PProducts

 

 

Overview

LDDC series Electromagnetic Flowmeter is composed of

sensor and convertor. It works on Faraday's electromagnetic

indication principle, used for the measuring of volumetric flow

rate of liquid whose conductance is greater than 5μ S/cm. It

also cn measure the corrosive liquids as strong acid, alkali,

etc. and two phase (liquid-solid) suspensions as mud, ore

pulp,  paper pulp,  etc.  It is widely applied in the field of

petroleum,    chemical    industry,   metallurgy,    textile ,

papermaking, environmental protection, food and municipal

administration, irrigation project, river dredge, etc.

 

Measuring principle

According to the Faraday's electromagnetic induction

principle, pair of measuring electrodes are installed on the

wall of tube whose axes are perpendicular both to the

measuring tube wall axis and the magnetic flux. As the

conductive liquid is moving long the tube axis, the conductive

liquid cuts the magnetic flux, an induced voltage is produced.

This voltage is picked up by the electrodes and is proportional

to the flow rate, its value is:

                E=KBVD

 

E=Induced voltage

 
 
K= coefficient related to the distribution of magnetic field etc.
 
B=magnetic flux intensity
 
V= average flow velocity of conductive liquid
 
D= distance between electrodes, (inner diameter of tube)
 
The induced voltage E is regarded as the flow signal of the sensor and is transmitted to the converter. 
 
After through amplifying, converting, filtration and a series of digital treatment the instantaneous and
 
tantalizer flow rate are displayed on the LCD. The converter has 4-2OmA output, alarm and frequency
 
outputs, and has  Rs- 485ect. Communication connection.
 

Characteristics

 

1.No obstacle existed the measuring tube, so the pressure loss is zero, hardly blocked.
 
2.If the proper electrodes and lining material are adopted, then the request of anticorrosion, wear
 
resistance canbe satisfied.
 
3.The measuring results have no relation with the physical parameters of the liquid, such as pressure,
 
temperature, density, viscosity, conductivity rate( but not below 5p S/cm!), etc... it is not influenced by the
 
circumstances, so the accuracy is high, working process is stable and reliable.
 
4.Adopt the dual row flow indicator of back lighted dot array, displays the instantaneous and totaled flow
 
rates,simultaneously, also displays the working status, parameters, measuring units, etc...

5.The measuring range of this flow meter is wide. Its range ability normally is 20:1, generally can reach
 
30:1 or evenlarger.
 
6.This flow meter has multi-functional outputs, can be matched with computer, combined instrument unit;
 
can meetthe requirement of printing, communication and networking.

 

 

 

 

Technical parameters

  Main technical

Conductivity

＞5μ S/cm.

Velocity

0.3-12m/s

Flow range

Within the measurement range of flow velocity,

the range of volumetric flow rate is programmable,

see the table

Accuracy

Measured value ±0.5%,±1%

Environment condition

Ambient temperature

-10℃-50℃

relative humidity

5%-90%

Medium temperature

T1≤65℃, T2≤120℃, T3≤180℃

Working pressure

DN10-80:PN≤4MPa

DN100-300:PN≤1.6MPa

DN350-1000:PN≤1MPa

Higher pressure can be specially ordered

Power supply

220V AC 50Hz(90-245V AC 50Hz)

24V DC (20-36V DC)

Power consumption

6.5VA

Protection grade

Standard type IP65, special type IP67 or IP68

Electrode material

316L,HC,HB,Pt,Ti,Ta

Liner material

1. NE         2. PUME           3.PTFE 

4.PFA        5. F46

 

Flow table

 

Diameter

(mm)

Minimum
Flow rate

(m3/h)

Selection of usual full-scale range

(m3/h)

