M_heater Pirobloc Eng

8/4/2019 M_heater Pirobloc Eng

http://slidepdf.com/reader/full/mheater-pirobloc-eng 1/11

Generadores de fluido termico

Calderas de vapor. Ingenieria

PIROBLOC, S.A. • P.I. Santiga • Av. Castell de Barberà,

31 •

08210 Barbera del Vallès (Barcelona)

Tel. 00 34 937 189 064 • Fax 00 34 902 908 812

E-mail: [email protected] • www.pirobloc.com

1

THERMAL FLUID BOILER PIROBLOC, S.A. 1- Introduction

The thermal fluid boilers from PIROBLOC, fulfill the effective directive European of devices to pressure D.E.97/23/CE (category I) and with the Regulation of Apparatuses to Pressure and Complementary TechnicalInstructions of the Industry and Energy.

The design of these generators isbased on the most renownedconstruction codes such as the EN-

13445.

All the materials which are used in theconstruction of the boilers, bear theOriginal Quality Certificate,nevertheless PIROBLOC, S.A.

performs a further checking on themechanical and chemical features, inan independent laboratory, whichallows to secure the complete reliabilityof the product.

The welding process and the welding

personnel is duly approved by aCooperating Entity to theAdministration. The user receives fulldocumentation proving all theseapprovals together with thecorresponding Quality Control Dossier. In the same also the Certificates for the Original Quality Control arecontained.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


2

2- Description

The thermal fluid heater, in vertical execution, without any adjusted or preset level, with automatic operationand indirect supervision, provides heat by means of liquid or gaseous fuels.

These heaters have cylindrical cover, (4) and (5), and they are prepared to increase the temperature of thethermal fluid that circulates through two concentric coils, by means of the combustion of liquid or gaseouscombustibles in a burner. This burner is located and fixed in the upper flat lid (12). There is a rockwoolisolation (10) between both covers, providing therefore a minimum structural loss and also avoiding harmfulburnings through involuntary contact with the boiler.

Item list:

1. Internal coil2. Coil lid3. Combustion chamber lid4. Internal cover5. External cover6. Connecting flanges7. Bottom combustion chamber8. Bottom isolation9. Kaowool10. Isolation11. UPN contour12. Boiler lid13. External coil14. Closing combustion chamber

The burner flame is projected towards the combustionchamber, then depending on the adjustment of thecombustion, it will strike the ceramic bed that closes thefireplace (7), changing then the sense so that thecombustion gases go up at high speed and withturbulence, between both coils until reaching the upperconic lid (2), at that stage their sense will get againdescending, until they are exhausted by the chimney whichis situated on the lower edge of the covers.

The coils (1 and 13) may be of one, two or three steps, depending on the model, being essential the highspeed in the circulation of the thermal fluid, in order to obtain a good heat transmission and also to avoid the"cracking" of the said fluid.

These coils are manufactured in stretched steel without any welding St. 35.8.1 special for boilers,according to DIN 17175, thickness according to DIN 2440.

The circulation of the thermal fluid is done initially through the outer coil (there where heat is transmittedalmost only by convection), passing later on to the internal coil (where heat is transmitted almost exclusivelyby radiation), obtaining then an excellent energetic result.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


3

The slightly conic lid, contains a detachable, moving part and a fixed part. This last one, that means the fixedpart, serves as closure to the smoke passage between the coils and disposes of the corresponding holes forthe passage of the coil pipes which are connected to the general collector, being connected to the circuit bymeans of flanges (6).

The detachable, moving part closes the combustion chamber, and is where the burner is attached.Easily this part can be taken out, providing an easy access to the combustion chamber for the necessarymaintenance works.

The external lid is flat and has the proper fastening tabs for transporting the boiler, facility that is possible inthe higher standard models. Also there is the possibility provided for fastening the boiler to the UPN profilesthat are located in the bottom (11).






