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HORA | POWER TECHNOLOGY DESUPERHEATERS TECHNICAL BULLETIN
HORA | POWER TECHNOLOGY
DESUPERHEATERS
TECHNICAL BULLETIN
HORA | POWER TECHNOLOGY 02
CONTENTDESUPERHEATERS
Injection lance Description of design 06Dimensions 07
Venturi desuperheaterDescription of design 08Dimensions 09
Multiple nozzle desuperheaterDescription of design 10Technical data - Pressure swirl spray nozzle 11Technical data - Standard duty 12Parts list - Standard duty 13Dimensions - Standard duty 14Features and benefits - Standard duty 15Technical data - Heavy duty 16Parts list - Heavy duty 17Dimensions - Heavy duty 18Features and benefits - Heavy duty 19Options 20
Radial desuperheaterDescription of design 21
AtomizerDescription of design 22Dimensions and technical data 23
Selection guide 24
Lifecycle servicesReliable solutions and service 25
CONTENT
Liability for Content - We make
every effort to keep the informa-
tion in this document current, but
accept no liability whatsoever for
the content provided.
Copyrights - The content and works
provided in this document are go-
verned by the copyright laws of
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mercialization of such material
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law shall require the prior written
consent of its respective author or
creator.
Rev: 02 | 06/18
Our aspiration 03Application area 04Fundamental issues 05
HOLTER REGELARMATUREN GMBH & CO. KGPOWER TECHNOLOGY
OUR ASPIRATIONAIMING FOR THE TOP
ENGINEERING & DESIGN MADE IN GERMANY QUALITY
For 50 years our customers have relied on HORA as a competent partner for innovative and reliable flow control solutions. HORA products provide superior customer benefits in power and other related in-dustries. From turbine bypass systems to balance of plant applications, HORA offers a comprehensive portfolio of standard and heavy duty control valve solutions. The HORA brand is increasing in global significance with an export share of more than 65 percent. We develop and engineer all our own core products, which are manufactured by us in Germany enabling us to guarantee our own product quality. All processes are organized to ensure short throughput times and the highest levels of delivery reliability.
HORA utilizes the most modern modelling tools during the design of the control valves, such as Com-putational Fluid Dynamics CFD, Finite Element Analysis FEA, 3D CAD design software and virtual reality solutions. These advanced tools are decisive in optimizing the design of the valves for impro-ved flow geometry and minimized stresses in the valve bodies.
HORA operates one of the most modern and efficient valve fa-cilities in the world. Continuous investment in the up to date pro-duction technologies, such as sub-merged 3D arc-welding, as well as complete machining centers ensure precision in manufacturing with higher productivity, shorter throughput times and lower costs.
HORA provides reliability and effi-ciency for our customers through continuous and consistent advan-cement of our own development and manufacturing processes. All non-destructive material testing (NDT) and final testing is performed in-house. Quality management and assurance, and comprehensive cer-tifications underline our claim to quality of the highest level.
EUROPEAustriaBulgariaDenmarkFinlandGreat BritainGreeceItalyLuxemburgThe NetherlandsPortugalRomaniaRussiaSwedenSpainSwitzerlandTurkey
AMERICASCanadaUSA
ASIA-PACIFICAustraliaChinaIndiaPhilippinesSingaporeTaiwan
MIDDLE EAST & AFRICA Dubai
HORA | POWER TECHNOLOGY 03
APPLICATION AREAOF HORA POWER TECHNOLOGY PRODUCTS
HORA is focused on providing customized flow control solutions for the energy-focused market sectors. Through our product line we offer a full spread of comprehensive high-grade products and worldwide expert advice in particular for water and steam applications for the greatest technical challenges. As trusted partner for new construction, extension and technical upgrading of an efficient power infrastructure, HORA offers utilities and the industry the portfolio they need.
The main purpose of a valve is to control media flow through a system. The valve may be used to start, stop, or throttle the flow. The requirements for control val-ves have increased significantly over the past years and demand higher flexibility in order to guarantee short response times and extended life. In addition higher process parameters are targeted in order to increase the efficiency of the plants significantly compromising compliance with environmental protection like redu-cing CO2 emissions in the power sector. HORA control technology allows a safe and material-saving mode of operation for an economically viable plant operation.
