GB2118222A

GB2118222A - Tiered tentering frame

Info

Publication number: GB2118222A
Application number: GB08308873A
Authority: GB
Inventors: Theo Schriffers
Original assignee: H Krantz GmbH and Co
Current assignee: H Krantz GmbH and Co
Priority date: 1982-04-01
Filing date: 1983-03-30
Publication date: 1983-10-26
Also published as: GB8308873D0; IT8320395A0; DE3212162C2; DE3212162A1; FR2524509B1; FR2524509A1; GB2118222B; IT1218345B

Abstract

A tiered tentering frame is equipped with an integrated heat recovery system, in which respect in each section 3 of the tentering frame on both sides an outgoing-air duct (5) (Fig. 2, not shown) extending over the height of the section is provided. The outgoing-air ducts (5) open out into outgoing-air collecting ducts 7, which lead to a respective heat exchanger 10 arranged inside the tiered tentering frame. Connected to each heat exchanger 10 is a further outgoing-air duct 12, in which respect the outgoing-air ducts 12 on each side open out into a collecting outgoing-air duct 13. Adjacent to the outgoing-air ducts 12 is a respective incoming- air duct 15, by way of which fresh air is fed to the heat exchanger 10 in transverse flow to the outgoing air. Arranged so as to be adjustable in the same direction in the ducts 12 and 15 are throttle valves 11 and 16 which are jointly adjustable by way of a coupling member 20. <IMAGE>

Description

SPECIFICATION Tiered tentering frame This invention relates to a tiered (or horizontal or horizontal hot-air) tentering frame comprising several sections, joined together vertically, for the treatment of a fabric web with a heated gaseous treatment which is conducted substantially in a circuit and a part of which flows off by way of a heat exchanger which feeds energy of the portion flowing off to a portion flowing towards the circuit.

In the case of generally known heat treatment apparatus having several treatment sections, the portion of the treatment medium that is to be carried off is sucked off by way of individual ducts from the individual treatment zones and is conducted to a central heat exchanger, connected subsequent to which is a ventilator or fan which delivers the spent and cooled treatment medium to the atmosphere. A portion of medium which corresponds quantitatively to the portion of the treatment medium that is to be carried off is preheated in counter-flow by way of the central heat exchanger and is supplied again by way of a blower as well as individual ducts connected thereto to the individual treatment zones.

For the heat treatment of a fabric web, already a device known with which several outgoing-air or waste air or vitiated air heat exchangers are associated (German Offenlegungsscchrift No. 27 1 9 670). The heat exchangers are, in this respect, superimposed directly onto the cover plate of the device, in which respect one heat exchanger each is intended for respectively two or three sections of the device which is designed as a dryer.

In the case of all known heat treatment devices with an external heat recovery system there emerges, from the duct or pipe system which is necessary in this respect, large expenditure which is additionally increased in that, besides the fans which are present anyway for the circuit conduction in the individual treatment zones, additionally a central fan, or even several fans which comprehend sections in groups are necessary, which require a corresponding erection space. Furthermore, fan(s), heat exchanger(s) and the entire duct and pipe system have to be carefully sealed off in order to separate the portion that is to be carried off from the portion that is to be supplied of the treatment medium, since otherwise the mode of operation of the heat exchanger is impaired, in that potentially recoverable energy is lost.Furthermore, the ducts and pipes have to be well insulated, since their comparatively large overall surface would, in the event of defecient or no insulation, cause correspondingly large heat losses.

For a heat treatment device designed as a single-layer tenter, it has therefore also already been proposed to integrate into each treatment zone at least one heat exchanger, with which the inflowing portion of the medium is feedable to the suction side of a fan which maintain the medium flow (German Gebrauchsmuster 7928210). As a result of a heat recovery system which is integrated into the treatment device, considerable disadvantages can be avoided as compared with the devices having an external heat recovery system. For example the extensive ducts and pipes for the portion of the treatment medium that is to be carried off and is to be supplied are abolished.

Furthermore, heat exchangers of constant size can be used and through the variation of their number undertake a simple adaptation to the performance required for a treatment zone, so that a fairly large number and therewith a more economical production of the heat exchangers is made possible. The operating costs of the device are lower by the driving power of an additional central fan.

The problem underlying the invention is to equip a tiered tentering frame, of the kind described, in such a way with a heat recovery system that the advantages of the known heat treatment device, equipped with an integrated heat system, in the form of a single layer tenter are taken over.

This problem is solved in that the present invention provides a tiered tentering frame characterised in that arranged inside each section on both sides is a respective outgoing-air duct which extends over the height of the section and which is provided with openings which open out on each tier, and in that the outgoing air ducts of each side open into a common collecting waste-air or outgoing-air duct, which leads to an integrated heat exchanger, to which an incomingair duct is connected, by way of which incoming air flows into the circuit of the treatment medium, whilst outgoing air flowing off from both heat exchangers arrives by way of a respective further outgoing-air duct in a common further collecting outgoing-air duct.

As a result of the design in accordance with the invention, it is possible also in the case of a tiered tentering frame, to associate, instead of one central external heat exchanger with each individual section, two correspondingly smaller heat exchangers, whereby considerable disadvantages of the previously known device can be avoided. For example, the extensive ducts and pipes outside the device for the portion of the treatment medium that is to be carried off and which is to be supplied are abolished. Instead, the tiered tentering frame in accordance with the invention requires merely at the end of the device a non-insulated outgoing-air duct which can be arranged on the machine ceiling. Furthermore, heat exchangers having a constant size can be used, which are adapted by their number to the performance required within the individual sections.Larger quantities emerge therefrom, whereby the price for a heat exchanger can be kept lower. Finally, also the operating costs of the device are lower, since the driving power for an additional central fan is abolished.