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


4

3- The heating circuit

A standard type circuit of thermal fluid, as the one shown on the included drawing, is formed by:

Its operating diagram is as follows :

The thermal fluid is suctioned by the circulating pump (3) through the pipe (1) and the valve and filter (2),after it is introduced in the generator (4). The thermal fluid flows out of the boiler passing through the valve (5)and through the general net (6), reaching the different consuming points (8), controlled by means of automaticvalves. These automatic valves can be of two or three tracks, the working temperature in the equipment istherefore precisely regulated by them.

Each consuming equipment can be independent of the general net thanks to manual valves that are installedin each line (7).

Once the heat is

"placed" in theconsumer equipment,the fluid will return tothe collecting bottle (9),there, in allPIROBLOC i n s t a l l a t i o n sAUTOMATICALLY the installation will bedrained and goes backagain to the circulatingpump in order torestart the cycle.

The valve (18),operates as general"by pass" to the circuit.These valves may beof mechanical drive(ballasted valve) or of electrical or pneumatic drive (automatic valve).

- The thermal fluid boiler or generator- The circulating pump- The collecting tank- The expansion tank- The consuming equipments- The pipes, valves and accessories






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


5

When heated, the thermal fluid gets expanded, by decreasing its density (see thermal fluid features). So. f.e.at 200ºC we get a volumetric increase of approx. 18% and at 300ºC of 30%. The expansion tank (11) shouldhave sufficient capacity so that it is not filled up totally, when the thermal fluid of the whole installation is at thehighest temperature, while at room temperature the expansion compensating pipe (10) should not remainwithout oil, causing therefore the failure of the circulating pump, which would remain unprimed.

Further on, this tank is also used for making the AUTOMATIC drainage of the circuit. Effectively, when thethermal fluid passes through the collecting bottle (9), the humidity and the gases will be detached and they arebrought through pipe (10) to the expansion tank, where they are either condensed or they are exhaustedthrough pipe (12) to the collecting tank (13).

It is a closed circuit, for this reason there is a thermal fluid pillow installed, in the collecting or gathering tank,

which absorbs the pressures and underpressures which could arise in the circuit, during operation. Thesiphon (14) avoids also the air entrance to the collecting tank.

The humidity will only be present during the start up of the installation, precisely at this moment the connectionof the expansion tank and the collecting tank should be avoided, as this fact would cause the storage ofhumidity in the collecting tank , and this of course could also cause its later entrance again in the circuit whenthis tank is filled up. During the operation, only the gases that are generated by heating up the thermal fluid,will be drained automatically.

The gathering tank has, besides the function of being the pillow for the gases, also the function of absorbingthe fluid of the installation for the complete drainage of the same, when any repair or maintenance works haveto be done. It should be situated in the lowest place of the installation, either on the surface or embedded.

The refilling and drainage group (16), enables to carry out these operations from cans (18) to the tank or tocircuit and reverse, by changing the valves (17).

Some consuming points could have recirculation groups (19) when uniform or very precise temperatures inthe product are needed (around +/-1ºC).






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


6

4- Controls and securities

The PIROBLOC boilers and installations accomplish the relevant present norms :

Besides, all the installations made by PIROBLOC satisfy also all the dispositions and lawscorresponding to the Municipality and/or Autonomous Community where the installation has to take place. On the included drawing, the securities and controls of the installation are shown. The operating and securityelements are indicated in blue color. In green color are the control elements and in red color the safetyelements.

The boiler and installation securities and controls are:

- Visual level in the collecting tank (LI) - Temperature security pyrometers for the thermal fluid and the smokes in chimney (TAH) - Electric level for minimum in the expansion tank (LSL)

- Manometers for boiler entrance and exit (PI) and temperature intake (TI) - Thermal relays for motor protection- Differential pressure switch (dPSL) - Maximum pressure switch (PAH) - Operating pyrometer (TIC)- Flame control (BAL) - Safety stop- Hour safety- Acoustic warning

- Directive 97/23/CE relative to the Pressure Equipments.- Regulations for Pressure Equipments and Complementary Technical Instructions.- UNE 9-310-92 Norm for "Heat transmitting installations by means of liquids other than water".