HORA organized and structured its portfolio manage-ment in the following product groups:
• Single seat control valves• Water pressure reducing valves• Desuperheaters• Steam conditioning valves• Automatic recirculation valves• Actuators
Power Technology
• Coal-fired power plants
• Combined cycle power plants
• Combined heat and power plants
• Concentrated solar power plants
• Biomass power plants
(incl. waste incineration plants)
Oil and Gas
• Extraction and
distribution
• Petrochemicals
Process and general industry
• Pulp and Paper
• Chemicals
• Food and Beverages
• Desalination
• Steel and Aluminium
• Cement
• Others
Service
• Spare Parts
• Repair, upgrades and retrofit
• Assembly
APPLICATION AREAMARKET AND PRODUCT SEGMENTS
04HORA | POWER TECHNOLOGY
05
GENERAL DESCRIPTIONDESUPERHEATERS
Desuperheaters, also referred to as attemperators, are used especially for temperature control of steam in the whole energy-focused market to meet the conditions required for the process. Serving as an example the heat recovery steam generator (HRSG) in combined cycle plants with daily cycling or reduced loads requires reliable superheater and reheater attemperation to avoid loss of control and piping damage downstream as a result of excess water. The fundamental principle is to use water in direct contact with steam with adjusting a target temperature through heat transfer. The required amount of water is determined from heat balance and mass balance cal-culations. In the theory of an idealized cooling section, the water is preheated in the first stage to reach its bo-iling point. After that, the droplets are evaporated into saturated steam and the saturated steam is eventually mixed with the superheated steam. Superpositions and parallel processes will occur.
HORA | POWER TECHNOLOGY
The complete evaporation time and distance to reach target temperature depends mainly on the size of the individual droplets, the water temperature, and the turbulence.
• Small droplets create a bigger surface area for the heat transfer and thus have a good cooling effect. The diameters are determined by the pressure drop between water and steam influenced by the diameter of the injection nozzle, called primary atomization.
• A high water temperature reduces the surface tension and the consequences of impacts on the hot metal parts.
• Due to high turbulence, called secondary atomiza- tion, by steam velocity and rotation/ twist of the water, the water droplets burst open. Smaller droplets stay evenly distributed in the steam flow.
Also the desired degree of superheating of the steam, the ratio of water to steam amount, the pipeline rou-ting and finally the control logic are important factors.
HORA has the engineering know-how to select the right desuperheater which avoids malfunction due to improper design details and wrong installation of the device, sensors and piping layout.
GENERAL DESCRIPTIONFUNDAMENTAL ISSUES
Water connection
Temperaturemeasuring point
Mixing sectionEvaporation section
Distance from the injection point
Satured steam temperature tS
Boiling water temperature
Temperature t1 of the non-cooled steam
Superheatednon-cooled
steamt1 > ts
Water+
superheated steam
Superheated cooled steamt1 > t2 = ϑsoll > ts
Temperature t2 of the cooled steam
Temperature of the cooling water
Superheated non-cooled steam Water
Heating of the water
Target temperature
06
DESCRIPTION OF DESIGNINJECTION LANCE
HORA | POWER TECHNOLOGY
Injection lances transport the water via a lance to a nozzle in the steam pipe. The mechanical atomization is typically realized by fixed area nozzles. Optionally spring loaded or multiple nozzles are used. The nozzle rod is flanged into the steam pipe. The cooling water amount is controlled by an external control valve.With a continuous pressure difference the cooling water is uniformly distributed over the cross-sectional area. The nozzles are using a venturi shape and swirl chamber to give turbulent flows with additional rotary motions for optimized atomization. This will ensure a fast and effective evaporation of the water. The design requires little service because it has no moving parts. The injection lance is widely used at fairly constant load in indus-trial plants, auxiliaries in power plants and in the process industry.