In accordance with a further aspect of the invention, advantageously the free cross-section of the openings, opening out on each tier, of the outgoing-air duct is variable by slides or slide valves in which respect arranged in each outgoing-air duct connected in the direction of flow behind the heat exchanger is a throttle valve which is adjustable synchronously and proportionally with a respective flap or valve arranged in the relevant incoming-air duct.

A further aspect of the invention is that the fresh-air and out-going-air valves may be adjusted jointly, whereby it is ensured that upon each adjustment a constant ratio between the amount of outgoing air and the amount of incoming air is established. This ratio is particularly important for the optimum efficiency of the heat recovery system.

In accordance with a further aspect of the invention, the collecting outgoing-air ducts, arranged in the direction of flow in front of the heat exchanger in the region of the tentering frame base extend preferably under-this and extend over the length of the tentering frame.

Preferably, in accordance with yet a further aspect of the invention, each outgoing-air duct connected in the direction of flow after the heat exchanger with the incoming-air duct is arranged on both sides at the end of the tentering frame.

To further improve the heat exchanger's effect, the invention additionally may provide for each outgoing-air duct to be connected in the direction of flow after the heat exchanger, and the respective incoming-air duct jointly to form a part of their pipe walling, so that in the direction of flow of the outgoing air behind the heat exchanger a further residual heat exchange can be effected.

The invention will be described further by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-section of a preferred embodiment of the tiered tentering frame of the invention; Figure 2 is a iongitudinal section through the embodiment of Fig. 1; and Figure 3 is a plan view of the embodiment of Figs. 1 and 2.

Referring to the drawings a fabric web 1 runs, deflected by way of rollers 2 through in each case 180 , in tiers through several sections 3 of the frame which is equipped with an insulated housing 4.

Associated with each section 3 on both sides in a respective outgoing-air duct 5 which extends over the height of the frame As shown more particularly by Fig. 3, the amount of the treatment medium sucked off from the frame can be dosed by sliders 6.

By way of the outgoing-air ducts 5, the treatment medium flows on each side of the frame downwards into a common collecting outgoing-air duct 7, which is cast-in a foundation base 8 of the frame. By way of the collecting outgoing-air duct 7, the treatment medium arrives at two corner regions of the end of the frame and flows there, as shown more particularly in Fig. 1, from bottomt to top through in each case a slub sieve 9 and subsequently through a heat exchanger 10, passes through a cross-section, regulatable by way of a throttle valve 11, of a further outgoing-air duct 12 and arrives by way of a collecting outgoing-air duct 1 3 at an outgoing-air fan (not shown).

The treatment medium to be supplied as fresh air is blown in on both sides of the device by way of fans 14 on the ceiling of the housing 4 and flows by way of an incomingair duct 15, in which a throttle valve 16 is arranged, by way of a slub sieve 1 7 transversely to the outgoing-air flow through the heat exchanger 10 further into the interior of the frame.

The heat exchangers 10 consists-as shown more particularly in Fig. 3---of similar modules 18, the number of which is governed by the size of the frame. The modules 1 8 can be withdrawn from the frame for cleaning in an equally easy manner as the slub sieves 9 and 1 7 on the outgoing-air side and fresh-air side.

The outgoing-air ducts 1 2 and incoming-air ducts 1 5 connected in parallel above the heat exchanger 10 form jointly a part 1 9 of their duct walling, whereby an additional heat exchange is made possible.

The throttle valves 7 and 9 connect a coupling member 20 in such a way that a common adjustment of these valves is ensured. In this way a constant relationship between the amount of outgoing air and the amount of incoming air is ensured, so that an optimum efficiency of the heatrecovery system is achievable.

Claims

1. A tiered tentering frame comprising several sections, joined together vertically, for the heat treatment of a fabric web with a heated gaseous treatment medium which is conducted substantially in a circuit and a part of which flows off by way of a heat exchanger which feeds energy of the portion flowing off to a portion flowing towards the circuit, chacterised in that arranged inside each section on both sides is a respective outgoing-air duct which extends over the height of the section and which is provided with openings which open out on each tier, and in that the outgoina-air ducts of each side open into a common collecting waste-air or outgoing air duct which leads to an intergated heat exchanger to which an incoming-air duct is connected, by way of which incoming air flows into the circuit of the treatment medium, whilst outgoing air flowing away from both heat exchangers arrives by way of a respective further outgoing-air duct in a common further collecting outgoing-air duct.

2. A tiered tentering frame as claimed in claim 1, characterised in that the free crosssection of the openings, opening out on each tier, of the outgoing-air duct is variable by slides or slide valves and in that arranged in each outgoing-air duct connected in the direction of flow behind the heat exchanger is a throttle valve which is adjustable synchronously and proportionally with a respective flap or valve which is arranged in the relevant incoming-air duct.

3. A tiered tentering frame as claimed in claims 1 and 2, characterised in that the collecting outgoing-air ducts arranged in the direction of flow in front of the heat exchangers extend in the region of the tentering frame base, preferably under this, and extend over the length of the tentering frame.

4. A tiered tentering frame as claimed in claims 1 to 3, characterised in that each outgoing-air duct connected in the direction of flow behind the heat exchanger with the incoming-air duct is arranged on both sides at the end of the tentering frame.

5. A tiered tentering frame as claimed in claims 1 to 4, characterised in that each outgoing-air duct connected in the direction of flow behind the heat exchanger and the respective incoming-air duct jointly form a part of their duct walling.

6. A tiered tentering frame substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings