Other products



Use:
Total aftercooling of condensate obtained from steam-water heat-exchanger plants employed for domestic hot water (DHW) preheating.

Technical description:
A condensate aftercooler comprises an all-stainless tank containing a couple of all-stainless coiled (helixes) heat-exchanging inset (usually 2 or 3). Through these, condensates of various pressures can pass (usually condensate obtained from central heating & domestic hot water exchanger, plus condensate coming from steam distributor). Through the aftercooler shell, preheated domestic hot water (DHW) passes in counter-flow. In the bottom part of the aftercooler, water is led through a built-in regulation grid ensuring optimum circulation of the water along heat-exchanging insets. The tank comprises two elliptical bottom plates plus a cylindrical shell, and rests upon three legs.
On the bottom plate, a spigot intended for the inlet of cool water is mounted. In the upper lid, there is a spigot serving as a preheated water outlet. In the tank shell, respective sleeves necessary for attaching technical instrumentation such as temperature, pressure gauges, etc., are located.

Technical specifications:
  • in the shell – standard working overpressure: 0,6 MPa and 1,0 MPa, maximum running temperature: 95 °C; AISI 304 material (ČSN 17240)

  • in heat-exchange insets – standard working overpressure: 2,5 Mpa; maximum running temperature: 165°C, AISI 321 material (ČSN 17248)
Other parameters available upon customer request.

Technical design and calculation of the aftercooler:
The product is manufactured to order. Typically, the Orderer chooses the volume size of the container/tank and indicates the number of condensate discharges/outlets (i.e. the number of head-exchange insets). In addition, with each condensate discharge, its throughput by weight (in kg/sec.) and inlet temperature (in °C) are to be indicated, as is the inlet temperature of the cooling medium. ELTE s.r.o. will then calculate the size of areas of individual heat-exchange insets, and will decide whether such insets are feasible to be installed into the given volume capacity of the container. As a general rule, the larger the container volume, the longer the period necessary for aftercooling the condensate – irrespective or whether or not domestic hot water is withdrawn.
The price quotation is set after performance job approval.

Delivery date:
Up to 3 weeks after receipt of binding order or, if deemed applicable, by agreement.

Series connection of MAX heat exchangers

Use:
State-of-the-art heating of domestic hot water in hot-water (DHW), war,-water and steam systems without the requirement of container heating.

Technical description:
Responding to customers´ requirements to carry out state-of-the-art heating of DHW whilst enjoying high utilisation of primary heat-transfer fluid, ELTE s.r.o. offers MAX heat exchangers connected in series and/or in parallel.

Technical parameters:
  • in the shell – maximum working overpressure: 2,5 Mpa; maximum running temperature(s):165 °C (185 °C), or maximum working overpressure 1,6 MPa, maximum running temperature 250 °C; AISI 321 material (ČSN 17248, W. Nr. 1.4541))

  • in heat-exchange insets – maximum working overpressure 2,5 Mpa, maximum running temperature(s) 165°C (185°C), or a maximum working overpressure 1,6 MPa, maximum running temperature 250°C; AISI 321 material (ČSN 17248, W. Nr. 1.4541)


Workmanship - connections:
ELTE s.r.o. offers exchangers connected in series or in parallel in versions as follows:
1) Exchangers on a base-stand
2) Exchangers inter-connected as per order (in black steel or all-stainless versions)
3) A set completely mounted with equipment as per customer requirements, i.e. inclusive of driving gears, baskets, jointing material)

The price quotation is set after performance job approval.

Heat accumulator for condensing boilers using forced circulation heating of DHW through a coiled ZTKK exchanger (hereafter only: “ZTKK heat accumulator” – see Catalogue.