TECHNICAL DATAINJECTION LANCE
STEAM PIPE STEAM CONNECTION WATER CONNECTION
DN NPS DN NPS PN Class DN NPS PN Class
100-300 4 - 12 80 3 10 - 160 150 - 600 25, 40, 50 1, 1½, 2 10 - 160 150 - 600
350-1200 14 - 48100 4 10 - 160 150 - 600
25, 40, 50 1, 1½, 2 10 - 160 150 - 600150 6 10 - 40 150 - 300
Special design on request
DESCRIPTION OF DESIGNINJECTION LANCE
07HORA | POWER TECHNOLOGY
DIMENSIONSINJECTION LANCE
A
A
L3
L1L2
L
D
A A-
Steam pipeSteam connection
Wat
er c
onne
ctio
n
STEAM PIPE DIMENSIONS [mm] NUMBER OF NOZZLES MATERIAL
DN NPS L1 L2 L D Standard L3 Option L3 EN ASME
100 4 200 315 - - 1 - - -
1.04
60 /
1.7
335
SA10
5 / S
A18
2 F1
2
125 5 225 340 - - 1 - - -150 6 225 340 - - 1 - - -200 8 250 365 - - 1 - - -250 10 275 390 - - 1 - - -300 12 300 415 - - 1 - - -350 14 300 415 630 60,3 2 100 4 75
Flan
ge: 1
.733
5Pi
pe: 1
.738
3
Flan
ge: S
A18
2 F1
2Pi
pe: S
A18
2 F2
2400 16 350 465 705 60,3 4 100 6 75
450 18 400 515 780 60,3 4 100 8 75
500 20 450 565 855 60,3 6 100 10 75
600 24 500 615 955 60,3 8 100 12 75
700 28 550 665 1055 60,3 10 100 14 75
800 32 600 715 1155 60,3 12 100 16 75
900 36 650 765 1255 60,3 14 100 18 75
1000 40 700 815 1355 60,3 16 100 20 75
1100 44 750 865 1455 60,3 18 100 22 75
1200 48 800 915 1555 60,3 20 100 24 75
Special design on request
L1
L2
Stea
m p
ipe
Steam connection
Water connection
DIMENSIONSINJECTION LANCE
08HORA | POWER TECHNOLOGY
DESCRIPTION OF DESIGNVENTURI DESUPERHEATER
The venturi type desuperheater creates superior water mixing due to higher steam velocities in combination with the advanced spray nozzles and enables the use at relatively low speed applications. The inline desuper-heater can be installed in piping systems with either flanged or welded connections horizontally or vertically upwards. The flow of the water is controlled by a separate spray water valve. The water enters the steam line via the water flange to a fixed area nozzle or a number of radial holes integ-rated in the venturi ring, sized to suit quantity and pressure drop in accordance to the requested flow. There at the narrowest cross section (highest speed) the water is dragged along and the evaporation of the finest droplets is rapid. A vortex flow for secondary atomization is created downstream when the steam exits the constricted section of the device. The design requires little service because it has no moving parts. These desu-perheaters are recommended for use under a wide range of conditions in industrial plants, auxiliaries in power plants and in the process industry, including constant and moderate variable loads.
DESCRIPTION OF DESIGNVENTURI DESUPERHEATER
09
DIMENSIONSVENTURI DESUPERHEATER
HORA | POWER TECHNOLOGY
L1L2
H
DIMENSIONSVENTURI DESUPERHEATER
DIMENSIONS [mm]
DIMENSIONS BW DESIGN DIMENSIONS FLANGE DESIGN
PN 16-100 / Class 150-600 PN 16-100 / Class 150-600 PN 160 / Class 900 PN 250 / Class 1500
DN PN Class L1 L2 H L1 L2 H L1 L2 H L2 L2 H
40 16-250 150-1500 200 100 150 250 125 150 300 150 150
Special design on request
50 16-250 150-1500 200 100 150 250 125 150 300 150 150
65 16-250 150-1500 200 100 150 300 150 175 350 175 200
80 16-250 150-1500 200 100 175 300 150 175 350 175 200
100 16-250 150-1500 225 100 175 300 150 175 400 200 225
125 16-250 150-1500 300 125 200 325 162,5 225 425 212,5 275
150 16-250 150-1500 300 125 200 325 162,5 225 425 212,5 275
200 16-250 150-1500 350 150 275
Special design on request
250 16-250 150-1500 400 175 300
300 16-250 150-1500 450 200 325
350 16-250 150-1500 500 225 350
400 16-250 150-1500 500 225 375
450 16-250 150-1500 550 225 400
500 16-250 150-1500 550 235 425
10HORA | POWER TECHNOLOGY
DESCRIPTION OF DESIGNMULTIPLE NOZZLE DESUPERHEATER
Multiple nozzle desuperheaters transport the water via a lance to the nozzles in the steam pipe center. The nozzle rod is flanged into the steam pipe. Release of the individual injection nozzles is controlled via a piston stroke, this means that the injection control valve is integrated and a separate valve is not needed. By using several nozzles in different dimensions, a high rangeability can be realized, corresponding to the given operation load cases. In the low load area, at least one nozzle is in use, while under full load all nozzles are charged with water. The pressure drop will thus stay nearly on the same level and will provide smallest droplet diameters even at partial load. The use of pressure swirl nozzles results in an additional rotational movement of the cooling water. In order to avoid weld seams on the pressure bearing body, high-quality desuperheaters are produced from forged solid material.