10

0.10

0.4、0.5、0.6 、0.8、 1.0 、1.6 、2.0、 2.5

15

0.20

1.0 、1.2、 1.6、 2.0 、3.0 、4.0 、5.0 、6.0

20

0.35

2.0、 2.5、 3.0、4.0、 5.0 、6.0、 8.0 、10.0、 12.0

25

0.55

3.0 、4.0、 5.0 、6.0 、8.0 、10 、12.0 、14.0、 16.0

32

1.0

5.0、6.0、8.0、10.0、12、16、20、25

40

1.5

8.0、10.0、12、16、20、25 、30、40

50

2.5

12、16、20、25 、30、40、50、60、70

65

4.0

20、25 、30、40、50、60、80、100、120

80

5.5

25 、30、40、50、60、80、100、120、160

100

8.5

40、50、60、80、100、120、160、200、250

125

14

60、80、100、120、160、200、250、300、400

150

20

100、120、160、200、250、300、400、500、600

200

35

160、200、250、300、400、500、600、800、1000

250

55

200、250、300、400、500、600、800、1000、1200、1600

300

80

300、400、500、600、800、1000、1200、1600、2000、2500

350

105

400、500、600、800、1000、1200、1600、2000、2500、3000

400

135

500、600、800、1000、1200、1600、2000、2500、3000、4000

450

175

600、800、1000、1200、1600、2000、2500、3000、4000、5000

500

215

800、1000、1200、1600、2000、2500、3000、4000、5000、6000

600

305

1000、1200、1600、2000、2500、3000、4000、5000、6000、10000

700

415

1200、1600、2000、2500、3000、4000、5000、6000、10000、12000

800

545

1600、2000、2500、3000、4000、5000、6000、10000、12000、16000

900

690

2000、2500、3000、4000、5000、6000、10000、12000、16000、20000

1000

850

2500、3000、4000、5000、6000、10000、12000、16000、20000、25000

 

 

 

 

Normally 2-6m/s flow velocity of the medium is advisable. If specially required, the minimum shall not lower
 
than 0.3m/s, the maximum not higher than 12m/s. Too low flow velocity will cause the going-down of the
 
electromagnetic signal, which will lead to a decrease of the measurement accuracy. In case the fluid 
 
containssolid particles, it is necessary to set the flow velocity at lower than 3m/s. For viscous liquids the
 
correspondingflow velocity shall be at a higher value, which is helpful for automatically eliminating the dirts
 
on the electrodesand also favorable to improving the measurement accuracy.

Formula to calculate the relation between the flow rate, flow velocity and diameter:

         

其中:  Q=  Flow rate  （m3/h）

           v=  Flow velocity（m/s）

          D=  Diameter（m）

 

 

After the diameter of the flow rate being determined, it is necessary to increase as the full measurement
 
rangevalue (by 15%-30%) according to the preset maximum technological flow. In the practical use, shall
 
do bestnot to allow the flow to exceed the full range value, otherwise, the flow measurement of this part
 
will have alarger error. In addition, the ratio between the maximum and minimum flows shall not be larger
 
than 20 toassure of precise measurements.

 

 

 

Dimension of integrated and split type (Flange: DIN)

                                                                                                                                                         mm

DN

MPa

L*

D

Do

H

h*

n-φ

Kg

10

4.0

200

90

60

220

102

4-φ14

4.5

15

200

95

65

222

106

4-φ14

5

20

200

105

75

230

110

4-φ14

5.5

25

200

115

85

235

115

4-φ14

6.5

32

200

140

100

255

122

4-φ18

8

40

200

150

110

260

127

4-φ18

9.5

50

200

165

125

270

140

4-φ18

11

65

200

185

145

275

148

8-φ18

14

80

200

200

160

280

154

8-φ18

17

100

1.6

250

220

180

290

163

8-φ18

20

125

250

250

210

320

175

8-φ18

27

150

300

285

240

330

200

8-φ22

32

200

350

340

295

340

220

12-φ22

44

250

40

405

355

360

240

12-φ26

84

300

500

460

410

405

285

12-φ26

89

350

1.0

500

505

460

440

320

16-φ26

92

400

600

565

515

470

350

16-φ26

115

450

600

615

565

500

380

20-φ26

135

500

600

670

620

530

410

20-φ26

240

600

600

780

725

590

470

20-φ30

320

700

700

895

840

650

530

24-φ30

420

800

800

1015

950

720

600

24-φ33

541

900

900

1115

1050

770

650

28-φ33

668

1000

1000

1230

1160

830

700

28-φ36

858

 

 

Selection of electrode materials

It  is  up  to  user  to select the material for electrode according  to the corrosiveness of the medium under
measurement. For normal media may consult the relevant anti-corrosion manual. For the mixed acids and
other else media with complicate components, material selection is subject to the sample trial.