- DIN 4754 “Heat Transfer systems operationg with organic heat transfer media” - Atmospheric Environmental Protective Rules and complementary dispositions.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


7

Following we will observe in detail the function of each one:

- Pyrometers for the first and second flame (operating pyrometer) (TIC) They send information (temperature) to the electric panel with respect to the heat demands of theequipment. Operating and control elements.

- Pyrometer for max. oil temperature (TAH) Warns about a possible failure on different elements, which could cause a considerable increase on thethermal fluid temperature. Safety element which locks the burner.

- Pyrometer for max. smoke temperature (TAH) Detects a too high increase of the combustion gases temperature by the boiler (chimney) exhaust, due tofailure in any control element. Safety element which locks the burner.

- Differential pressure switch (dPSL) Detects a faulty circulation of the thermal fluid, due to insufficient pressure between the entrance and theoutlet of the boiler. Safety element, which locks the burner.

- Maximum pressure switchDetects a faulty circulation of the thermal fluid, due to an increase in the pressure, which is delivered by thecirculating pump. Safety element, which locks the burner.

- Acoustic warning Acts in front of any kind of safety, in order to inform on the same. Safety element.

- Thermal relaysThey serve as protection to the pump motors and to the burner fan. Operating and safety elements.

- Cooling timer (safety stop)Prevents that the circulating pump of the thermal fluid is disconnected before a preadjustment time haselapsed, avoiding tightness at high temperatures, which could be harmful to the oil load. Operating andsafety element.

- Hour safety timerObliges to make periodical inspections (every two hours) by the personnel in charge, to verify the correct

state of the equipment. Safety element.

-

Visual level (LI) Allows to observe the fluid quantity inside the installation. Control element.

- Electric Level (LSL) This element inhibits start up of the equipment when thermal fluid is missing in the installation. Safetyelement.

- Manometers (PI) and thermometers (TI) Pressure and temperature indicators at boiler entrance and exit, informing on thecorrect circulation of the thermal fluid. Control elements.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


8

Other standard elements, belonging to the own function of any burner are :

- Electrovalve for the first and the second flameThey allow a greater or smaller quantity flow of the combustible, depending on theneeds of the equipment. Operating and control elements.

- Safety electrovalveCuts the flow of combustible off, when there is no demand on it, at the same timeas the electrovalve for the first and second flame, acting as safety for those. Safetyelement.

- Burner control

Element that is indicating all steps that the burner has to follow. Operating and safetyelement.

- Ultra-violet cell, or ionization probe (Flame control) (BAL) Light detecting, therefore detection of flame forming, indicating that combustion has started,informing on false ignitions. Safety and control element.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


9

5- Instructions for start-up

The first start-up of the boiler and the installation will be done by a specialized PIROBLOC technician,who will also give instructions and train about the correct use, the personnel in charge of operating theequipment. Before the routine start-up, following points will have to be checked:

1) Verify the correct filling of the installation, observing that the luminous signal of Oil level, in the electricpanel is out, once the voltage has been connected. Also the visual level installed on the expansion tank, willhave to be checked.

2) Verify that the manometer readings installed at the pump drive and boiler exit, indicate the usual staticlevel, corresponding approx. to 0.08 times the value of the geometric height of the expansion tank.

3) Verify that all the valves are positioned in the desired and correct position.

4) Verify the correct state of the combustible feeding installation.

5) Verify the correct set-point selection in the temperature regulators for the thermal fluid of the boiler and ofthe automatic valves.

6) Verify the correct set-point selection in the thermal fluid temperature limiters and for the smokes.

7) Checking of the correct adjustment of the differential pressure switch.

8) Checking of the correct adjustment of the thermal relays.

Some of these operations (7) and (8), are not precisely necessary, if the person in charge of the boiler isalways the same one. However, when there takes place a shift change, variations may happen in theoperating state, if these are not passed on to the entering person in charge, misalignments may occur.