STANDARD DUTYThe HORA Standard Duty Desuperheater is specifi-cally developed for use on low and medium pressure applications. It primarily serves to control the tempe-rature providing process steam.
Pressure class:PN 40 to PN 160 Class 300 to Class 900
Max. design temperature:530°C986°F
HEAVY DUTY The HORA Heavy Duty Desuperheater is specifically de-veloped for flexible steam plants at high pressure ap-plications. It primarily serves to control extremely high steam temperatures in boiler and turbine installations.
Pressure class:PN 250 and PN 400 Class 1500 and 2500
Max. design temperature:600°C1112°F
DESCRIPTION OF DESIGNMULTIPLE NOZZLE DESUPERHEATER
11HORA | POWER TECHNOLOGY
To suit a wide range of load conditions a variety of nozzle sizes is available with different mounting positions around the spray head. A uniform and fine atomization is achieved across the entire range of flow conditions. By travelling the pis-ton downwards the water is fed in axially via a series of multiple bore holes and subsequentially bringing the nozzles in service. Each nozzle assembly has a swirl unit and the water emerges through the nozzle cone tip at high speed creating a rotating mist of water. Using stainless steel material prevents wear even at higher differential pressures and temperatures. To keep the risk of clogging to a minimum a dirt catcher with a fine sieve (<= 0,5mm) should be installed upstream the water inlet.
SIZE 1 2 3
RATED TRAVEL 60 80 100 120 150
NUMBER OF NOZZLES
6
8 10 12 159
12*
18* 16* 20* 24* 30*
NOZZLE TYPE M16 M24 M24 M24 M24
*both sides injection
NOZZLE SIZE M16 1600 1601 1602 1603 1604 1605 1606
KV-NOZZLE [m³/h] 0,006 0,0083 0,013 0,016 0,03 0,08 0,13
NOZZLE SIZE M24 2410 2411 2412 2413 2414 2415 2416
KV-NOZZLE [m³/h] 0,013 0,016 0,03 0,08 0,13 0,2 0,33
NOZZLE SIZE M24 2417 2418 2419 - - - -
KV-NOZZLE [m³/h] 0,63 1,1 1,33 - - - -
Min. ∆p 5 bar for nozzle size M16 and min ∆p 8 bar for nozzle size M24
Cv = 1,16 x Kv
TECHNICAL DATAPRESSURE - SWIRL SPRAY NOZZLE
TECHNICAL DATAMULTIPLE NOZZLE DESUPERHEATER
12
TECHNICAL DATAMULTIPLE NOZZLE DESUPERHEATER
DESCRIPTION TECHNICAL DATA
Body materialEN 1.5415 / 1.7383
ASME SA 182 F12 / SA 182 F22
Max. design temperature [°C] 530°C
Flow rate water [kg/h] < 20.500 >20.500 - 39.500
Size 1 2
Nominal size water connection flangeDN 25 / 40 /50 50 / 65 / 80
NPS 1/ 1½ / 2 2 / 2½ / 3
Pressure rating water connection flangePN 40 - 160
Class 300 - 900
Nominal size steam connection flangeDN 80 125
NPS 3 5
Pressure rating steam connectionPN 40 - 160
Class 300 - 900
Nominal size steam pipe DN [inch] 150 - 600 >600 on request (6“ - 24“)
Spray water pressure above steam pressure [bar] 5≤ ∆p ≤45 35≤ ∆p ≤75 50≤ ∆p ≤110
Stages 1 2 3
Rated travel [mm] 60 80 100 120 150
Qty. of nozzles 6 / 9 8 10 12 15
Nozzle size M16 M24
Seat diameter [mm] 19/25 40
Piston diameter [mm] 35 50
Stem diameter [mm] 18/22 26/32
Trim material≤ 400°C 1.4122
> 400°C 1.4922
TECHNICAL DATASTANDARD DUTY
HORA | POWER TECHNOLOGY
