Gutxieneko sarrera presioaren kalkulua

Ponpa presioa euskarriaren presioaren presioa baino txikiagoa bada, zuntzek eragingo dute ponpa errendimenduan. Cavitation saihesteko eta pump sarrerako presio gutxieneko bat du, gehienezko xurgatze burua kalkulatu behar da honako hau:

H=Pbx10.2-NPSH-Hf-hv-Hs

Pb: Atmospheric pressure, bar (In close pipeline system, it can be considered as the system pressure );
NPSH: Xurgatze posizio garbia, m (Balioa Q-NPSH kurba maximoa balioa);
Hf: Suction pipa linearen galera (dagokion kanalaren fluxuaren gehienezko balioa);
Hv: Lurruneko presio ertaina, m (tenperatura egokia duen lurruneko presio ertaina, lehenetsitako erdia ura da, eskuineko irudian4).
Hs: Segurtasun marjina, m, balio orokorra 0.5 da.
Calculation result: if H is positive, the pump is installed in suction way, otherwise, it is installed in downdraft way.

Note: It is not necessary to do above calculation under general conditions. Only when we use pump in the following situations do we need to calculate the H:
1. Tenperatura ertaina altua da;
2. Fluxuaren abiadura balioa baino handiagoa da;
3.Suction head is big or inlet pipeline is long;
4. Sistema presioa txikiegia da.
5.Inlet egoera txarra da.

Selection Of Pumps

Ponpa aukeraketak honakoa izan behar du:
Ponpa puntua.
Dimensional data such as pressure loss as aresult of height differences,friction loss in the pipework,
Ponpa eraginkortasuna, etab.
Pump materials
Pump connections
Ohiko erabilitako seal konfigurazio taulak

1. Ponpa puntuala:

Duten betebeharretatik ponpa bat hautatzea posible da, & quot; performancecurves / technical & quot; datuak.

2. Dimentsio datuak:

When sizing a pump the following must be taken into accounting: •Required flow and pressure at the draw-off point. •Pressure loss as a result of height differences. •Friction loss in the pipework(Hf) (Refer to Fig.1) It may. •Best efficiency at the estimated duty point. •NPSH value. •For calculation of the NPSH value, see corresponding curves chart.

3. Pump efficiency:

Before determining the best efficiency point, the operation pattern of the pump needs to be identified. If the pump expected to operate as the same duty point, then select a BL pump which is operating at a duty point corresponding with the best efficiency of the pump.
As the pump is sized on the basis of the highest possible flow, it is important always to have the duty point to the right on the efficiency curve(eta) in order to keep efficiency high when the flow drops.

4. Pump material:

Pump konexioaren aukeraketa presio eta kanalizazioko lanen araberakoa da. Ponpa konexio erraztasuna zabala eskaintzen du, hala nola:

5. Commonly used mechanical seal configuration tables

Aplikazioen eremua

Shaft seal type

Shaft seal materiala

Normal

Berezia

1

2

3

4 5

Type key

Biraketa zati

Kodea

Stationary part

Kodea

elastomeroak

Kodea

Konpresioaren udaberria

Collor

Kodea

0â "ƒ to + 90â" ƒ ur garbia

a-

Graphite

A

SiC

S

FPM

F

SUS304

C

ASFC

0â "ƒ to + 90â" ƒ ur garbia

a-

Komunak

W

Graphite

A

FPM

F

SUS304

C

WAFC

+90℃ to +120℃ corrosion resistance

a-

SiC

S

SiC

S

EPDM

E

SUS304

C

SSEC

up to 0℃

a-

Komunak

W

Komunak

W

EPDM

E

SUS304

C

WWEC

Mechanical seal type	Pump model	d1	d2	h
NJK	BL (T) 2/4	12	12	55
	BL (T) 8/12/16/20	16	16	57.5
	BL (T) 32/45/60/90	22	22	72
NDA	BW (J) 2/4	12,7	16	32
	BW(J)8/16	17.4	20	33,5