General description:
The ZTKK heat accumulator is intended for collection of cool water coming back from the heating process, and for preparation of DHW held at the container´s bottom for the use of a boiler with full non-regulated output during interrupted operation, functioning as a compensation bypass between boiler circuit and heating circuit, with control of the loading function using two thermometers shouldered in the container, with forced circulation heating of DHW through a coiled exchanger shouldered in the container. Condensation boilers only work highly efficiently provided that there is a low surplus of burning air, and low temperature water returning to the boiler.
Given the sliding output of the heater system appropriate to pursuing a year-round heating, the output of the boiler burner needs to be regulated, namely largely at the expense of increasing burning air surplus. With the output being reduced, burner air surplus increases during incineration exactly at a time when the boiler is supposed to run in the condensation mode. That has an impact upon the boiler that is far more adversive than normal operation with zero condensation.
Concurrently, using the coiled vertical exchanger, a feed of coolest water is ensured in ZTKK heat accumulator from the DHW preparation circle to the place where return water - flowing from the heating system - is gathered.

The ZTKK heat accumulator provides for:
  • the option of running the condensation boiler on rated performance without having to regulate output at the lowest surplus of burning air;

  • conjugation of coolest water in the bottom part of container both on DHW circuit and on heating circuit;

  • hydraulic alignment of boiler circuit with the heating system – substitution of compensation bypass;

  • effective DHW heating using forced circulation of heater water around the helical exchanger, hygienic heating, decrease of heat-exchanging area.


Major pros of the ZTKK heat accumulator include:
  • gathering in the bottom part of the heat accumulator the coolest water coming from both the heater system and DHW heating system;

  • the option of running the boiler at full non-regulated capacity with a pre-set least air surplus (using a simple “turn on/turn off” mode of regulation, and hence cutting costs);

  • hydraulic alignment of boiler circuit with heating; in ZTKK, a replacement is used for the levelling bypass that - in terms of condensation boilers - is disadvantageous as it diminishes efficacity;

  • the possibility of setting-off the performance of a source with diverse outputs for DHW production and heating without lowering efficacy;

  • simple, hygienic and efficient through-flow DHW heating whilst using a small heat-exchange area of the exchanger;

  • compared with the most frequently used DHW containers that in effect are pressurized vessels, a ZTKK heat accumulator is only under the pressure that is within the heating system.


Otherness of ZTKK heat accumulator from other heat accumulators:
The ZTKK heat accumulator disposes with: regulated distribution of water temperature using Z- and V-type thermometers as a way of harnessing the coolest water from at the bottom of the accumulator; a forced circulation heating of DHW through an inset coiled exchanger whereby water drawn from the heating circuit and from DHW production circuit is gathered at the bottom plate; DHW heating is separated from the heating of circuit service water (CSW); and the expansion clutch is replaced with an accumulator-type heater.

Heat accumulator of bivalent solar & boiler sources (ZTBZ) – see Catalogue

General description:
ZTBZ accumulators serve for combined gathering of heating water from alternative sources, largely from solar collectors and from standard or condensing boilers. When a solar collector is connected a ZTBZ accumulator, heating water passes through the solar circuit. In winter, however, when temperature drops below performance value, heating water is automatically or manually discharged from the system.

Major pros of a ZTBZ system:
  • generally – all pros mentioned above in connection with ZTKK accumulators;

  • more efficient utilisation of solar energy through removal of heat into the accumulator; accumulation to a temperature up to 110°C, i.e. exceeding that achieved in warm-water accumulators;

  • no need to add antifreeze solutions, i.e. achieving maximum caloric receptivity;

  • concentration of coldest water to intake points on water inlet into collector;

  • concentration of hottest water in the upper part of accumulator, ensuring that DHW is heated more efficiently than in case of natural convection taking place in the warm-water accumulator;

  • utilisation of solar energy for heating pending transition periods when the temperature of heating water in the system is low;

  • possibility to concentrate heating, to heat DHW concurrently with, e.g. heating water for the swimming pool, using one single transfer point.


Otherness of ZTBZ from other heat accumulators using bivalent sources:
Setting the solar circuit jointly with another source into the heat accumulator entails a solution that is not commonly used. It namely requires that, in winter, water from collectors is discharged. The solution employs forced heating of DHW in a spirally coiled heat exchanger, a temperature distribution along the accumulators height, and it moreover provides for loading/unloading of accumulators through on/off thermometers.


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