PARTS LISTMULTIPLE NOZZLE DESUPERHEATER
13
POS. DESCRIPTIONMATERIAL SPARE PARTS
EN ASME COMMISSIONING RECOMMENDED
1. Body 1.5415 / 1.7383 SA182 F12 / SA182 F22
2. Flange 1.5415 / 1.7383 SA182 F12 / SA182 F22
3. Flange 1.5415 / 1.7383 SA182 F12 / SA182 F22
4. Ring 1.5415 / 1.7383 SA182 F12 / SA182 F22
5. Plug with stem 1.4122 / 1.4922 x
6. Piston ring 1.4923 x
7. Seat 1.4122 / 1.4922 x
8. Stuffing box packing Graphite x x
9. Bonnet 1.5415 / 1.7383 SA182 F12 / SA182 F22
10. Flange 1.5415 / 1.7383 SA182 F12 / SA182 F22
11. Stud bolt 1.7711 / SA193-B16
12. Hexagon nut 1.7225 / SA194-Gr.4
13. Bottom ring 1.4112
14. Stem packing Graphite/K80S x x
15. Stuffing box 1.4057
16. Stuffing box flange 1.7380 SA182 F22
17. Stud bolt 1.7711
18. Hexagon nut 1.7225
19. Gasket 1.7362 x x
20. Nozzle head with nozzles 1.4122 / 1.4922 x
PARTS LISTSTANDARD DUTY
HORA | POWER TECHNOLOGY
19
1
20
4
39
1617185
131415
2
1211
10
7
6
8
14
DIMENSIONS [mm]
FLANGEPN 40 - PN 160CLASS 300 - CLASS 900
SIZERATED TRAVEL
A B C D
STEAM PIPE DN (INCH) UP TO:
150 (6“) 200 (8") 250 (10") 300 (12") 400 (16") 500 (20") 600 (24")
1 60 150* 200 460 560 69
1 80 150* 200 480 580 69
2 100 250 300 - - 450 500 550 600 90
2 120 250 300 - - 470 520 570 620 90
*for class 900 flanges is A=200 mm
DIMENSIONSMULTIPLE NOZZLE DESUPERHEATER
HORA | POWER TECHNOLOGY
B
A
C
D
DIMENSIONSSTANDARD DUTY
FEATURES AND BENEFITSMULTIPLE NOZZLE DESUPERHEATER
15
Integrated flow control All commonly used actuators can be fitted, a separate spray water
control valve is not needed
Various connection options Water inlet and steam pipe connection flange matched up tocustomer requirements
Easy maintenance Quick change trim (cartridge-style), ease of access to the internal components
High Rangeability Multiple pressure-swirl spray
nozzles with sequential opening and optimized spray coverage for
accurate temperature control
Repeatable and long-term tight shut-off
Seat position outside the hot steam pipe
Reliable operation Trim material made of alloyed tool steel
Low-wear pressure reduction Optional multi-stage design for
optimum pressure division
FEATURES AND BENEFITSSTANDARD DUTY
16
DESCRIPTION TECHNICAL DATA
Body materialEN 1.7383 / 1.4903
ASME SA 182 F22 / SA 182 F91
Max. design temperature [°C] 600°C
Flow rate water [kg/h] < 20.500 >20.500 - 39.500 >39.500 - 60.000
Size 1 2 3
Nominal size water connection flangeDN 25 / 40 /50 50 / 65 / 80 80 / 100 / 125
NPS 1 / 1½ / 2 2 / 2½ / 3 3 / 4 / 5
Pressure rating water connection flangePN 250 - 400
Class 1500 - 2500
Nominal size steam connection flangeDN 80 125 150
NPS 3 5 6
Pressure rating steam connection flangePN 250 - 400
Class 1500 - 2500
Nominal size steam pipe DN [inch] 150 - 600 >600 on request (6“ - 24“)
Spray water pressure above steam pressure [bar] 5≤ ∆p ≤45 35≤ ∆p ≤75 50≤ ∆p ≤110
Stages 1 2 3
Rated travel [mm] 60 (2,362) 80 (3,149) 100 (3,936) 120 (4,724) 150 (5,905)
Qty. of nozzles 6 / 9 8 10 12 15
Nozzle type 16 24
Seat diameter [mm] 19/25 40 55
Piston diameter [mm] 35 50 70