Corrosion-proof performance of the electrode materials

Electrode

Materials

Corrosion-proof performance

316L

(Stainless steel)

 

    Corrosion-proof performance
    Quite strongly resistant to corrosion from nitric acid≤5% sulphuric acid, formic acid
    and alkali solutions. Sulfurous acid under a certain pressure, sea water, acetic acid
    and others. Can be widely used in petroleum, chemical, urea and winy on industries,
    etc.

 

Pt

(Platinum)

 

    Resistant to corrosion of oxidated acids, such as nitric acid, mixed acid or mixture of
    chromic acid with sulphuric acid, also resistant to corrosion of oxidated salts, such
    as Fe+++ Cu++ak or to corrosion of other oxidizing agents, such as hypo-argonate
    solution than normal temperature and sea water, etc.

 

HC

(Hastelloy C)

 

    Suitable for almost all the acid solution, alkali solution and Salt Dolution(Including
    sulfuric acid fuming and nitric acid Fuming), but not suitable for nine hydrochloric
    acid and Ammonium.

 

Ti

(Titanium)

 

    Resistant to corrosion of sea water, diverse chlorides, hypo-chlorinated acids(
    including fuming, nitric acids), Organic acids, basses, etc.
    Not resistant to corrosion of fairly purereductive acids(such as sulphuric acid,
    hydrochloric acid)。
    But if they contain fluoridating agent, the corrosiveness will decrease a lot.

 

Ta

(Tantalum)

 

    Excellently resistant to corrosion, very similar to glass almost resistant to corrosion
    of whatever chemical medium except hydrofluoric acid, fuming sulphuric acid and
    basses.

 

Selection of liner materials

 

Shall carry out selection according to the corrosiveness of the medium under measurement.
Chloroprene rubber can resist against corrosion of common weak acids, weak bases. It can
withstand 65'C and also is wear-resistant.PTFE can resist against corrosion of almost all the
strong acids and alkali except phosphoric acid, withstand maximum 180℃  of the medium
temperature, but not wear-resistant. PUNE have good wear-resistant, but only can withstand 65℃.

 

Liner Materials

Mostly performance

Scope of application

PTFE

(Teflon)

 

1.   It  is  a  material   with   the   most   stable   chemical
performance among the plastic materials. Can withstand
boiling hydrochloric acid, sulphuric acid, nitric acid and
aquaregia as well as concentrated basses and diver
seorganic solvents.
2. Poor wear-resistance and adhesion.

 

1. -40℃- 180℃

2. strong corrosive medium,such 

as acide and alkali

3. Sanitary medium

4. Not suitable for negative

pressure pipeline

NE

(Polychloroprene

rubber) 

1. Excellent elasticity, top breaking strength and good

wear-resistance.

2.  Resistant to corrosion of common low concentration

acids,bases salts,but not to non-oxidating medium.

1.＜65℃

2.  to measure common water,

sewage,mud,ore-pulp

PUNE

(Polyurethare)

1. Have good wear-resistant.

2. Acid and alkali resistant performance is poor.

 1. ≤65℃

2. Neutral strong wear of ore pulp,

coal-water slurry, mud

F46

(Polyperfluorinated

Ethylene Propylene)

Chemical property is similar to FTFE,

Negative pressure resistance ability is better than

PTFE.

 1. ≤180℃

2. Strong corrosive medium like

strong acids, alkali

3. Sanitary medium

PFA

(Polytrtrafluoro

ethylene) 

Chemical property is similar to FTFE,

Negative pressure resistance ability is better than PTFE.

 

 

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