Once these operations have been done, you may proceed to start up the thermal fluid circulating pump,observing that the dynamic pressures in the impulsion manometers of the pump and the boiler exit must bethe usual ones for start up. These are higher pressures than those of the installation in normal operation,having in mind the variation of the physical changes in the thermal fluid regarding with the temperature. Theburner is connected as soon as the circulating pump is in normal operation. This one cannot be connectedwithout the operating presence of the circulating pump, existing a lock-in.

The installations do not require any special care during normal operation. However checking of the pressuresand the temperatures is necessary, when relieving the timer after the obligatory stop (every two hours).

When labor day is ending, the cooling circuit MUST be connected, in order to avoid stopping at hightemperature as this may damage the thermal fluid load, causing a quicker degradation of the same.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


10

6- Maintenance

6.1 Preventive maintenance

Besides the special instructions given in each section concerning the pump and the burner, periodicallyfollowing reduced maintenance steps should be taken into account and performed in order to dispose alwaysof the best working conditions of the boiler and of the installation in general :

- Daily

1) As already mentioned before, checking of the oil level in the expansion tank. If there is not sufficient oil

inside, it must be filled up, until reaching about 1/3 of the tank. This operation must always be done when theinstallation is IN COLD condition.

2) Verify the consumption of the pump motor.

3) Verify the temperature of the smokes.

- Weekly

1) Checking of the correct function and the state of all the electrical material, connections and automaticdevices.

2) Verify the pyrometers, either by means of a mercury thermometer, or by means of the electrical signal

readings that the controller receives. Please keep in mind, that in those installations with thermocouple type(FeKonst), to the indicated value on the table, the room temperature has to be added.

- Quarterly

1) Analysis of the combustion.

2) Partial emptying in order to check the correct function of the electric level in the expansion tank.

3) Check the circuit safety devices ( acoustic warning, differential pressure switch, temperature limiters, etc.).

- Every semester

1) Extraction of a thermal fluid sample and analysis of the same. The most convenient point for thisextraction lays in the emptying-filling up circuit, rejecting the fluid that is inside this circuit.

- Yearly

1) At least once, a PIROBLOC technician or any other competent person, should make an overhaul,following the norms stated in the prevailing Rules for Pressure Equipments. 2) Cleaning and internal overhaul.






31 •


Tel. 00 34 937 189 064 • Fax 00 34 902 908 812


11

6.2. - Corrective maintenance

The most frequent failures in a thermal fluid installation, are related to the burner and the pump. Thesefailures are already described in the corresponding section herewith. On the other hand, normally a thermalfluid boiler or installation does not have failures, due to their simple ness the maintenance functions are justas easy to carry out.

However, some possible failures, peculiar to the circuit, could be :

FAILURE CAUSE SOLUTION

Thermal fluid filter is dirty Sieve cleaning. Pass an entire process in cold, closing

previously the suction valves of the pump and drive Lack of thermal fluid in theinstallation

Proceed to fill up in cool state

The installation contains humidity

Proceed to automatic drainage of the installation, veryslowly increasing the working temperature after 100ºConwards. Try to find out how the humidity could enterinto the installation (exchangers) and solve the problem

Pressureoscillations.Cavitation

Degradation of the thermal fluidload

Analysis of a sample and change the thermal fluid ifnecessary. Make a circuit cleaning

Working temperature increases,whereas the other adjustmentsdo not increase

Modify according the temperature adjustments of thesmokes and the safety

Casual modification of theadjustments

Proceed to adjust new values



Locking dueto the

temperaturesof thesmokes or

due tosecurity

Dirt inside the boiler Boiler inside cleaning



Important leakages in theinstallation

Check the sealing and tightness of the circuit

Frequentlyfilling-up ofthe thermal

fluid Leakage in a secondary circuit Check the sealing and tightness of the circuit

Change of the set-point Readjust the set-point

Humidity in the circuit

Proceed to automatic drainage of the installation,increasing very slowly the working temperature after100ºC onwards. Try to find out how the humidity couldenter into the installation (exchangers) and solve theproblem



The pressureswitch islocked

Change in the hydraulic circuit(enlargement)

Check the operating point of the pump

Documents

M_heater Pirobloc Eng