Stem diameter [mm] 18/22 26/32 32/45
Trim material≤ 400°C 1.4122
> 400°C 1.4922
TECHNICAL DATAHEAVY DUTY
TECHNICAL DATAMULTIPLE NOZZLE DESUPERHEATER
HORA | POWER TECHNOLOGY
17
POS. DESCRIPTIONMATERIAL SPARE PARTS
EN ASME COMMISSIONING RECOMMENDED
1. Body 1.7383 / 1.4903 SA182 F22 / SA182 F91
2. Flange 1.7383 / 1.4903 SA182 F22 / SA182 F91
3. Seat 1.4122 / 1.4922 x
4. Plug with stem 1.4122 / 1.4922 x
5. Piston ring 1.4923 x
6. Stuffing box packing Graphite x x
7. Cage 1.4122 / 1.4922
8. Stuffing box packing Graphite x x
9. Stud bolt 1.7711 / SA193-B16
10. Hexagon nut 1.7225 / SA194-Gr.4
11. Bonnet 1.7383 / 1.4903 SA182 F22 / SA182 F91
12. Bottom ring 1.4112 / 1.4122
13. Stem packing Graphite/K80S x x
14. Stuffing box 1.4057
15. Stuffing box flange 1.7380 SA182 F22
16. Stud bolt 1.7711
17. Hexagon nut 1.7225
18. Nozzle pipe 1.4122 / 1.4922 x
19. Packing ring Graphite x x
20. Guide bush 1.4122 / 1.4922
PARTS LISTHEAVY DUTY
PARTS LISTMULTIPLE NOZZLE DESUPERHEATER
HORA | POWER TECHNOLOGY
118193
69
1011
17 16
12
14
87
20
2
15 135
4
18HORA | POWER TECHNOLOGY
DIMENSIONS [mm]
FLANGEPN 250 - PN 400CLASS 1500 - CLASS 2500
SIZERATED TRAVEL
A B C D
STEAM PIPE DN (INCH) UP TO:
150 (6“) 200 (8") 250 (10") 300 (12") 400 (16") 500 (20") 600 (24")
1 60 200 250 460 560 67
1 80 200 250 480 580 67
2 100 300 350 - - 450 550 600 700 82
2 120 300 350 - - 470 570 620 720 82
3 150 350 450 - - - 650 700 800 108
DIMENSIONSMULTIPLE NOZZLE DESUPERHEATER
DIMENSIONSHEAVY DUTY
B
A
C
D
19HORA | POWER TECHNOLOGY
FEATURES AND BENEFITSMULTIPLE NOZZLE DESUPERHEATER
Various connection options Water inlet and steam pipe connection flange matched up tocustomer requirements
Easy maintenance Quick change trim (cartridge-style), ease of access to the internal components including inline maintenance of nozzle head
High rangeability Multiple pressure-swirl spray
nozzles with sequential opening and optimized spray coverage for
accurate temperature control
Repeatable and long-term tight shut-off
Seat position outside the hot steam pipe
Reliable operation Trim material made of alloyed tool steel
High service-life under flexible operation One piece injection lance, free of screwed or welded nozzle head
High fatigue Stress optimized contoured valve
body with thin and even wall thickness and large radii of
curvature
Integrated flow control All commonly used actuators can be fitted, a separate spray water
control valve is not needed
Low-wear pressure reduction Optional multi-stage design for
optimum pressure division
FEATURES AND BENEFITSHEAVY DUTY
OPTIONSMULTIPLE NOZZLE DESUPERHEATER
HORA | POWER TECHNOLOGY 20
OPTIONS
MULTI-STAGE DESIGNAt very large pressure drops above 40 bar, a multi-sta-ge low-wear pressure reduction is required. Via a pa-rabolic contoured stem, up to 3 additional control stages provide constant and optimum pressure ratios at the nozzles forming evenly distributed spray. The optimum pressure division between all stages is part of the HORA sizing software.
