its products for use by engineers. In 1954, it was the first manufacturer of regenerative turbine pumps to publish NPSH data on individual models. At that time, the Roy E. Roth Company developed and published the first NPSH curves on regenerative turbine pumps in a format now used throughout the industry. It is the only manufacturer of regenerative turbine pumps today with numerous patents designed to improve the NPSH characteristics of its pumps. Roth one-foot NPSH pumps— The Roth Pump Company, the manufacturing successor, is the only pump manufacturer in the world today that offers a line of pumps with full performance at one-foot NPSH at speeds of both 1750 and 3500 rpm in a range of differential heads up to 600 feet TDH and capacities up to 190 GPM. All Roth pumps in this bulletin are guaranteed to deliver the full-rated capacity of water to the boiler. Roth one-foot NPSH pumps were originally developed to pump 230° F deaerated water from the deaerator to the boiler. Now the original design has been improved to include high-capacity models fully functional at one-foot NPSH. Standard equipment— • All deaerators are constructed to ASME Section VIII, Div. 1 for 50 psig, 300° F • Easily accessible manways and access doors for internal inspection and servicing • Standard storage capacity: 10 minutes of operation. Optional larger storage capacities available • Structural steel stand and pump platform • High and low level control alarms • External make-up water level control (field adjustable) • Make-up water valve with three-valve bypass • Pilot operated steam pressure reducing valve (when required) • Relief valve sized for full output of the pressure reducing valve set at 50 psig • Manual vent valve(s) with properly sized orifice in gate • Vacuum breaker • Pressure gauge and thermometer • Overflow trap sized to relieve full capacity of deaerator • Full range sight glass • Drain valve Roth Pump Company P.O. Box 4330, Rock Island, IL 61204 U.S.A. Toll-Free: 1.888.444.ROTH (1.888.444.7684) 309.787.1791 . Fax: 309.787.5142 www.rothpump.com Contact your Authorized Roth Representative Today! 3070.40.2603 © 2000, Roth Pump Company Printed in USA