Operation of heat exchangers

Transcription

1 Operation of heat exchangers Delivery to site, downloading, receipt/acceptance Check state Transport on site Storage Short term Long term Installation Requirements of installation area Adjustment Connection of pipes Commissioning Check installation, pipe connections Filling, deaeration Check operating parameters Putting out of operation Short term Long term Maintenance General maintenance Repair of errors

2 Delivery to site, download Suitable lifting device Transport on site Receipt/acceptance Check status Status of packing, PHE by eye survey Error reports Check datasheet Confirmation od receipt

3 Storage Protect against sunshine Dry place Close to room temperature Avoid freezing (water from pressure test remains in PHE) Ozone free atmosphere (no welding) Solvent free atmosphere Long term: Corrosion protection of bolts Loose platepack (A+10%) (note on PHE!!!) Avoid contamination on or between the plates

4 Requirements of area Strong enough horizontal plane Space to walk around, to work Installation Pipe connections (flow directions!!) No load to connections (support pipes) Connections on follower: use compensators

5 Commissioning Check installation and pipe connections (counter flow) Check operating parameters Fluids Temperature and pressure may not exceed the limit/design values on the nameplate, not even for a short time (pressure shock) Filling, deaeration Start cold side first, then warm side (when freezing danger: opposite) The valve between pump and PHE shall be closed The other valve shall be opened Start pump Slowly open the valve between pump and PHE Deaerate if necessary. Steam: Before start steam valve shall be closed Condensate shall be drained Does the condense trap work? Slowly open the steam valve Check system for vibrations Check for leaking

6 Putting out of operation Slowly stop hot side valve (keep flow on cold side) (when freezing danger: opposite) Stop hot side pump Let PHE cool down Close cold side valve Stop cold side pump Close all valves Long term stop: Drain PHE Same as at storage

7 Maintenance

8 Maintenance Cleaning Cleaning in Place(CIP) Only for soluble contamination can be removed by this The prescriptions of the cleaning agent manufacturers has to be taken inti consideration Protecting clothes (gloves, glasses, etc.) The cleaning agent can not harm the construction materials (No HCl) Possible highest flow rate Rinsing!! Oil and grease can be removed with a water emulsifying oil solvent. Organic and grease cover can be removed with sodium hydroxide (NaOH) maximum concentration 1,5% - max. temp. 85 ºC. Mixture for 1,5% concentration = 5 ltr. 30% NaOH per 100 ltr. water. Stone and limestone can be removed with nitric acid (HNO 3 ) max. concentration 1,5 % - max. temp. 65 ºC. Mixture for 1,5% concentration = 2.4 ltr. HNO 3 62% per 100 ltr. water. Nitric acid has an affective build up effect on the passivation film of stainless steel

9 Opening the PHE Measure and note the actual "A" size; Use the correct tools and lubricant; Shut down the heat exchanger Make sure the heat exchanger cools down (<40 ºC) Ensure there is no pressure on any part of the unit Clean the tightening bolts and grease the threads Loosen the tie clamping bolts equally in the correct order (fig. 10) i.e. that the follower shall have a parallel opening motion Pull the follower back towards the column Remove the plates without damaging the gaskets

10 Gasket and plate replacement Check hanging list. The right (R) and left (L) plates follow one-by-one alternating Check for honeycomb pattern

11 Tightening the platepack Lightly oil the tie (clamping) bolt threads. Do not allow oil or grease onto the gaskets or the gasket seating faces Evenly tighten all bolts in the correct order Ensure clamping is as uniform as possible, thus keeping the frames and plates parallel Tightening is complete when the distance between the inside faces of both frame plates equals the A distance Finally check that all tie (clamping) bolts are in tension and clean any spilt oil off the head, follower and plates. On completion the unit can be pressure tested (test pressure is stated on the nameplate).

12 Pressure test On room temperature On both sides, independently Other side empty or at least under no pressure At least for 20 minutes Check leaking Check keeping pressure Unsuccessful pressure test: Further tighten, (not below A min ) Find reason and repair Successfull: GO!