COOLING JACKETDesuperheater systems have a restricted service life especially at cycling service. The temperature diffe-rences between water and steam and load changes create thermal induced mechanical stresses through thermal expansion (i.e. thermal stresses) in the desu-perheater body. This alternating stress occurs without any external influence of forces and can lead – de-pending on the extent – to premature crack develop-ment up to component failure. A jacket cooling as a barrier extends the service life and is recommended at applications with temperature differences bet-ween steam and cooling water of more than 400°C.
21HORA | POWER TECHNOLOGY
DESCRIPTION OF DESIGNRADIAL DESUPERHEATER
The water injection with radial type desuperheater is executed radially around large steam pipes over the circumference through pressure-controlled nozzles, which are characterized by changing the open nozzle area with the flow. The flow of the water is controlled by a separate spray water valve. The radial type desuperheater consists of multiple spring loaded nozzles that are circumferentially wall moun-ted. The spraywater is uniformly distributed over the cross-sectional area. The plug of the nozzles, executed in combination with a non-return function, is pre-loaded with a spring and moves up to an adjustable mechani-cal stop. Due to the different spring loads and nozzle areas, the individual nozzle is opened sequentially and enables good partial load behaviour. The injection line is normally executed with a protective shell downstre-am, also called liner, to protect the steam pipe against thermal stresses and erosion.These desuperheaters are recommended handling large spray water flows and are typically used on boilers, either between superheater stages or at the boiler exit, to control superheat temperatures at partial loads in power plants.
DESCRIPTION OF DESIGNRADIAL DESUPERHEATER
Pressure class:Up to max. PN 630 / Class 4500(Intermediate class as per design data)
Max. design temperature:610°C / 1130°F
HORA | POWER TECHNOLOGY 22
DESCRIPTION OF DESIGNATOMIZER
DESCRIPTION OF DESIGNATOMIZER
When critical requirements have to be fulfilled an atomizer for the cooling water injection offers the best possible results by using the kinetic energy of high pressure steam with the shortest distance for evaporation of any downstream desuperheating system. Due to strong turbulences, the cooling water is atomized, drawn into the steam flow and mixed effectively. The source of higher pressure steam must be available during the entire load regime and ensures excellent partial load behaviour. If higher pressure steam is not always avai-lable a mechanical type desuperheater must be used. The flow of the water is controlled by a separate spray water valve and a additional support steam shut-off valve is required. The water enters the centre of the spray head and then the number of radial holes, sized to suit quantity and pressure drop in accordance to the requested flow. There at the narrowest cross section (highest speed) the water is dragged along and atomized by the tapped high pressure steam. The steam is reduced preferably super-critically and thereby generates a pressure drop with its high velocity. The evaporation of the finest dro-plets is rapid. The atomizer is recommended for severe process steam installations where the steam load varies heavily or where the steam flow velocity is constantly low.
23HORA | POWER TECHNOLOGY
DIMENSIONS AND TECHNICAL DATAATOMIZER
DIMENSIONS AND TECHNICAL DATAATOMIZER
DIMENSIONS [mm]
DN NPS L1 L2 L3 L4
SIZE 1
150 6
Wat
er c
ontr
ol v
alve
DN
25
Stea
m o
n/of
f val
ve D
N 2
5
Stea
m c
onne
ctio
n fla
nge
DN 1
50
max
wat
er fl
ow 1
0 t/h
400 200 450 250200 8
250 10450 250 500 300
300 12
350 14500 300 550 350
400 16
450 18550 350 600 400
500 20
600 24 600 400 650 450
SIZE 2
200 8
Wat
er c
ontr
ol v
alve
DN
40
Stea
m o
n/of
f val
ve D
N 4
0
Stea
m c
onne
ctio
n fla
nge
DN 2
00
max
wat
er fl
ow 2
5 t/h
500 250 550 300250 10
300 12550 300 600 350
350 14
400 16600 350 650 400
450 18
500 20700 450 750 500
600 24
700 28800 550 850 600
800 32
SIZE 3
400 16
Wat
er c
ontr
ol v
alve
DN
50
Stea
m o
n/of
f val
ve D
N 5
0
Stea
m c
onne
ctio
n fla
nge
DN 2
50
max
wat
er fl
ow 5
0 t/h
650 350 700 450450 18
500 20750 450 800 550
600 24
700 28850 550 900 650
800 32
900 36950 650 1000 750
1000 40
special design on request
L1
L1
L2
L3
L4
DN
Steam connection
rem
ova
l m
easu
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Steam Water connection
HORA | POWER TECHNOLOGY
SELECTION GUIDESTANDARD FEATURES
HORA offers a complete portfolio of desuperheater solutions to meet the requirements on temperature control of steam. The range in severity require high attention in selection and sizing of desuperheaters.
Injection lanceVenturi type desuperheater
Multiple nozzle desuperheater
Radial desuperheater
Atomizer
Description of design
Fixed area nozzle(s) or spring loaded nozzle(s)
Fixed area nozzle or holes integrated in Venturi ring
Multiple pressure swirl nozzles controlled by piston
Spring loaded nozzles around diameter of pipe
High pressure support steam (20-30% of max. water amount)
Control External control valve External control valveIntegrated water control valve (Maximum 3+1 stages)
External control valveExternal control valve + steam shut-off valve
steam pipe size ≥ DN 100 DN 40 - DN 500 DN 150 - DN 600 DN 200 - DN 1000 ≥ DN 150
Typical turndown 20:1 10:1 (8:1) 50:1 (on spray water flow) 20:1 40:1
Water capacity Max. 250 t/h Max. 20 t/h (<15%) Max. 60 t/h (<15%) Max. 250 t/h Max. 50 t/h
Minimum steam velocity
8 m/s12 m/s (steam pipe size > DN 200)
8 m/s (secondary atomi-zation by steam velocity in venturi at max. 250 m/s)
8 m/s12 m/s (steam pipe size > DN 200)
12 m/s 4 m/s
Spray water pressure above steam pressure
line pressure + 8 bar or more
line pressure + 5 bar or more
line pressure + 5 bar (max +180 bar)
line pressure + 15 bar or more
well suited when delta p is low
set point temperature
Minimum 15K-30K above saturation for direct temperature control
Minimum 10K-15K above saturation for direct temperature control
Typical application
Process steam with optional pressure reducing valve up-stream; HRH/ LP bypass system
Process steam with low pressure drop in steam line;
Process steam and extraction steam; boiler interstage and final/ terminal desuper-heater
HP turbine bypass system; boiler interstage and final/ terminal desuperheater
Severe process steam (greater pipe sizes); HP and HRH/ LP turbine bypass system
Distance to temperature sensor rule of thumb based on field experience
water/steam < 15% (>15%):0,2s (0,3s) x steam velocity [m/s]
water/steam < 15% (>15%):0,15s (0,2s) x steam velocity [m/s]
All the information could be subject to errors or omissions and are given only for title of indication. Solutions can be be customized for special applications. Please refer to HORA for on any questions, concerns or more detailed information regarding the proper selection of the desuperheating system.
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HORA | POWER TECHNOLOGY
EXEMPLARY SPECIAL TOOLS
LIFECYCLE SERVICESDESUPERHEATERS
LIFECYCLE SERVICES RELIABLE SOLUTIONS AND SERVICE
The HORA brand stands both for the longevity and reliability of its products as well as for the quality of our services, which support our valves and actuators in plants around the globe. We cover the entire value chain of a plant from engineering through to construction and operation of energy-focused facilities. More than a conventional service provider, HORA offers a complete range of excellent consultation, support and assistance throughout the lifecycle of the product. The HORA service department offers regular inspection and maintenance to ensure the reliable operation of its products. Any required special component beyond the scope of our normal spare parts needed, tools or machines for commissioning or repair work is available.At the completion of water-tube steam generating plants, the associated pipework and system is contamina-ted with debris: Residual material from fabrication, assembly and corrosion products. Typically water systems are flushed with high velocity water, boiler surfaces are chemically cleaned and steam pipes are blown with steam to remove particulate material that would potentially damage sensitive devices.
HORA‘s service tools include:
Removal tool Kit for flushing Hydro test kit
• Kits to hydro test of the inlet and outlet system• Kits for flushing during chemical cleaning• Blow-out/ blow-through devices and sacrificial trims to operate during steam blows
• Instrumentation and calibration equipment• Removal and compression tool for internals• Machining based on assessment
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Holter Regelarmaturen GmbH & Co. KGHelleforthstraße 58-60 | 33758 Schloß Holte-StukenbrockPhone +49 5207 8903-0 | [email protected]
HORA | POWER TECHNOLOGY
